Foreword
Related to the source code have
frameworks\base\services\core\java\com\android\server\policy\PhoneWindowManager.java
vendor\mediatek\proprietary\packages\apps\SystemUI\src\com\android\systemui\screenshot\TakeScreenshotService.java
vendor\mediatek\proprietary\packages\apps\SystemUI\src\com\android\systemui\screenshot\GlobalScreenshot.java
Key processing are in PhoneWindowManager, the real screenshot function is implemented in GlobalScreenshot, the PhoneWindowManager and systemui to achieve the screenshot function via bind TakeScreenshotService
Process
General has not been special custom Android system, screen shots are by simultaneously holding down the volume down key and power key to screenshots, and later some of Huawei, oppo and other vendor systems we use you will find it sliding screenshots of the three fingers, the next we will customize this feature articles, and screenshots show style similar to iphone screenshot thumbnail display, click to jump magnified view, no operation left after 3s disappear automatically slide in the bottom left corner.
Well, now let's take a look at the process management system screenshot
system_process D/WindowManager: interceptKeyTi keyCode=25 down=true repeatCount=0 keyguardOn=false mHomePressed=false canceled=false metaState:0
system_process D/WindowManager: interceptKeyTq keycode=25 interactive=true keyguardActive=false policyFlags=22000000 down =false canceled = false isWakeKey=false mVolumeDownKeyTriggered =true result = 1 useHapticFeedback = false isInjected = false
system_process D/WindowManager: interceptKeyTi keyCode=25 down=false repeatCount=0 keyguardOn=false mHomePressed=false canceled=false metaState:0
system_process D/WindowManager: interceptKeyTq keycode=26 interactive=true keyguardActive=false policyFlags=22000000 down =false canceled = false isWakeKey=false mVolumeDownKeyTriggered =false result = 1 useHapticFeedback = false isInjected = false
The above is the log key and power key is pressed at the volume corresponding to the volume key keyCode = 25, corresponding to the power key keyCode = 26, to see PhoneWindowManager in interceptKeyBeforeQueueing () method, where a key operation process
/** {@inheritDoc} */
@Override
public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) {
if (!mSystemBooted) {
// If we have not yet booted, don't let key events do anything.
return 0;
}
.....
if (DEBUG_INPUT) {
Log.d(TAG, "interceptKeyTq keycode=" + keyCode
+ " interactive=" + interactive + " keyguardActive=" + keyguardActive
+ " policyFlags=" + Integer.toHexString(policyFlags));
}
.....
// Handle special keys.
switch (keyCode) {
.......
case KeyEvent.KEYCODE_VOLUME_DOWN:
case KeyEvent.KEYCODE_VOLUME_UP:
case KeyEvent.KEYCODE_VOLUME_MUTE: {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
if (down) {
if (interactive && !mScreenshotChordVolumeDownKeyTriggered
&& (event.getFlags() & KeyEvent.FLAG_FALLBACK) == 0) {
mScreenshotChordVolumeDownKeyTriggered = true;
mScreenshotChordVolumeDownKeyTime = event.getDownTime();
mScreenshotChordVolumeDownKeyConsumed = false;
cancelPendingPowerKeyAction();
interceptScreenshotChord();
interceptAccessibilityShortcutChord();
}
} else {
mScreenshotChordVolumeDownKeyTriggered = false;
cancelPendingScreenshotChordAction();
cancelPendingAccessibilityShortcutAction();
}
}
....
