Definição de compatibilidade do Android 4.1
Revisão 3
Última atualização: 24 de junho de 2013
Copyright © 2012, Google Inc. Todos os direitos reservados.
compatibilidade@android.com
Índice
1. Introdução
2. Recursos
3. Software
3.1. Compatibilidade de API de homem
3 .2. Compatibilidade de API suave
3.2.1. Permissões
3 .2.2. Parâmetros de construção
3 .2.3. Compatibilidade de intenção
3.2.3.1. Intenções de aplicativos principais
3 .2.3.2. Substituições de intenção
3 .2.3.3. Namespaces de intenção
3 .2.3.4. Intenções de transmissão
3.3. Compatibilidade de API nativa
3.3.1 Interfaces binárias de aplicativos
3.4. Compatibilidade Web
3.4.1. Compatibilidade do WebView
3.4.2. Compatibilidade do navegador
3.5. Compatibilidade Comportamental da API
3.6. Espaços de nome da API
3.7. Compatibilidade da máquina virtual
3 .8. Compatibilidade da interface do usuário
3.8.1. Widgets
3.8.2. Notificações
3 .8.3. Procurar
3 .8.4. Torradas
3 .8.5. Temas
3 .8.6. Papéis ao vivo
3 .8.7. Exibição de aplicativo recente
3 .8.8. Configurações de gerenciamento de entrada
3 .8.9. Controle remoto da tela de bloqueio
3.9 Administração do dispositivo
3.10 Acessibilidade
3 .11 Texto para fala
4. Compatibilidade da embalagem do aplicativo
5. Compatibilidade Multimídia
5.1. Codecs de mídia
5.2. Codificação de vídeo
5.3. Gravação de áudio
5.4. Latência de áudio
5 .5. Protocolos de rede
6. Compatibilidade da ferramenta do desenvolvedor
7. Compatibilidade de hardware
7 .1. Exibição e Gráficos
7.1.1. Configuração de tela
7.1.2. Métricas de Exibição
7.1.3. Orientação da Tela
7 .1.4. Aceleração de Gráficos 2D e 3D
7 .1.5. Modo de compatibilidade de aplicativos herdados
7 .1.6. Tipos de tela
7 .1.7. Tecnologia de tela
7.2. Dispositivos de entrada
7 .2.1. Teclado
7 .2.2. Navegação sem toque
7.2.3. Teclas de navegação
7.2.4. Entrada da tela sensível ao toque
7.2.5. Entrada de toque falso
7.2.6. Microfone
7.3. Sensores
7 .3.1. Acelerômetro
7.3.1. Acelerômetro
7 .3.2. Magnetômetro
7 .3.3. GPS
7 .3.4. giroscópio
7 .3.5. Barômetro
7 .3.6. Termômetro
7 .3.7. Fotômetro
7 .3.8. Sensor de proximidade
7 .4. Conectividade de dados
7.4.1. Telefonia
7.4.2. IEEE 802.11 (Wi-Fi)
7.4.2.1. wi-fi direto
7.4.3. Bluetooth
7.4.4. Comunicações de campo próximo
7 .4.5. Capacidade mínima de rede
7.5. câmeras
7.5.1. Câmera traseira
7 .5.2. Câmera frontal
7 .5.3. Comportamento da API da câmera
7 .5.4. Orientação da câmera
7.6. Memória e armazenamento
7.6.1. Memória e armazenamento mínimos
7 .6.2. Armazenamento compartilhado de aplicativos
7.7. U SB
8. Compatibilidade de desempenho
9. Compatibilidade do modelo de segurança
9.1. Permissões
9 .2. UID e Isolamento de Processo
9 .3. Permissões do sistema de arquivos
9.4. Ambientes alternativos de execução
10. Teste de compatibilidade de software
10.1. Conjunto de teste de compatibilidade
10.2. Verificador CTS
10.3. Aplicativos de referência
11. Software atualizável
12. C ontate-nos
Apêndice A - Procedimento de teste de Bluetooth
1. Introdução
Este documento enumera os requisitos que devem ser atendidos para que os dispositivos
ser compatível com Android 4.1.
O uso de "must", "must not", "required", "shal", "shal not", "should", "should not",
"recomendado", "pode" e "opcional" é de acordo com o padrão IETF definido no RFC2119
[ Recursos, 1].
Conforme usado neste documento, um "implementador de dispositivo" ou "implementador" é uma pessoa ou
organização que desenvolve uma solução de hardware/software executando o Android 4.1. Um dispositivo
implementação" ou "implementação" é a solução de hardware/software assim desenvolvida.
Para serem consideradas compatíveis com Android 4.1, as implementações de dispositivos DEVEM atender
os requisitos apresentados nesta Definição de Compatibilidade, incluindo quaisquer documentos
incorporado por referência.
Quando esta definição ou os testes de software descritos na Seção 10 forem omissos,
ambíguo ou incompleto, é responsabilidade do implementador do dispositivo garantir
compatibilidade com implementações existentes.
Por esse motivo, o Android Open Source Project [Recursos, 3] é a referência
e implementação preferencial do Android. Os implementadores de dispositivos são fortemente
incentivados a basear suas implementações, tanto quanto possível, no
código-fonte "upstream" disponível no Android Open Source Project. Enquanto alguns
os componentes podem hipoteticamente ser substituídos por implementações alternativas
prática é fortemente desencorajada, pois passar nos testes de software se tornará
substancialmente mais difícil. É responsabilidade do implementador garantir o pleno comportamento
compatibilidade com a implementação padrão do Android, incluindo e além do
Conjunto de teste de compatibilidade. Finalmente, observe que certas substituições de componentes e
modificações são expressamente proibidas por este documento.
2. Recursos
1. Níveis de requisitos IETF RFC2119: http://www.ietf.org/rfc/rfc2119.txt
2. Visão geral do programa de compatibilidade do Android:
http://source.android.com/compatibility/i ndex.html
3. Projeto Android Open Source: http://source.android.com/
4. Definições e documentação da API:
http://developer.android.com/refe rence/packages.html
5. Referência de permissões do Android:
http://developer.android.com/reference/android/Manifest.p ermission.html
6. referência android.os.Build:
http://developer.android.com/reference/android/os/Build.html
7. Sequências de versão permitidas do Android 4.1:
http://source.android.com/compatibility/4.1/versions.html
8. Renderscript:
http://developer.android.com/guide/topics/graphics/rendersc ript.html
9. Aceleração de Hardware:
http://developer.android.com/guide/topics/graphics/hardware-accel.html
10. classe android.webkit.WebView:
http://developer.android.com/reference/android/webkit/WebView.html
11. HTML5: http://www.whatwg.org/specs/web-apps/current-work/multipage/
12. Recursos offline do HTML5: http://dev.w3.org/html5/spec/Overview.html#offline
13. Tag de vídeo HTML5: http://dev.w3.org/html5/spec/Overview.html#video
14. API de geolocalização HTML5/ W3C: http://www.w3.org/TR/geolocation-API/
15. HTML5/W3C webdatabase A PI: http://www.w3.org/TR/webdatabase/
16. API HTML5/W3C Indexe dDB: http://www.w3.org/TR/IndexedDB/
17. Especificação da Dalvik Virtual Machine: disponível no código-fonte do Android, em
dalvik/docs
18. AppWidgets:
http://developer.android.com/guide/practices/ui_guidelines/widget_design.html
19. Notificações:
http://developer.android.com/guide/topics/ui/notifiers/notifications.html
20. Recursos do aplicativo: http://code.google.com/android/reference/available-
recursos.html
21. Guia de estilo do ícone da barra de status:
http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_b ar.html
22. Gerenciador de Pesquisa:
http://developer.android.com/reference/android/app/SearchManager.html
23. Brindes: http://developer.android.com/reference/android/widget/Toast.html
24. Temas: http://developer.android.com/guide/topics/ui/themes.html
25. Classe R.style: h ttp://developer.android.com/reference/android/R.style.html
26. Papéis Live Wal: http://developer.android.com/resources/articles/live-
wal papers.html
27. Administração de dispositivos Android:
http://developer.android.com/guide/topics/admin/device-admin.html
28. Classe android.app.admin.DevicePolicyManager:
http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html
29. APIs do serviço de acessibilidade do Android:
http://developer.android.com/reference/android/accessibilityservice/package-
resumo.html
30. APIs de acessibilidade do Android:
http://developer.android.com/reference/android/view/accessibility/package-
resumo.html
31. Projeto Eyes Free: http://code.google.com/p/eyes-free
32. APIs de conversão de texto em fala :
http://developer.android.com/reference/android/speech/tts/package-
resumo.html
33. Documentação da ferramenta de referência (para adb, aapt, ddms):
http://developer.android.com/guide/developing/tools/index.html
34. Descrição do arquivo apk do Android:
http://developer.android.com/guide/topics/fundamentals.html
35. Arquivos de manifesto: http://developer.android.com/guide/topics/manifes t/manifest-
i ntro.html
36. Ferramenta de teste de macaco:
https://developer.android.com/studio/test/other-testing-tools/monkey
37. Classe android.content.pm.PackageManager do Android e recursos de hardware
Lista:
http://developer.android.com/reference/android/content/pm/PackageManager.html
38. Compatível com várias telas:
http://developer.android.com/guide/practices/screens_support.html
39. android.util.DisplayMetrics:
http://developer.android.com/reference/android/util/DisplayMetrics.html
40. android.content.res.Configuração:
http://developer.android.com/reference/android/content/res/Configuration.htm l
41. android.hardware.SensorEvent:
http://developer.android.com/reference/android/hardware/SensorEvent.html
42. API Bluetooth:
http://developer.android.com/reference/android/bluetooth/package-summary.html
43. Protocolo NDEF Push: http://source.android.com/compatibility/ndef-push-
protocolo.pdf
44. MIFARE MF1S503X: http://www.nxp.com/documents/data_sheet/MF1S503x.p df
45. MIFARE MF1S703X: http://www.nxp.com/documents/data_sheet/MF1S703x.p df
46. MIFARE MF0ICU1 : http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf
47. MIFARE MF0ICU2:
http://www.nxp.com/d ocuments/short_data_sheet/MF0ICU2_SDS.pdf
48. MIFARE AN130511:
http://www.nxp.com/documents/application_note/AN130511.pdf
49. MIFARE AN130411:
http://www.nxp.com/documents/application_note/AN130411.pdf
50. API de orientação da câmera:
http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)
51. android.hardware.Câmera:
http://developer.android.com/reference/android/hardware/Camera.html
52. Acessórios Android Open:
http://developer.android.com/guide/topics/usb/accessory.html
53. API de host USB: http://developer.android.com/guide/topics/usb/host.html
54. Referência de segurança e permissões do Android:
http://developer.android.com/guide/topics/security/security.html
55. Aplicativos para Android : http://code.google.com/p/apps-for-android
56. classe android.app.DownloadManager:
http://developer.android.com/reference/android/app/DownloadMana ger.html
57. Transferência de arquivos do Android : http://www.android.com/filetransfer
58. Formatos de mídia Android: http://developer.android.com/guide/appendix/media-
f ormats.html
59. Protocolo de rascunho de transmissão ao vivo HTTP: http://tools.ietf.org/html/d raft-pantos-http-
transmissão ao vivo-03
60. Transferência de conexão NFC: http://www.nfc-
forum.org/specs/spec_list/#conn_handover
61. Emparelhamento simples seguro por Bluetooth usando NFC: http://www.nfc-
forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf
62. API Wifi Multicast:
http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html
63. Assistência de ação:
http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST
64. Especificação de Carregamento USB:
http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf
65. Android Beam: h ttp://developer.android.com/guide/topics/nfc/nfc.html
66. Áudio USB do Android:
http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO
67. Configurações de compartilhamento NFC do Android:
http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS
68. Wi-Fi direto (Wi-Fi P2P):
http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html
69. Cliente de controle remoto de mídia:
http://developer.android.com/reference/android/media/RemoteControlClient.html
70. API de evento de movimento:
http://developer.android.com/reference/android/view/MotionEvent.html
71. Configuração de entrada de toque: http://source.android.com/tech/input/touch-
devices.html
Muitos desses recursos são derivados direta ou indiretamente do Android 4.1 SDK,
e será funcionalmente idêntico às informações na documentação do SDK. Em qualquer
casos em que esta Definição de Compatibilidade ou o Conjunto de Testes de Compatibilidade discorda
a documentação do SDK, a documentação do SDK é considerada oficial. Nenhum
detalhes técnicos fornecidos nas referências incluídas acima são considerados por
inclusão para fazer parte desta Definição de Compatibilidade.
3. Software
3.1. Compatibilidade de API Gerenciada
O ambiente de execução gerenciado (baseado em Dalvik) é o principal veículo para o Android
formulários. A interface de programação de aplicativos (API) do Android é o conjunto de
Interfaces da plataforma Android expostas a aplicativos em execução na VM gerenciada
ambiente. As implementações de dispositivos DEVEM fornecer implementações completas,
incluindo todos os comportamentos documentados, de qualquer API documentada exposta pelo Android
4.1 SDK [Recursos, 4].
As implementações de dispositivos NÃO DEVEM omitir nenhuma API gerenciada, alterar interfaces de API ou
assinaturas, desviar-se do comportamento documentado ou incluir no-ops, exceto onde
especificamente permitido por esta Definição de Compatibilidade.
