Android 输入法框架源码分析总结（1）

1 IMF主要包含三个部分

1.ager（IMM）运行于客户端进程

- -Input (IMM)是负责管理其他部分交互的中心，以-side API的形式存在于每一个应用上下文中，同时和rvice（IMMF）进行通信，用来沟通管理所有进程间交互的全局系统服务，可以通过.()来获取一个的实例。

2. （IMS）运行于输入法进程

3.rvice （IMMS）运行于系统进程，负责管理系统所有输入法

获取焦点

请求绑定解绑

显示输入法

输入法框架

2 创建

每个程序都会有一个 实例，IMM是程序和IMMS通信的接口，IMM实例在初始化的时候被创建 ， imm = .();

// ViewRootImpl.java
public final class ViewRootImpl implements ViewParent,View.AttachInfo.Callbacks, ThreadedRenderer.HardwareDrawCallbacks {public ViewRootImpl(Context context, Display display) {...mWindowSession = WindowManagerGlobal.getWindowSession();...}// WindowManagerGlobal.javapublic static IWindowSession getWindowSession() {synchronized (WindowManagerGlobal.class) {if (sWindowSession == null) {try {// 生成 InputMethodManager 实例InputMethodManager imm = InputMethodManager.getInstance();IWindowManager windowManager = getWindowManagerService();sWindowSession = windowManager.openSession(new IWindowSessionCallback.Stub() {@Overridepublic void onAnimatorScaleChanged(float scale) {ValueAnimator.setDurationScale(scale);}},imm.getClient(), imm.getInputContext());} catch (RemoteException e) {throw e.rethrowFromSystemServer();}}return sWindowSession;}}// InputMethodManager.java/*** Retrieve the global InputMethodManager instance, creating it if it* doesn't already exist.* @hide*/public static InputMethodManager getInstance() {synchronized (InputMethodManager.class) {if (sInstance == null) {try {sInstance = new InputMethodManager(service, Looper.getMainLooper());} cathch () {throw new IllegalStateException(e);}}return sInstance;}}

3 程序获取焦点

// **WindowManagerService.java**
private boolean updateFocusedWindowLocked(int mode, boolean updateInputWindows) {  //计算焦点window  WindowState newFocus = computeFocusedWindowLocked();  if (mCurrentFocus != newFocus) {  //焦点window发生变化，post一个message来通知程序焦点发生变化了  mH.removeMessages(H.REPORT_FOCUS_CHANGE);  mH.sendEmptyMessage(H.REPORT_FOCUS_CHANGE);  return true;  }  return false;  
}  private WindowState computeFocusedWindowLocked() {  if (mAnimator.mUniverseBackground != null  && mAnimator.mUniverseBackground.mWin.canReceiveKeys()) {  return mAnimator.mUniverseBackground.mWin;  }  final int displayCount = mDisplayContents.size();  for (int i = 0; i < displayCount; i++) {  final DisplayContent displayContent = mDisplayContents.valueAt(i);  WindowState win = findFocusedWindowLocked(displayContent);  if (win != null) {  return win;  }  }  return null;  
}  //该函数就是找出最top的可以接收按键事件的window，这个window就获得焦点  
private WindowState findFocusedWindowLocked(DisplayContent displayContent) {  final WindowList windows = displayContent.getWindowList();  for (int i = windows.size() - 1; i >= 0; i--) {  final WindowState win = windows.get(i);  //是否为activity的window  AppWindowToken wtoken = win.mAppToken;  //重要函数，window是否可以获取焦点  if (!win.canReceiveKeys()) {  continue;  }  // mFocusedApp是最top的activity ，下面逻辑是为了确保焦点window的app  //必须是焦点程序之上，所以这个逻辑其实并没有多大作用，只是为了检测出  //错误  if (wtoken != null && win.mAttrs.type != TYPE_APPLICATION_STARTING &&  mFocusedApp != null) {  ArrayList tasks = displayContent.getTasks();  for (int taskNdx = tasks.size() - 1; taskNdx >= 0; --taskNdx) {  AppTokenList tokens = tasks.get(taskNdx).mAppTokens;  int tokenNdx = tokens.size() - 1;  for ( ; tokenNdx >= 0; --tokenNdx) {  final AppWindowToken token = tokens.get(tokenNdx);  if (wtoken == token) {  break;  }  if (mFocusedApp == token) {  return null;  }  }  }  }  return win;  }  return null;  
}  public final boolean canReceiveKeys() {  return isVisibleOrAdding()  && (mViewVisibility == View.VISIBLE)  && ((mAttrs.flags & WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE) == 0);  
}  
//由于输入法的window带有FLAG_NOT_FOCUSABLE, 从上可见其不可能是焦点window  
//接下来系统开始通知程序端哪个window获得了焦点。  final class H extends Handler {  @Override  public void handleMessage(Message msg) {  switch (msg.what) {  case REPORT_FOCUS_CHANGE: {  WindowState lastFocus;  WindowState newFocus;  synchronized(mWindowMap) {  lastFocus = mLastFocus;  newFocus = mCurrentFocus;  if (lastFocus == newFocus) {  // Focus is not changing, so nothing to do.  return;  }  mLastFocus = newFocus;  }  if (newFocus != null) {  //通知新的焦点程序其获得了焦点  newFocus.reportFocusChangedSerialized(true, mInTouchMode);  notifyFocusChanged();  }  if (lastFocus != null) {  //通知老的焦点程序其获得了焦点  lastFocus.reportFocusChangedSerialized(false, mInTouchMode);  }  } break;  }  public void reportFocusChangedSerialized(boolean focused, boolean inTouchMode) {  try {  //这个就是通过Binder告知client其获得或失去了焦点  mClient.windowFocusChanged(focused, inTouchMode);  } catch (RemoteException e) {  }  
}  

