WMS的启动：
/**
* Starts a miscellaneous grab bag of stuff that has yet to be refactored
* and organized.
*/
private void startOtherServices() {
..........
wm = WindowManagerService.main(context, inputManager,
mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL,
!mFirstBoot, mOnlyCore, new PhoneWindowManager());
ServiceManager.addService(Context.WINDOW_SERVICE, wm);
............
}
WMS的基础功能：
WMS使用AILD的方式类描述他的接口
/**
* System private interface to the window manager.
*
* {@hide}
*/
interface IWindowManager
{
/**
* ===== NOTICE =====
* The first three methods must remain the first three methods. Scripts
* and tools rely on their transaction number to work properly.
*/
// This is used for debugging
boolean startViewServer(int port); // Transaction #1
boolean stopViewServer(); // Transaction #2
boolean isViewServerRunning(); // Transaction #3
//与WMS建立一个Session连接
IWindowSession openSession(in IWindowSessionCallback callback, in IInputMethodClient client,
in IInputContext inputContext);
boolean inputMethodClientHasFocus(IInputMethodClient client);
void getInitialDisplaySize(int displayId, out Point size);
void getBaseDisplaySize(int displayId, out Point size);
void setForcedDisplaySize(int displayId, int width, int height);
void clearForcedDisplaySize(int displayId);
int getInitialDisplayDensity(int displayId);
int getBaseDisplayDensity(int displayId);
void setForcedDisplayDensityForUser(int displayId, int density, int userId);
void clearForcedDisplayDensityForUser(int displayId, int userId);
void setForcedDisplayScalingMode(int displayId, int mode); // 0 = auto, 1 = disable
void setOverscan(int displayId, int left, int top, int right, int bottom);
// These can only be called when holding the MANAGE_APP_TOKENS permission.
void setEventDispatching(boolean enabled);
//例如：创建Activity并且通知WMS启动的时候，需要addWindowToken
void addWindowToken(IBinder token, int type, int displayId);
void removeWindowToken(IBinder token, int displayId);
void setFocusedApp(IBinder token, boolean moveFocusNow);
void prepareAppTransition(int transit, boolean alwaysKeepCurrent);
int getPendingAppTransition();
void overridePendingAppTransition(String packageName, int enterAnim, int exitAnim,
IRemoteCallback startedCallback);
void overridePendingAppTransitionScaleUp(int startX, int startY, int startWidth,
int startHeight);
void overridePendingAppTransitionClipReveal(int startX, int startY,
int startWidth, int startHeight);
void overridePendingAppTransitionThumb(in GraphicBuffer srcThumb, int startX, int startY,
IRemoteCallback startedCallback, boolean scaleUp);
void overridePendingAppTransitionAspectScaledThumb(in GraphicBuffer srcThumb, int startX,
int startY, int targetWidth, int targetHeight, IRemoteCallback startedCallback,
boolean scaleUp);
/**
* Overrides animation for app transition that exits from an application to a multi-window
* environment and allows specifying transition animation parameters for each window.
*
* @param specs Array of transition animation descriptions for entering windows.
*
* @hide
*/
void overridePendingAppTransitionMultiThumb(in AppTransitionAnimationSpec[] specs,
IRemoteCallback startedCallback, IRemoteCallback finishedCallback, boolean scaleUp);
void overridePendingAppTransitionInPlace(String packageName, int anim);
/**
* Like overridePendingAppTransitionMultiThumb, but uses a future to supply the specs. This is
* used for recents, where generating the thumbnails of the specs takes a non-trivial amount of
* time, so we want to move that off the critical path for starting the new activity.
*/
void overridePendingAppTransitionMultiThumbFuture(
IAppTransitionAnimationSpecsFuture specsFuture, IRemoteCallback startedCallback,
boolean scaleUp);
void executeAppTransition();
/** Used by system ui to report that recents has shown itself. */
void endProlongedAnimations();
// Re-evaluate the current orientation from the caller's state.
// If there is a change, the new Configuration is returned and the
// caller must call setNewConfiguration() sometime later.