Esta Definição de Compatibilidade permite alguns tipos de hardware para os quais o Android
inclui APIs a serem omitidas por implementações de dispositivos. Nesses casos, as APIs DEVEM
ainda estar presente e se comportar de maneira razoável. Consulte a Seção 7 para informações específicas
requisitos para este cenário.
3.2. Compatibilidade de API suave
Além das APIs gerenciadas da Seção 3.1, o Android também inclui um
API "suave" somente em tempo de execução, na forma de coisas como intenções, permissões e
aspectos semelhantes de aplicativos Android que não podem ser aplicados na compilação do aplicativo
Tempo.
3.2.1. Permissões
Os implementadores de dispositivos DEVEM oferecer suporte e impor todas as constantes de permissão conforme
documentado pela página de referência de permissão [Recursos, 5]. Observe que a Seção 10
lista requisitos adicionais relacionados ao modelo de segurança do Android.
3.2.2. Parâmetros de construção
As APIs do Android incluem várias constantes na classe android.os.Build
[Recursos, 6] que se destinam a descrever o dispositivo atual. Para fornecer consistente,
valores significativos em implementações de dispositivos, a tabela abaixo inclui
restrições sobre os formatos desses valores para os quais as implementações de dispositivos DEVEM
conforme.
Parâmetro
Comentários
A versão do sistema Android atualmente em execução, em formato legível por humanos. Este campo DEVE ter um
android.os.Build.VERSION.RELEASE
dos valores de string definidos em [Recursos, 7].
A versão do sistema Android atualmente em execução, em um formato acessível ao código do aplicativo de terceiros.
android.os.Build.VERSION.SDK
Para Android 4.1, este campo DEVE ter o valor inteiro 16.
A versão do sistema Android atualmente em execução, em um formato acessível ao código do aplicativo de terceiros.
android.os.Build.VERSION.SDK_INT
Para Android 4.1, este campo DEVE ter o valor inteiro 16.
Um valor escolhido pelo implementador do dispositivo que designa a compilação específica do Android atualmente em execução
sistema, em formato legível por humanos. Este valor NÃO DEVE ser reutilizado para diferentes compilações disponibilizadas para
android.os.Build.VERSION.INCREMENTAL
usuários finais. Um uso típico desse campo é indicar qual número de compilação ou identificador de alteração de controle de origem foi
usado para gerar a compilação. Não há requisitos sobre o formato específico deste campo, exceto que DEVE
NÃO seja nulo ou a string vazia ("").
Um valor escolhido pelo implementador do dispositivo identificando o hardware interno específico usado pelo dispositivo, em
formato legível por humanos. Uma possível utilização deste campo é indicar a revisão específica da placa de alimentação
android.os.Build.BOARD
o dispositivo. O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder à expressão regular
"^[a-zA-Z0-9.,_-]+$".
Um valor escolhido pelo implementador do dispositivo identificando o nome da empresa, organização, indivíduo, etc.
que produziu o dispositivo, em formato legível por humanos. Uma possível utilização deste campo é indicar o OEM
android.os.Build.BRAND
e/ou operadora que vendeu o dispositivo. O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder ao
expressão regular "^[a-zA-Z0-9.,_-]+$".
O nome do conjunto de instruções (tipo de CPU + convenção ABI) do código nativo. Consulte a Seção 3.3: API nativa
android.os.Build.CPU_ABI
Compatibilidade.
O nome do segundo conjunto de instruções (tipo de CPU + convenção ABI) do código nativo. Consulte a Seção 3.3: Nativo
android.os.Build.CPU_ABI2
Compatibilidade AP I.
Um valor escolhido pelo implementador do dispositivo identificando a configuração ou revisão específica do corpo
android.os.Build.DEVICE
(às vezes chamado de "design industrial") do dispositivo. O valor deste campo DEVE ser codificável como 7 bits
ASCI e corresponda à expressão regular "^[a-zA-Z0-9.,_-]+$".
Uma cadeia de caracteres que identifica exclusivamente esta compilação. DEVE ser razoavelmente legível por humanos. DEVE seguir isso
modelo:
$(MARCA)/$(PRODUTO)/$(DISPOSITIVO):$(VERSÃO.LANÇAMENTO)/$(ID)/$(VERSÃO.INCREMENTAL):$(TIPO)/$(TAGS)
Por exemplo:
android.os.Build.FINGERPRINT
acme/mydevice/generic:4.1/JRN53/3359:userdebug/test-keys
A impressão digital NÃO DEVE incluir caracteres de espaço em branco. Se outros campos incluídos no modelo acima tiverem
caracteres de espaço em branco, eles DEVEM ser substituídos na impressão digital de construção por outro caractere, como o
caractere de sublinhado ("_"). O valor deste campo DEVE ser codificado como ASCI de 7 bits.
O nome do hardware (da linha de comando do kernel ou /proc). DEVE ser razoavelmente humano-
android.os.Build.HARDWARE
legível. O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder à expressão regular "^[a-
zA-Z0-9.,_-]+$".
Uma cadeia de caracteres que identifica exclusivamente o host no qual a compilação foi construída, em formato legível por humanos. Não há
android.os.Build.HOST
requisitos no formato específico deste campo, exceto que NÃO DEVE ser nulo ou a string vazia ("").
Um identificador escolhido pelo implementador do dispositivo para se referir a uma versão específica, em formato legível por humanos. Esta
campo pode ser o mesmo que android.os.Build.VERSION.INCREMENTAL, mas DEVE ser um valor suficientemente
android.os.Build.ID
significativo para os usuários finais distinguir entre as compilações de software. O valor deste campo DEVE ser codificável
como ASCI de 7 bits e corresponda à expressão regular "^[a-zA-Z0-9.,_-]+$".
O nome comercial do fabricante do equipamento original (OEM) do produto. Não há requisitos de
android.os.Build.MANUFACTURER
o formato específico deste campo, exceto que NÃO DEVE ser nulo ou uma string vazia ("").
Um valor escolhido pelo implementador do dispositivo contendo o nome do dispositivo conhecido pelo usuário final. Esta
android.os.Build.MODEL
DEVE ser o mesmo nome sob o qual o dispositivo é comercializado e vendido aos usuários finais. Não há
requisitos no formato específico deste campo, exceto que NÃO DEVE ser nulo ou a string vazia ("").
Um valor escolhido pelo implementador do dispositivo contendo o nome de desenvolvimento ou nome de código do produto
android.os.Build.PRODUCT
(SKU). DEVE ser legível por humanos, mas não se destina necessariamente à visualização pelos usuários finais. o valor disso
O campo DEVE ser codificado como ASCI de 7 bits e corresponder à expressão regular "^[a-zA-Z0-9.,_-]+$".
Um número de série de hardware, se disponível. O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder
android.os.Build.SERIAL
a expressão regular "^([a-zA-Z0-9]{0,20})$".
Uma lista separada por vírgulas de tags escolhidas pelo implementador do dispositivo que distinguem ainda mais o build. Para
android.os.Build.TAGS
exemplo, "unsigned,debug". O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder ao normal
expressão "^[a-zA-Z0-9.,_-]+$".
android.os.Build.TIME
Um valor que representa o carimbo de data/hora de quando a compilação ocorreu.
Um valor escolhido pelo implementador do dispositivo especificando a configuração de tempo de execução do build. Este campo
DEVE ter um dos valores correspondentes às três configurações típicas de tempo de execução do Android: "user",
android.os.Build.TYPE
"userdebug" ou "eng". O valor deste campo DEVE ser codificado como ASCI de 7 bits e corresponder ao normal
expressão "^[a-zA-Z0-9.,_-]+$".
Um nome ou ID do usuário (ou usuário automatizado) que gerou o build. Não há requisitos de
android.os.Build.USER
o formato específico deste campo, exceto que NÃO DEVE ser nulo ou uma string vazia ("").
3.2.3. Compatibilidade de intenção
As implementações de dispositivos DEVEM respeitar o sistema Intent de baixo acoplamento do Android, como
descritos nas seções abaixo. Por "honrado", entende-se que o implementador do dispositivo
DEVE fornecer uma atividade ou serviço do Android que especifique um filtro de intenção correspondente e
vincula e implementa o comportamento correto para cada padrão de intenção especificado.
3.2.3.1. Objetivos principais do aplicativo
O projeto upstream do Android define uma série de aplicativos principais, como contatos,
calendário, galeria de fotos, reprodutor de música e assim por diante. Os implementadores de dispositivos PODEM substituir
esses aplicativos com versões alternativas.
No entanto, tais versões alternativas DEVEM respeitar os mesmos padrões de intenção fornecidos
pelo projeto upstream. Por exemplo, se um dispositivo contiver um reprodutor de música alternativo,
ele ainda deve honrar o padrão Intent emitido por aplicativos de terceiros para escolher uma música.
Os seguintes aplicativos são considerados aplicativos principais do sistema Android:
Relógio de mesa
Navegador
Calendário
Contatos
Galeria
Pesquisa Global
lançador
Música
Configurações
Os principais aplicativos do sistema Android incluem vários componentes de atividade ou serviço
considerados "públicos". Ou seja, o atributo "android:exported" pode estar ausente ou
pode ter o valor "verdadeiro".
Para cada atividade ou serviço definido em um dos principais aplicativos do sistema Android que não é
marcado como não público por meio de um atributo android:exported com o valor "false", device
implementações DEVEM incluir um componente do mesmo tipo implementando o
mesmos padrões de filtro de intenção do aplicativo principal do sistema Android.
Em outras palavras, uma implementação de dispositivo PODE substituir os principais aplicativos do sistema Android;
no entanto, se o fizer, a implementação do dispositivo DEVE suportar todos os padrões de intenção definidos
por cada aplicativo principal do sistema Android sendo substituído.
3.2.3.2. Substituições de intenção
Como o Android é uma plataforma extensível, as implementações de dispositivos DEVEM permitir que cada Intent
padrão referenciado na Seção 3.2.3.2 seja substituído por aplicativos de terceiros. o
a implementação de código aberto do Android upstream permite isso por padrão; dispositivo
os implementadores NÃO DEVEM atribuir privilégios especiais ao uso de aplicativos do sistema de
esses padrões de intenção ou impedir que aplicativos de terceiros se liguem e assumam
controle desses padrões. Esta proibição inclui especificamente, mas não está limitada a
desativando a interface de usuário "Chooser" que permite ao usuário selecionar entre vários
aplicativos que lidam com o mesmo padrão de intenção.
No entanto, as implementações de dispositivos PODEM fornecer atividades padrão para URIs específicos
padrões (por exemplo, http://play.google.com) se a atividade padrão fornecer um filtro mais específico
para o URI de dados. Por exemplo, um filtro de intenção especificando o URI de dados
"http://www.android.com" é mais específico do que o filtro do navegador para "http://". Dispositivo
as implementações DEVEM fornecer uma interface de usuário para que os usuários modifiquem a atividade padrão
para intenções.
3.2.3.3. Namespaces de intenção
As implementações de dispositivos NÃO DEVEM incluir nenhum componente Android que honre qualquer
novos padrões de Intenção ou Intenção de Transmissão usando uma AÇÃO, CATEGORIA ou outra chave
string no namespace android.* ou com.android.*. Os implementadores de dispositivos NÃO DEVEM
inclua quaisquer componentes do Android que respeitem quaisquer novos padrões de Intent ou Broadcast Intent
usando uma ACTION, CATEGORY ou outra sequência de chave em um espaço de pacote pertencente a
outra organização. Os implementadores de dispositivos NÃO DEVEM alterar ou estender qualquer uma das Intenções
padrões usados pelos aplicativos principais listados na Seção 3.2.3.1. Implementações de dispositivos MAIO
incluir padrões de intenção usando namespaces clara e obviamente associados a seus
própria organização.
Essa proibição é análoga àquela especificada para classes de linguagem Java na Seção
3.6.
3.2.3.4. Intenções de transmissão
Aplicativos de terceiros dependem da plataforma para transmitir determinados Intents para notificá-los
de mudanças no ambiente de hardware ou software. Dispositivos compatíveis com Android
DEVE transmitir as Intenções de transmissão pública em resposta ao sistema apropriado
eventos. As intenções de transmissão são descritas na documentação do SDK.
3.3. Compatibilidade de API nativa
3.3.1 Interfaces binárias de aplicativos
O código gerenciado em execução no Dalvik pode ser chamado no código nativo fornecido no aplicativo
.apk como um arquivo ELF .so compilado para a arquitetura de hardware do dispositivo apropriado.