4.程序变更焦点，获得焦点变更事件

// ViewRootImpl.javapublic void windowFocusChanged(boolean hasFocus, boolean inTouchMode) {Message msg = Message.obtain();msg.what = MSG_WINDOW_FOCUS_CHANGED;msg.arg1 = hasFocus ? 1 : 0;msg.arg2 = inTouchMode ? 1 : 0;mHandler.sendMessage(msg);}//程序获得焦点会通过调用mView.dispatchWindowFocusChanged和  
//imm.onPostWindowFocus来通知IMMS焦点信息发生改变，需要更新输入法了  @Overridepublic void handleMessage(Message msg) {switch (msg.what) {case MSG_WINDOW_FOCUS_CHANGED: {if (mAdded) {boolean hasWindowFocus = msg.arg1 != 0;mAttachInfo.mHasWindowFocus = hasWindowFocus;profileRendering(hasWindowFocus);if (hasWindowFocus) {...}mLastWasImTarget = WindowManager.LayoutParams.mayUseInputMethod(mWindowAttributes.flags);InputMethodManager imm = InputMethodManager.peekInstance();if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {imm.onPreWindowFocus(mView, hasWindowFocus);}if (mView != null) {mAttachInfo.mKeyDispatchState.reset();// 6.1 调用根 view的 dispatchWindowFocusChanged()，通知view程序获得焦点mView.dispatchWindowFocusChanged(hasWindowFocus);mAttachInfo.mTreeObserver.dispatchOnWindowFocusChange(hasWindowFocus);}// Note: must be done after the focus change callbacks,// so all of the view state is set up correctly.if (hasWindowFocus) {if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {// 6.2 通知 InputMethodManager 该 window 获得焦点imm.onPostWindowFocus(mView, mView.findFocus(),mWindowAttributes.softInputMode,!mHasHadWindowFocus, mWindowAttributes.flags);}// Clear the forward bit.  We can just do this directly, since// the window manager doesn't care about it.mWindowAttributes.softInputMode &=~WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION;((WindowManager.LayoutParams)mView.getLayoutParams()).softInputMode &=~WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION;mHasHadWindowFocus = true;}}} break;...}}

5 焦点View向IMMS请求绑定输入法

获得焦点的 view 通过 向 通知自己获得焦点

imm.(this);

