1.简介

本文基于 android N，借鉴 http://blog.csdn.net/huangyabin001/article/details/28434989 ，记录一下输入法显示的流程，相当于一篇读书笔记，方便记忆与学习

大体流程如下：

InputMethodManagerService（下文也称IMMS）负责管理系统的所有输入法，包括输入法service(InputMethodService简称IMS)加载及切换。程序获得焦点时，就会通过 InputMethodManager 向 InputMethodManagerService 发出请求绑定自己到当前输入法上。当程序的某个需要输入法的view比如 EditView 获得焦点时，就会通过 InputMethodManager 向 InputMethodManagerService 请求显示输入法，而这时 InputMethodManagerService 收到请求后，会将请求的 EditText 的数据通信接口发送给当前输入法，并请求显示输入法。输入法收到请求后，就显示自己的 UI dialog,同时保存目标 view 的数据结构，当用户实现输入后，直接通过 view 的数据通信接口将字符传递到对应的 View 。接下来就来分析这些过程。

2. InputMethodManager 创建

// ViewRootImpl.java public final class ViewRootImpl implements ViewParent, View.AttachInfo.Callbacks, ThreadedRenderer.HardwareDrawCallbacks { public ViewRootImpl(Context context, Display display) { ... mWindowSession = WindowManagerGlobal.getWindowSession(); ... } // WindowManagerGlobal.java public 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() { @Override public 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) { IBinder b = ServiceManager.getService(Context.INPUT_METHOD_SERVICE); IInputMethodManager service = IInputMethodManager.Stub.asInterface(b); sInstance = new InputMethodManager(service, Looper.getMainLooper()); } return sInstance; } }