Como o código nativo é altamente dependente da tecnologia do processador subjacente, o Android
define uma série de Application Binary Interfaces (ABIs) no Android NDK, no arquivo
docs/CPU-ARCH-ABIS.html. Se uma implementação de dispositivo for compatível com um ou mais
ABIs definidas, DEVE implementar compatibilidade com o Android NDK, conforme abaixo.
Se uma implementação de dispositivo incluir suporte para uma ABI do Android, ela:
DEVE incluir suporte para código em execução no ambiente gerenciado para entrar
código nativo, usando a semântica Java Native Interface (JNI) padrão.
DEVE ser compatível com fonte (ou seja, cabeçalho compatível) e compatível com binário (para
a ABI) com cada biblioteca necessária na lista abaixo
DEVE relatar com precisão a Application Binary Interface (ABI) nativa suportada
pelo dispositivo, por meio da API android.os.Build.CPU_ABI
DEVE relatar apenas as ABIs documentadas na versão mais recente do Android
NDK, no arquivo docs/CPU-ARCH-ABIS.txt
DEVE ser construído usando o código-fonte e os arquivos de cabeçalho disponíveis no
projeto de código aberto Android upstream
As seguintes APIs de código nativo DEVEM estar disponíveis para aplicativos que incluem código nativo:
libc (biblioteca C)
libm (biblioteca matemática)
Suporte mínimo para C++
Interface JNI
liblog (registro do Android)
libz (compressão Zlib)
libdl (linker dinâmico)
libGLESv1_CM.so (OpenGL ES 1.0)
libGLESv2.so (OpenGL ES 2.0)
libEGL.so (gerenciamento de superfície OpenGL nativo)
libjnigraphics.so
libOpenSLES.so (suporte de áudio OpenSL ES 1.0.1)
libOpenMAXAL.so (suporte OpenMAX AL 1.0.1)
libandroid.so (suporte a atividades nativas do Android)
Suporte para OpenGL, conforme descrito abaixo
Observe que versões futuras do Android NDK podem apresentar suporte para
ABIs. Se uma implementação de dispositivo não for compatível com uma ABI predefinida existente, ela
NÃO DEVE relatar suporte para qualquer ABI em al.
A compatibilidade do código nativo é um desafio. Por esta razão, deve-se repetir que
implementadores de dispositivos são MUITO fortemente encorajados a usar o upstream
implementações das bibliotecas listadas acima para ajudar a garantir a compatibilidade.
3.4. Compatibilidade Web
3.4.1. Compatibilidade do WebView
A implementação do Android Open Source usa o mecanismo de renderização WebKit para
implemente o android.webkit.WebView. Porque não é viável desenvolver um
conjunto de testes abrangente para um sistema de renderização da web, os implementadores de dispositivos DEVEM usar
a compilação upstream específica do WebKit na implementação do WebView. Especificamente:
As implementações android.webkit.WebView das implementações do dispositivo DEVEM ser
baseado na compilação 534.30 WebKit da árvore Android Open Source upstream
para Android 4.1. Esta compilação inclui um conjunto específico de funcionalidade e segurança
correções para o WebView. Os implementadores de dispositivos PODEM incluir personalizações para o
Implementação do WebKit; no entanto, tais personalizações NÃO DEVEM alterar o
comportamento do WebView, incluindo comportamento de renderização.
A string do agente do usuário relatada pelo WebView DEVE estar neste formato:
Mozilla/5.0 (Linux; U; Android $(VERSÃO); $(LOCALE); $(MODELO)
Build/$(BUILD)) AppleWebKit/534.30 (KHTML, como Gecko) Versão/4.1
Safari móvel/534.30
O valor da string $(VERSION) DEVE ser o mesmo que o valor para
O valor da string $(VERSION) DEVE ser o mesmo que o valor para
android.os.Build.VERSION.RELEASE
O valor da string $(LOCALE) DEVE seguir as convenções ISO para
código do país e idioma, e DEVE referir-se ao atual configurado
localidade do dispositivo
O valor da string $(MODEL) DEVE ser o mesmo que o valor para
android.os.Build.MODEL
O valor da string $(BUILD) DEVE ser o mesmo que o valor para
android.os.Build.ID
As implementações de dispositivos PODEM omitir Mobile na string do agente do usuário
O componente WebView DEVE incluir suporte para o máximo de HTML5
[Recursos, 11] possível. No mínimo, as implementações de dispositivos DEVEM suportar cada um dos
estas APIs associadas ao HTML5 no WebView:
cache de aplicativo/operação offline [Recursos, 12]
a tag <video> [Recursos, 13]
geolocalização [ Recursos, 14]
As implementações adicionais do dispositivo DEVEM oferecer suporte à API de armazenamento na web HTML5/W3C
[Recursos, 15] e DEVE oferecer suporte à API HTML5/W3C IndexedDB [Recursos,
16]. Observe que, à medida que os órgãos de padrões de desenvolvimento da Web estão fazendo a transição para favorecer
IndexedDB sobre webstorage, espera-se que o IndexedDB se torne um
componente em uma versão futura do Android.
As APIs HTML5, como todas as APIs JavaScript, DEVEM ser desativadas por padrão em um WebView,
a menos que o desenvolvedor os habilite explicitamente por meio das APIs normais do Android.
3.4.2. Compatibilidade do navegador
As implementações de dispositivos DEVEM incluir um aplicativo de navegador autônomo para uso geral
navegação na web do usuário. O navegador autônomo PODE ser baseado em uma tecnologia de navegador
além do WebKit. No entanto, mesmo se um aplicativo de navegador alternativo for usado, o
O componente android.webkit.WebView fornecido para aplicativos de terceiros DEVE ser
baseado no WebKit, conforme descrito na Seção 3.4.1.
As implementações PODEM enviar uma string de agente de usuário personalizada no navegador autônomo
aplicativo.
O aplicativo de navegador autônomo (seja baseado no navegador WebKit upstream
aplicativo ou um substituto de terceiros) DEVE incluir suporte para o máximo de
HTML5 [Recursos, 11] possível. No mínimo, as implementações de dispositivos DEVEM suportar
cada uma dessas APIs associadas ao HTML5:
cache de aplicativo/operação offline [Recursos, 12]
a tag <video> [Recursos, 13]
geolocalização [Recursos, 14]
As implementações adicionais do dispositivo DEVEM oferecer suporte à API de armazenamento na web HTML5/W3C
[Recursos, 15], e DEVE oferecer suporte à API HTML5/W3C IndexedDB [Recursos,
16]. Observe que, à medida que os órgãos de padrões de desenvolvimento da Web estão fazendo a transição para favorecer
IndexedDB sobre webstorage, espera-se que o IndexedDB se torne um
componente em uma versão futura do Android.
3.5. Compatibilidade Comportamental da API
Os comportamentos de cada um dos tipos de API (gerenciado, soft, nativo e web) devem ser
consistente com a implementação preferida do código aberto upstream do Android
projeto [Recursos, 3]. Algumas áreas específicas de compatibilidade são:
Os dispositivos NÃO DEVEM alterar o comportamento ou a semântica de uma Intenção padrão
Os dispositivos NÃO DEVEM alterar o ciclo de vida ou a semântica do ciclo de vida de um tipo específico
do componente do sistema (como Service, Activity, ContentProvider, etc.)
Os dispositivos NÃO DEVEM alterar a semântica de uma permissão padrão
A lista acima não é abrangente. Os testes do Compatibility Test Suite (CTS)
porções significativas da plataforma para compatibilidade comportamental, mas não al . É o
responsabilidade do implementador para garantir a compatibilidade comportamental com o Android
Projeto de Código Aberto. Por esse motivo, os implementadores de dispositivos DEVEM usar a fonte
código disponível através do Android Open Source Project sempre que possível, em vez de re-
implementar partes significativas do sistema.
3.6. Espaços de nome da API
O Android segue as convenções de namespace de pacote e classe definidas pelo Java
linguagem de programação. Para garantir a compatibilidade com aplicativos de terceiros, o dispositivo
os implementadores NÃO DEVEM fazer nenhuma modificação proibida (veja abaixo) nestes
espaços de nomes do pacote:
Java.*
javax.*
Sol.*
andróide.*
com.android.*
As modificações proibidas incluem:
As implementações de dispositivos NÃO DEVEM modificar as APIs expostas publicamente no
plataforma Android alterando qualquer assinatura de método ou classe ou removendo
classes ou campos de classe.
Os implementadores de dispositivos PODEM modificar a implementação subjacente das APIs, mas
tais modificações NÃO DEVEM afetar o comportamento declarado e a linguagem Java
assinatura de qualquer API exposta publicamente.
Os implementadores de dispositivos NÃO DEVEM adicionar nenhum elemento exposto publicamente (como
classes ou interfaces, ou campos ou métodos para classes ou interfaces existentes) para o
API acima.
Um "elemento exposto publicamente" é qualquer construção que não seja decorada com o "@hide"
marcador conforme usado no código-fonte upstream do Android. Em outras palavras, dispositivo
implementadores NÃO DEVEM expor novas APIs ou alterar APIs existentes nos namespaces
anotado acima. Device implementers MAY make internal-only modifications, but those
modifications MUST NOT be advertised or otherwise exposed to developers.
Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
namespace owned by or referring to another organization. For instance, device
implementers MUST NOT add APIs to the com.google.* or similar namespace; only
Google may do so. Similarly, Google MUST NOT add APIs to other companies'
namespaces. Additional y, if a device implementation includes custom APIs outside
the standard Android namespace, those APIs MUST be packaged in an Android
shared library so that only apps that explicitly use them (via the <uses-library>
mechanism) are affected by the increased memory usage of such APIs.
If a device implementer proposes to improve one of the package namespaces above
(such as by adding useful new functionality to an existing API, or adding a new API), the
implementer SHOULD visit source.android.com and begin the process for contributing
changes and code, according to the information on that site.
Note that the restrictions above correspond to standard conventions for naming APIs in
the Java programming language; this section simply aims to reinforce those
conventions and make them binding through inclusion in this compatibility definition.
3.7. Virtual Machine Compatibility
Device implementations MUST support the ful Dalvik Executable (DEX) bytecode
specification and Dalvik Virtual Machine semantics [Resources, 17].
Device implementations MUST configure Dalvik to al ocate memory in accordance
with the upstream Android platform, and as specified b y the fol owing ta ble. (See
Section 7.1.1 for screen size and screen density definitions.)
Note that memory values specified below are considered minimum values, and device
i mplementation s MAY al ocate more memory per application.
Screen Size
Screen Density
Application Memory
smal / normal / large
ldpi / mdpi
16MB
smal / normal / large
tvdpi / hdpi
32MB
smal / normal / large
xhdpi
64MB
xlarge
mdpi
32MB
xlarge
tvdpi / hdpi
64MB
xlarge
xhdpi
128MB
3.8. User Interface Compatibility
3.8.1. Widgets
Android defines a component type and corresponding API and lifecycle that al ows
applications to expose an "AppWidget" to the end user [Re sources, 18]. The Android
Open Source reference release includes a Launcher application that includes user
interface affordances al owing the user to add, view, and remove AppWidgets from the
home screen.
Device implementations MAY substitute an alternative to the reference Launcher (ie
home screen). Alternative Launchers SHOULD include built-in support for AppWidgets,
and expose user interface affordances to add, configure, view, and remove
AppWidgets directly within the Launcher. Alternative Launchers MAY omit these user
interface elements; however, if they are omitted, the device implementation MUST
provide a separate application accessible from the Launcher that al ows users to add,
configure, view, and remove AppWidgets.
Device implementations MUST be capable of rendering widgets that are 4 x 4 in the
standard grid size. (See the App Widget Design Guidelines in the Android SDK
documentation [Resources, 18] for details.
3.8.2. Notifications
Android includes APIs that al ow developers to notify users of notable events
[Resources, 19], using hardware and software features of the device.
Some APIs al ow applications to perform notifications or attract attention using
hardware, specifical y sound, vibration, and light. Device implementations MUST
support notifications that use hardware features, as described in the SDK
documentation, and to the extent possible with the device implementation hardware.
For instance, if a device implementation includes a vibrator, it MUST correctly
implement the vibration APIs. If a device implementation lacks hardware, the
corresponding APIs MUST be implemented as no-ops. Note that this behavior is
further detailed in Section 7.
Additional y, the im plementatio n MUST correctly render al resources (icons, sound
files, etc.) provided for in the APIs [Resources, 20], or in the Status/System Bar icon
style guide [Resources, 21]. Device implementers MAY provide an alternative user
experience for notifications than that provided by the reference Android Open Source
implementati on; however, suc h alternative notification systems MUST support existing
notification resources, as above.
Android 4.1 includes support for rich notifications, such as interactive Views for
ongoing notifications. Device implementations MUST properly display and execute rich
notifications, as documented in the Android APIs.
3.8.3. Search
Android includes APIs [Resources, 22] that al ow developers to incorporate search into
their applications, and expose their application's data into the global system search.
General y speaking, this f unctionality cons ists of a single, system-wide user interface
that al ows users to enter queries, displays suggestions as users type, and displays
results. The Android APIs al ow developers to reuse this interface to provide search
within their own apps, and al ow developers to supply results to the common global
search user interface.