6.1 之后的流程

// ViewGroup.java@Overridepublic void dispatchWindowFocusChanged(boolean hasFocus) {super.dispatchWindowFocusChanged(hasFocus);final int count = mChildrenCount;final View[] children = mChildren;for (int i = 0; i < count; i++) {children[i].dispatchWindowFocusChanged(hasFocus);}}
// View.java/*** Called when the window containing this view gains or loses window focus.* ViewGroups should override to route to their children.** @param hasFocus True if the window containing this view now has focus,*        false otherwise.*/public void dispatchWindowFocusChanged(boolean hasFocus) {onWindowFocusChanged(hasFocus);}/*** Called when the window containing this view gains or loses focus.  Note* that this is separate from view focus: to receive key events, both* your view and its window must have focus.  If a window is displayed* on top of yours that takes input focus, then your own window will lose* focus but the view focus will remain unchanged.** @param hasWindowFocus True if the window containing this view now has*        focus, false otherwise.*/public void onWindowFocusChanged(boolean hasWindowFocus) {InputMethodManager imm = InputMethodManager.peekInstance();if (!hasWindowFocus) {if (isPressed()) {setPressed(false);}if (imm != null && (mPrivateFlags & PFLAG_FOCUSED) != 0) {imm.focusOut(this);}removeLongPressCallback();removeTapCallback();onFocusLost();} else if (imm != null && (mPrivateFlags & PFLAG_FOCUSED) != 0) {// 获得焦点的 view 通过 InputMethodManager 向 Service 通知自己获得焦点imm.focusIn(this);}refreshDrawableState();}// InputMethodManager.java/*** Call this when a view receives focus.* @hide*/public void focusIn(View view) {synchronized (mH) {focusInLocked(view);}}// InputMethodManager.java/*** Call this when a view receives focus.* @hide*/public void focusIn(View view) {synchronized (mH) {focusInLocked(view);}}void focusInLocked(View view) {if (DEBUG) Log.v(TAG, "focusIn: " + dumpViewInfo(view));if (view != null && view.isTemporarilyDetached()) {// This is a request from a view that is temporarily detached from a window.if (DEBUG) Log.v(TAG, "Temporarily detached view, ignoring");return;}if (mCurRootView != view.getRootView()) {// This is a request from a window that isn't in the window with// IME focus, so ignore it.if (DEBUG) Log.v(TAG, "Not IME target window, ignoring");return;}mNextServedView = view;// 保存焦点view的变量scheduleCheckFocusLocked(view);}static void scheduleCheckFocusLocked(View view) {ViewRootImpl viewRootImpl = view.getViewRootImpl();if (viewRootImpl != null) {viewRootImpl.dispatchCheckFocus();}}// ViewRootImpl.javapublic void dispatchCheckFocus() {if (!mHandler.hasMessages(MSG_CHECK_FOCUS)) {// This will result in a call to checkFocus() below.mHandler.sendEmptyMessage(MSG_CHECK_FOCUS);}}case MSG_CHECK_FOCUS: {InputMethodManager imm = InputMethodManager.peekInstance();if (imm != null) {imm.checkFocus();}} break;// InputMethodManager.java/*** @hide*/public void checkFocus() {// 确认当前 focused view 是否已经调用过 startInputInner() 来绑定输入法，// 因为前面 mView.dispatchWindowFocusChanged() 已经完成了 focused view 的绑定，// 大部分情况下，该函数返回 false , 不会再次调用  startInputInner()if (checkFocusNoStartInput(false)) {startInputInner(InputMethodClient.START_INPUT_REASON_CHECK_FOCUS, null, 0, 0, 0);}}private boolean checkFocusNoStartInput(boolean forceNewFocus) {// This is called a lot, so short-circuit before locking.if (mServedView == mNextServedView && !forceNewFocus) {return false;}final ControlledInputConnectionWrapper ic;synchronized (mH) {if (mServedView == mNextServedView && !forceNewFocus) {return false;}if (DEBUG) Log.v(TAG, "checkFocus: view=" + mServedView+ " next=" + mNextServedView+ " forceNewFocus=" + forceNewFocus+ " package="+ (mServedView != null ? mServedView.getContext().getPackageName() : ""));if (mNextServedView == null) {finishInputLocked();// In this case, we used to have a focused view on the window,// but no longer do.  We should make sure the input method is// no longer shown, since it serves no purpose.closeCurrentInput();return false;}ic = mServedInputConnectionWrapper;mServedView = mNextServedView;mCurrentTextBoxAttribute = null;mCompletions = null;mServedConnecting = true;}if (ic != null) {ic.finishComposingText();}return true;}boolean startInputInner(@InputMethodClient.StartInputReason final int startInputReason,IBinder windowGainingFocus, int controlFlags, int softInputMode,int windowFlags) {final View view;synchronized (mH) {// 获得上面的焦点viewview = mServedView;// Make sure we have a window token for the served view.if (DEBUG) {Log.v(TAG, "Starting input: view=" + dumpViewInfo(view) +" reason=" + InputMethodClient.getStartInputReason(startInputReason));}if (view == null) {if (DEBUG) Log.v(TAG, "ABORT input: no served view!");return false;}}// Now we need to get an input connection from the served view.// This is complicated in a couple ways: we can't be holding our lock// when calling out to the view, and we need to make sure we call into// the view on the same thread that is driving its view hierarchy.Handler vh = view.getHandler();if (vh == null) {// If the view doesn't have a handler, something has changed out// from under us, so just close the current input.// If we don't close the current input, the current input method can remain on the// screen without a connection.if (DEBUG) Log.v(TAG, "ABORT input: no handler for view! Close current input.");closeCurrentInput();return false;}if (vh.getLooper() != Looper.myLooper()) {// The view is running on a different thread than our own, so// we need to reschedule our work for over there.if (DEBUG) Log.v(TAG, "Starting input: reschedule to view thread");vh.post(new Runnable() {@Overridepublic void run() {startInputInner(startInputReason, null, 0, 0, 0);}});return false;}// Okay we are now ready to call into the served view and have it// do its stuff.