Android N版本 三指截屏

首先自己恭喜自己找到新的工作，這段時間也把自己的寫過的一些功能做個總結。

手勢快捷操作現在很多手機廠商都有做，三指截屏隻是一個例子，可以通過這個例子去實作某個操作<->某個動作。本文隻是寫個簡單的需求，後期可能自己擴充，例如像OPPO系統的上三指分屏，下三指截圖。

一：修改的檔案如下

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

修改檔案分類

1）frameworks/base/

2）packages/apps/Settings/

這個部落客要記錄frameworks/base/相關的修改與實作 Settings子產品的修改可以參考我從前的部落格

Android N Settings實戰開發（1）一，二級界面增加

https://blog.csdn.net/qq_24716151/article/details/78619044

Android N Settings實戰開發（2）一級界面狀态更新

https://blog.csdn.net/qq_24716151/article/details/78675743

二：實作原理

實作原理：

1）Settings中開關控制狀态，

Settings.System.putInt(getActivity().getContentResolver(), Settings.System.SCREENSHOTPOINTER, 1);

0代表關，1代表開。

2）ViewGroup.java中的事件分發中增加parse3PointerScreenShot（ev）手勢判斷邏輯

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

3）parse3PointerScreenShot（ev）手勢邏輯判斷，如果符合邏輯發送截屏廣播

private void parse3PointerScreenShot(MotionEvent ev) {
        int actionMasked = ev.getActionMasked();
        int pointerCount = ev.getPointerCount();

        //擷取Settings中是否允許三指截屏，1為允許，非1為不允許
        //最好是在framework中加入
        int value = Settings.System.getInt(mContext.getContentResolver(), Settings.System.SCREENSHOTPOINTER, );
        Log.i("WHB11111","SCREENSHOTPOINTER="+value);
        if (value != ) {
            return ;
        }

        if (pointerCount == ) {
            switch (actionMasked) {
            case MotionEvent.ACTION_POINTER_DOWN:
                for (int i = ; i < pointerCount; i++) {
                    int pointerId = ev.getPointerId(i);
                    downY[pointerId] = ev.getY(i);
                }
                is3Pointer = true;
                break;
            case MotionEvent.ACTION_POINTER_UP:
                if (is3Pointer) { 
                    //如果是三個手指，就擷取每個手指的滑動間距，否則就清空資料
                    for (int i = ; 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 = ; i < pointerCount; i++) {
                int pointerId = ev.getPointerId(i);
                //三個手指劃過的距離是否大于最大預定值
                if (matchY[pointerId] > Y_OFFSET) {
                    flag[i] = true;
                    matchY[pointerId] = ;
                }
            }

            //如果三個指頭都劃過了最大預定值，就開始截屏
            if (flag[] && flag[] && flag[]) {
                Intent intent = new Intent("com.whb.screenshot");
                //Send broadcast to PhoneWindowManager to cature screen
                getContext().sendBroadcast(intent);
                Log.d(TAG, "Intercept the key Three finger to capture screen"); 
            }
        } else {
            is3Pointer = false;
        }
    }
           

4)PhoneWindowManager接收廣播實作截屏操作

注冊廣播

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

接收廣播通過調用SystemUI的截圖方法實作截圖操作

BroadcastReceiver mScreenShotReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            if ("com.qucii.screenshot".equals(intent.getAction())) {
                Log.i("WHB11111","begin-----SCREENSHOTPOINTER=");
                mHandler.post(mScreenshotRunnable); // 調用系統代碼,執行截屏邏輯
            }
        }
    };
           

如果想調用SystemUI的截圖方法，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：解決ListView事件沖突

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()==
+               &&Settings.System.getInt(mContext.getContentResolver(), +Settings.System.SCREENSHOTPOINTER, )==) {
+           return true;
+           }
        return false;
    }
           

四：預設狀态控制

1.frameworks/base/packages/SettingsProvider/res/values/defaults.xml設定預設指控制三指截屏操作是預設開還是關。

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"></integer>
           

2.編譯遇到不過的時候

******************************
You have tried to change the API from what has been previously approved.
To make these errors go away, you have two choices:
    ) You can add "@hide" javadoc comments to the methods, etc. listed in the
      errors above.

    ) You can update current.txt by executing the following command:
         make update-api
      To submit the revised current.txt to the main Android repository,
      you will need approval.
******************************
           

執行make update-api,并把相關的current.txt送出上