android4.4如何开机横屏

软件环境：android4.4

硬件平台：marvell

之前调试过在android4.0上将屏幕开机旋转90度，找到了契合点，调整起来还是相对简单，只需设置一个名称为ro.sf.hwrotation = 90即可，android的surface系统显示的时候会读取该系统属性的值，从而将显示界面旋转，但是android4.4的surfaceflinger机制做了调整，自始至终没有发现对该属性的处理判断，可能有其他的暗门，我暂时没发现，因此就把4.0判断属性的那一套移植了过来，具体改动如下：

--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -384,6 +384,11 @@ status_t DisplayDevice::orientationToTransfrom(
int orientation, int w, int h, Transform* tr)
{
uint32_t flags = 0;
+ char property[PROPERTY_VALUE_MAX];
+ if (property_get("ro.sf.hwrotation", property, NULL) > 0) {
+ if (atoi(property) == 90)
+ orientation = DisplayState::eOrientation90;
+ }
switch (orientation) {
case DisplayState::eOrientationDefault:
flags = Transform::ROT_0;
@@ -411,6 +416,7 @@ void DisplayDevice::setProjection(int orientation,

const int w = mDisplayWidth;
const int h = mDisplayHeight;
+ char property[PROPERTY_VALUE_MAX];

Transform R;
DisplayDevice::orientationToTransfrom(orientation, w, h, &R);
@@ -418,7 +424,12 @@ void DisplayDevice::setProjection(int orientation,
if (!frame.isValid()) {
// the destination frame can be invalid if it has never been set,
// in that case we assume the whole display frame.
- frame = Rect(w, h);www.2cto.com
+ if (property_get("ro.sf.hwrotation", property, NULL) > 0) {
+ if (atoi(property) == 90)
+ frame = Rect(h, w);
+ } else {
+ frame = Rect(w, h);
+ }
}

--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -674,6 +674,7 @@ status_t SurfaceFlinger::getDisplayInfo(const sp& display, DisplayInfo*
const HWComposer& hwc(getHwComposer());
float xdpi = hwc.getDpiX(type);
float ydpi = hwc.getDpiY(type);
+ char property[PROPERTY_VALUE_MAX];

// TODO: Not sure if display density should handled by SF any longer
class Density {
@@ -718,8 +719,15 @@ status_t SurfaceFlinger::getDisplayInfo(const sp& display, DisplayInfo*
info->orientation = 0;
}

- info->w = hwc.getWidth(type);
- info->h = hwc.getHeight(type);
+ if (property_get("ro.sf.hwrotation", property, NULL) > 0) {
+ if (atoi(property) == 90) {
+ info->w = hwc.getHeight(type);
+ info->h = hwc.getWidth(type);
+ }
+ } else {
+ info->w = hwc.getWidth(type);
+ info->h = hwc.getHeight(type);
+ }

这两个文件做完相应的修改之后，问题来了，开机以及后续的一系列显示确实进入了横屏模式，但是触摸屏却依然没有旋转过来，上层对touch点位的处理还是按竖屏模式处理的。。。接着尝试修改了surface的不少地方企图扭转touch点位，均告失败，最终选择了一个能解决问题但未必最优的方案，修改Input系统的处理。改动如下：

--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -42,6 +42,7 @@
#include "InputReader.h"

#include
+#include
#include
#include

@@ -2954,6 +2955,12 @@ void TouchInputMapper::configureSurface(nsecs_t when, bool* outResetNeeded) {
int32_t naturalPhysicalWidth, naturalPhysicalHeight;
int32_t naturalPhysicalLeft, naturalPhysicalTop;
int32_t naturalDeviceWidth, naturalDeviceHeight;
+
+ char property[PROPERTY_VALUE_MAX];
+ if (property_get("ro.sf.hwrotation", property, NULL) > 0) {
+ if (atoi(property) == 90)
+ mViewport.orientation = DISPLAY_ORIENTATION_90;
+ }
switch (mViewport.orientation) {
case DISPLAY_ORIENTATION_90:
naturalLogicalWidth = mViewport.logicalBottom - mViewport.logicalTop;
@@ -4246,6 +4253,11 @@ void TouchInputMapper::cookPointerData() {
// X, Y, and the bounding box for coverage information
// Adjust coords for surface orientation.
float x, y, left, top, right, bottom;
+ char property[PROPERTY_VALUE_MAX];
+ if (property_get("ro.sf.hwrotation", property, NULL) > 0) {
+ if (atoi(property) == 90)
+ mSurfaceOrientation = DISPLAY_ORIENTATION_90;
+ }
switch (mSurfaceOrientation) {
case DISPLAY_ORIENTATION_90:

至此，触摸屏旋转成功。

本人是本着遇到问题解决问题的原则，也许4.4有类似4.0的关卡可以一步属性设置即可，只是本人没有发现这道关，上述提供的方案仅供参考以及笔者作为记录之用，稳定性还有待考究，本人未做全面的测试。有问题的同仁可以和我探讨，有更好方案的朋友还望不吝赐教。谢谢~~~