// Life is good: let's hook everything up!EditorInfo tba = new EditorInfo();// Note: Use Context#getOpPackageName() rather than Context#getPackageName() so that the// system can verify the consistency between the uid of this process and package name passed// from here. See comment of Context#getOpPackageName() for details.tba.packageName = view.getContext().getOpPackageName();tba.fieldId = view.getId();// 创建数据通信连接接口 InputConnection，这个会传送到InputMethodService  // InputMethodService 后面就是通过这个connection将输入法的字符传给该viewInputConnection ic = view.onCreateInputConnection(tba);if (DEBUG) Log.v(TAG, "Starting input: tba=" + tba + " ic=" + ic);synchronized (mH) {// Now that we are locked again, validate that our state hasn't// changed.if (mServedView != view || !mServedConnecting) {// Something else happened, so abort.if (DEBUG) Log.v(TAG,"Starting input: finished by someone else. view=" + dumpViewInfo(view)+ " mServedView=" + dumpViewInfo(mServedView)+ " mServedConnecting=" + mServedConnecting);return false;}// If we already have a text box, then this view is already// connected so we want to restart it.if (mCurrentTextBoxAttribute == null) {controlFlags |= CONTROL_START_INITIAL;}// Hook 'em up and let 'er rip.mCurrentTextBoxAttribute = tba;mServedConnecting = false;if (mServedInputConnectionWrapper != null) {mServedInputConnectionWrapper.deactivate();mServedInputConnectionWrapper = null;}ControlledInputConnectionWrapper servedContext;final int missingMethodFlags;if (ic != null) {mCursorSelStart = tba.initialSelStart;mCursorSelEnd = tba.initialSelEnd;mCursorCandStart = -1;mCursorCandEnd = -1;mCursorRect.setEmpty();mCursorAnchorInfo = null;final Handler icHandler;missingMethodFlags = InputConnectionInspector.getMissingMethodFlags(ic);if ((missingMethodFlags & InputConnectionInspector.MissingMethodFlags.GET_HANDLER)!= 0) {// InputConnection#getHandler() is not implemented.icHandler = null;} else {icHandler = ic.getHandler();}// 将 InputConnection 封装为 binder 对象，这个是真正可以实现跨进程通信的封装类servedContext = new ControlledInputConnectionWrapper(icHandler != null ? icHandler.getLooper() : vh.getLooper(), ic, this);} else {servedContext = null;missingMethodFlags = 0;}mServedInputConnectionWrapper = servedContext;try {if (DEBUG) Log.v(TAG, "START INPUT: view=" + dumpViewInfo(view) + " ic="+ ic + " tba=" + tba + " controlFlags=#"+ Integer.toHexString(controlFlags));final InputBindResult res = mService.startInputOrWindowGainedFocus(startInputReason, mClient, windowGainingFocus, controlFlags, softInputMode,windowFlags, tba, servedContext, missingMethodFlags);if (DEBUG) Log.v(TAG, "Starting input: Bind result=" + res);if (res != null) {if (res.id != null) {setInputChannelLocked(res.channel);mBindSequence = res.sequence;// 获得输入法的通信接口mCurMethod = res.method;mCurId = res.id;mNextUserActionNotificationSequenceNumber =res.userActionNotificationSequenceNumber;if (mServedInputConnectionWrapper != null) {mServedInputConnectionWrapper.setInputMethodId(mCurId);}} else {if (res.channel != null && res.channel != mCurChannel) {res.channel.dispose();}if (mCurMethod == null) {// This means there is no input method available.if (DEBUG) Log.v(TAG, "ABORT input: no input method!");return true;}}} else {if (startInputReason== InputMethodClient.START_INPUT_REASON_WINDOW_FOCUS_GAIN) {// We are here probably because of an obsolete window-focus-in message sent// to windowGainingFocus.  Since IMMS determines whether a Window can have// IME focus or not by using the latest window focus state maintained in the// WMS, this kind of race condition cannot be avoided.  One obvious example// would be that we have already received a window-focus-out message but the// UI thread is still handling previous window-focus-in message here.// TODO: InputBindResult should have the error code.if (DEBUG) Log.w(TAG, "startInputOrWindowGainedFocus failed. "+ "Window focus may have already been lost. "+ "win=" + windowGainingFocus + " view=" + dumpViewInfo(view));if (!mActive) {// mHasBeenInactive is a latch switch to forcefully refresh IME focus// state when an inactive (mActive == false) client is gaining window// focus. In case we have unnecessary disable the latch due to this// spurious wakeup, we re-enable the latch here.// TODO: Come up with more robust solution.mHasBeenInactive = true;}}}if (mCurMethod != null && mCompletions != null) {try {mCurMethod.displayCompletions(mCompletions);} catch (RemoteException e) {}}} catch (RemoteException e) {Log.w(TAG, "IME died: " + mCurId, e);}}return true;}// InputMethodManagerService.java@Overridepublic InputBindResult startInputOrWindowGainedFocus(/* @InputMethodClient.StartInputReason */ final int startInputReason,IInputMethodClient client, IBinder windowToken, int controlFlags, int softInputMode,int windowFlags, @Nullable EditorInfo attribute, IInputContext inputContext,/* @InputConnectionInspector.missingMethods */ final int missingMethods) {if (windowToken != null) {// focusIn 不走该分支return windowGainedFocus(startInputReason, client, windowToken, controlFlags,softInputMode, windowFlags, attribute, inputContext, missingMethods);} else {//通知InputMethodManagerService,该程序的view获得焦点，IMMS将这个 view 和 输入法绑定return startInput(startInputReason, client, inputContext, missingMethods, attribute,controlFlags);}}

