一、前言

有时候需要系统的某个应用强制衡平显示，不管他是如何配置的。我们只需要简单的拿到top的Task下面的ActivityRecord，并判断包名来强制实现。

二、调整wms

com.android.server.wm.DisplayRotation

 /*** Given an orientation constant, returns the appropriate surface rotation, taking into account* sensors, docking mode, rotation lock, and other factors.** @param orientation  An orientation constant, such as*                     {@link ActivityInfo#SCREEN_ORIENTATION_LANDSCAPE}.* @param lastRotation The most recently used rotation.* @return The surface rotation to use.*/@Surface.Rotationint rotationForOrientation(@ScreenOrientation int orientation,@Surface.Rotation int lastRotation) {ProtoLog.v(WM_DEBUG_ORIENTATION,"rotationForOrientation(orient=%s (%d), last=%s (%d)); user=%s (%d) %s",ActivityInfo.screenOrientationToString(orientation), orientation,Surface.rotationToString(lastRotation), lastRotation,Surface.rotationToString(mUserRotation), mUserRotation,mUserRotationMode == WindowManagerPolicy.USER_ROTATION_LOCKED? "USER_ROTATION_LOCKED" : "");if (isFixedToUserRotation()) {return mUserRotation;}+    if(isTopActivityIsMyPackage()){+       return Surface.ROTATION_90;+    }@Surface.Rotationint sensorRotation = mOrientationListener != null? mOrientationListener.getProposedRotation() // may be -1: -1;if (mFoldController != null && mFoldController.shouldIgnoreSensorRotation()) {sensorRotation = -1;}if (mDeviceStateController.shouldReverseRotationDirectionAroundZAxis(mDisplayContent)) {sensorRotation = RotationUtils.reverseRotationDirectionAroundZAxis(sensorRotation);}mLastSensorRotation = sensorRotation;if (sensorRotation < 0) {sensorRotation = lastRotation;}final int lidState = mDisplayPolicy.getLidState();final int dockMode = mDisplayPolicy.getDockMode();final boolean hdmiPlugged = mDisplayPolicy.isHdmiPlugged();final boolean carDockEnablesAccelerometer =mDisplayPolicy.isCarDockEnablesAccelerometer();final boolean deskDockEnablesAccelerometer =mDisplayPolicy.isDeskDockEnablesAccelerometer();@Surface.Rotationfinal int preferredRotation;if (!isDefaultDisplay) {// For secondary displays we ignore things like displays sensors, docking mode and// rotation lock, and always prefer user rotation.preferredRotation = mUserRotation;} else if (lidState == LID_OPEN && mLidOpenRotation >= 0) {// Ignore sensor when lid switch is open and rotation is forced.preferredRotation = mLidOpenRotation;} else if (dockMode == Intent.EXTRA_DOCK_STATE_CAR&& (carDockEnablesAccelerometer || mCarDockRotation >= 0)) {// Ignore sensor when in car dock unless explicitly enabled.// This case can override the behavior of NOSENSOR, and can also// enable 180 degree rotation while docked.preferredRotation = carDockEnablesAccelerometer ? sensorRotation : mCarDockRotation;} else if ((dockMode == Intent.EXTRA_DOCK_STATE_DESK|| dockMode == Intent.EXTRA_DOCK_STATE_LE_DESK|| dockMode == Intent.EXTRA_DOCK_STATE_HE_DESK)&& (deskDockEnablesAccelerometer || mDeskDockRotation >= 0)&& !(orientation == ActivityInfo.SCREEN_ORIENTATION_LOCKED|| orientation == ActivityInfo.SCREEN_ORIENTATION_NOSENSOR)) {// Ignore sensor when in desk dock unless explicitly enabled.// This case can enable 180 degree rotation while docked.preferredRotation = deskDockEnablesAccelerometer ? sensorRotation : mDeskDockRotation;} else if (hdmiPlugged && mDemoHdmiRotationLock) {// Ignore sensor when plugged into HDMI when demo HDMI rotation lock enabled.// Note that the dock orientation overrides the HDMI orientation.preferredRotation = mDemoHdmiRotation;} else if (hdmiPlugged && dockMode == Intent.EXTRA_DOCK_STATE_UNDOCKED&& mUndockedHdmiRotation >= 0) {// Ignore sensor when plugged into HDMI and an undocked orientation has// been specified in the configuration (only for legacy devices without// full multi-display support).// Note that the dock orientation overrides the HDMI orientation.preferredRotation = mUndockedHdmiRotation;} else if (mDemoRotationLock) {// Ignore sensor when demo rotation lock is enabled.// Note that the dock orientation and HDMI rotation lock override this.preferredRotation = mDemoRotation;} else if (mDisplayPolicy.isPersistentVrModeEnabled()) {// While in VR, apps always prefer a portrait rotation. This does not change// any apps that explicitly set landscape, but does cause sensors be ignored,// and ignored any orientation lock that the user has set (this conditional// should remain above the ORIENTATION_LOCKED conditional below).preferredRotation = mPortraitRotation;} else if (orientation == ActivityInfo.SCREEN_ORIENTATION_LOCKED) {// Application just wants to remain locked in the last rotation.preferredRotation = lastRotation;} else if (!mSupportAutoRotation) {if (mFixedToUserRotation == IWindowManager.FIXED_TO_USER_ROTATION_IF_NO_AUTO_ROTATION) {preferredRotation = mUserRotation;} else {// If we don't support auto-rotation then bail out here and ignore// the sensor and any rotation lock settings.preferredRotation = -1;}} else if (((mUserRotationMode == WindowManagerPolicy.USER_ROTATION_FREE|| isTabletopAutoRotateOverrideEnabled())&& (orientation == ActivityInfo.SCREEN_ORIENTATION_USER|| orientation == ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED|| orientation == ActivityInfo.SCREEN_ORIENTATION_USER_LANDSCAPE|| orientation == ActivityInfo.SCREEN_ORIENTATION_USER_PORTRAIT|| orientation == ActivityInfo.SCREEN_ORIENTATION_FULL_USER))|| orientation == ActivityInfo.SCREEN_ORIENTATION_SENSOR|| orientation == ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR|| orientation == ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE|| orientation == ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT) {// Otherwise, use sensor only if requested by the application or enabled// by default for USER or UNSPECIFIED modes.  Does not apply to NOSENSOR.boolean allowed = true;if (orientation != ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR&& orientation != ActivityInfo.SCREEN_ORIENTATION_FULL_USER) {allowed = RotationPolicy.isRotationAllowed(sensorRotation, mUserRotationAngles,getAllowAllRotations() != ALLOW_ALL_ROTATIONS_DISABLED);}if (allowed) {preferredRotation = sensorRotation;} else {preferredRotation = lastRotation;}} else if (mUserRotationMode == WindowManagerPolicy.USER_ROTATION_LOCKED&& orientation != ActivityInfo.SCREEN_ORIENTATION_NOSENSOR&& orientation != ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE&& orientation != ActivityInfo.SCREEN_ORIENTATION_PORTRAIT&& orientation != ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE&& orientation != ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT) {// Apply rotation lock. Does not apply to NOSENSOR or specific rotations.// The idea is that the user rotation expresses a weak preference for the direction// of gravity and as NOSENSOR is never affected by gravity, then neither should// NOSENSOR be affected by rotation lock (although it will be affected by docks).// Also avoid setting user rotation when app has preference over one particular rotation// to avoid leaving the rotation to the reverse of it which has the compatible// orientation, but isn't what app wants, when the user rotation is the reverse of the// preferred rotation.preferredRotation = mUserRotation;} else {// No overriding preference.// We will do exactly what the application asked us to do.preferredRotation = -1;}switch (orientation) {case ActivityInfo.SCREEN_ORIENTATION_PORTRAIT:// Return portrait unless overridden.if (isAnyPortrait(preferredRotation)) {return preferredRotation;}return mPortraitRotation;case ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE:// Return landscape unless overridden.if (isLandscapeOrSeascape(preferredRotation)) {return preferredRotation;}return mLandscapeRotation;case ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT:// Return reverse portrait unless overridden.if (isAnyPortrait(preferredRotation)) {return preferredRotation;}return mUpsideDownRotation;case ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE:// Return seascape unless overridden.if (isLandscapeOrSeascape(preferredRotation)) {return preferredRotation;}return mSeascapeRotation;case ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE:case ActivityInfo.SCREEN_ORIENTATION_USER_LANDSCAPE:// Return either landscape rotation.if (isLandscapeOrSeascape(preferredRotation)) {return preferredRotation;}if (isLandscapeOrSeascape(lastRotation)) {return lastRotation;}return mLandscapeRotation;case ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT:case ActivityInfo.SCREEN_ORIENTATION_USER_PORTRAIT:// Return either portrait rotation.if (isAnyPortrait(preferredRotation)) {return preferredRotation;}if (isAnyPortrait(lastRotation)) {return lastRotation;}return mPortraitRotation;default:// For USER, UNSPECIFIED, NOSENSOR, SENSOR and FULL_SENSOR,// just return the preferred orientation we already calculated.if (preferredRotation >= 0) {return preferredRotation;}return Surface.ROTATION_0;}}

这里是传入一个配置的选装方法和当前的方法，来判断后面要进行旋转的操作，我们Activity没有配置横竖屏的时候传入的
orientation都是SCREEN_ORIENTATION_UNSPECIFIED(-1)，不过我们强制横屏可以不考虑这么多，加一个方法判断即可。

 boolean isTopActivityIsMyPackage(){try {Task rootTask = mDisplayContent.getTopRootTask();if(rootTask!=null&&rootTask.hasChild()&&rootTask.getChildAt(0) instanceof ActivityRecord){return  ((ActivityRecord) rootTask.getChildAt(0)).packageName.equals("com.example.cloudclient");}}catch (Exception e){return false;}return false;}

这里的包名换成自己的就行，然后编译打包重启

make -j12 services
adb push lineageos/out/target/product/blueline/system/framework/services.jar /system/framework/services.jar