安卓系统强制旋转屏幕实现横竖屏切换
我们要实现开机强制系统横屏或者竖屏，并且可以再系统中实时切换横竖屏，首先分析代码找到
WindowManagerService.java
@Override
public int getRotation() {
return mRotation;
}
查看WindowManagerService.java代码发现我们获取当前屏幕参数时返回的是mRotation参数，继续查看mRotation初始化调用
/** All DisplayContents in the world, kept here */
SparseArray mDisplayContents = new SparseArray<>(2);
int mRotation = 0; //初始化
int rotation = mPolicy.rotationForOrientationLw(mForcedAppOrientation, mRotation);
boolean altOrientation = !mPolicy.rotationHasCompatibleMetricsLw(
mForcedAppOrientation, rotation);
if (DEBUG_ORIENTATION) {
Slog.v(TAG, "Application requested orientation "
+ mForcedAppOrientation + ", got rotation " + rotation
+ " which has " + (altOrientation ? "incompatible" : "compatible")
+ " metrics");
}
if (mRotation == rotation && mAltOrientation == altOrientation) {
// No change.
return false;
}
if (DEBUG_ORIENTATION) {
Slog.v(TAG,
"Rotation changed to " + rotation + (altOrientation ? " (alt)" : "")
+ " from " + mRotation + (mAltOrientation ? " (alt)" : "")
+ ", forceApp=" + mForcedAppOrientation);
}
mRotation = rotation;//代码中唯一一次赋值 发现代码中只有一次赋值，我们先尝试初始化时直接修改我这里为0 显示是横屏，修改为1，编译后发现开机刚进去时竖了过来，但是马上又横了过来，说明有别的地方重新设置了参数，查看log发现是上述代码修改了参数
int rotation = mPolicy.rotationForOrientationLw(mForcedAppOrientation, mRotation);
boolean altOrientation = !mPolicy.rotationHasCompatibleMetricsLw(
mForcedAppOrientation, rotation);
if (DEBUG_ORIENTATION) {
Slog.v(TAG, "Application requested orientation "
+ mForcedAppOrientation + ", got rotation " + rotation
+ " which has " + (altOrientation ? "incompatible" : "compatible")
+ " metrics");
}
if (mRotation == rotation && mAltOrientation == altOrientation) {
// No change.
return false;
}
if (DEBUG_ORIENTATION) {
Slog.v(TAG,
"Rotation changed to " + rotation + (altOrientation ? " (alt)" : "")
+ " from " + mRotation + (mAltOrientation ? " (alt)" : "")
+ ", forceApp=" + mForcedAppOrientation);
}
mRotation = rotation;
mAltOrientation = altOrientation;
mPolicy.setRotationLw(mRotation);
根据mPolicy.rotationForOrientationLw查看发现
PhoneWindowManager.java
@Override
public int rotationForOrientationLw(int orientation, int lastRotation) {
if (false) {
Slog.v(TAG, "rotationForOrientationLw(orient="
+ orientation + ", last=" + lastRotation
+ "); user=" + mUserRotation + " "
+ ((mUserRotationMode == WindowManagerPolicy.USER_ROTATION_LOCKED)
? "USER_ROTATION_LOCKED" : "")
);
}
if (mForceDefaultOrientation) {
return Surface.ROTATION_0;
}
synchronized (mLock) {
int sensorRotation = mOrientationListener.getProposedRotation(); // may be -1
if (sensorRotation < 0) {
sensorRotation = lastRotation;
}
final int preferredRotation;
if (mLidState == LID_OPEN && mLidOpenRotation >= 0) {
// Ignore sensor when lid switch is open and rotation is forced.
preferredRotation = mLidOpenRotation;
} else if (mDockMode == Intent.EXTRA_DOCK_STATE_CAR
&& (mCarDockEnablesAccelerometer || 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 = mCarDockEnablesAccelerometer
? sensorRotation : mCarDockRotation;
} else if ((mDockMode == Intent.EXTRA_DOCK_STATE_DESK
|| mDockMode == Intent.EXTRA_DOCK_STATE_LE_DESK
|| mDockMode == Intent.EXTRA_DOCK_STATE_HE_DESK)
&& (mDeskDockEnablesAccelerometer || mDeskDockRotation >= 0)) {
// Ignore sensor when in desk dock unless explicitly enabled.