6 IMMS处理View绑定输入法事件

为了讲解整个绑定过程，我们假设此时输入法还没启动，这个情况下的输入法绑定是最长的，整个过程经历过如下过程：

1) 启动输入法

2) 绑定输入法的token

3) 请求输入法为焦点程序创建一个连接会话-

4) 将输入法的接口传递回程序端

5) 绑定输入法和焦点view

      1-4是和程序相关的，而5是和view相关的。所以你可以说1~4是用来绑定程序window和输入法，而5是用来绑定程序view和输入法。输入法还没启动时，弹出输入法会经过1~5，输入法已经启动，但是焦点window发生变化时会经历3~5，焦点window没有变化，只是改变了焦点view,则只会经历5。

6.1启动输入法

// InputMethodManagerService.java@Overridepublic InputBindResult startInputOrWindowGainedFocus(/* @InputMethodClient.StartInputReason */ final int startInputReason,IInputMethodClient client, IBinder windowToken, int controlFlags, int softInputMode,int windowFlags, @Nullable EditorInfo attribute, IInputContext inputContext,/* @InputConnectionInspector.missingMethods */ final int missingMethods) {if (windowToken != null) {// focusIn 不走该分支return windowGainedFocus(startInputReason, client, windowToken, controlFlags,softInputMode, windowFlags, attribute, inputContext, missingMethods);} else {// view 获得焦点，IMMS将这个 view 和 输入法绑定return startInput(startInputReason, client, inputContext, missingMethods, attribute,controlFlags);}}private InputBindResult startInput(/* @InputMethodClient.StartInputReason */ final int startInputReason,IInputMethodClient client, IInputContext inputContext,/* @InputConnectionInspector.missingMethods */ final int missingMethods,@Nullable EditorInfo attribute, int controlFlags) {if (!calledFromValidUser()) {return null;}synchronized (mMethodMap) {if (DEBUG) {Slog.v(TAG, "startInput: reason="+ InputMethodClient.getStartInputReason(startInputReason)+ " client = " + client.asBinder()+ " inputContext=" + inputContext+ " missingMethods="+ InputConnectionInspector.getMissingMethodFlagsAsString(missingMethods)+ " attribute=" + attribute+ " controlFlags=#" + Integer.toHexString(controlFlags));}final long ident = Binder.clearCallingIdentity();try {return startInputLocked(startInputReason, client, inputContext, missingMethods,attribute, controlFlags);} finally {Binder.restoreCallingIdentity(ident);}}}   InputBindResult startInputLocked(/* @InputMethodClient.StartInputReason */ final int startInputReason,IInputMethodClient client, IInputContext inputContext,/* @InputConnectionInspector.missingMethods */ final int missingMethods,@Nullable EditorInfo attribute, int controlFlags) {// If no method is currently selected, do nothing.if (mCurMethodId == null) {return mNoBinding;}// 程序在 Service 端 对应的数据结构ClientState cs = mClients.get(client.asBinder());...return startInputUncheckedLocked(cs, inputContext, missingMethods, attribute,controlFlags);}InputBindResult startInputUncheckedLocked(@NonNull ClientState cs, IInputContext inputContext,/* @InputConnectionInspector.missingMethods */ final int missingMethods,@NonNull EditorInfo attribute, int controlFlags) {// If no method is currently selected, do nothing.if (mCurMethodId == null) {return mNoBinding;}if (!InputMethodUtils.checkIfPackageBelongsToUid(mAppOpsManager, cs.uid,attribute.packageName)) {Slog.e(TAG, "Rejecting this client as it reported an invalid package name."+ " uid=" + cs.uid + " package=" + attribute.packageName);return mNoBinding;}if (mCurClient != cs) {// 如果新程序和当前活动的程序不同，取消当前活动程序与输入法的绑定// Was the keyguard locked when switching over to the new client?mCurClientInKeyguard = isKeyguardLocked();// If the client is changing, we need to switch over to the new// one.unbindCurrentClientLocked(InputMethodClient.UNBIND_REASON_SWITCH_CLIENT);if (DEBUG) Slog.v(TAG, "switching to client: client="+ cs.client.asBinder() + " keyguard=" + mCurClientInKeyguard);// If the screen is on, inform the new client it is activeif (mIsInteractive) {executeOrSendMessage(cs.client, mCaller.obtainMessageIO(MSG_SET_ACTIVE, mIsInteractive ? 1 : 0, cs));}}// Bump up the sequence for this client and attach it.mCurSeq++;if (mCurSeq <= 0) mCurSeq = 1;// 将新程序设置为当前活动的程序mCurClient = cs;mCurInputContext = inputContext;mCurInputContextMissingMethods = missingMethods;mCurAttribute = attribute;// Check if the input method is changing.if (mCurId != null && mCurId.equals(mCurMethodId)) {if (cs.curSession != null) {// Fast case: if we are already connected to the input method,// then just return it.// 连接已经建立，开始绑定return attachNewInputLocked((controlFlags&InputMethodManager.CONTROL_START_INITIAL) != 0);}if (mHaveConnection) {if (mCurMethod != null) {// 如果 输入法的连接 已经创建，直接传递给程序 client 端// Return to client, and we will get back with it when// we have had a session made for it.requestClientSessionLocked(cs);return new InputBindResult(null, null, mCurId, mCurSeq,mCurUserActionNotificationSequenceNumber);} else if (SystemClock.uptimeMillis()< (mLastBindTime+TIME_TO_RECONNECT)) {// In this case we have connected to the service, but// don't yet have its interface.  If it hasn't been too// long since we did the connection, we'll return to// the client and wait to get the service interface so// we can report back.  If it has been too long, we want// to fall through so we can try a disconnect/reconnect// to see if we can get back in touch with the service.return new InputBindResult(null, null, mCurId, mCurSeq,mCurUserActionNotificationSequenceNumber);} else {EventLog.writeEvent(EventLogTags.IMF_FORCE_RECONNECT_IME,mCurMethodId, SystemClock.uptimeMillis()-mLastBindTime, 0);}}}// 启动输入法并建立连接return startInputInnerLocked();}InputBindResult startInputInnerLocked() {if (mCurMethodId == null) {return mNoBinding;}if (!mSystemReady) {// If the system is not yet ready, we shouldn't be running third// party code.return new InputBindResult(null, null, mCurMethodId, mCurSeq,mCurUserActionNotificationSequenceNumber);}InputMethodInfo info = mMethodMap.get(mCurMethodId);if (info == null) {throw new IllegalArgumentException("Unknown id: " + mCurMethodId);}unbindCurrentMethodLocked(true);// 启动输入法ServicemCurIntent = new Intent(InputMethod.SERVICE_INTERFACE);mCurIntent.setComponent(info.getComponent());mCurIntent.putExtra(Intent.EXTRA_CLIENT_LABEL,com.android.internal.R.string.input_method_binding_label);mCurIntent.putExtra(Intent.EXTRA_CLIENT_INTENT, PendingIntent.getActivity(mContext, 0, new Intent(Settings.ACTION_INPUT_METHOD_SETTINGS), 0));if (bindCurrentInputMethodService(mCurIntent, this, Context.BIND_AUTO_CREATE| Context.BIND_NOT_VISIBLE | Context.BIND_NOT_FOREGROUND| Context.BIND_SHOWING_UI)) {mLastBindTime = SystemClock.uptimeMillis();mHaveConnection = true;mCurId = info.getId();// mCurToken 是给输入法Service 来绑定输入法window的// 通过 mCurToken ，InputMethodManagerService 直接管理 输入法windowmCurToken = new Binder();try {if (true || DEBUG) Slog.v(TAG, "Adding window token: " + mCurToken);mIWindowManager.addWindowToken(mCurToken,WindowManager.LayoutParams.TYPE_INPUT_METHOD);} catch (RemoteException e) {}return new InputBindResult(null, null, mCurId, mCurSeq,mCurUserActionNotificationSequenceNumber);} else {mCurIntent = null;Slog.w(TAG, "Failure connecting to input method service: "+ mCurIntent);}return null;}private boolean bindCurrentInputMethodService(Intent service, ServiceConnection conn, int flags) {if (service == null || conn == null) {Slog.e(TAG, "--- bind failed: service = " + service + ", conn = " + conn);return false;}return mContext.bindServiceAsUser(service, conn, flags,new UserHandle(mSettings.getCurrentUserId()));}// AbstractInputMethodService.java
//输入法启动完成后就在函数onBind 传回一个binder接口 @Overridefinal public IBinder onBind(Intent intent) {if (mInputMethod == null) {mInputMethod = onCreateInputMethodInterface();}// IInputMethodWrapper 将 IMMS的调用转化为 message，// 然后在 message 线程调用 mInputMethod 对应的接口，// 实现输入法的异步处理return new IInputMethodWrapper(this, mInputMethod);}// InputMethodService.java/*** Implement to return our standard {@link InputMethodImpl}.  Subclasses* can override to provide their own customized version.*/@Overridepublic AbstractInputMethodImpl onCreateInputMethodInterface() {return new InputMethodImpl();}// 由于IMMS是以bindService的方式启动输入法service，所以当输入法service启动完  
// 成后它就会回调IMMS的onServiceConnected  
// InputMethodManagerService.java@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {synchronized (mMethodMap) {if (mCurIntent != null && name.equals(mCurIntent.getComponent())) {// 保存输入法Service 传递过来的 通信接口IInputMethodmCurMethod = IInputMethod.Stub.asInterface(service);if (mCurToken == null) {Slog.w(TAG, "Service connected without a token!");unbindCurrentMethodLocked(false);return;}if (DEBUG) Slog.v(TAG, "Initiating attach with token: " + mCurToken);// 将刚刚创建的window token传递给输入法service,然后输入用这个token  // 创建window,这样IMMS可以用根据这个token找到输入法在IMMS里  // 的数据及输入法window在WMS里的数据executeOrSendMessage(mCurMethod, mCaller.obtainMessageOO(MSG_ATTACH_TOKEN, mCurMethod, mCurToken));if (mCurClient != null) {clearClientSessionLocked(mCurClient);// 请求为程序和输入法建立一个连接会话，这样client就可以直接和  // 输入法通信了requestClientSessionLocked(mCurClient);}}}}case MSG_ATTACH_TOKEN:args = (SomeArgs)msg.obj;try {if (DEBUG) Slog.v(TAG, "Sending attach of token: " + args.arg2);// 和输入法通信((IInputMethod)args.arg1).attachToken((IBinder)args.arg2);} catch (RemoteException e) {}args.recycle();return true;