Device implementations MUST include a single, shared, system-wide search user
interface capable of real-time suggestions in response to user input. Device
implementations MUST implement the APIs that al ow developers to reuse this user
interface to provide search within their own applications. Device implementations
MUST implement the APIs that al ow third-party applications to add suggestions to the
search box when it is run in global search mode. If no third-party applications are
instal ed that make use of this functionality, the default behavior SHOULD be to display
web search engine results and suggestions.
3.8.4. Toasts
Applications can use the "Toast" API (defined in [Resources, 23]) to display short non-
modal strings to the end user, that disappear after a brief period of time. Device
implementations MUST display Toasts from applications to end users in some high-
visibility manner.
3.8.5. Themes
Android provides "themes" as a mechanism for applications to apply styles across an
entire Activity or application. Android 3.0 introduced a new "Holo" or "holographic"
theme as a set of defined styles for application developers to use if they want to match
the Holo theme look and feel as defined by the Android SDK [Resources, 24]. Device
implementations MUST NOT alter any of the Holo theme attributes exposed to
applications [ Resources, 25].
Android 4.0 introduced a new "Device Default" theme as a set of defined styles for
application developers to use if they want to match the look and feel of the device
theme as defined by the device implementer. Device implementations MAY modify the
DeviceDefault theme attributes exposed to applications [Re sources, 25].
3.8.6. Live Wallpapers
Android defines a component type and corresponding API and lifecycle that al ows
applications to expose one or more "Live Wal papers" to the end user [Resources, 26].
Live Wal papers are animations, patterns, or similar images with limited input
capabilities that display as a wal paper, behind other applications.
Hardware is considered capable of reliably running live wal papers if it can run al live
wal papers, with no limitations on functionality, at a reasonable framerate with no
adverse affects on other applications. If limitations in the hardware cause wal papers
and/or applications to crash, malfunction, consume excessive CPU or battery power, or
run at unacceptably low frame rates, the hardware is considered incapable of running
live wal paper. As an example, some live wal papers may use an Open GL 1.0 or 2.0
context to render their content. Live wal paper wil not run reliably on hardware that
does not support multiple OpenGL contexts because the live wal paper use of an
OpenGL context may conflict with other applications that also use an OpenGL context.
Device implementations capable of running live wal papers reliably as described
above SHOULD implement live wal papers. Device implementations determined to not
run live wal papers reliably as described above MUST NOT implement live wal papers.
3.8.7. Recent Application Display
The upstream Android 4.1 source code includes a user interface for displaying recent
applications using a thumbnail image of the application's graphical state at the
moment the user last left the application. Device implementations MAY alter or
eliminate this user interface; however, a future version of Android is planned to make
more extensive use of this functionality. Device implementations are strongly
encouraged to use the upstream Android 4.1 user interface (or a similar thumbnail-
based interface) for recent applications, or else they may not be compatible with a
future version of Android.
3.8.8. Input Management Settings
Android 4.1 includes support for Input Management Engines. The Android 4.1 APIs
al ow custom app IMEs to specify user-tunable settings. Device implementations
MUST include a way for the user to access IME settings at al times when an IME that
provides such user settings is displayed.
3.8.9. Lock Screen Remote Control
Android 4.0 introduced support for Remote Control API that lets media applications
integrate with playback controls that are displayed in a remote view like the device
lock screen [Resources, 69]. Device implementations SHOULD include support for
embedding remote controls in the device lock screen.
3.9 Device Administration
Android 4.1 includes features that al ow security-aware applications to perform device
administration functions at the system level, such as enforcing password policies or
performing remote wipe, through the Android Device Administration API [Resources,
27]. Device implementations MUST provide an implementation of the
DevicePolicyManager class [Resources, 28], and SHOULD support the ful range of
device administration policies defined in the Android SDK documentation [Resources,
27].
Note: while some of the requirements outlined above are stated as "SHOULD" for
Android 4.1, the Compatibility Definition for a future version is planned to change these
to "MUST". That is, these requirements are optional in Android 4.1 but will be
required by a future version. Existing and new devices that run Android 4.1 are very
strongly encouraged to meet these requirements in Android 4.1 , or they wil not
be able to attain Android compatibility when upgraded to the future version.
3.10 Accessibility
Android 4.1 provides an accessibility layer that helps users with disabilities to navigate
their devices more easily. In addition, Android 4.1 provides platform APIs that enable
accessibility service implementations to receive cal backs for user and system events
and generate alternate feedback mechanisms, such as text-to-speech, haptic
feedback, and trackbal /d-pad navigation [R esources, 29]. D evice implementations
MUST provide an implementation of the Android accessibility framework consistent
with the default Android implementation. Specifical y, device implementations MUST
meet the fol owing requirements.
Device implementations MUST support third party accessibility service
i mplementations through the android.accessibilityservice APIs [Resources,
30].
Device implementations MUST generate AccessibilityEvents and deliver
these events to al registered AccessibilityService implementations in a
manner consistent with the default Android implementation.
Device implementations MUST provide a user-accessible mechanism to enable
and disable accessibility services, and MUST display this interface in response
to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.
Additional y, device implementations SHOULD provide an implementation of an
accessibility service on the device, and SHOULD provide a mechanism for users to
enable the accessibility service during device setup. An open source implementation
of an accessibility service is available from the Eyes Free project [Resources, 31].
3.11 Text-to-Speech
Android 4.1 includes APIs that al ow applications to make use of text-to-speech (TTS)
services, and al ows service providers to provide implementations of TTS services
[Resources, 32]. Device implementations MUST meet these requirements related to
t he Android TTS framework:
Device implementations MUST support the Android TTS framework APIs and
SHOULD include a TTS engine supporting the languages available on the
device. Note that the upstream Android open source software includes a ful -
featured TTS engine implementation.
Device implementations MUST support instal ation of third-party TTS engines.
Device implementations MUST provide a user-accessible interface that al ows
users to select a TTS engine for use at the system level.
4. Application Packaging Compatibility
Device implementations MUST instal and run Android ".apk" files as generated by the
"aapt" tool included in the official Android SDK [Resources, 33].
Devices implementations MUST NOT extend eithe r the .apk [Reso urces, 34], Android
Manifest [Resources, 35], Dalvik bytecode [Resources, 17], or renderscript bytecode
formats in such a way that would prevent those files from instal in g and running co rrectly
on other c ompatible device s. Device impleme nters SHOULD u se the reference
upstream implementation of Dalvik, and the reference implementation's package
management system.
5. Multimedia Compatibility
Device implementations MUST include at least one form of audio output, such as
speakers, headphone jack, external speaker connection, etc.
5.1. Media Codecs
Device implementations MUST support the core media formats specified in the
Android SDK documentation [Resources, 58] except where explicitly permitted in this
document. Specifical y, device implementations MUST support the media formats,
encoders, decoders, file types and container formats defined in the tables below. Al of
these codecs are provided as s oftware impleme ntations in the preferred Android
implementation from the Android Open Source Project.
Please note that neither Google nor the Open Handset Alliance make any
representation that these codecs are unencumbered by third-party patents.
Those intending to use this source code in hardware or software products are
advised that implementations of this code, including in open source software
or shareware, may require patent licenses from the relevant patent holders.
Note that these tables do not list specific bitrate requirements for most video codecs
because current device hardware does not necessarily support bitrates that map
exactly to the required bitrates specified by the relevant standards. Instead, device
implementations SHOULD support the highest bitrate practical on the hardware, up to
the limits defined by the specifications.
File Type(s) /
Format /
Type
Encoder
Decoder
Details
Container
Codec
Formats
Support for
REQUIRED
mono/stereo/5.0/5.1*
MPEG-4
Required for device implementations
content with
AAC Profile
that include microphone hardware
REQUIRED
standard sampling
(AAC LC)
and define
3GPP
rates from 8 to 48
android.hardware.microphone.
(.3gp)
kHz.
MPEG-4
Support for
(.mp4,
MPEG-4
mono/stereo/5.0/5.1*
.m4a)
HE AAC
content with
ADTS raw
REQUIRED
Profile
standard sampling
AAC (.aac,
(AAC+)
rates from 16 to 48
decode in
kHz.
Android
3.1+,
Support for
MPEG-4
REQUIRED for device
encode in
mono/stereo/5.0/5.1*
HE AAC v2
implementations that include
Android
content with
Profile
microphone hardware and
4.0+, ADIF
standard sampling
(enhanced
define
not
rates from 16 to 48
AAC+)
android.hardware.microphone
supported)
kHz.
MPEG-TS
MPEG-4
(.ts, not
Audio
REQUIRED for device
Support for
seekable,
Object Type
implementations that include
mono/stereo content
Android
ER AAC
microphone hardware and
REQUIRED
with standard
3.0+)
ELD
define
sampling rates from
(Enhanced
android.hardware.microphone
16 to 48 kHz.
Low Delay
AAC)
REQUIRED
Required for device implementations
4.75 to 12.2 kbps
AMR-NB
that include microphone hardware
REQUIRED
3GPP (.3gp)
sampled @ 8kHz
and define
android.hardware.microphone.
REQUIRED
Required for device implementations
9 rates from 6.60
AMR-WB
that include microphone hardware
REQUIRED
kbit/s to 23.85 kbit/s
3GPP (.3gp)
and define
sampled @ 16kHz
android.hardware.microphone.
Mono/Stereo (no
multichannel).
Audio
Sample rates up to
48 kHz (but up to
44.1 kHz is
recommended on
devices with 44.1
REQUIRED
FLAC
kHz output, as the 48
FLAC (.flac) only
(Android 3.1+)
to 44.1 kHz
downsampler does
not include a low-
pass filter). 16-bit
recommended; no
dither applied for 24-
bit.
Mono/Stereo 8-
320Kbps constant
MP3
REQUIRED
MP3 (.mp3)
(CBR) or variable
bit-rate (VBR)
Type 0 and
MIDI Type 0 and 1.
1 (.mid,
DLS Version 1 and
.xmf, .mxmf)
2. XMF and Mobile
RTTTL/RTX
MIDI
REQUIRED
XMF. Support for
(.rtttl, .rtx)
ringtone formats
OTA (.ota)
RTTTL/RTX, OTA,
iMelody
and iMelody
(.imy)
Ogg (.ogg)
Vorbis
REQUIRED
Matroska
(.mkv)
8-bit and 16-bit
linear PCM** (rates
up to limit of
hardware).Devices
MUST support
PCM/WAVE
REQUIRED
REQUIRED
WAVE (.wav)
sampling rates for
raw PCM recording
at 8000,16000 and
44100 Hz
frequencies
JPEG
REQUIRED
REQUIRED
Base+progressive
JPEG (.jpg)
GIF
REQUIRED
GIF (.gif)
Image
PNG
REQUIRED
REQUIRED
PNG (.png)
BMP
REQUIRED
BMP (.bmp)
WEBP
REQUIRED
REQUIRED
WebP (.webp)
REQUIRED
Required for device implementations
3GPP
that include camera hardware and
(.3gp)
H.263
REQUIRED
define android.hardware.camera
MPEG-4
or
(.mp4)
android.hardware.camera.front.
3GPP
(.3gp)
REQUIRED
MPEG-4
(.mp4)
Required for device implementations
MPEG-TS
that include camera hardware and
Baseline Profile
Video
H.264 AVC
REQUIRED
(.ts, AAC
define android.hardware.camera
(BP)
audio only,
or
not
android.hardware.camera.front.
seekable,
Android
3.0+)
MPEG-4
REQUIRED
3GPP (.3gp)
SP
WebM (.webm)
REQUIRED
and Matroska
VP8
(Android
(.mkv, Android
2.3.3+)
4.0+)
*Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2
channels is optional. **Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM
capture is not mandatory.
5.2 Video Encoding
Android device implementations that include a rear-facing camera and declare
android.hardware.camera SHOULD support the fol owing video encoding profiles.
HD (When supported by
SD (Low quality) SD (High quality)
hardware)
H.264 Baseline
H.264 Baseline
Video codec
H.264 Baseline Profile
Profile
Profile
Video
176 x 144 px
480 x 360 px
1280 x 720 px
resolution
Video frame 12 fps
30 fps
30 fps
rate
500 Kbps or
Video bitrate 56 Kbps
2 Mbps or higher
higher
Audio codec AAC-LC
AAC-LC
AAC-LC
Audio
1 (mono)
2 (stereo)
2 (stereo)
channels
Audio bitrate 24 Kbps
128 Kbps
192 Kbps
5.3. Audio Recording
When an application has used the android.media.AudioRecord API to start recording
an audio stream, device implementations that include microphone hardware and
declare android.hardware.microphone MUST sample and record audio with each of
these behaviors:
The device SHOULD exhibit approximately flat amplitude versus frequency
characteristics; specifical y, ±3 dB, from 100 Hz to 4000 Hz
Audio input sensitivity SHOULD be set such that a 90 dB sound power level
(SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.