}See KEYCODE_VOLUME_DOWN, the recording volume of the current key press time mScreenshotChordVolumeDownKeyTime, cancelPendingPowerKeyAction () to remove the power button press message MSG_POWER_LONG_PRESS, look at core methods interceptScreenshotChord ()
// Time to volume and power must be pressed within this interval of each other.
private static final long SCREENSHOT_CHORD_DEBOUNCE_DELAY_MILLIS = 150;
private void interceptScreenshotChord() {
if (mScreenshotChordEnabled
&& mScreenshotChordVolumeDownKeyTriggered && mScreenshotChordPowerKeyTriggered
&& !mA11yShortcutChordVolumeUpKeyTriggered) {
final long now = SystemClock.uptimeMillis();
if (now <= mScreenshotChordVolumeDownKeyTime + SCREENSHOT_CHORD_DEBOUNCE_DELAY_MILLIS
&& now <= mScreenshotChordPowerKeyTime
+ SCREENSHOT_CHORD_DEBOUNCE_DELAY_MILLIS) {
mScreenshotChordVolumeDownKeyConsumed = true;
cancelPendingPowerKeyAction();
mScreenshotRunnable.setScreenshotType(TAKE_SCREENSHOT_FULLSCREEN);
mHandler.postDelayed(mScreenshotRunnable, getScreenshotChordLongPressDelay());
}
}
}Only when the power key is pressed mScreenshotChordPowerKeyTriggered was true, the time when the two buttons are pressed more than 150, to delay execution task mScreenshotRunnable screenshots
private long getScreenshotChordLongPressDelay() {
if (mKeyguardDelegate.isShowing()) {
// Double the time it takes to take a screenshot from the keyguard
return (long) (KEYGUARD_SCREENSHOT_CHORD_DELAY_MULTIPLIER *
ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());
}
return ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout();
}If the current input box is open, the closing delay time of the input frame timeout time plus key system configuration, if the current input block is not directly open key system configuration timeout processing time
Then look mScreenshotRunnable have done what action
private class ScreenshotRunnable implements Runnable {
private int mScreenshotType = TAKE_SCREENSHOT_FULLSCREEN;
public void setScreenshotType(int screenshotType) {
mScreenshotType = screenshotType;
}
@Override
public void run() {
takeScreenshot(mScreenshotType);
}
}
private final ScreenshotRunnable mScreenshotRunnable = new ScreenshotRunnable();TakeScreenshot can see the call in the thread (), the default type is not set up full-screen screenshots, screenshots types TAKE_SCREENSHOT_SELECTED_REGION selected regions and two types of full-screen TAKE_SCREENSHOT_FULLSCREEN
// Assume this is called from the Handler thread.
private void takeScreenshot(final int screenshotType) {
synchronized (mScreenshotLock) {
if (mScreenshotConnection != null) {
return;
}
final ComponentName serviceComponent = new ComponentName(SYSUI_PACKAGE,
SYSUI_SCREENSHOT_SERVICE);
final Intent serviceIntent = new Intent();
serviceIntent.setComponent(serviceComponent);
ServiceConnection conn = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
synchronized (mScreenshotLock) {
if (mScreenshotConnection != this) {
return;
}
Messenger messenger = new Messenger(service);
Message msg = Message.obtain(null, screenshotType);
final ServiceConnection myConn = this;
Handler h = new Handler(mHandler.getLooper()) {
@Override
public void handleMessage(Message msg) {
synchronized (mScreenshotLock) {
if (mScreenshotConnection == myConn) {
mContext.unbindService(mScreenshotConnection);
mScreenshotConnection = null;
mHandler.removeCallbacks(mScreenshotTimeout);
}
}
}
};
msg.replyTo = new Messenger(h);
msg.arg1 = msg.arg2 = 0;
if (mStatusBar != null && mStatusBar.isVisibleLw())
msg.arg1 = 1;
if (mNavigationBar != null && mNavigationBar.isVisibleLw())
msg.arg2 = 1;
try {
messenger.send(msg);
} catch (RemoteException e) {
}
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
synchronized (mScreenshotLock) {
if (mScreenshotConnection != null) {
mContext.unbindService(mScreenshotConnection);
mScreenshotConnection = null;
mHandler.removeCallbacks(mScreenshotTimeout);
notifyScreenshotError();
}
}
}
};
if (mContext.bindServiceAsUser(serviceIntent, conn,
Context.BIND_AUTO_CREATE | Context.BIND_FOREGROUND_SERVICE_WHILE_AWAKE,
UserHandle.CURRENT)) {
mScreenshotConnection = conn;
mHandler.postDelayed(mScreenshotTimeout, 10000);
}
}
}takeScreenshot bind SystemUI established by the TakeScreenshotService connection, the process of passing messages in two after a successful connection via Messenger traffic, somewhat similar AIDL, About Messenger may refer to inter-process communication of Android Messenger Messenger main transfer current mStatusBar and whether mNavigationBar visible, look TakeScreenshotService how reception processing
public class TakeScreenshotService extends Service {
private static final String TAG = "TakeScreenshotService";
private static GlobalScreenshot mScreenshot;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
final Messenger callback = msg.replyTo;
Runnable finisher = new Runnable() {
@Override
public void run() {
Message reply = Message.obtain(null, 1);
try {
callback.send(reply);
} catch (RemoteException e) {
}
}
};
// If the storage for this user is locked, we have no place to store
// the screenshot, so skip taking it instead of showing a misleading
// animation and error notification.