6.2-1输入法 token的绑定及使用分析

  输入法Window token绑定IMMS在输入法启动完成并回调onServiceConnected时会将一个Window token传递给输入法。

// InputMethodManagerService.java
@Override  
public void onServiceConnected(ComponentName name, IBinder service) {  synchronized (mMethodMap) {  if (mCurIntent != null && name.equals(mCurIntent.getComponent())) {  mCurMethod = IInputMethod.Stub.asInterface(service);  executeOrSendMessage(mCurMethod, mCaller.obtainMessageOO(  MSG_ATTACH_TOKEN, mCurMethod, mCurToken));  if (mCurClient != null) {  clearClientSessionLocked(mCurClient);  requestClientSessionLocked(mCurClient);  }  }  }  
}  case MSG_ATTACH_TOKEN:  args = (SomeArgs)msg.obj;  try {  //和输入法通信  ((IInputMethod)args.arg1).attachToken((IBinder)args.arg2);  } catch (RemoteException e) {  }  args.recycle();  public class InputMethodService extends AbstractInputMethodService {  
public class InputMethodImpl extends AbstractInputMethodImpl {  public void attachToken(IBinder token) {  if (mToken == null) {  //保存token  mToken = token;  //这样输入法的window就绑定这个window token  mWindow.setToken(token);  }  }  
}  

6.2-2输入法 token使用

   由于系统存在多个输入法，所以输入法要和IMMS通信，必须要个机制来标示自己是哪个输入法，这个就是通过上面的输入法Window token来实现的,比如输入法自己关闭自己：

