Tv Develop of Android TIF Study

The article is mainly recording the following skills
–>Android TIF code Structure and flow
–>How to use TIF in Tv App
References:
http://blog.csdn.net/wangmxe/article/details/50528682
http://blog.csdn.net/zhudaozhuan/article/details/50849542

1: TIF architecture

1.1: TIF OverView

The Android TV Input Framework (TIF) simplifies the delivery of content to Android TV. The TIF provides a standard API for manufacturers to use in constructing input modules for controlling
Android TV.

The Android TV Input Framework includes a TV Input Manager and an example TV App that works with a special remote control to access builtin and IP tuner channels.

In all, the TV Input Framework consists of:
● TV Provider (com.android.providers.tv.TvProvider) a database of channels, programs and associated permissions
● TV Input Manager (android.media.tv.TvInputManager) brokers
communication between the TV Inputs and TV App
● TV Input an application provided by the OEM, Google or third parties to route content
● TV App (com.android.tv.TvActivity) the application provided by the OEM or Google for user interaction
● HDMICEC the technology to allow remote control of various devices over HDMI

1.2: TIF Directory Structure

1.3: TIF Main Class

• TvView: Displays TV contents. The TvView class provides a high level interface for applications to show TV programs from various TV sources that implement {@link TvInputService}
  
  –>TvInputCallback: Callback used to receive various status updates on the {@link TvView}
• TvInputManager: Central system API to the overall TV input framework (TIF) architecture, which arbitrates interaction between applications and the selected TV inputs.
  
  –>SessionCallback: Interface used to receive the created session,
  –>TvInputCallback: Callback used to monitor status of the TV input
  –>Session: The Session provides the per-session functionality of TV inputs
• TvInputManagerService: This class provides a system service that manages television inputs.
  
• TvInputService: all of the input device must inherit the class.The TvInputService class represents a TV input or source such as HDMI or built-in tuner which provides pass-through video or broadcast TV programs.

1.4: TIS init flow

2: how to use TIF

2.1: create session

           {                mTvInputManager = (TvInputManager) getSystemService(Context.TV_INPUT_SERVICE);                if (mTvInputManager != null) {                    observerCallback = new ObserverSessionCallback();                    List inputlist = mTvInputManager.getTvInputList();                    if (inputlist != null) {                        for (int i = 0; i < inputlist.size(); i++) {                            TvInputInfo tinfo = (TvInputInfo) inputlist.get(i);                            if ((tinfo.getType() == TvInputInfo.TYPE_TUNER) &&                                (tinfo.getComponent().getPackageName().equals(ITVSessionContext.TUNERSERVICE_PKG_ID))) {                                tunerServiceId = tinfo.getId();                                Log.d(tag, "TunerService ID = " + tunerServiceId);                                break;                            }                        }                    }                    if (mTvInputManager.getInputState(tunerServiceId) == TvInputManager.INPUT_STATE_CONNECTED) {                        Log.d(tag, "creating the session,waiting for call back");                        mTvInputManager.createSession(tunerServiceId, observerCallback, mSessionHandler);                    } else {                        Log.d(tag, "input tuner not added yet,waiting for call back");                    }                } else {                    Log.d(tag, "Could not get system service TV_INPUT_SERVICE!!");                }            }

2.2: inherit SessionCallback

    public class ObserverSessionCallback extends SessionCallback {        Session mySession = null;        public void onSessionCreated(Session session) {            Log.d(tag, "onSessionCreated ");            if (session != null) {                Log.d(tag, "Session creation successful");                mySession = session;                String action = ITVSessionContext.APP_PRIVATE_COMMAND_SESSION_TYPE;                Bundle bundle = new Bundle();                bundle.putString(ITVSessionContext.KEY_SESSION_TYPE, ITVSessionContext.SESSION_TYPE_MAIN_OBSERVER);                mySession.sendAppPrivateCommand(action, bundle);            } else {                Log.d(tag, "Session creation failed");            }        }        public void onSessionReleased(Session session) {            Log.d(tag, "onSessionReleased called");            mySession = null;            mObserverSessionContext = null;        }        public void onChannelRetuned(Session session, Uri channelUri) {        }        public void onVideoUnavailable(Session session, int reason) {        }        public void onSessionEvent(Session session, String eventType, Bundle eventArgs) {            Log.i(tag, "onSessionEvent " + this);            if (eventType.equals(ITVSessionContext.EVENT_SESSION_CONTEXT_CREATED)) {                IBinder binder = eventArgs.getBinder(ITVSessionContext.SESSION_CONTEXT);                mObserverSessionContext = ITVSessionContext.instance.asInterface(binder);                ObserverSessionContextCallbacks mainSessionContextCallbacks = new ObserverSessionContextCallbacks();                mObserverSessionContext.registerSessionContextCallbacks(mainSessionContextCallbacks);            }        }    }

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