if (!getSystemService(UserManager.class).isUserUnlocked()) {
Log.w(TAG, "Skipping screenshot because storage is locked!");
post(finisher);
return;
}
if (mScreenshot == null) {
mScreenshot = new GlobalScreenshot(TakeScreenshotService.this);
}
switch (msg.what) {
case WindowManager.TAKE_SCREENSHOT_FULLSCREEN:
mScreenshot.takeScreenshot(finisher, msg.arg1 > 0, msg.arg2 > 0);
break;
case WindowManager.TAKE_SCREENSHOT_SELECTED_REGION:
mScreenshot.takeScreenshotPartial(finisher, msg.arg1 > 0, msg.arg2 > 0);
break;
}
}
};
@Override
public IBinder onBind(Intent intent) {
return new Messenger(mHandler).getBinder();
}
@Override
public boolean onUnbind(Intent intent) {
if (mScreenshot != null) mScreenshot.stopScreenshot();
return true;
}
}You can see the transfer of messages received by mHandler, get screenshots type and whether to include a status bar, navigation bar, by creating GlobalScreenshot objects (the real work comes), call takeScreenshot perform the screenshots, follow up
void takeScreenshot(Runnable finisher, boolean statusBarVisible, boolean navBarVisible) {
mDisplay.getRealMetrics(mDisplayMetrics);
takeScreenshot(finisher, statusBarVisible, navBarVisible, 0, 0, mDisplayMetrics.widthPixels,
mDisplayMetrics.heightPixels);
}
/**
* Takes a screenshot of the current display and shows an animation.
*/
void takeScreenshot(Runnable finisher, boolean statusBarVisible, boolean navBarVisible,
int x, int y, int width, int height) {
// We need to orient the screenshot correctly (and the Surface api seems to take screenshots
// only in the natural orientation of the device :!)