//InputMethodService.java输入法接口  
public void requestHideSelf(int flags) {  //mToken就是上面提到的过程----IMMS传递给输入法的  mImm.hideSoftInputFromInputMethod(mToken, flags);  
}  
//InputMethodManager.java  
public void hideSoftInputFromInputMethod(IBinder token, int flags) {  try {  mService.hideMySoftInput(token, flags);  } catch (RemoteException e) {  throw new RuntimeException(e);  }  
}  //IMMS  
@Override  
public void hideMySoftInput(IBinder token, int flags) {  if (!calledFromValidUser()) {  return;  }  synchronized (mMethodMap) {  if (token == null || mCurToken != token) {  if (DEBUG) Slog.w(TAG, "Ignoring hideInputMethod of uid "  + Binder.getCallingUid() + " token: " + token);  return;  }  long ident = Binder.clearCallingIdentity();  try {  hideCurrentInputLocked(flags, null);  } finally {  Binder.restoreCallingIdentity(ident);  }  }  
}  

6.3输入法连接会话创建

   到此程序和输入法的session就建立了

// InputMethodManagerService.java@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {synchronized (mMethodMap) {if (mCurIntent != null && name.equals(mCurIntent.getComponent())) {// 保存输入法Service 传递过来的 通信接口IInputMethodmCurMethod = IInputMethod.Stub.asInterface(service);if (mCurToken == null) {Slog.w(TAG, "Service connected without a token!");unbindCurrentMethodLocked(false);return;}if (DEBUG) Slog.v(TAG, "Initiating attach with token: " + mCurToken);// 将刚刚创建的window token传递给输入法service,然后输入用这个token  // 创建window,这样IMMS可以用根据这个token找到输入法在IMMS里  // 的数据及输入法window在WMS里的数据executeOrSendMessage(mCurMethod, mCaller.obtainMessageOO(MSG_ATTACH_TOKEN, mCurMethod, mCurToken));if (mCurClient != null) {clearClientSessionLocked(mCurClient);// 请求为程序和输入法建立一个连接会话，这样client就可以直接和  // 输入法通信了requestClientSessionLocked(mCurClient);}}}}case MSG_ATTACH_TOKEN:args = (SomeArgs)msg.obj;try {if (DEBUG) Slog.v(TAG, "Sending attach of token: " + args.arg2);// 和输入法通信((IInputMethod)args.arg1).attachToken((IBinder)args.arg2);} catch (RemoteException e) {}args.recycle();return true;// InputMethodService.java/*** Concrete implementation of* {@link AbstractInputMethodService.AbstractInputMethodImpl} that provides* all of the standard behavior for an input method.*/public class InputMethodImpl extends AbstractInputMethodImpl {/*** Take care of attaching the given window token provided by the system.*/public void attachToken(IBinder token) {if (mToken == null) {// 保存token  mToken = token;// 这样输入法的window就绑定这个window tokenmWindow.setToken(token);}}}// InputMethodManagerService.javavoid requestClientSessionLocked(ClientState cs) {if (!cs.sessionRequested) {if (DEBUG) Slog.v(TAG, "Creating new session for client " + cs);// 这里又出现了InputChannel对，很面熟吧，在前面几篇文章已经详细分析过  // 了，可见它已经成为一种通用的跨平台的数据通信接口了 InputChannel[] channels = InputChannel.openInputChannelPair(cs.toString());cs.sessionRequested = true;executeOrSendMessage(mCurMethod, mCaller.obtainMessageOOO(MSG_CREATE_SESSION, mCurMethod, channels[1],new MethodCallback(this, mCurMethod, channels[0])));}}case MSG_CREATE_SESSION: {args = (SomeArgs)msg.obj;IInputMethod method = (IInputMethod)args.arg1;InputChannel channel = (InputChannel)args.arg2;try {method.createSession(channel, (IInputSessionCallback)args.arg3);} catch (RemoteException e) {} finally {// Dispose the channel if the input method is not local to this process// because the remote proxy will get its own copy when unparceled.if (channel != null && Binder.isProxy(method)) {channel.dispose();}}args.recycle();return true;}//上面是IMMS端，下面就看IMS输入法端的处理 
// IInputMethodWrapper.java@Overridepublic void createSession(InputChannel channel, IInputSessionCallback callback) {mCaller.executeOrSendMessage(mCaller.obtainMessageOO(DO_CREATE_SESSION,channel, callback));}case DO_CREATE_SESSION: {SomeArgs args = (SomeArgs)msg.obj;inputMethod.createSession(new InputMethodSessionCallbackWrapper(mContext, (InputChannel)args.arg1,(IInputSessionCallback)args.arg2));args.recycle();return;}   // AbstractInputMethodService.java/*** Base class for derived classes to implement their {@link InputMethod}* interface.  This takes care of basic maintenance of the input method,* but most behavior must be implemented in a derived class.*/public abstract class AbstractInputMethodImpl implements InputMethod {/*** Instantiate a new client session for the input method, by calling* back to {@link AbstractInputMethodService#onCreateInputMethodSessionInterface()* AbstractInputMethodService.onCreateInputMethodSessionInterface()}.*/public void createSession(SessionCallback callback) {callback.sessionCreated(onCreateInputMethodSessionInterface());}}// InputMethodManagerService.java@Overridepublic void sessionCreated(IInputMethodSession session) {long ident = Binder.clearCallingIdentity();try {mParentIMMS.onSessionCreated(mMethod, session, mChannel);} finally {Binder.restoreCallingIdentity(ident);}}}