3. window 获得焦点

流程图上传后不太清晰，在csdn中上传了原图：http://download.csdn.net/detail/jieqiong1/9835293

// WindowManagerService.java boolean updateFocusedWindowLocked(int mode, boolean updateInputWindows) { // 计算焦点 window WindowState newFocus = computeFocusedWindowLocked(); if (mCurrentFocus != newFocus) { Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER, "wmUpdateFocus"); // This check makes sure that we don't already have the focus // change message pending. mH.removeMessages(H.REPORT_FOCUS_CHANGE); mH.sendEmptyMessage(H.REPORT_FOCUS_CHANGE); ... return true; } return false; } private WindowState computeFocusedWindowLocked() { 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; } // 找出 top 需要获得焦点的 window WindowState findFocusedWindowLocked(DisplayContent displayContent) { final WindowList windows = displayContent.getWindowList(); for (int i = windows.size() - 1; i >= 0; i--) { final WindowState win = windows.get(i); if (localLOGV || DEBUG_FOCUS) Slog.v( TAG_WM, "Looking for focus: " + i + " = " + win + ", flags=" + win.mAttrs.flags + ", canReceive=" + win.canReceiveKeys()); // 判断 window 是否可以获取焦点 if (!win.canReceiveKeys()) { continue; } // win.mAppToken != null win描述的是一个Activity窗口 AppWindowToken wtoken = win.mAppToken; // If this window's application has been removed, just skip it. if (wtoken != null && (wtoken.removed || wtoken.sendingToBottom)) { if (DEBUG_FOCUS) Slog.v(TAG_WM, "Skipping " + wtoken + " because " + (wtoken.removed ? "removed" : "sendingToBottom")); continue; } // Descend through all of the app tokens and find the first that either matches // win.mAppToken (return win) or mFocusedApp (return null). // mFocusedApp 是 top Activity，下边的逻辑是为了确保焦点window的app 必须是焦点程序上的，主要是为了检测出错误 if (wtoken != null && win.mAttrs.type != TYPE_APPLICATION_STARTING && mFocusedApp != null) { ArrayList<Task> 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 && token.windowsAreFocusable()) { // Whoops, we are below the focused app whose windows are focusable... // No focus for you!!! if (localLOGV || DEBUG_FOCUS_LIGHT) Slog.v(TAG_WM, "findFocusedWindow: Reached focused app=" + mFocusedApp); return null; } } if (tokenNdx >= 0) { // Early exit from loop, must have found the matching token. break; } } } if (DEBUG_FOCUS_LIGHT) Slog.v(TAG_WM, "findFocusedWindow: Found new focus @ " + i + " = " + win); return win; } if (DEBUG_FOCUS_LIGHT) Slog.v(TAG_WM, "findFocusedWindow: No focusable windows."); return null; } @Override public void handleMessage(Message msg) { if (DEBUG_WINDOW_TRACE) { Slog.v(TAG_WM, "handleMessage: entry what=" + msg.what); } switch (msg.what) { case REPORT_FOCUS_CHANGE: { WindowState lastFocus; WindowState newFocus; AccessibilityController accessibilityController = null; synchronized(mWindowMap) { // TODO(multidisplay): Accessibility supported only of default desiplay. if (mAccessibilityController != null && getDefaultDisplayContentLocked() .getDisplayId() == Display.DEFAULT_DISPLAY) { accessibilityController = mAccessibilityController; } lastFocus = mLastFocus; newFocus = mCurrentFocus; if (lastFocus == newFocus) { // Focus is not changing, so nothing to do. return; } mLastFocus = newFocus; if (DEBUG_FOCUS_LIGHT) Slog.i(TAG_WM, "Focus moving from " + lastFocus + " to " + newFocus); if (newFocus != null && lastFocus != null && !newFocus.isDisplayedLw()) { //Slog.i(TAG_WM, "Delaying loss of focus..."); mLosingFocus.add(lastFocus); lastFocus = null; } } // First notify the accessibility manager for the change so it has // the windows before the newly focused one starts firing eventgs. if (accessibilityController != null) { accessibilityController.onWindowFocusChangedNotLocked(); } //System.out.println("Changing focus from " + lastFocus // + " to " + newFocus); if (newFocus != null) { if (DEBUG_FOCUS_LIGHT) Slog.i(TAG_WM, "Gaining focus: " + newFocus); // 通知新的焦点程序 获得了焦点 newFocus.reportFocusChangedSerialized(true, mInTouchMode); notifyFocusChanged(); } if (lastFocus != null) { if (DEBUG_FOCUS_LIGHT) Slog.i(TAG_WM, "Losing focus: " + lastFocus); // 通知老的焦点程序 获得了焦点 lastFocus.reportFocusChangedSerialized(false, mInTouchMode); } } break; ... } // WindowState.java /** * Report a focus change. Must be called with no locks held, and consistently * from the same serialized thread (such as dispatched from a handler). */ public void reportFocusChangedSerialized(boolean focused, boolean inTouchMode) { try { // 通过 Binder 告知 client端 其获得或失去了焦点 mClient.windowFocusChanged(focused, inTouchMode); } catch (RemoteException e) { } if (mFocusCallbacks != null) { final int N = mFocusCallbacks.beginBroadcast(); for (int i=0; i<N; i++) { IWindowFocusObserver obs = mFocusCallbacks.getBroadcastItem(i); try { if (focused) { obs.focusGained(mWindowId.asBinder()); } else { obs.focusLost(mWindowId.asBinder()); } } catch (RemoteException e) { } } mFocusCallbacks.finishBroadcast(); } }

4.程序变更焦点，程序获得焦点变更事件

// ViewRootImpl.java public 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); } @Override public 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; ... } }

一.1 焦点View向IMMS请求绑定输入法

6.1 之后的流程

// ViewGroup.java @Override public 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.java public 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() : "<none>")); 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view view = 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() { @Override public 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 // InputMethodService 后面就是通过这个connection将输入法的字符传给该view InputConnection 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 @Override public 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); } }

一.2 IMMS处理view绑定输入法事件

// InputMethodManagerService.java @Override public 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 active if (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Service mCurIntent = 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window mCurToken = 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 @Override final 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. */ @Override public 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 @Override public 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IInputMethod mCurMethod = 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 token mWindow.setToken(token); } } } // InputMethodManagerService.java void 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 @Override public 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 @Override public void sessionCreated(IInputMethodSession session) { long ident = Binder.clearCallingIdentity(); try { mParentIMMS.onSessionCreated(mMethod, session, mChannel); } finally { Binder.restoreCallingIdentity(ident); } } } void 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(); } // 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 @Override public 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view IInputContext 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.java public 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startInput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windowGainFocus来显示输入法。 6.2 onPostWindowFocus() 之后的逻辑下次再写

