Android N版本三指截屏

首先自己恭喜自己找到新的工作，这段时间也把自己的写过的一些功能做个总结。
手势快捷操作现在很多手机厂商都有做，三指截屏只是一个例子，可以通过这个例子去实现某个操作<->某个动作。本文只是写个简单的需求，后期可能自己扩展，例如像OPPO系统的上三指分屏，下三指截图。

一：修改的文件如下

M alps/frameworks/base/api/current.txt
M alps/frameworks/base/api/system-current.txt
M alps/frameworks/base/api/test-current.txt
M alps/frameworks/base/core/java/android/provider/Settings.java
M alps/frameworks/base/core/java/android/view/ViewGroup.java
M alps/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
M alps/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
M alps/frameworks/base/packages/SystemUI/AndroidManifest.xml
M alps/frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
M alps/packages/apps/Settings/AndroidManifest.xml
A alps/packages/apps/Settings/res/drawable-xhdpi/ic_settings_three_screenshot.png
M alps/packages/apps/Settings/res/values-zh-rCN/strings.xml
M alps/packages/apps/Settings/res/values/strings.xml
M alps/packages/apps/Settings/src/com/android/settings/Settings.java
M alps/packages/apps/Settings/src/com/android/settings/SettingsActivity.java
A alps/packages/apps/Settings/src/com/android/settings/fuzhu/ThreeScreenShot.java
修改文件分类
1）frameworks/base/
2）packages/apps/Settings/
这个博客主要记录frameworks/base/相关的修改与实现 Settings模块的修改可以参考我从前的博客
Android N Settings实战开发（1）一，二级界面增加
https://blog.csdn.net/qq_24716151/article/details/78619044
Android N Settings实战开发（2）一级界面状态更新
https://blog.csdn.net/qq_24716151/article/details/78675743

二：实现原理

实现原理：
1）Settings中开关控制状态，
Settings.System.putInt(getActivity().getContentResolver(), Settings.System.SCREENSHOTPOINTER, 1);
0代表关，1代表开。
2）ViewGroup.java中的事件分发中增加parse3PointerScreenShot（ev）手势判断逻辑

public boolean dispatchTouchEvent(MotionEvent ev) {if (mInputEventConsistencyVerifier != null) {mInputEventConsistencyVerifier.onTouchEvent(ev, 1);}parse3PointerScreenShot(ev);Log.i("WHB11111","parse3PointerScreenShot-----PWM=");   ........}

3）parse3PointerScreenShot（ev）手势逻辑判断，如果符合逻辑发送截屏广播

private void parse3PointerScreenShot(MotionEvent ev) {int actionMasked = ev.getActionMasked();int pointerCount = ev.getPointerCount();//获取Settings中是否允许三指截屏，1为允许，非1为不允许//最好是在framework中加入int value = Settings.System.getInt(mContext.getContentResolver(), Settings.System.SCREENSHOTPOINTER, 0);Log.i("WHB11111","SCREENSHOTPOINTER="+value);if (value != 1) {return ;}if (pointerCount == 3) {switch (actionMasked) {case MotionEvent.ACTION_POINTER_DOWN:for (int i = 0; i < pointerCount; i++) {int pointerId = ev.getPointerId(i);downY[pointerId] = ev.getY(i);}is3Pointer = true;break;case MotionEvent.ACTION_POINTER_UP:if (is3Pointer) { //如果是三个手指，就获取每个手指的滑动间距，否则就清空数据for (int i = 0; i < pointerCount; i++) {int pointerId = ev.getPointerId(i);upY[pointerId] = ev.getY(i);matchY[pointerId] = Math.abs(upY[pointerId] - downY[pointerId]);}} else {clearArrayData(downY);clearArrayData(upY);clearArrayData(matchY);}break;default:break;}boolean[] flag = new boolean[] {false, false, false,};for (int i = 0; i < pointerCount; i++) {int pointerId = ev.getPointerId(i);//三个手指划过的距离是否大于最大预定值if (matchY[pointerId] > Y_OFFSET) {flag[i] = true;matchY[pointerId] = 0;}}//如果三个指头都划过了最大预定值，就开始截屏if (flag[0] && flag[1] && flag[2]) {Intent intent = new Intent("com.whb.screenshot");//Send broadcast to PhoneWindowManager to cature screengetContext().sendBroadcast(intent);Log.d(TAG, "Intercept the key Three finger to capture screen"); }} else {is3Pointer = false;}}

4)PhoneWindowManager接收广播实现截屏操作
注册广播

        filter = new IntentFilter("com.whb.screenshot");context.registerReceiver(mScreenShotReceiver, filter);

接收广播通过调用SystemUI的截图方法实现截图操作

    BroadcastReceiver mScreenShotReceiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {if ("com.qucii.screenshot".equals(intent.getAction())) {Log.i("WHB11111","begin-----SCREENSHOTPOINTER=");mHandler.post(mScreenshotRunnable); // 调用系统代码,执行截屏逻辑}}};

如果想调用SystemUI的截图方法，要做如下修改

--- a/alps/frameworks/base/packages/SystemUI/AndroidManifest.xml
+++ b/alps/frameworks/base/packages/SystemUI/AndroidManifest.xml<service android:name=".screenshot.TakeScreenshotService"android:process=":screenshot"
-            android:exported="false" />
+            android:exported="true" /><!-- Called from PhoneWindowManager --><receiver android:name=".screenshot.ScreenshotServiceErrorReceiver"

三：解决ListView事件冲突

public boolean onInterceptTouchEvent(MotionEvent ev) {if (ev.isFromSource(InputDevice.SOURCE_MOUSE)&& ev.getAction() == MotionEvent.ACTION_DOWN&& ev.isButtonPressed(MotionEvent.BUTTON_PRIMARY)&& isOnScrollbarThumb(ev.getX(), ev.getY())) {return true;}
+       if (ev.getPointerCount()==3
+               &&Settings.System.getInt(mContext.getContentResolver(), +Settings.System.SCREENSHOTPOINTER, 0)==1) {
+           return true;
+           }return false;}

四：默认状态控制

1.frameworks/base/packages/SettingsProvider/res/values/defaults.xml设置默认指控制三指截屏操作是默认开还是关。
M alps/frameworks/base/core/java/android/provider/Settings.java
M alps/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
M alps/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
Settings.java

+          public static final String SCREENSHOTPOINTER = "screenshot_pointer";

DatabaseHelper.java

+          loadIntegerSetting(stmt, Settings.System.SCREENSHOTPOINTER,
+                                       R.integer.screenshot_pointer);

defaults.xml

+         <integer name="screenshot_pointer">0</integer>

2.编译遇到不过的时候

******************************
You have tried to change the API from what has been previously approved.
To make these errors go away, you have two choices:1) You can add "@hide" javadoc comments to the methods, etc. listed in theerrors above.2) You can update current.txt by executing the following command:make update-apiTo submit the revised current.txt to the main Android repository,you will need approval.
******************************

执行make update-api,并把相关的current.txt提交上