PCM amplitude levels SHOULD linearly track input SPL changes over at least a
30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input
level.
In addition to the above recording specifications, when an application has started
recording an audio stream using the
android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:
Noise reduction processing, if present, MUST be disabled.
Automatic gain control, if present, MUST be disabled.
Note: while some of the requirements outlined above are stated as "SHOULD" for
Android 4.1, the Compatibility Definition for a future version is planned to change these
to "MUST". That is, these requirements are optional in Android 4.1 but will be
required by a future version. Existing and new devices that run Android 4.1 are very
strongly encouraged to meet these requirements in Android 4.1 , or they wil not
be able to attain Android compatibility when upgraded to the future version.
5.4. Audio Latency
Audio latency is broadly defined as the interval between when an application requests
an audio playback or record operation, and when the device implementation actual y
begins the operation. Many classes of applications rely on short latencies, to achieve
real-time effects such sound effects or VOIP communication. Device implementations
that include microphone hardware and declare android.hardware.microphone
SHOULD meet al audio latency requirements outlined in this section. See Section 7
for details on the conditions under which microphone hardware may be omitted by
device implementations.
For the purposes of this section:
"cold output latency" is defined to be the interval between when an application
requests audio playback and when sound begins playing, when the audio system
has been idle and powered down prior to the request
"warm output latency" is defined to be the interval between when an application
requests audio playback and when sound begins playing, when the audio system
has been recently used but is currently idle (that is, silent)
"continuous output latency" is defined to be the interval between when an
application issues a sample to be played and when the speaker physical y plays
the corresponding sound, while the device is currently playing back audio
"cold input latency" is defined to be the interval between when an application
requests audio recording and when the first sample is delivered to the
application via its cal back, when the audio system and microphone has been
idle and powered down prior to the request
"continuous input latency" is defined to be when an ambient sound occurs and
when the sample corresponding to that sound is delivered to a recording
application via its cal back, while the device is in recording mode
Using the above definitions, device implementations SHOULD exhibit each of these
properties:
cold output latency of 100 mil iseconds or less
warm output latency of 10 mil iseconds or less
continuous output latency of 45 mil iseconds or less
cold input latency of 100 mil iseconds or less
continuous input latency of 50 mil iseconds or less
Note: while the requirements outlined above are stated as "SHOULD" for Android 4.1,
the Compatibility Definition for a future version is planned to change these to "MUST".
That is, these requirements are optional in Android 4.1 but will be required by a future
version. Existing and new devices that run Android 4.1 are very strongly
encouraged to meet these requirements in Android 4.1 , or they wil not be able to
attain Android compatibility when upgraded to the future version.
If a device implementation meets the requirements of this section, it MAY report
support for low-latency audio, by reporting the feature "android.hardware.audio.low-
latency" via the android.content.pm.PackageManager class. [Re sources, 37]
Conversely, if the device implementation does not meet these requirements it MUST
NOT report support for low-latency audio.
5.5. Network Protocols
Devices MUST support the media network protocols for audio and video playback as
specified in the Android SDK documentation [Resources, 58]. Specifical y, devices
MUST support the fol owing media network proto cols:
RTSP (RTP, SDP)
HTTP(S) progressive streaming
HTTP(S) Live Streaming draft protocol, Version 3 [Resources, 59]
6. Developer Tool Compatibility
Device implementations MUST support the Android Developer Tools provided in the
Android SDK. Specifical y, Android-compatible devices MUST be compatible with:
Android Debug Bridge (known as adb) [Resources, 33]
Device implementations MUST support al adb functions as doc umented in the
Android SDK. The device-side adb daemon MUST be inactive by default, and
there MUST be a user-accessible mechanism to turn on the Android Debug
Bridge.
Dalvik Debug Monitor Service (known as ddms) [Resources, 33]
Device implementations MUST support al ddms features as documented in the
Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by
default, but MUST be supported whenever the user has activated the Android
Debug Bridge, as above.
Monkey [Resources, 36]
Device implementations MUST include the Monkey framework, and make it
available f or applications to use.
Most Linux-based systems and Apple Macintosh systems recognize Android devices
using the standard Android SDK tools, without additional support; however Microsoft
Windows systems typical y require a driver for new Android devices. (For instance,
new vendor IDs and sometimes new device IDs require custom USB drivers for
Windows systems.) If a device implementation is unrecognized by the adb tool as
provided in the standard Android SDK, device implementers MUST provide Windows
drivers al owing developers to connect to the device using the adb protocol. These
drivers MUST be provided for Windows XP, Windows Vista, and Windows 7, in both
32-bit and 64-bit versions.
7. Hardware Compatibility
If a device includes a particular hardware component that has a corresponding API for
third-party developers, the device implementation MUST implement that API as
described in the Android SDK documentation. If an API in the SDK interacts with a
hardware component that is stated to be optional and the device implementation does
not possess that component:
complete class definitions (as documented by the SDK) for the component's
APIs MUST stil be present
the API's behaviors MUST be implemented as no-ops in some reasonable
fashion
API methods MUST return nul values where permitted by the SDK
documentation
API methods MUST return no-op implementations of classes where nul values
are not permitted by the SDK documentation
API methods MUST NOT throw exceptions not documented by the SDK
documentation
A typical example of a scenario where these requirements apply is the telephony API:
even on non-phone devices, these APIs must be implemented as reasonable no-ops.
Device implementations MUST accurately report accurate hardware configuration
information via the getSystemAvailableFeatures() and hasSystemFeature(String)
methods on the android.content.pm.PackageManager class. [Re sources, 37]
7.1. Display and Graphics
Android 4.1 includes facilities that automatical y adjust application assets and UI
layouts appropriately for the device, to ensure that third-party applications run wel on a
variety of hardware configurations [Resources, 38]. Devices MUST properly implement
these APIs and behaviors, as detailed in this section.
The units referenced by the requirements in this section are defined as fol ows:
"Physical diagonal size" is the distance in inches between two opposing corners
of the il uminated portion of the display.
"dpi" (meaning "dots per inch") is the number of pixels encompassed by a linear
horizontal or vertical span of 1". Where dpi values are listed, both horizontal and
vertical dpi must fal within the range.
"Aspect ratio" is the ratio of the longer dimension of the screen to the shorter
dimension. For example, a display of 480x854 pixels would be 854 / 480 =
1.779, or roughly "16:9".
A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 160
dpi screen, calculated as: pixels = dps * (density / 160).
7.1.1. Screen Configuration
Screen Size
The Android UI framework supports a variety of different screen sizes, and al ows
applications to query the device screen size (aka "screen layout") via
android.content.res.Configuration.screenLayout with the
SCREENLAYOUT_SIZE_MASK. Device implementations MUST report the correct screen
size as defined in the Android SDK documentation [Resources, 38] and determined by
the upstream Android platform. Specifical y, device implementations must report the
correct screen size according to the fol owing logical d ensity-independe nt pixel (dp)
screen dimensions.
Devices MUST have screen sizes of at least 426 dp x 320 dp ('smal ')
Devices that report screen size 'normal' MUST have screen sizes of at least 480
dp x 320 dp
Devices that report screen size 'large' MUST have screen sizes of at least 640
dp x 480 dp
Devices that report screen size 'xlarge' MUST have screen sizes of at least 960
dp x 720 dp
In addition, devices MUST have screen sizes of at least 2.5 inches in physical diagonal
size.
Devices MUST NOT change their reported screen size at any time.
Applications optional y indicate which screen sizes they support via the <supports-
screens> attribute in the AndroidManifest.xml file. Device implementations MUST
correctly honor applications' stated support for smal , normal, large, and xlarge
screens, as described in the Android SDK documentation.
Screen Aspect Ratio
The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).
Screen Density
The Android UI framework defines a set of standard logical densities to help
application developers target application resources. Device implementations MUST
report one of the fol owing logical Android framework densities through the
android.util.DisplayMetrics APIs, and MUST execute applications at this standard
density.
120 dpi, known as 'ldpi'
160 dpi, known as 'mdpi'
213 dpi, known as 'tvdpi'
240 dpi, known as 'hdpi'
320 dpi, known as 'xhdpi'
480 dpi, known as 'xxhdpi'
Device implementations SHOULD define the standard Android framework density that
is numerical y closest to the physical density of the screen, unless that logical density
is numerical y closest to the physical density of the screen, unless that logical density
pushes the reported screen size below the minimum supported. If the standard Android
framework density that is numerical y closest to the physical density results in a screen
size that is smal er than the smal est supported compatible screen size (320 dp width),
device implementations SHOULD report the next lowest standard Android framework
density.
7.1.2. Display Metrics
Device implementations MUST report correct values for al display metrics defined in
android.util.DisplayMetrics [Resources, 39].
7.1.3. Screen Orientation
Devices MUST support dynamic orientation by applications to either portrait or
landscape screen orientation. That is, the device must respect the application's
request for a specific screen orientation. Device implementations MAY select either
portrait or landscape orientation as the default.
Devices MUST report the correct value for the device's current orientation, whenever
queried via the android.content.res.Configuration.orientation,
android.view.Display.getOrientation(), or other APIs.
Devices MUST NOT change the reported screen size or density when changing
orientation.
Devices MUST report which screen orientations they support (
android.hardware.screen.portrait and/or android.hardware.screen.landscape)
and MUST report at least one supported orientation. For example, a device with a
fixed-orientation landscape screen, such as a television or laptop, MUST only report
android.hardware.screen.landscape.
7.1.4. 2D and 3D Graphics Acceleration
Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied
and detailed in the Android SDK documentations. Device implementations MUST also
support Android Renderscript, as detailed in the Android SDK documentation
[Resources, 8].
Device impleme ntations MUST also correctly identify themselves as supporting
OpenGL ES 1.0 and 2.0. That is:
The managed APIs (such as via the GLES10.getString() method) MUST report
support for OpenGL ES 1.0 and 2.0
The native C/C++ OpenGL APIs (that is, those available to apps via
libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for
OpenGL ES 1.0 and 2.0.
Device implementations MAY implement any desired OpenGL ES extensions.
However, device implementations MUST report via the OpenGL ES managed and
native APIs al extension strings that they do support, and conversely MUST NOT report
extension strings that they do not support.
Note that Android 4.1 includes support for applications to optional y specify that they
require specific OpenGL texture compression formats. These formats are typical y
vendor-specific. Device implementations are not required by Android 4.1 to implement
any specific texture compression format. However, they SHOULD accurately report any
texture compression formats that they do support, via the getString() method in the
OpenGL API.
Android 4.1 includes a mechanism for applications to declare that they wanted to
enable hardware acceleration for 2D graphics at the Application, Activity, Window or
View level through the use of a manifest tag android:hardwareAccelerated or direct
API cal s [Resources, 9].
In Android 4.1, device implementations MUST enable hardware acceleration by
default, and MUST disable hardware acceleration if the developer so requests by
setting android:hardwareAccelerated="false" or disabling hardware acceleration
directly through the Android View APIs.
In addition, device implementations MUST exhibit behavior consistent with the Android
SDK documentation on hardware acceleration [Resources, 9].
Android 4.1 includes a TextureView object that lets developers directly integrate
hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy.
Device implementations MUST support the Textur eView API, and MUST exhibit
consistent behavior with the upstream Android implementation.
7.1.5. Legacy Application Compatibility Mode
Android 4.1 specifies a "compatibility mode" in which the framework operates in an
'normal' screen size equivalent (320dp width) mode for the benefit of legacy
applications not developed for old versions of Android that pre-date screen-size
independence. Device implementations MUST include support for legacy application
compatibility mode as implemented by the upstream Android open source code. That
is, device implementations MUST NOT alter the triggers or thresholds at which
compatibility mode is activated, and MUST NOT alter the behavior of the compatibility
mode itself.
7.1.6. Screen Types
Device implementation screens are classified as one of two types:
Fixed-pixel display implementations: the screen is a single panel that supports
only a single pixel width and height. Typical y the screen is physical y integrated
with the device. Examples include mobile phones, tablets, and so on.
Variable-pixel display implementations: the device implementation either has no
embedded screen and includes a video output port such as VGA, HDMI or a
wireless port for display, or has an embedded screen that can change pixel
dimensions. Examples include televisions, set-top boxes, and so on.
Fixed-Pixel Device Implementations
Fixed-pixel device implementations MAY use screens of any pixel dimensions,
provided that they meet the requirements defined this Compatibility Definition.
Fixed-pixel implementations MAY include a video output port for use with an external
display. However, if that display is ever used for running apps, the device MUST meet
the fol owing requirements:
The device MUST report the same screen configuration and display metrics, as
detailed in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.
The device MUST report the same logical density as the fixed-pixel display.
The device MUST report screen dimensions that are the same as, or very close
to, the fixed-pixel display.
For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is
considered a fixed-pixel large mdpi display implementation. If it contains a video
output port that displays at 720p or 1080p, the device implementation MUST scale the
output so that applications are only executed in a large mdpi window, regardless of
whether the fixed-pixel display or video output port is in use.