// This case can override the behavior of NOSENSOR, and can also
// enable 180 degree rotation while docked.
preferredRotation = mDeskDockEnablesAccelerometer
? sensorRotation : mDeskDockRotation;
} else if (mHdmiPlugged && 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 (mHdmiPlugged && mDockMode == 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 (orientation == ActivityInfo.SCREEN_ORIENTATION_LOCKED) {
// Application just wants to remain locked in the last rotation.
preferredRotation = lastRotation;
} else if (!mSupportAutoRotation) {
// 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
&& (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.
if (mAllowAllRotations < 0) {
// Can't read this during init() because the context doesn't
// have display metrics at that time so we cannot determine
// tablet vs. phone then.
mAllowAllRotations = mContext.getResources().getBoolean(
com.android.internal.R.bool.config_allowAllRotations) ? 1 : 0;
}
if (sensorRotation != Surface.ROTATION_180
|| mAllowAllRotations == 1
|| orientation == ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR
|| orientation == ActivityInfo.SCREEN_ORIENTATION_FULL_USER) {
preferredRotation = sensorRotation;
} else {
preferredRotation = lastRotation;
}
} else if (mUserRotationMode == WindowManagerPolicy.USER_ROTATION_LOCKED
&& orientation != ActivityInfo.SCREEN_ORIENTATION_NOSENSOR) {
// Apply rotation lock. Does not apply to NOSENSOR.
// 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).
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;
}
}
}发现是这个方法修改了屏幕方向参数，由于我们这边直接强制修改，不需要动态判断所以实行简单粗暴的方法直接在最上面return我们想要的参数，写上我们自己修改屏幕方向的参数。
这里我们实现了修改参数后重新开机实现横竖屏切换，但是我们要实现开机时动态修改横竖屏并实时显示，
/**
* Recalculate the current rotation.
*
* Called by the window manager policy whenever the state of the system changes
* such that the current rotation might need to be updated, such as when the
* device is docked or rotated into a new posture.
*/
@Override
public void updateRotation(boolean alwaysSendConfiguration, boolean forceRelayout) {
updateRotationUnchecked(alwaysSendConfiguration, forceRelayout);
}
//
public void updateRotationUnchecked(boolean alwaysSendConfiguration, boolean
forceRelayout) {
if(DEBUG_ORIENTATION) Slog.v(TAG, "updateRotationUnchecked("
+ "alwaysSendConfiguration=" + alwaysSendConfiguration + ")");
long origId = Binder.clearCallingIdentity();
boolean changed;
synchronized(mWindowMap) {
changed = updateRotationUncheckedLocked(false);
if (!changed || forceRelayout) {
getDefaultDisplayContentLocked().layoutNeeded = true;
performLayoutAndPlaceSurfacesLocked();
}
}
if (changed || alwaysSendConfiguration) {
sendNewConfiguration();
}
Binder.restoreCallingIdentity(origId);
}
查看上述代码发现是此处刷新，我们可以再此刷新我们的参数，然后在应用界面设置的旋转参数，然后通过系统服务调用updateRotation方法进行刷新
try {
IWindowManager mWm =
IWindowManager.Stub.asInterface(ServiceManager.getService("window"));
mWm.updateRotation(true, true);
} catch (SecurityException e) {
// expected
} catch (RemoteException e) {
}此时旋转成功，但是发现在竖屏时有的软件是写了强制横屏的参数的话会出现显示异常的情况，参考mstar设置强制横屏属性mstar.forcelandscape
// MStar Android Patch Begin
public int screenOrientation = (1 == SystemProperties.getInt("mstar.forcelandscape", 0) ?
ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE : ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
// MStar Android Patch End
//查看activityinfo文件
/** @hide */
@IntDef({
SCREEN_ORIENTATION_UNSPECIFIED,
SCREEN_ORIENTATION_LANDSCAPE,
SCREEN_ORIENTATION_PORTRAIT,
SCREEN_ORIENTATION_USER,
SCREEN_ORIENTATION_BEHIND,
SCREEN_ORIENTATION_SENSOR,
SCREEN_ORIENTATION_NOSENSOR,
SCREEN_ORIENTATION_SENSOR_LANDSCAPE,
SCREEN_ORIENTATION_SENSOR_PORTRAIT,
SCREEN_ORIENTATION_REVERSE_LANDSCAPE,
SCREEN_ORIENTATION_REVERSE_PORTRAIT,
SCREEN_ORIENTATION_FULL_SENSOR,
SCREEN_ORIENTATION_USER_LANDSCAPE,
SCREEN_ORIENTATION_USER_PORTRAIT,
SCREEN_ORIENTATION_FULL_USER,
SCREEN_ORIENTATION_LOCKED
})这里强制竖屏我们用到SCREEN_ORIENTATION_PORTRAIT，所以修改系统中mstar所有mstar.forcelandscape属性判断操作的
SCREEN_ORIENTATION_UNSPECIFIED 为 SCREEN_ORIENTATION_PORTRAIT
开机动画修改为竖屏
BootAnimation.cpp
sp control = session()->createSurface(String8("BootAnimation"),
forcelandscape ? dinfo.h : dinfo.w,
forcelandscape ? dinfo.w : dinfo.h,