6.5传递输入法接口给程序端

// InputMethodManagerService.javavoid onSessionCreated(IInputMethod method, IInputMethodSession session,InputChannel channel) {synchronized (mMethodMap) {if (mCurMethod != null && method != null&& mCurMethod.asBinder() == method.asBinder()) {if (mCurClient != null) {clearClientSessionLocked(mCurClient);mCurClient.curSession = new SessionState(mCurClient,method, session, channel);InputBindResult res = attachNewInputLocked(true);if (res.method != null) {executeOrSendMessage(mCurClient.client, mCaller.obtainMessageOO(MSG_BIND_CLIENT, mCurClient.client, res));}return;}}}// Session abandoned.  Close its associated input channel.channel.dispose();}

6.5绑定输入法和焦点view

// 输入法和view绑定InputBindResult attachNewInputLocked(boolean initial) {if (!mBoundToMethod) {executeOrSendMessage(mCurMethod, mCaller.obtainMessageOO(MSG_BIND_INPUT, mCurMethod, mCurClient.binding));mBoundToMethod = true;}final SessionState session = mCurClient.curSession;if (initial) {executeOrSendMessage(session.method, mCaller.obtainMessageIOOO(MSG_START_INPUT, mCurInputContextMissingMethods, session, mCurInputContext,mCurAttribute));} else {executeOrSendMessage(session.method, mCaller.obtainMessageIOOO(MSG_RESTART_INPUT, mCurInputContextMissingMethods, session, mCurInputContext,mCurAttribute));}if (mShowRequested) {if (DEBUG) Slog.v(TAG, "Attach new input asks to show input");showCurrentInputLocked(getAppShowFlags(), null);}return new InputBindResult(session.session,(session.channel != null ? session.channel.dup() : null),mCurId, mCurSeq, mCurUserActionNotificationSequenceNumber);}case MSG_BIND_INPUT:args = (SomeArgs)msg.obj;try {((IInputMethod)args.arg1).bindInput((InputBinding)args.arg2);} catch (RemoteException e) {}args.recycle();return true;case MSG_START_INPUT: {int missingMethods = msg.arg1;args = (SomeArgs) msg.obj;try {SessionState session = (SessionState) args.arg1;setEnabledSessionInMainThread(session);session.method.startInput((IInputContext) args.arg2, missingMethods,(EditorInfo) args.arg3);} catch (RemoteException e) {}args.recycle();return true;}case MSG_BIND_CLIENT: {args = (SomeArgs)msg.obj;IInputMethodClient client = (IInputMethodClient)args.arg1;InputBindResult res = (InputBindResult)args.arg2;try {// 调回到程序端,InputMethodManager.onBindMethod()client.onBindMethod(res);} catch (RemoteException e) {Slog.w(TAG, "Client died receiving input method " + args.arg2);} finally {// Dispose the channel if the input method is not local to this process// because the remote proxy will get its own copy when unparceled.if (res.channel != null && Binder.isProxy(client)) {res.channel.dispose();}}args.recycle();return true;}// IInputMethodWrapper.java @Overridepublic void startInput(IInputContext inputContext,@InputConnectionInspector.MissingMethodFlags final int missingMethods,EditorInfo attribute) {mCaller.executeOrSendMessage(mCaller.obtainMessageIOO(DO_START_INPUT,missingMethods, inputContext, attribute));}   case DO_START_INPUT: {SomeArgs args = (SomeArgs)msg.obj;int missingMethods = msg.arg1;// IInputContext就是输入法和文本输入view的通信接口  // 通过这个接口，输入法能够获取view的信息，也能够直接将文本传送给viewIInputContext inputContext = (IInputContext)args.arg1;InputConnection ic = inputContext != null? new InputConnectionWrapper(inputContext, missingMethods) : null;EditorInfo info = (EditorInfo)args.arg2;info.makeCompatible(mTargetSdkVersion);inputMethod.startInput(ic, info);args.recycle();return;}// InputMethodService.javapublic void startInput(InputConnection ic, EditorInfo attribute) {if (DEBUG) Log.v(TAG, "startInput(): editor=" + attribute);doStartInput(ic, attribute, false);}void doStartInput(InputConnection ic, EditorInfo attribute, boolean restarting) {if (!restarting) {doFinishInput();}mInputStarted = true;mStartedInputConnection = ic;mInputEditorInfo = attribute;initialize();if (DEBUG) Log.v(TAG, "CALL: onStartInput");onStartInput(attribute, restarting);if (mWindowVisible) {if (mShowInputRequested) {if (DEBUG) Log.v(TAG, "CALL: onStartInputView");mInputViewStarted = true;onStartInputView(mInputEditorInfo, restarting);startExtractingText(true);} else if (mCandidatesVisibility == View.VISIBLE) {if (DEBUG) Log.v(TAG, "CALL: onStartCandidatesView");mCandidatesViewStarted = true;onStartCandidatesView(mInputEditorInfo, restarting);}}}

到此焦点view已经通过调用IMMS的和输入法绑定了，但是此时输入法还没有显示。但是系统紧接着会调用来显示输入法

未完待续。。。。

- 参考文档

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