二. 显示输入法

6.2 onPostWindowFocus() 之后的流程 下边的时序图不太清晰，csdn上传了下 原图：http://download.csdn.net/detail/jieqiong1/9836368

// InputMethodManager.java /** * Called by ViewAncestor when its window gets input focus. * @hide */ public void onPostWindowFocus(View rootView, View focusedView, int softInputMode, boolean first, int windowFlags) { boolean forceNewFocus = false; synchronized (mH) { if (DEBUG) Log.v(TAG, "onWindowFocus: " + focusedView + " softInputMode=" + softInputMode + " first=" + first + " flags=#" + Integer.toHexString(windowFlags)); if (mHasBeenInactive) { if (DEBUG) Log.v(TAG, "Has been inactive! Starting fresh"); mHasBeenInactive = false; forceNewFocus = true; } // view 获取焦点 focusInLocked(focusedView != null ? focusedView : rootView); } int controlFlags = 0; if (focusedView != null) { controlFlags |= CONTROL_WINDOW_VIEW_HAS_FOCUS; if (focusedView.onCheckIsTextEditor()) { controlFlags |= CONTROL_WINDOW_IS_TEXT_EDITOR; } } if (first) { controlFlags |= CONTROL_WINDOW_FIRST; } // 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(forceNewFocus)) { // We need to restart input on the current focus view. This // should be done in conjunction with telling the system service // about the window gaining focus, to help make the transition // smooth. if (startInputInner(InputMethodClient.START_INPUT_REASON_WINDOW_FOCUS_GAIN, rootView.getWindowToken(), controlFlags, softInputMode, windowFlags)) { return; } } // For some reason we didn't do a startInput + windowFocusGain, so // we'll just do a window focus gain and call it a day. synchronized (mH) { try { if (DEBUG) Log.v(TAG, "Reporting focus gain, without startInput"); // //调用IMMS windowGainedFocus函数 mService.startInputOrWindowGainedFocus( InputMethodClient.START_INPUT_REASON_WINDOW_FOCUS_GAIN_REPORT_ONLY, mClient, rootView.getWindowToken(), controlFlags, softInputMode, windowFlags, null, null, 0 /* missingMethodFlags */); } catch (RemoteException e) { throw e.rethrowFromSystemServer(); } } } 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; scheduleCheckFocusLocked(view); } // InputMethodManagerService.java @Override public 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) { return windowGainedFocus(startInputReason, client, windowToken, controlFlags, softInputMode, windowFlags, attribute, inputContext, missingMethods); } else { return startInput(startInputReason, client, inputContext, missingMethods, attribute, controlFlags); } } private InputBindResult windowGainedFocus( /* @InputMethodClient.StartInputReason */ final int startInputReason, IInputMethodClient client, IBinder windowToken, int controlFlags, int softInputMode, int windowFlags, EditorInfo attribute, IInputContext inputContext, /* @InputConnectionInspector.missingMethods */ final int missingMethods) { // Needs to check the validity before clearing calling identity final boolean calledFromValidUser = calledFromValidUser(); InputBindResult res = null; long ident = Binder.clearCallingIdentity(); try { synchronized (mMethodMap) { ... mCurFocusedWindow = windowToken; mCurFocusedWindowClient = cs; // Should we auto-show the IME even if the caller has not // specified what should be done with it? // We only do this automatically if the window can resize // to accommodate the IME (so what the user sees will give // them good context without input information being obscured // by the IME) or if running on a large screen where there // is more room for the target window + IME. final boolean doAutoShow = (softInputMode & WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST) == WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE || mRes.getConfiguration().isLayoutSizeAtLeast( Configuration.SCREENLAYOUT_SIZE_LARGE); final boolean isTextEditor = (controlFlags&InputMethodManager.CONTROL_WINDOW_IS_TEXT_EDITOR) != 0; // We want to start input before showing the IME, but after closing // it. We want to do this after closing it to help the IME disappear // more quickly (not get stuck behind it initializing itself for the // new focused input, even if its window wants to hide the IME). boolean didStart = false; switch (softInputMode&WindowManager.LayoutParams.SOFT_INPUT_MASK_STATE) { case WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED: if (!isTextEditor || !doAutoShow) { if (WindowManager.LayoutParams.mayUseInputMethod(windowFlags)) { // There is no focus view, and this window will // be behind any soft input window, so hide the // soft input window if it is shown. if (DEBUG) Slog.v(TAG, "Unspecified window will hide input"); hideCurrentInputLocked(InputMethodManager.HIDE_NOT_ALWAYS, null); } } else if (isTextEditor && doAutoShow && (softInputMode & WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION) != 0) { // There is a focus view, and we are navigating forward // into the window, so show the input window for the user. // We only do this automatically if the window can resize // to accommodate the IME (so what the user sees will give // them good context without input information being obscured // by the IME) or if running on a large screen where there // is more room for the target window + IME. if (DEBUG) Slog.v(TAG, "Unspecified window will show input"); if (attribute != null) { res = startInputUncheckedLocked(cs, inputContext, missingMethods, attribute, controlFlags); didStart = true; } // 调用 showCurrentInputLocked() showCurrentInputLocked(InputMethodManager.SHOW_IMPLICIT, null); } break; case WindowManager.LayoutParams.SOFT_INPUT_STATE_UNCHANGED: // Do nothing. break; case WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN: if ((softInputMode & WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION) != 0) { if (DEBUG) Slog.v(TAG, "Window asks to hide input going forward"); hideCurrentInputLocked(0, null); } break; case WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN: if (DEBUG) Slog.v(TAG, "Window asks to hide input"); hideCurrentInputLocked(0, null); break; case WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE: if ((softInputMode & WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION) != 0) { if (DEBUG) Slog.v(TAG, "Window asks to show input going forward"); if (attribute != null) { res = startInputUncheckedLocked(cs, inputContext, missingMethods, attribute, controlFlags); didStart = true; } showCurrentInputLocked(InputMethodManager.SHOW_IMPLICIT, null); } break; case WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE: if (DEBUG) Slog.v(TAG, "Window asks to always show input"); if (attribute != null) { res = startInputUncheckedLocked(cs, inputContext, missingMethods, attribute, controlFlags); didStart = true; } showCurrentInputLocked(InputMethodManager.SHOW_IMPLICIT, null); break; } if (!didStart && attribute != null) { res = startInputUncheckedLocked(cs, inputContext, missingMethods, attribute, controlFlags); } } } finally { Binder.restoreCallingIdentity(ident); } return res; } boolean showCurrentInputLocked(int flags, ResultReceiver resultReceiver) { mShowRequested = true; if (mAccessibilityRequestingNoSoftKeyboard) { return false; } if ((flags&InputMethodManager.SHOW_FORCED) != 0) { mShowExplicitlyRequested = true; mShowForced = true; } else if ((flags&InputMethodManager.SHOW_IMPLICIT) == 