關於Android6.0開機默認橫屏顯示,網上有一些文章提到過,但是我仔細研究了下,要麼不全,要麼修改方式會引入新的問題。爲了讓開機強制橫屏顯示,並且又不影響sensor的屏幕自動旋轉功能,我對旋轉的修改方式做了很多嘗試,最後終於找到了一種可行的方式。既保證開機啓動的時候按照指定的方向顯示logo和開機動畫,又可以在打開自動旋轉開關後,通過轉動設備來自動旋轉屏幕。具體做法如下:
開機默認橫屏顯示,需要修改幾個部分,包括bootloader,開機動畫,SurfaceFlinger以及進入桌面後的Launcher顯示方向。
1. bootloader
不同的平臺,bootloader的顯示部分有差異,可以根據平臺的代碼特點去修改,比如調換x、y的數據。
2. 開機動畫
開機動畫主要修改BootAnimation.cpp -> readyToRun ()
if (dinfo.w < dinfo.h)
control = session()->createSurface(String8("BootAnimation"),
dinfo.h, dinfo.w, PIXEL_FORMAT_RGB_565);
else
control = session()->createSurface(String8("BootAnimation"),
dinfo.w, dinfo.h, PIXEL_FORMAT_RGB_565);
3. SurfaceFlinger
SurfaceFlinger部分主要修改DisplayDevice.cpp -> DisplayDevice() 最後一行:
if (!strcmp(property, "DT370CR"))
rotate_default = DisplayState::eOrientation270;
else if (!strcmp(property, "DT317CR"))
rotate_default = DisplayState::eOrientation90;
setProjection(rotate_default, mViewport, mFrame);
然後進入setProjection()裏面進行如下修改:
if (!frame.isValid()) {
// the destination frame can be invalid if it has never been set,
// in that case we assume the whole display frame.
if (w < h)
frame = Rect(h, w); //此處調換x、y順序,若不調換,開機動畫前半段會有偏移
else
frame = Rect(w, h);
}
4. Framework
(1) WindowManagerService.java
修改四個變量的初始值:
int mRotation = ("DT370CR".equals(Build.MODEL))?3:(("DT317CR".equals(Build.MODEL))?1:0);
int mForcedAppOrientation = ("DT370CR".equals(Build.MODEL))?8:(("DT317CR".equals(Build.MODEL))?0:-1);
int mLastWindowForcedOrientation = ("DT370CR".equals(Build.MODEL))?8:(("DT317CR".equals(Build.MODEL))?0:-1);
int mLastKeyguardForcedOrientation = ("DT370CR".equals(Build.MODEL))?8:(("DT317CR".equals(Build.MODEL))?0:-1);
修改boolean updateOrientationFromAppTokensLocked(boolean inTransaction),增加下面一段:
if (req == 5)
req = ("DT370CR".equals(Build.MODEL))?8:(("DT317CR".equals(Build.MODEL))?0:5);
(2) PhoneWindowManager.java
修改一個變量的初始值:
int mUserRotation = (("DT370CR".equals(Build.MODEL))?3:(("DT317CR".equals(Build.MODEL))?1:0));
修改public void updateSettings(),給userRotation重新賦值,增加如下一段代碼:
int userRotation = Settings.System.getIntForUser(resolver,
Settings.System.USER_ROTATION,
(("DT370CR".equals(Build.MODEL))?3:(("DT317CR".equals(Build.MODEL))?1:0)),
UserHandle.USER_CURRENT);
if (userRotation < 0) {
userRotation = (("DT370CR".equals(Build.MODEL))?3:(("DT317CR".equals(Build.MODEL))?1:0));
}
修改public int rotationForOrientationLw(int orientation, int lastRotation)如下:
if (mForceDefaultOrientation) {
if ("DT370CR".equals(Build.MODEL))
return Surface.ROTATION_270;
else if ("DT317CR".equals(Build.MODEL))
return Surface.ROTATION_90;
else
return Surface.ROTATION_0;
}
(3) ~/framework/base/packages/SettingsProvider/res/values/defaults.xml
將def_user_rotation的值修改爲-1
至此,所有代碼修改完畢,重新編譯代碼,燒錄固件後會發現屏幕已經橫過來了。