Variable-Pixel Device Implementations
Variable-pixel device implementations MUST support one or both of 1280x720, or
1920x1080 (that is, 720p or 1080p). Device implementations with variable-pixel
displays MUST NOT support any other screen configuration or mode. Device
implementations with variable-pixel screens MAY change screen configuration or
mode at runtime or boot-time. For example, a user of a set-top box may replace a
720p display with a 1080p display, and the device implementation may adjust
accordingly.
Additional y, variable-pixel device implementations MUST report the fol owing
configuration buckets for these pixel dimensions:
1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) density
1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) density
For clarity, device implementations with variable pixel dimensions are restricted to
720p or 1080p in Android 4.1, and MUST be configured to report screen size and
density buckets as noted above.
7.1.7. Screen Technology
The Android platform includes APIs that al ow applications to render rich graphics to
the display. Devices MUST support al of these APIs as defined by the Android SDK
unless specifical y al owed in this document. Specifical y:
Devices MUST support displays capable of rendering 16-bit color graphics and
SHOULD support displays capable of 24-bit color graphics.
Devices MUST support displays capable of rendering animations.
The display technology used MUST have a pixel aspect ratio (PAR) between 0.9
and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with a 10%
tolerance.
7.2. Input Devices
7.2.1. Keyboard
Device implementations:
MUST include support for the Input Management Framework (which al ows third
party developers to create Input Management Engines - ie soft keyboard) as
detailed at http://developer.android.com
MUST provide at least one soft keyboard implementation (regardless of whether
a hard keyboard is present)
MAY include additional soft keyboard implementations
MAY include a hardware keyboard
MUST NOT include a hardware keyboard that does not match one of the formats
specified in android.content.res.Configuration.keyboard [Resources, 40]
(that is, QWERTY, or 12-key)
7.2.2. Non-touch Navigation
Device implementations:
MAY omit a non-touch navigation option (that is, may omit a trackbal , d-pad, or
wheel)
MUST report the correct value for
android.content.res.Configuration.navigation [Resources, 40]
MUST provide a reasonable alternative user interface m echanism for the
selection and editing of text, compatible with Input Management Engines. The
upstream Android open source software includes a selection mechanism
suitable for use with devices that lack non-touch navigation inputs.
7.2.3. Navigation keys
The Home, Menu and Back functions are essential to the Android navigation
paradigm. Device implementations MUST make these functions available to the user
at al times when running applications. These functions MAY be implemented via
dedicated physical buttons (such as mechanical or capacitive touch buttons), or MAY
be implemented using dedicated software keys, gestures, touch panel, etc. Android
4.1 supports both implementations.
Android 4.1 introduces support for assist action [Resources, 63]. Device
implementations MUST make the assist action available to the user at al times when
running applications. This function MAY be impleme nted via hardwa re or software
keys.
Device implementations MAY use a distinct portion of the screen to display the
navigation keys, but if so, MUST meet these requirements:
Device implementation navigation keys MUST use a distinct portion of the
screen, not available to applications, and MUST NOT obscure or otherwise
interfere with the portion of the screen available to applications.
Device implementations MUST make available a portion of the display to
applications that meets the requirements defined in Section 7.1.1.
Device implementations MUST display the navigation keys when applications do
not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.
Device implementations MUST present the navigation keys in an unob trusive
"low profile" (eg. dimmed) mode when applications specify
SYSTEM_UI_FLAG_LOW_PROFILE.
Device implementations MUST hide the navigation keys when applications
specify SYSTEM_UI_FLAG_HIDE_NAVIGATION.
Device implementation MUST present a Menu key to applications when
targetSdkVersion <= 10 and SHOULD NOT present a Menu key when the
targetSdkVersion > 10.
Device implementations MUST make available a portion of the display to
applications that meets the requirements defined in Section 7.1.1.
7.2.4. Touchscreen input
Device implementations SHOULD have a pointer input syste m of some kind (either
mouse-like, or touch). However, if a device implementation does not support a pointer
input system, it MUST NOT report the android.hardware.touchscreen or
android.hardware.faketouch feature constant. Device implementations that do
include a pointer input system:
SHOULD support ful y independently tracked pointers, if the device input system
supports multiple pointers
MUST report the value of android.content.res.Configuration.touchscreen
[ Resources, 40] c orresponding to the type of the specific touchscreen on the
device
Android 4.0 includes support for a variety of touch screens, touch pads, and fake touch
input devices. Touch screen based device implementations are associated with a
display [Resources, 71] such that the user has the impression of directly manipulating
items on screen. Since the user is directly touching the screen, the system does not
require any additional affordances to indicate the objects being manipulated. In
contrast, a fake touch interface provides a user input system that approximates a
subset of touchscreen capabilities. For example, a mouse or remote control that drives
an on-screen cursor approximates touch, but requires the user to first point or focus
then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse,
gyro-pointer, joystick, and multi-touch trackpad can support fake touch interactions.
Android 4.0 includes the feature constant android.hardware.faketouch, which
corresponds to a high-fidelity non-touch (that is, pointer-based) input device such as a
mouse or trackpad that can adequately emulate touch-based input (including basic
gesture support), and indicates that the device supports an emulated subset of
touchscreen functionality. Device implementations that declare the fake touch feature
MUST meet the fake touch requirements in Section 7.2.5.
Device implementations MUST report the correct feature corresponding to the type of
input used. Device implementations that include a touchscreen (single-touch or better)
MUST report the platform feature constant android.hardware.touchscreen. Device
implementations that report the platform feature constant
android.hardware.touchscreen MUST also report the platform feature constant
android.hardware.faketouch. Device implementations that do not include a
touchscreen (and rely on a pointer device only) MUST NOT report any touchscreen
feature, and MUST report only android.hardware.faketouch if they meet the fake
touch requirements in Section 7.2.5.
7.2.5. Fake touch inp ut
Device implementations that declare support for android.hardware.faketouch
MUST report the absolute X and Y screen positions of the pointer location and
display a visual pointer on the screen[Resources, 70]
MUST report touch event with the action code [Resources, 70] that specifies the
state change that occurs on the pointer g oing down or up on the screen
[Resources, 70]
MUST support pointer down and up on an object on the screen, which al ows
u sers to emulate tap on an object on the screen
MUST support pointer down, pointer up, pointer down then pointer up in the same
place on an object on the screen within a time threshold, which al ows users to
emulate double tap on an object on the screen [Resources, 70]
MUST support pointer down on an arbitrary point on the screen, pointer move to
any other arbitrary point on the screen, fol owed by a pointer up , which al ows
users to emulate a touch drag
MUST support pointer down then al ow users to quickly move the object to a
different position on the screen and then pointer up on the screen, which al ows
users to fling an object on the screen
Devices that declare support for android.hardware.faketouch.multitouch.distinct
MUST meet the requirements for faketouch above, and MUST also support distinct
tracking of two or more independent pointer inputs.
7.2.6. Microphone
Device implementations MAY omit a microphone. However, if a device implementation
omits a microphone, it MUST NOT report the android.hardware.microphone feature
constant, and must implement the audio recording API as no-ops, per Section 7.
Conversely, device implementations that do possess a microphone:
MUST report the android.hardware.microphone feature constant
SHOULD meet the audio quality requirements in Section 5.4
SHOULD meet the audio latency requirements in Section 5.5
7.3. Sensors
Android 4.1 includes APIs for accessing a variety of sensor types. Devices
implementations general y MAY omit these sensors, as provided for in the fol owing
subsections. If a device includes a particular sensor type that has a corresponding API
for third-party developers, the device implementation MUST implement that API as
described in the Android SDK documentation. For example, device implementations:
MUST accurately report the presence or absence of sensors per the
android.content.pm.PackageManager class. [Re sources, 37]
MUST return an accurate list of supported sensors via the
SensorManager.getSensorList() and similar methods
MUST behave reasonably for al other sensor APIs (for example, by returning true
or false as appropriate when applications attempt to register listeners, not cal ing
sensor listeners when the corresponding sensors are not present; etc.)
MUST report al sensor measurements using the relevant International System of
Units (ie metric) values for each sensor type as defined in the Android SDK
documentation [Resources, 41]
The list above is not comprehensive; the documented behavior of the Android SDK is
to be considered authoritative.
Some sensor types are synthetic, meaning they can be derived from data provided by
one or more other sensors. (Examples include the orientation sensor, and the linear
acceleration sensor.) Device implementations SHOULD implement these sensor
types, when they include the prerequisite physical sensors.
The Android 4.1 APIs introduce a notion of a "streaming" sensor, which is one that
returns data continuously, rather than only when the data changes. Device
implementations MUST continuously provide periodic data samples for any API
indicated by the Android 4.1 SDK documentation to be a streaming sensor.
7.3.1. Accelerometer
Device implementations SHOULD include a 3-axis accelerometer. If a device
implementation does include a 3-axis accelerometer, it:
SHOULD be able to deliver events at 120 Hz or greater. Note that while the
accelerometer frequency above is stated as "SHOULD" for Android 4.1, the
Compatibility Definition for a future version is planned to change these to
"MUST". That is, these standards are optional in Android 4.1 but will be
required in future versions. Existing and new devices that run Android 4.1 are
very strongly encouraged to meet these requirements in Android 4.1 so
they wil be able to upgrade to the future platform releases
MUST comply with the Android sensor coordinate system as detailed in the
Android APIs (see [Resources, 41])
MUST be capable of measuring from freefal up to twice gravity (2g) or more on
any three-dimension al vector
MUST have 8-bits of accuracy or more
MUST have a standard deviation no greater than 0.05 m/s^2
7.3.2. Magnetometer
Device implementations SHOULD include a 3-axis magnetometer (ie compass.) If a
device does include a 3-axis magnetometer, it:
MUST be able to deliver events at 10 Hz or greater
MUST comply with the Android sensor coordinate system as detailed in the
Android APIs (see [Resources, 41]).
MUST be capable of sampling a range of field strengths adequate to cover the
geomagnetic field
MUST have 8-bits of accuracy or mor e
MUST have a standard deviation no greater than 0.5 µT
7.3.3. GPS
Device implementations SHOULD include a GPS receiver. If a device implementation
does include a GPS receiver, it SHOULD include some form of "assisted GPS"
technique to minimize GPS lock-on time.
7.3.4. Gyroscope
Device implementations SHOULD include a gyroscope (ie angular change sensor.)
Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is
also included. If a device implementation includes a gyroscope, it:
MUST be temperature compensated
MUST be capable of measuring orientation changes up to 5.5*Pi
radians/second (that is, approximately 1,000 degrees per second)
SHOULD be able to deliver events at 200 Hz or greater. Note that while the
gyroscope frequency above is stated as "SHOULD" for Android 4.1, the
Compatibility Definition for a future version is planned to change these to
"MUST". That is, these standards are optional in Android 4.1 but will be
required in future versions. Existing and new devices that run Android 4.1 are
very strongly encouraged to meet these requirements in Android 4.1 so
they wil be able to upgrade to the future platform releases
MUST have 12-bits of accuracy or more
MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz,
or rad^2 / s). The variance is al owed to vary with the sampling rate, but must be
constrained by this value. In other words, if you measure the variance of the gyro
at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.
MUST have timestamps as close to when the hardware event happened as
possible. The constant latency must be removed.
7.3.5. Barometer
Device implementations MAY include a barometer (ie ambient air pressure sensor.) If
a device implementation includes a barometer, it:
MUST be able to deliver events at 5 Hz or greater
MUST have adequate precision to enable estimating altitude
MUST be temperature compensated
7.3.7. Thermometer
Device implementations MAY but SHOULD NOT include a thermometer (ie
temperature sensor.) If a device implementation does include a thermometer, it MUST
measure the temperature of the device CPU. It MUST NOT measure any other
temperature. (Note that this sensor type is deprecated in the Android 4.1 APIs.)
7.3.7. Photometer
Device implementations MAY include a photometer (ie ambient light sensor.)
7.3.8. Proximity Sensor
Device implementations MAY include a proximity sensor. If a device implementation
does include a proximity sensor, it MUST measure the proximity of an object in the
same direction as the screen. That is, the proximity sensor MUST be oriented to detect
objects close to the screen, as the primary intent of this sensor type is to detect a
phone in use by the user. If a device implementation includes a proximity sensor with
any other orientation, it MUST NOT be accessible through this API. If a device
implementation has a proximity sensor, it MUST be have 1-bit of accuracy or more.
7.4. Data Connectivity
7.4.1. Telephony
"Telephony" as used by the Android 4.1 APIs and this document refers specifical y to
hardware related to placing voice cal s and sending SMS messages via a GSM or
CDMA network. While these voice cal s may or may not be packet-switched, they are
for the purposes of Android 4.1 considered independent of any data connectivity that
may be implemented using the same network. In other words, the Android "telephony"
functionality and APIs refer specifical y to voice cal s and SMS; for instance, device
implementations that cannot place cal s or send/receive SMS messages MUST NOT
report the "android.hardware.telephony" feature or any sub-features, regardless of
whether they use a cel ular network for data connectivity.