Configuration updateOrientationFromAppTokens(in Configuration currentConfig,
IBinder freezeThisOneIfNeeded, int displayId);
// Notify window manager of the new display override configuration. Returns an array of stack
// ids that were affected by the update, ActivityManager should resize these stacks.
int[] setNewDisplayOverrideConfiguration(in Configuration overrideConfig, int displayId);
void startFreezingScreen(int exitAnim, int enterAnim);
void stopFreezingScreen();
// these require DISABLE_KEYGUARD permission
// 屏幕解锁相关
void disableKeyguard(IBinder token, String tag);
void reenableKeyguard(IBinder token);
void exitKeyguardSecurely(IOnKeyguardExitResult callback);
boolean isKeyguardLocked();
boolean isKeyguardSecure();
boolean inKeyguardRestrictedInputMode();
void dismissKeyguard(IKeyguardDismissCallback callback);
// Requires INTERACT_ACROSS_USERS_FULL permission
void setSwitchingUser(boolean switching);
void closeSystemDialogs(String reason);
// These can only be called with the SET_ANIMATON_SCALE permission.
float getAnimationScale(int which);
float[] getAnimationScales();
void setAnimationScale(int which, float scale);
void setAnimationScales(in float[] scales);
float getCurrentAnimatorScale();
// For testing
void setInTouchMode(boolean showFocus);
// For StrictMode flashing a red border on violations from the UI
// thread. The uid/pid is implicit from the Binder call, and the Window
// Manager uses that to determine whether or not the red border should
// actually be shown. (it will be ignored that pid doesn't have windows
// on screen)
void showStrictModeViolation(boolean on);
// Proxy to set the system property for whether the flashing
// should be enabled. The 'enabled' value is null or blank for
// the system default (differs per build variant) or any valid
// boolean string as parsed by SystemProperties.getBoolean().
void setStrictModeVisualIndicatorPreference(String enabled);
/**
* Set whether screen capture is disabled for all windows of a specific user
*/
void setScreenCaptureDisabled(int userId, boolean disabled);
/**
* Testing and debugging infrastructure for writing surface events
* to given FD. See RemoteSurfaceTrace.java or Wm.java for format.
*/
void enableSurfaceTrace(in ParcelFileDescriptor fd);
void disableSurfaceTrace();
// These can only be called with the SET_ORIENTATION permission.
/**
* Update the current screen rotation based on the current state of
* the world.
* @param alwaysSendConfiguration Flag to force a new configuration to
* be evaluated. This can be used when there are other parameters in
* configuration that are changing.
* @param forceRelayout If true, the window manager will always do a relayout
* of its windows even if the rotation hasn't changed.
*/
void updateRotation(boolean alwaysSendConfiguration, boolean forceRelayout);
/**
* 获得屏幕当前方向
* @return Constant as per {@link android.view.Surface.Rotation}.
*
* @see android.view.Display#DEFAULT_DISPLAY
*/
int getDefaultDisplayRotation();
/**
* Watch the rotation of the specified screen. Returns the current rotation,
* calls back when it changes.
* 屏幕旋转时回调
*/
int watchRotation(IRotationWatcher watcher, int displayId);
/**
* Remove a rotation watcher set using watchRotation.
* 移除回调
*/
void removeRotationWatcher(IRotationWatcher watcher);
/**
* Determine the preferred edge of the screen to pin the compact options menu against.
* @return a Gravity value for the options menu panel
* @hide
*/
int getPreferredOptionsPanelGravity();
/**
* 冻结屏幕旋转功能，保持当前设备方向
*/
void freezeRotation(int rotation);
/**
* 释放 冻结屏幕旋转功能
*/
void thawRotation();
/**
* Gets whether the rotation is frozen.
*
* @return Whether the rotation is frozen.
*/
boolean isRotationFrozen();
/**
* Screenshot the current wallpaper layer, including the whole screen.
*/
Bitmap screenshotWallpaper();
/**
* Registers a wallpaper visibility listener.
* @return Current visibility.
*/
boolean registerWallpaperVisibilityListener(IWallpaperVisibilityListener listener,
int displayId);
/**
* Remove a visibility watcher that was added using registerWallpaperVisibilityListener.
*/
void unregisterWallpaperVisibilityListener(IWallpaperVisibilityListener listener,
int displayId);
/**
* Used only for assist -- 请求当前屏幕截屏
*/
boolean requestAssistScreenshot(IAssistScreenshotReceiver receiver);
/**
* Status Bar 通知WMS可见性发生变化
*/
oneway void statusBarVisibilityChanged(int visibility);
/**
* Called by System UI to notify of changes to the visibility of Recents.
*/
oneway void setRecentsVisibility(boolean visible);
/**
* Called by System UI to notify of changes to the visibility of PIP.
*/
oneway void setPipVisibility(boolean visible);
/**
* Device has a software navigation bar (separate from the status bar).