0) { mShowExplicitlyRequested = true; } if (!mSystemReady) { return false; } boolean res = false; if (mCurMethod != null) { if (DEBUG) Slog.d(TAG, "showCurrentInputLocked: mCurToken=" + mCurToken); // 发消息 MSG_SHOW_SOFT_INPUT executeOrSendMessage(mCurMethod, mCaller.obtainMessageIOO( MSG_SHOW_SOFT_INPUT, getImeShowFlags(), mCurMethod, resultReceiver)); mInputShown = true; if (mHaveConnection && !mVisibleBound) { bindCurrentInputMethodService( mCurIntent, mVisibleConnection, Context.BIND_AUTO_CREATE | Context.BIND_TREAT_LIKE_ACTIVITY | Context.BIND_FOREGROUND_SERVICE); mVisibleBound = true; } res = true; } else if (mHaveConnection && SystemClock.uptimeMillis() >= (mLastBindTime+TIME_TO_RECONNECT)) { // The client has asked to have the input method shown, but // we have been sitting here too long with a connection to the // service and no interface received, so let's disconnect/connect // to try to prod things along. EventLog.writeEvent(EventLogTags.IMF_FORCE_RECONNECT_IME, mCurMethodId, SystemClock.uptimeMillis()-mLastBindTime,1); Slog.w(TAG, "Force disconnect/connect to the IME in showCurrentInputLocked()"); mContext.unbindService(this); bindCurrentInputMethodService(mCurIntent, this, Context.BIND_AUTO_CREATE | Context.BIND_NOT_VISIBLE); } else { if (DEBUG) { Slog.d(TAG, "Can't show input: connection = " + mHaveConnection + ", time = " + ((mLastBindTime+TIME_TO_RECONNECT) - SystemClock.uptimeMillis())); } } return res; } case MSG_SHOW_SOFT_INPUT: args = (SomeArgs)msg.obj; try { if (DEBUG) Slog.v(TAG, "Calling " + args.arg1 + ".showSoftInput(" + msg.arg1 + ", " + args.arg2 + ")"); // IInputMethod.showSoftInput() 即 IInputMethodWrapper.showSoftInput() ((IInputMethod)args.arg1).showSoftInput(msg.arg1, (ResultReceiver)args.arg2); } catch (RemoteException e) { } args.recycle(); return true; // IInputMethodWrapper.java @Override public void showSoftInput(int flags, ResultReceiver resultReceiver) { mCaller.executeOrSendMessage(mCaller.obtainMessageIO(DO_SHOW_SOFT_INPUT, flags, resultReceiver)); } case DO_SHOW_SOFT_INPUT: // 这个inputMethod是通过onCreateInputMethodInterface函数创建的 // InputMethodImpl对象 inputMethod.showSoftInput(msg.arg1, (ResultReceiver)msg.obj); return; // InputMethodService.InputMethodImpl.showSoftInput() /** * Handle a request by the system to show the soft input area. */ public void showSoftInput(int flags, ResultReceiver resultReceiver) { if (DEBUG) Log.v(TAG, "showSoftInput()"); boolean wasVis = isInputViewShown(); if (dispatchOnShowInputRequested(flags, false)) { try { // 这个是真正显示UI的函数 showWindow(true); } catch (BadTokenException e) { // We have ignored BadTokenException here since Jelly Bean MR-2 (API Level 18). // We could ignore BadTokenException in InputMethodService#showWindow() instead, // but it may break assumptions for those who override #showWindow() that we can // detect errors in #showWindow() by checking BadTokenException. // TODO: Investigate its feasibility. Update JavaDoc of #showWindow() of // whether it's OK to override #showWindow() or not. } } clearInsetOfPreviousIme(); // If user uses hard keyboard, IME button should always be shown. boolean showing = isInputViewShown(); mImm.setImeWindowStatus(mToken, IME_ACTIVE | (showing ? IME_VISIBLE : 0), mBackDisposition); if (resultReceiver != null) { resultReceiver.send(wasVis != isInputViewShown() ? InputMethodManager.RESULT_SHOWN : (wasVis ? InputMethodManager.RESULT_UNCHANGED_SHOWN : InputMethodManager.RESULT_UNCHANGED_HIDDEN), null); } } public void showWindow(boolean showInput) { if (DEBUG) Log.v(TAG, "Showing window: showInput=" + showInput + " mShowInputRequested=" + mShowInputRequested + " mWindowAdded=" + mWindowAdded + " mWindowCreated=" + mWindowCreated + " mWindowVisible=" + mWindowVisible + " mInputStarted=" + mInputStarted + " mShowInputFlags=" + mShowInputFlags); if (mInShowWindow) { Log.w(TAG, "Re-entrance in to showWindow"); return; } try { mWindowWasVisible = mWindowVisible; mInShowWindow = true; // 调用 showWindowInner() showWindowInner(showInput); } catch (BadTokenException e) { // BadTokenException is a normal consequence in certain situations, e.g., swapping IMEs // while there is a DO_SHOW_SOFT_INPUT message in the IIMethodWrapper queue. if (DEBUG) Log.v(TAG, "BadTokenException: IME is done."); mWindowVisible = false; mWindowAdded = false; // Rethrow the exception to preserve the existing behavior. Some IMEs may have directly // called this method and relied on this exception for some clean-up tasks. // TODO: Give developers a clear guideline of whether it's OK to call this method or // InputMethodManager#showSoftInputFromInputMethod() should always be used instead. throw e; } finally { // TODO: Is it OK to set true when we get BadTokenException? mWindowWasVisible = true; mInShowWindow = false; } } void showWindowInner(boolean showInput) { boolean doShowInput = false; final int previousImeWindowStatus = (mWindowVisible ? IME_ACTIVE : 0) | (isInputViewShown() ? IME_VISIBLE : 0); mWindowVisible = true; if (!mShowInputRequested && mInputStarted && showInput) { doShowInput = true; mShowInputRequested = true; } if (DEBUG) Log.v(TAG, "showWindow: updating UI"); initialize(); updateFullscreenMode(); // 这个函数会创建输入法的键盘 updateInputViewShown(); if (!mWindowAdded || !mWindowCreated) { mWindowAdded = true; mWindowCreated = true; initialize(); if (DEBUG) Log.v(TAG, "CALL: onCreateCandidatesView"); // 创建输入法dialog里的词条选择View View v = onCreateCandidatesView(); if (DEBUG) Log.v(TAG, "showWindow: candidates=" + v); if (v != null) { setCandidatesView(v); } } if (mShowInputRequested) { if (!mInputViewStarted) { if (DEBUG) Log.v(TAG, "CALL: onStartInputView"); mInputViewStarted = true; onStartInputView(mInputEditorInfo, false); } } else if (!mCandidatesViewStarted) { if (DEBUG) Log.v(TAG, "CALL: onStartCandidatesView"); mCandidatesViewStarted = true; onStartCandidatesView(mInputEditorInfo, false); } if (doShowInput) { startExtractingText(false); } final int nextImeWindowStatus = IME_ACTIVE | (isInputViewShown() ? IME_VISIBLE : 0); if (previousImeWindowStatus != nextImeWindowStatus) { mImm.setImeWindowStatus(mToken, nextImeWindowStatus, mBackDisposition); } if ((previousImeWindowStatus & IME_ACTIVE) == 0) { if (DEBUG) Log.v(TAG, "showWindow: showing!"); onWindowShown(); // 这个是输入法Dialog的window,这里开始就显示UI了 mWindow.show(); // Put here rather than in onWindowShown() in case people forget to call // super.onWindowShown(). mShouldClearInsetOfPreviousIme = false; } } /** * Re-evaluate whether the soft input area should currently be shown, and * update its UI if this has changed since the last time it * was evaluated. This will call {@link #onEvaluateInputViewShown()} to * determine whether the input view should currently be shown. You * can use {@link #isInputViewShown()} to determine if the input view * is currently shown. */ public void updateInputViewShown() { boolean isShown = mShowInputRequested && onEvaluateInputViewShown(); if (mIsInputViewShown != isShown && mWindowVisible) { mIsInputViewShown = isShown; mInputFrame.setVisibility(isShown ? View.VISIBLE : View.GONE); if (mInputView == null) { initialize(); // 这个是核心view，创建显示键盘的根view View v = onCreateInputView(); if (v != null) { setInputView(v); } } } }