Android 4.1 MAY be used on devices that do not include telephony hardware. That is,
Android 4.1 is compatible with devices that are not phones. However, if a device
implementation does include GSM or CDMA telephony, it MUST implement ful support
for the API for that technology. Device implementations that do not include telephony
hardware MUST implement the ful APIs as no-ops.
7.4.2. IEEE 802.11 (WiFi)
Android 4.1 device implementations SHOULD include support for one or more forms
of 802.11 (b/g/a/n, etc.) If a device implementation does include support for 802.11, it
MUST implement the corresponding Android API.
Device implementations MUST implement the multicast API as described in the SDK
documentation [ Resources, 62]. D evice implementations that do include Wifi support
MUST support multicast DNS (mDNS). Device implementations MUST not filter mDNS
packets (224.0.0.251) at any time of operation including when the screen is not in an
active state.
7.4.2.1. WiFi Direct
Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer). If
a device implementation does include support for Wifi direct, it MUST implement the
corresponding Android API as described in the SDK documentation [Resources, 68]. If
a device implementation includes support for Wifi direct, then it:
MUST support regular Wifi operation
SHOULD support concurrent wifi and wifi Direct operation
7.4.3. Bluetooth
Device implementations SHOULD include a Bluetooth transceiver. Device
implementations that do include a Bluetooth transceiver MUST enable the RFCOMM-
based Bluetooth API as described in the SDK documentation [Resources, 42]. Device
implementations SHOULD implement relevant Bluetooth profiles, such as A2DP,
AVRCP, OBEX, etc. as appropriate for the device.
The Compatibility Test Suite includes cases that cover basic operation of the Android
RFCOMM Bluetooth API. However, since Bluetooth is a communications protocol
between devices, it cannot be ful y tested by unit tests running on a single device.
Consequently, device implementations MUST also pass the human-driven Bluetooth
test procedure described in Appendix A.
7.4.4. Near-Field Communications
Device implementations SHOULD include a transceiver and related hardware for
Near-Field Communications (NFC). If a device implementation does include NFC
hardware, then it:
MUST report the android.hardware.nfc feature from the
android.content.pm.PackageManager.hasSystemFeature() method.
[Resources, 37]
MUST be capable of reading and writing NDEF messages via the fol owing NFC
s tandards:
MUST be capable of acting as an NFC Forum reader/writer (as defined by
the NFC Forum technical specification NFCForum-TS-DigitalProtocol-1.0)
via the fol owing NFC standards:
NfcA (ISO14443-3A)
NfcB (ISO14443-3B)
NfcF (JIS 6319-4)
IsoDep (ISO 14443-4)
NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)
SHOULD be capable of reading and writing NDEF messages via the fol owing
NFC standards. Note that while the NFC standards below are stated as
"SHOULD" for Android 4.1, the Compatibility Definition for a future version is
planned to change these to "MUST". That is, these standards are optional in
Android 4.1 but will be required in future versions. Existing and new devices
that run Android 4.1 are very strongly encouraged to meet these
requirements in Android 4.1 so they wil be able to upgrade to the future
platform releases.
NfcV (ISO 15693)
MUST be capable of transmitting and receiving data via the fol owing peer-to-
peer standards and protocols:
ISO 18092
LLCP 1.0 (defined by the NFC Forum)
SDP 1.0 (defined by the NFC Forum)
NDEF Push Protocol [Resources, 43]
SNEP 1.0 (defined by the NFC Forum)
MUST include support for Android Beam [Resources, 65]:
MUST implement the S NEP default serv er. Valid NDEF messages
received by the default SNEP server MUST be dispatched to applications
using the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling
Android Beam in settings MUST NOT disable dispatch of incoming NDEF
message.
Device implementations MUST honor the
android.settings.NFCSHARING_SETTINGS intent to show NFC sharing
settings [R esources, 67].
MUST implement the NPP server. Messages received by the NPP server
MUST be processed the same way as the SNEP default server.
MUST implement a SNEP client and attempt to send outbound P2P NDEF
to the default SNEP server when Android Beam is enabled. If no default
SNEP server is found then the client MUST attempt to send to an NPP
server.
MUST al ow foreground activities to set the outbound P2P NDEF message
using android.nfc.NfcAdapter.setNdefPushMessage, and
android.nfc.NfcAdapter.setNdefPushMessageCal back, and
android.nfc.NfcAdapter.enableForegroundNdefPush.
SHOULD use a gesture or on-screen confirmation, such as 'Touch to
Beam', before sending outbound P2P NDEF messages.
SHOULD enable Android Beam by default
MUST support NFC Connection handover to Bluetooth when the device
supports Bluetooth Object Push Profile. Device implementations must
support connection handover to Bluetooth when using
android.nfc.NfcAdapter.setBeamPushUris, by implementing the
"Connection Handover version 1.2" [Resources, 60] and "Bluetooth Secure
Simple Pairing Using NFC version 1.0" [Resources, 61 ] specs from the
NFC Forum. Such an implementation SHO ULD use SNEP G ET requests
for exchanging the handover request / select records over NFC, and it
MUST use the Bluetooth Object Push Profile for the actual Bluetooth data
transfer.
MUST pol for al supported technologies while in NFC discovery mode.
SHOULD be in NFC discovery mode while the device is awake with the screen
active and the lock-screen unlocked.
(Note that publicly available links are not available for the JIS, ISO, and NFC Forum
specifications cited above.)
Additional y, device implementations MAY include reader/writer support for the
fol owing MIFARE technologies.
MIFARE Classic (NXP MF1S503x [Resources, 44], MF1S703x [Resources, 44])
MIFARE Ultralight (NXP MF0ICU1 [Resources, 46], MF0ICU2 [Resources, 46])
NDEF on MIFARE Classic (NXP AN1 30511 [Resourc es, 48], AN13 0411
[Resources, 49])
Note th at Android 4.1 in cludes APIs for these MIFARE types. If a device
implementation supports MIFARE in the reader/writer role, it:
MUST implement the corresponding Android APIs as documented by the
Android SDK
MUST report the feature com.nxp.mifare from the
android.content.pm.PackageManager.hasSystemFeature() method.
[Resources, 37] Note that this is not a standard Android feature, and as such
does not appear as a constant on the PackageManager class.
MUST NOT imple ment the corresponding Android APIs nor report the
com.nxp.mifare feature unless it also implements general NFC support as
described in this section
If a device implementation does not include NFC hardware, it MUST NOT declare the
android.hardware.nfc feature from the
android.content.pm.PackageManager.hasSystemFeature() method [Resources, 37],
and MUST implement the Android 4.1 NFC API as a no-op.
As the classes android.nfc.NdefMessage and android.nfc.NdefRecord r epresent a
protocol-independent data representation format, device implementations MUST
implement these APIs even if they do not include support for NFC or declare the
android.hardware.nfc feature.
7.4.5. Minimum Network Capability
Device implementations MUST include support for one or more forms of data
networking. Specifical y, device implementations MUST include support for at least one
data standard capable of 200Kbit/sec or greater. Examples of technologies that
satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, Ethernet, etc.
Device implementations where a physical networking standard (such as Ethernet) is
the primary data connection SHOULD also include support for at least one common
wireless data standard, such as 802.11 (WiFi).
Devices MAY implement more than one form of data connectivity.
7.5. Cameras
Device implementations SHOULD include a rear-facing camera, and MAY include a
front-facing camera. A rear-facing camera is a camera located on the side of the
device opposite the display; that is, it images scenes on the far side of the device, like
a traditional camera. A front-facing camera is a camera located on the same side of
the device as the display; that is, a camera typical y used to image the user, such as for
video conferencing and similar applications.
7.5.1. Rear-Facing Camera
Device implementations SHOULD include a rear-facing camera. If a device
implementation includes a rear-facing camera, it:
MUST have a resolution of at least 2 megapixels
SHOULD have either hardware auto-focus, or software auto-focus implemented
in the camera driver (transparent to application software)
MAY have fixed-focus or EDOF (extended depth of field) hardware
MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be
lit while an android.hardware.Camera.PreviewCal back instance has been
registered on a Camera preview surface, unless the application has explicitly
enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes
of a Camera.Parameters object. Note that this constraint does not apply to the
device's built-in system camera application, but only to third-party applications
using Camera.PreviewCallback.
7.5.2. Front-Facing Camera
Device implementations MAY include a front-facing camera. If a device implementation
includes a front-facing camera, it:
MUST have a resolution of at least VGA (that is, 640x480 pixels)
MUST NOT use a front-facing camera as the default for the Camera API. That is,
the camera API in Android 4.1 has specific support for front-facing cameras, and
device implementations MUST NOT configure the API to to treat a front-facing
camera as the default rear-facing camera, even if it is the only camera on the
device.
MAY include features (such as auto-focus, flash, etc.) available to rear-facing
cameras as described in Section 7.5.1.
MUST horizontal y reflect (ie mirror) the stream displayed by an app in a
CameraPreview, as fol ows:
If the device implementation is capable of being rotated by user (such as
automatical y via an accelerometer or manual y via user input), the camera
preview MUST be mirrored horizontal y relative to the device's current
orientation.
If the current application has explicitly requested that the Camera display
be rotated via a cal to the
android.hardware.Camera.setDisplayOrientation() [Resources, 50]
method, the camera preview MUST be mirrored horizontal y relative to the
orientation specified by the application.
Otherwise, the preview MUST be mirrored along the device's default
horizontal axis.
MUST mirror the image displayed by the postview in the same manner as the
camera preview image stream. (If the device implementation does not support
postview, this requirement obviously does not apply.)
MUST NOT mirror the final captured stil image or video streams returned to
application cal backs or committed to media storage
7.5.3. Camera API Behavior
Device implementations MUST implement the fol owing behaviors for the camera-
related APIs, for both front- and rear-facing cameras:
1. If an application has never cal ed
android.hardware.Camera.Parameters.setPreviewFormat(int), then the
device MUST use android.hardware.PixelFormat.YCbCr_420_SP for preview
data provided to application cal backs.
2. If an application registers an android.hardware.Camera.PreviewCallback
instance and the system cal s the onPreviewFrame() method when the preview
format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame()
must further be in the NV21 encoding format. That is, NV21 MUST be the default.
3. Device implementations MUST support the YV12 format (as denoted by the
android.graphics.ImageFormat.YV12 constant) for camera previews for both
front- and rear-facing cameras. (The hardware video decoder and camera may
use any native pixel format, but the device implementation MUST support
conversion to YV12.)
Device implementations MUST implement the ful Camera API included in the Android
4.1 SDK documentation [R esources, 51]), r egardless of whether the device includes
hardware autofocus or other capabilities. For instance, cameras that lack autofocus
MUST stil cal any registered android.hardware.Camera.AutoFocusCallback
instances (even though this has no relevance to a non-autofocus camera.) Note that
this does apply to front-facing cameras; for instance, even though most front-facing
cameras do not support autofocus, the API cal backs must stil be "faked" as
described.
Device implementations MUST recognize and honor each parameter name defined as
a constant on the android.hardware.Camera.Parameters class, if the underlying
hardware supports the feature. If the device hardware does not support a feature, the
API must behave as documented. Conversely, Device implementations MUST NOT
honor or recognize string constants passed to the
android.hardware.Camera.setParameters() method other than those documented as
constants on the android.hardware.Camera.Parameters. That is, device
implementations MUST support al standard Camera parameters if the hardware
al ows, and MUST NOT support custom Camera parameter types.
Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent
whenever a new picture is taken by the camera and the entry of the picture has been
added to the media store.
Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent
whenever a new video is recorded by the camera and the entry of the picture has been
added to the media store.
7.5.4. Camera Orientation
Both front- and rear-facing cameras, if present, MUST be oriented so that the long
dimension of the camera aligns with the screen's long dimention. That is, when the
device is held in the landscape orientation, cameras MUST capture images in the
landscape orientation. This applies regardless of the device's natural orientation; that
is, it applies to landscape-primary devices as wel as portrait-primary devices.
7.6. Memory and Storage
7.6.1. Minimum Memory and Storage
Device implementations MUST have at least 340MB of memory available to the kernel
and userspace. The 340MB MUST be in addition to any memory dedicated to
hardware components such as radio, video, and so on that is not under the kernel's
control.
Device implementations MUST have at least 350MB of non-volatile storage available
for application private data. That is, the /data partition MUST be at least 350MB.
The Android APIs include a Download Manager that applications may use to download
data files [Resources, 56]. The device implementation of the Download Manager
MUST be capable of downloading individual files of at least 100MB in size to the
default "cache" location.
7.6.2. Application Shared Storage
Device implementations MUST offer shared storage for applications. The shared
storage provided MUST be at least 1GB in size.
Device implementations MUST be configured with shared storage mounted by default,
"out of the box". If the shared storage is not mounted on the Linux path /sdcard, then
the device MUST include a Linux symbolic link from /sdcard to the actual mount point.
Device implementations MUST enforce as documented the
android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage.