* 是否含有导航栏
*/
boolean hasNavigationBar();
/**
* Lock the device immediately with the specified options (can be null).
*/
void lockNow(in Bundle options);
/**
* Device is in safe mode.
*/
boolean isSafeModeEnabled();
/**
* Enables the screen if all conditions are met.
*/
void enableScreenIfNeeded();
/**
* Clears the frame statistics for a given window.
*
* @param token The window token.
* @return Whether the frame statistics were cleared.
*/
boolean clearWindowContentFrameStats(IBinder token);
/**
* Gets the content frame statistics for a given window.
*
* @param token The window token.
* @return The frame statistics or null if the window does not exist.
*/
WindowContentFrameStats getWindowContentFrameStats(IBinder token);
/**
* @return the dock side the current docked stack is at; must be one of the
* WindowManagerGlobal.DOCKED_* values
*/
int getDockedStackSide();
/**
* Sets whether we are currently in a drag resize operation where we are changing the docked
* stack size.
*/
void setDockedStackResizing(boolean resizing);
/**
* Sets the region the user can touch the divider. This region will be excluded from the region
* which is used to cause a focus switch when dispatching touch.
*/
void setDockedStackDividerTouchRegion(in Rect touchableRegion);
/**
* Registers a listener that will be called when the dock divider changes its visibility or when
* the docked stack gets added/removed.
*/
void registerDockedStackListener(IDockedStackListener listener);
/**
* Registers a listener that will be called when the pinned stack state changes.
*/
void registerPinnedStackListener(int displayId, IPinnedStackListener listener);
/**
* Updates the dim layer used while resizing.
*
* @param visible Whether the dim layer should be visible.
* @param targetStackId The id of the task stack the dim layer should be placed on.
* @param alpha The translucency of the dim layer, between 0 and 1.
*/
void setResizeDimLayer(boolean visible, int targetStackId, float alpha);
/**
* Requests Keyboard Shortcuts from the displayed window.
*
* @param receiver The receiver to deliver the results to.
*/
void requestAppKeyboardShortcuts(IResultReceiver receiver, int deviceId);
/**
* Retrieves the current stable insets from the primary display.
*/
void getStableInsets(int displayId, out Rect outInsets);
/**
* Register shortcut key. Shortcut code is packed as:
* (MetaState << Integer.SIZE) | KeyCode
* 快捷方式相关
*/
void registerShortcutKey(in long shortcutCode, IShortcutService keySubscriber);
/**
* Create an input consumer by name.
*/
void createInputConsumer(String name, out InputChannel inputChannel);
/**
* Destroy an input consumer by name. This method will also dispose the input channels
* associated with that InputConsumer.
*/
boolean destroyInputConsumer(String name);
/**
* Return the touch region for the current IME window, or an empty region if there is none.
*/
Region getCurrentImeTouchRegion();
}
WMS自己创建了线程，来处理投递到这个线程的事件和请求
public static WindowManagerService main(final Context context, final InputManagerService im,
final boolean haveInputMethods, final boolean showBootMsgs, final boolean onlyCore,
WindowManagerPolicy policy) {
DisplayThread.getHandler().runWithScissors(() ->
sInstance = new WindowManagerService(context, im, haveInputMethods, showBootMsgs,
onlyCore, policy), 0);
return sInstance;
}
public final class DisplayThread extends ServiceThread {
private static DisplayThread sInstance;
private static Handler sHandler;
private DisplayThread() {
// DisplayThread runs important stuff, but these are not as important as things running in
// AnimationThread. Thus, set the priority to one lower.
super("android.display", Process.THREAD_PRIORITY_DISPLAY + 1, false /*allowIo*/);
}
private static void ensureThreadLocked() {
if (sInstance == null) {
sInstance = new DisplayThread();
sInstance.start();
sInstance.getLooper().setTraceTag(Trace.TRACE_TAG_ACTIVITY_MANAGER);
sHandler = new Handler(sInstance.getLooper());
}
}
public static DisplayThread get() {
synchronized (DisplayThread.class) {
ensureThreadLocked();
return sInstance;
}
}
//获得Handler来进行投递
public static Handler getHandler() {
synchronized (DisplayThread.class) {
ensureThreadLocked();
return sHandler;
}
}
}
除了可以通过Handler投递事件，还可以通过直接调用来处理比较紧急的事件
例如 WindowManagerService.java
@Override
public boolean isKeyguardLocked() {
return WindowManagerService.this.isKeyguardLocked();
}
参考：
《深入理解Android内核设计与思想》