5. 用户单击输入框显示输入法

http://blog.csdn.net/huangyabin001/article/details/28435093 中 作者从 InputEventReceiver.dispatchInputEvent()开始分析的，本文从 TextView.onTouchEvent()开始写。

// TextView.java @Override public boolean onTouchEvent(MotionEvent event) { final int action = event.getActionMasked(); if (mEditor != null) { mEditor.onTouchEvent(event); if (mEditor.mSelectionModifierCursorController != null && mEditor.mSelectionModifierCursorController.isDragAcceleratorActive()) { return true; } } //非 EditText 只会执行 View.onTouchEvent(),该函数是另一种将view和输入法绑定的调用 //而 EditText 会调用 imm.showSoftInput() 会显示输入法 final boolean superResult = super.onTouchEvent(event); /* * Don't handle the release after a long press, because it will move the selection away from * whatever the menu action was trying to affect. If the long press should have triggered an * insertion action mode, we can now actually show it. */ if (mEditor != null && mEditor.mDiscardNextActionUp && action == MotionEvent.ACTION_UP) { mEditor.mDiscardNextActionUp = false; if (mEditor.mIsInsertionActionModeStartPending) { mEditor.startInsertionActionMode(); mEditor.mIsInsertionActionModeStartPending = false; } return superResult; } final boolean touchIsFinished = (action == MotionEvent.ACTION_UP) && (mEditor == null || !mEditor.mIgnoreActionUpEvent) && isFocused(); if ((mMovement != null || onCheckIsTextEditor()) && isEnabled() && mText instanceof Spannable && mLayout != null) { boolean handled = false; if (mMovement != null) { handled |= mMovement.onTouchEvent(this, (Spannable) mText, event); } final boolean textIsSelectable = isTextSelectable(); if (touchIsFinished && mLinksClickable && mAutoLinkMask != 0 && textIsSelectable) { // The LinkMovementMethod which should handle taps on links has not been installed // on non editable text that support text selection. // We reproduce its behavior here to open links for these. ClickableSpan[] links = ((Spannable) mText).getSpans(getSelectionStart(), getSelectionEnd(), ClickableSpan.class); if (links.length > 0) { links[0].onClick(this); handled = true; } } if (touchIsFinished && (isTextEditable() || textIsSelectable)) { // Show the IME, except when selecting in read-only text. final InputMethodManager imm = InputMethodManager.peekInstance(); viewClicked(imm); // 这个是真正显示输入法的调用 if (!textIsSelectable && mEditor.mShowSoftInputOnFocus) { handled |= imm != null && imm.showSoftInput(this, 0); } // The above condition ensures that the mEditor is not null mEditor.onTouchUpEvent(event); handled = true; } if (handled) { return true; } } return superResult; } // View.java /** * Implement this method to handle touch screen motion events. * <p> * If this method is used to detect click actions, it is recommended that * the actions be performed by implementing and calling * {@link #performClick()}. This will ensure consistent system behavior, * including: * <ul> * <li>obeying click sound preferences * <li>dispatching OnClickListener calls * <li>handling {@link AccessibilityNodeInfo#ACTION_CLICK ACTION_CLICK} when * accessibility features are enabled * </ul> * * @param event The motion event. * @return True if the event was handled, false otherwise. */ public boolean onTouchEvent(MotionEvent event) { final float x = event.getX(); final float y = event.getY(); final int viewFlags = mViewFlags; final int action = event.getAction(); ... if (((viewFlags & CLICKABLE) == CLICKABLE || (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) || (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE) { switch (action) { case MotionEvent.ACTION_UP: boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0; if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) { // take focus if we don't have it already and we should in // touch mode. boolean focusTaken = false; // 让view获得焦点 if (isFocusable() && isFocusableInTouchMode() && !isFocused()) { focusTaken = requestFocus(); } ... } mIgnoreNextUpEvent = false; break; ... } return true; } return false; } /** * Call this to try to give focus to a specific view or to one of its descendants * and give it hints about the direction and a specific rectangle that the focus * is coming from. The rectangle can help give larger views a finer grained hint * about where focus is coming from, and therefore, where to show selection, or * forward focus change internally. * * A view will not actually take focus if it is not focusable ({@link #isFocusable} returns * false), or if it is focusable and it is not focusable in touch mode * ({@link #isFocusableInTouchMode}) while the device is in touch mode. * * A View will not take focus if it is not visible. * * A View