mDisplay.getRealMetrics(mDisplayMetrics);
float[] dims = {mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels};
float degrees = getDegreesForRotation(mDisplay.getRotation());
boolean requiresRotation = (degrees > 0);
if (requiresRotation) {
// Get the dimensions of the device in its native orientation
mDisplayMatrix.reset();
mDisplayMatrix.preRotate(-degrees);
mDisplayMatrix.mapPoints(dims);
dims[0] = Math.abs(dims[0]);
dims[1] = Math.abs(dims[1]);
}
// Take the screenshot
mScreenBitmap = SurfaceControl.screenshot((int) dims[0], (int) dims[1]);
if (mScreenBitmap == null) {
notifyScreenshotError(mContext, mNotificationManager,
R.string.screenshot_failed_to_capture_text);
finisher.run();
return;
}
if (requiresRotation) {
// Rotate the screenshot to the current orientation
Bitmap ss = Bitmap.createBitmap(mDisplayMetrics.widthPixels,
mDisplayMetrics.heightPixels, Bitmap.Config.ARGB_8888,
mScreenBitmap.hasAlpha(), mScreenBitmap.getColorSpace());
Canvas c = new Canvas(ss);
c.translate(ss.getWidth() / 2, ss.getHeight() / 2);
c.rotate(degrees);
c.translate(-dims[0] / 2, -dims[1] / 2);
c.drawBitmap(mScreenBitmap, 0, 0, null);
c.setBitmap(null);
// Recycle the previous bitmap
mScreenBitmap.recycle();
mScreenBitmap = ss;
}
if (width != mDisplayMetrics.widthPixels || height != mDisplayMetrics.heightPixels) {
// Crop the screenshot to selected region
Bitmap cropped = Bitmap.createBitmap(mScreenBitmap, x, y, width, height);
mScreenBitmap.recycle();
mScreenBitmap = cropped;
}
// Optimizations
mScreenBitmap.setHasAlpha(false);
mScreenBitmap.prepareToDraw();
// Start the post-screenshot animation
startAnimation(finisher, mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels,
statusBarVisible, navBarVisible);
}Gets the current screen width and height and orientation of the screen to determine whether to rotate the picture, then SurfaceControl.screenshot screenshots, well, then continue down to see
public static Bitmap screenshot(int width, int height) {
// TODO: should take the display as a parameter
IBinder displayToken = SurfaceControl.getBuiltInDisplay(
SurfaceControl.BUILT_IN_DISPLAY_ID_MAIN);
return nativeScreenshot(displayToken, new Rect(), width, height, 0, 0, true,
false, Surface.ROTATION_0);
}Here the call is nativeScreenshot method, which is a native method, the specific implementation in the JNI layer here is not to do too much introduced. Continue back to our takeScreenshot method, after calling a screen capture method screentshot, to determine whether the success of screenshots:
screenshot fails to call notifyScreenshotError notification is sent. Screen shot is successful, the call startAnimation play the animation, the animation have to analyze, we will change later this animation effect
/**
* Starts the animation after taking the screenshot
*/
private void startAnimation(final Runnable finisher, int w, int h, boolean statusBarVisible,
boolean navBarVisible) {
// If power save is on, show a toast so there is some visual indication that a screenshot
// has been taken.
PowerManager powerManager = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
if (powerManager.isPowerSaveMode()) {
Toast.makeText(mContext, R.string.screenshot_saved_title, Toast.LENGTH_SHORT).show();
}
// Add the view for the animation
mScreenshotView.setImageBitmap(mScreenBitmap);
mScreenshotLayout.requestFocus();
// Setup the animation with the screenshot just taken
if (mScreenshotAnimation != null) {
if (mScreenshotAnimation.isStarted()) {
mScreenshotAnimation.end();
}
mScreenshotAnimation.removeAllListeners();
}
mWindowManager.addView(mScreenshotLayout, mWindowLayoutParams);
ValueAnimator screenshotDropInAnim = createScreenshotDropInAnimation();
ValueAnimator screenshotFadeOutAnim = createScreenshotDropOutAnimation(w, h,
statusBarVisible, navBarVisible);
mScreenshotAnimation = new AnimatorSet();
mScreenshotAnimation.playSequentially(screenshotDropInAnim, screenshotFadeOutAnim);
mScreenshotAnimation.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
// Save the screenshot once we have a bit of time now
saveScreenshotInWorkerThread(finisher);
mWindowManager.removeView(mScreenshotLayout);
// Clear any references to the bitmap
mScreenBitmap = null;
mScreenshotView.setImageBitmap(null);
}
});
mScreenshotLayout.post(new Runnable() {
@Override
public void run() {
// Play the shutter sound to notify that we've taken a screenshot
mCameraSound.play(MediaActionSound.SHUTTER_CLICK);
mScreenshotView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
mScreenshotView.buildLayer();
mScreenshotAnimation.start();
}
});
}First determine whether the low battery mode, if sent Capture screenshots of toast, then add WindowManager by the middle of the screen with a screen shot of a thumbnail view, while creating two animated portfolio, by mCameraSound player clicks screen shots and perform animation , after the removal of the animation view just added, while calling saveScreenshotInWorkerThread save pictures to the media library, look at us directly SaveImageInBackgroundTask
class SaveImageInBackgroundTask extends AsyncTask<Void, Void, Void> {
.....