Shared storage MUST otherwise be writable by any application that obtains that
permission.
Device implementations MAY have hardware for user-accessible removable storage,
such as a Secure Digital card. Alternatively, device implementations MAY al ocate
internal (non-removable) storage as shared storage for apps.
Regardless of the form of shared storage used, device implementations MUST
provide some mechanism to access the contents of shared storage from a host
computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP).
Device implementations MAY use USB mass storage, but SHOULD use Media
Transfer Protocol. If the device implementation supports Media Transfer Protocol:
The device implementation SHOULD be compatible with the reference Android
MTP host, Android File Transfer [R esources, 57].
The device implementation SHOULD report a USB device class of 0x00.
The device implementation SHOULD report a USB interface name of 'MTP'.
If the device implementation lacks USB ports, it MUST provide a host computer with
access to the contents of shared storage by some other means, such as a network file
system.
It is il ustrative to consider two common examples. If a device implementation includes
an SD card slot to satisfy the shared storage requirement, a FAT-formatted SD card
1GB in size or larger MUST be included with the device as sold to users, and MUST
be mounted by default. Alternatively, if a device implementation uses internal fixed
storage to satisfy this requirement, that storage MUST be 1GB in size or larger and
mounted on /sdcard (or /sdcard MUST be a symbolic link to the physical location if it
is mounted elsewhere.)
Device implementations that include multiple shared storage paths (such as both an
SD card slot and shared internal storage) SHOULD modify the core applications such
as the media scanner and ContentProvider to transparently support files placed in both
locations.
7.7. USB
Device implementations SHOULD include a USB client port, and SHOULD include a
USB host port.
If a device implementation includes a USB client port:
the port MUST be connectable to a USB host with a standard USB-A port
the port SHOULD use the micro USB form factor on the device side. Existing
and new devices that run Android 4.1 are very strongly encouraged to meet
these requirements in Android 4.1 so they wil be able to upgrade to the future
platform releases
the port SHOULD be centered in the middle of an edge. Device implementations
SHOULD either locate the port on the bottom of the device (according to natural
orientation) or enable software screen rotation for al apps (including home
screen), so that the display draws correctly when the device is oriented with the
port at bottom. Existing and new devices that run Android 4.1 are very strongly
encouraged to meet these requirements in Android 4.1 so they wil be able
to upgrade to future platform releases.
if the device has other ports (such as a non-USB charging port) it SHOULD be
on the same edge as the micro-USB port
it MUST al ow a host connected to the device to access the contents of the
shared storage volume using either USB mass storage or Media Transfer
Protocol
it MUST implement the Android Open Accessory API and specification as
documented in the Android SDK documentation, and MUST declare support for
the hardware feature android.hardware.usb.accessory [Resources, 52]
it MUST implement the USB audio class as documented in the Android SDK
documentation [Resources, 66]
it SHOULD implement support for USB battery charging spec ification
[Resources, 64] Existing and new devices that run Android 4.1 are very
strongly encour aged to meet th ese requirements in Android 4.1 so they
wil be able to upgrade to the future platform releases
If a device implementation includes a USB host port:
it MAY use a non-standard port form factor, but if so MUST ship with a cable or
cables adapting the port to standard USB-A
it MUST implement the Android USB host API as documented in the Android
SDK, and MUST declare support for the hardware feature
android.hardware.usb.host [Resources, 53]
Device implementations MUST implement the Android Debug Bridge. If a device
implementation omits a USB client port, it MUST implement the Android Debug Bridge
via local-area network (such as Ethern et or 802.11)
8. Performance Compatibility
Device implementations MUST meet the key performance metrics of an Android 4.1
compatible device defined in the table below:
Metric
Performance Threshold
Comments
The fol owing applications
should launch within the
specified time.
The launch time is measured as the
total time to complete loading the
Browser: less than
default activity for the application,
Application
1300ms
including the time it takes to start the
Launch Time
Contacts: less than
Linux process, load the Android
700ms
package into the Dalvik VM, and cal
Settings: less than
onCreate.
700ms
When multiple applications
have been launched, re-
launching an already-
Simultaneous
running application after it
Applications
has been launched must
take less than the original
launch time.
9. Security Model Compatibility
Device implementations MUST implement a security model consistent with the Android
platform security model as defined in Security and Permissions reference document in
the APIs [Resources, 54] in the Android developer documentation. Device
implementations MUST support instal ation of self-signed applications without
requiring any additional permissions/certificates from any third parties/authorities.
Specifical y, compatible devices MUST support the security mechanisms described in
the fol ow sub-sections.
9.1. Permissions
Device implementations MUST support the Android permissions model as defined in
the Android developer documentation [Resources, 54]. Specifical y, implementations
MUST enforce each permission defined as described in the SDK documentation; no
permissions may be omitted, altered, or i gnored. Impleme ntations MAY add additional
permissions, provided the new permission ID strings are not in the android.*
namespace.
9.2. UID and Process Isolation
Device implementations MUST support the Android application sandbox model, in
which each application runs as a unique Unix-style UID and in a separate process.
Device implementations MUST support running multiple applications as the same
Linux user ID, provided that the applications are properly signed and constructed, as
defined in the Security and Permissions reference [Resources, 54].
9.3. Filesystem Permissions
Device implementations MUST support the Android file access permissions model as
defined in as defined in the Security and Permissions reference [Resources, 54].
9.4. Alternate Execution Environments
Device implementations MAY include runtime environments that execute applications
using some other software or technology than the Dalvik virtual machine or native
code. However, such alternate execution environments MUST NOT compromise the
Android security model or the security of instal ed Android applications, as described
in this section.
Alternate runtimes MUST themselves be Android applications, and abide by the
standard Android security model, as described elsewhere in Section 9.
Alternate runtimes MUST NOT be granted access to resources protected by
permissions not requested in the runtime's AndroidManifest.xml file via the <uses-
permission> mechanism.
Alternate runtimes MUST NOT permit applications to make use of features protected
by Android permissions restricted to system applications.
Alternate runtimes MUST abide by the Android sandbox model. Specifical y:
Alternate runtimes SHOULD instal apps via the PackageManager into separate
Android sandboxes (that is, Linux user IDs, etc.)
Alternate runtimes MAY provide a single Android sandbox shared by al
applications using the alternate runtime
Alternate runtimes and instal ed applications using an alternate runtime MUST
NOT reuse the sandbox of any other app instal ed on the device, except through
the standard Android mechanisms of shared user ID and signing certificate
Alternate runtimes MUST NOT launch with, grant, or be granted access to the
sandboxes corresponding to other Android applications
Alternate runtimes MUST NOT be launched with, be granted, or grant to other
applications any privileges of the superuser (root), or of any other user ID.
The .apk files of alternate runtimes MAY be included in the system image of a device
implementation, but MUST be signed with a key distinct from the key used to sign other
applications included with the device implementation.
When instal ing applications, alternate runtimes MUST obtain user consent for the
Android permissions used by the application. That is, if an application needs to make
use of a device resource for which there is a corresponding Android permission (such
as Camera, GPS, etc.), the alternate runtime MUST inform the user that the application
wil be able to access that resource. If the runtime environment does not record
application capabilities in this manner, the runtime environment MUST list al
permissions held by the runtime itself when instal ing any application using that runtime.
10. Software Compatibility Testing
Device implementations MUST pass al tests described in this section.
However, note that no software test package is ful y comprehensive. For this reason,
device implementers are very strongly encouraged to make the minimum number of
changes as possible to the reference and preferred implementation of Android 4.1
available from the Android Open Source Project. This wil minimize the risk of
introducing bugs that create incompatibilities requiring rework and potential device
updates.
10.1. Compatibility Test Suite
Device implementations MUST pass the Android Compatibility Test Suite (CTS)
[Resources, 2] available from the Android Open Source Project, using the final
shipping software on the device. Additional y, device implementers SHOULD use the
r eference imple mentation in the Android Open Source tree as much as possible, and
MUST ensure compatibility in cases of ambiguity in CTS and for any
reimplementations of parts of the reference source code.
The CTS is designed to be run on an actual device. Like any software, the CTS may
itself contain bugs. The CTS wil be versioned independently of this Compatibility
Definition, and multiple revisions of the CTS may be released for Android 4.1. Device
implementations MUST pass the latest CTS version available at the time the device
software is completed.
10.2. CTS Verifier
Device implementations MUST correctly execute al applicable cases in the CTS
Verifier. The CTS Verifier is included with the Compatibility Test Suite, and is intended
to be run by a human operator to test functionality that cannot be tested by an
automated system, such as correct functioning of a camera and sensors.
The CTS Verifier has tests for many kinds of hardware, including some hardware that
is optional. Device implementations MUST pass al tests for hardware which they
possess; for instance, if a device possesses an accelerometer, it MUST correctly
execute the Accelerometer test case in the CTS Verifier. Test cases for features noted
as optional by this Compatibility Definition Document MAY be skipped or omitted.
Every device and every build MUST correctly run the CTS Verifier, as noted above.
However, since many builds are very similar, device implementers are not expected to
explicitly run the CTS Verifier on builds that differ only in trivial ways. Specifical y,
device implementations that differ from an implementation that has passed the CTS
Verfier only by the set of included locales, branding, etc. MAY omit the CTS Verifier
test.
10.3. Reference Applications
Device implementers MUST test implementation compatibility using the fol owing open
source applications:
The "Apps for Android" applications [Re sources, 55]
Replica Island (available in Android Market)
Each app above MUST launch and behave correctly on the implementation, for the
implementation to be considered compatible.
11. Updatable Software
Device implementations MUST include a mechanism to replace the entirety of the
system software. The mechanism need not perform "live" upgrades - that is, a device
restart MAY be required.
Any method can be used, provided that it can replace the entirety of the software
preinstal ed on the device. For instance, any of the fol owing approaches wil satisfy
this requirement:
Over-the-air (OTA) downloads with offline update via reboot
"Tethered" updates over USB from a host PC
"Offline" updates via a reboot and update from a file on removable storage
The update mechanism used MUST support updates without wiping user data. That is,
the update mechanism MUST preserve application private data and application
shared data. Note that the upstream Android software includes an update mechanism
that satisfies this requirement.
If an error is found in a device implementation after it has been released but within its
reasonable product lifetime that is determined in consultation with the Android
Compatibility Team to affect the compatibility of third-party applications, the device
implementer MUST correct the error via a software update available that can be
applied per the mechanism just described.
12. Contact Us
You can contact the document authors at compatibility@android.com for clarifications
and to bring up any issues that you think the document does not cover.
Appendix A - Bluetooth Test Procedure
The Compatibility Test Suite includes cases that cover basic operation of the Android
RFCOMM Bluetooth API. However, since Bluetooth is a communications protocol
between devices, it cannot be ful y tested by unit tests running on a single device.
Consequently, device implementations MUST also pass the human-operated Bluetooth
test procedure described below.
The test procedure is based on the BluetoothChat sample app included in the Android
open source project tree. The procedure requires two devices:
a candidate device implementation running the software build to be tested
a separate device implementation already known to be compatible, and of a
model from the device implementation being tested - that is, a "known good"
device implementation
The test procedure below refers to these devices as the "candidate" and "known
good" devices, respectively.
Setup and Installation
1. Build BluetoothChat.apk via 'make samples' from an Android source code tree
2. Instal BluetoothChat.apk on the known-good device
3. Instal BluetoothChat.apk on the candidate device
Test Bluetooth Control by Apps
1. Launch BluetoothChat on the candidate device, while Bluetooth is disabled
2. Verify that the candidate device either turns on Bluetooth, or prompts the user
with a dialog to turn on Bluetooth
Test Pairing and Communication
1. Launch the Bluetooth Chat app on both devices
2. Make the known-good device discoverable from within BluetoothChat (using the
Menu)
3. On the candidate device, scan for Bluetooth devices from within BluetoothChat
(using the Menu) and pair with the known-good device
4. Send 10 or more messages from each device, and verify that the other device
receives them correctly
5. Close the BluetoothChat app on both devices by pressing Home
6. Unpair each device from the other, using the device Settings app
Test Pairing and Communication in the Reverse
Direction
1. Launch the Bluetooth Chat app on both devices.
2. Make the candidate device discoverable from within BluetoothChat (using the
Menu).
3. On the known-good device, scan for Bluetooth devices from within BluetoothChat
(using the Menu) and pair with the candidate device.
4. Send 10 or messages from each device, and verify that the other device
receives them correctly.
5. Close the Bluetooth Chat app on both devices by pressing Back repeatedly to
get to the Launcher.
Test Re-Launches
1. Re-launch the Bluetooth Chat app on both devices.
2. Send 10 or messages from each device, and verify that the other device
receives them correctly.
Note: the above tests have some cases which end a test section by using Home, and
some using Back. These tests are not redundant and are not optional: the objective is
to verify that the Bluetooth API and stack works correctly both when Activities are
explicitly terminated (via the user pressing Back, which cal s finish()), and implicitly sent
to background (via the user pressing Home.) Each test sequence MUST be performed
as described.