will not take focus if one of its parents has * {@link android.view.ViewGroup#getDescendantFocusability()} equal to * {@link ViewGroup#FOCUS_BLOCK_DESCENDANTS}. * * See also {@link #focusSearch(int)}, which is what you call to say that you * have focus, and you want your parent to look for the next one. * * You may wish to override this method if your custom {@link View} has an internal * {@link View} that it wishes to forward the request to. * * @param direction One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT * @param previouslyFocusedRect The rectangle (in this View's coordinate system) * to give a finer grained hint about where focus is coming from. May be null * if there is no hint. * @return Whether this view or one of its descendants actually took focus. */ public boolean requestFocus(int direction, Rect previouslyFocusedRect) { return requestFocusNoSearch(direction, previouslyFocusedRect); } private boolean requestFocusNoSearch(int direction, Rect previouslyFocusedRect) { // need to be focusable // 该view必须是可以获取焦点的 if ((mViewFlags & FOCUSABLE_MASK) != FOCUSABLE || (mViewFlags & VISIBILITY_MASK) != VISIBLE) { return false; } // need to be focusable in touch mode if in touch mode if (isInTouchMode() && (FOCUSABLE_IN_TOUCH_MODE != (mViewFlags & FOCUSABLE_IN_TOUCH_MODE))) { return false; } // 检查的是属性：android:descendantFocusability=”blocksDescendants”， // 这个属性可以解决 listView 等容器类View没法获取点击事件问题, // 当父亲设置了这个属性, 子view就没法获取焦点了 // need to not have any parents blocking us if (hasAncestorThatBlocksDescendantFocus()) { return false; } // 获取焦点的处理逻辑 handleFocusGainInternal(direction, previouslyFocusedRect); return true; } /** * Give this view focus. This will cause * {@link #onFocusChanged(boolean, int, android.graphics.Rect)} to be called. * * Note: this does not check whether this {@link View} should get focus, it just * gives it focus no matter what. It should only be called internally by framework * code that knows what it is doing, namely {@link #requestFocus(int, Rect)}. * * @param direction values are {@link View#FOCUS_UP}, {@link View#FOCUS_DOWN}, * {@link View#FOCUS_LEFT} or {@link View#FOCUS_RIGHT}. This is the direction which * focus moved when requestFocus() is called. It may not always * apply, in which case use the default View.FOCUS_DOWN. * @param previouslyFocusedRect The rectangle of the view that had focus * prior in this View's coordinate system. */ void handleFocusGainInternal(@FocusRealDirection int direction, Rect previouslyFocusedRect) { if (DBG) { System.out.println(this + " requestFocus()"); } if ((mPrivateFlags & PFLAG_FOCUSED) == 0) { mPrivateFlags |= PFLAG_FOCUSED; View oldFocus = (mAttachInfo != null) ? getRootView().findFocus() : null; if (mParent != null) { // 父亲告诉旧的焦点view，焦点变更，失去了焦点 mParent.requestChildFocus(this, this); } if (mAttachInfo != null) { mAttachInfo.mTreeObserver.dispatchOnGlobalFocusChange(oldFocus, this); } // 这个函数很重要，编辑类view(比如EditText)和普通view的差别就在此 // 和输入法相关的处理也在此 onFocusChanged(true, direction, previouslyFocusedRect); refreshDrawableState(); } } /** * Called by the view system when the focus state of this view changes. * When the focus change event is caused by directional navigation, direction * and previouslyFocusedRect provide insight into where the focus is coming from. * When overriding, be sure to call up through to the super class so that * the standard focus handling will occur. * * @param gainFocus True if the View has focus; false otherwise. * @param direction The direction focus has moved when requestFocus() * is called to give this view focus. Values are * {@link #FOCUS_UP}, {@link #FOCUS_DOWN}, {@link #FOCUS_LEFT}, * {@link #FOCUS_RIGHT}, {@link #FOCUS_FORWARD}, or {@link #FOCUS_BACKWARD}. * It may not always apply, in which case use the default. * @param previouslyFocusedRect The rectangle, in this view's coordinate * system, of the previously focused view. If applicable, this will be * passed in as finer grained information about where the focus is coming * from (in addition to direction). Will be <code>null</code> otherwise. */ @CallSuper protected void onFocusChanged(boolean gainFocus, @FocusDirection int direction, @Nullable Rect previouslyFocusedRect) { ... InputMethodManager imm = InputMethodManager.peekInstance(); if (!gainFocus) { if (isPressed()) { setPressed(false); } if (imm != null && mAttachInfo != null && mAttachInfo.mHasWindowFocus) { imm.focusOut(this); } onFocusLost(); } else if (imm != null && mAttachInfo != null && mAttachInfo.mHasWindowFocus) { // 通知IMMS该view获得了焦点，到此，这后面的逻辑就和上面的window获 // 得焦点导致view和输入法绑定的逻辑一样了 imm.focusIn(this); } invalidate(true); ... }