SaveImageInBackgroundTask(Context context, SaveImageInBackgroundData data,
NotificationManager nManager) {
......
mNotificationBuilder = new Notification.Builder(context, NotificationChannels.SCREENSHOTS)
.setTicker(r.getString(R.string.screenshot_saving_ticker)
+ (mTickerAddSpace ? " " : ""))
.setContentTitle(r.getString(R.string.screenshot_saving_title))
.setContentText(r.getString(R.string.screenshot_saving_text))
.setSmallIcon(R.drawable.stat_notify_image)
.setWhen(now)
.setShowWhen(true)
.setColor(r.getColor(com.android.internal.R.color.system_notification_accent_color))
.setStyle(mNotificationStyle)
.setPublicVersion(mPublicNotificationBuilder.build());
mNotificationBuilder.setFlag(Notification.FLAG_NO_CLEAR, true);
SystemUI.overrideNotificationAppName(context, mNotificationBuilder);
mNotificationManager.notify(SystemMessage.NOTE_GLOBAL_SCREENSHOT,
mNotificationBuilder.build());
}
@Override
protected Void doInBackground(Void... params) {
if (isCancelled()) {
return null;
}
// By default, AsyncTask sets the worker thread to have background thread priority, so bump
// it back up so that we save a little quicker.
Process.setThreadPriority(Process.THREAD_PRIORITY_FOREGROUND);
Context context = mParams.context;
Bitmap image = mParams.image;
Resources r = context.getResources();
try {
// Create screenshot directory if it doesn't exist
mScreenshotDir.mkdirs();
// media provider uses seconds for DATE_MODIFIED and DATE_ADDED, but milliseconds
// for DATE_TAKEN
long dateSeconds = mImageTime / 1000;
// Save
OutputStream out = new FileOutputStream(mImageFilePath);
image.compress(Bitmap.CompressFormat.PNG, 100, out);
out.flush();
out.close();
// Save the screenshot to the MediaStore
ContentValues values = new ContentValues();
ContentResolver resolver = context.getContentResolver();
values.put(MediaStore.Images.ImageColumns.DATA, mImageFilePath);
values.put(MediaStore.Images.ImageColumns.TITLE, mImageFileName);
values.put(MediaStore.Images.ImageColumns.DISPLAY_NAME, mImageFileName);
values.put(MediaStore.Images.ImageColumns.DATE_TAKEN, mImageTime);
values.put(MediaStore.Images.ImageColumns.DATE_ADDED, dateSeconds);
values.put(MediaStore.Images.ImageColumns.DATE_MODIFIED, dateSeconds);
values.put(MediaStore.Images.ImageColumns.MIME_TYPE, "image/png");
values.put(MediaStore.Images.ImageColumns.WIDTH, mImageWidth);
values.put(MediaStore.Images.ImageColumns.HEIGHT, mImageHeight);
values.put(MediaStore.Images.ImageColumns.SIZE, new File(mImageFilePath).length());
Uri uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
// Create a share intent
String subjectDate = DateFormat.getDateTimeInstance().format(new Date(mImageTime));
String subject = String.format(SCREENSHOT_SHARE_SUBJECT_TEMPLATE, subjectDate);
Intent sharingIntent = new Intent(Intent.ACTION_SEND);
sharingIntent.setType("image/png");
sharingIntent.putExtra(Intent.EXTRA_STREAM, uri);
sharingIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
// Create a share action for the notification. Note, we proxy the call to ShareReceiver
// because RemoteViews currently forces an activity options on the PendingIntent being
// launched, and since we don't want to trigger the share sheet in this case, we will
// start the chooser activitiy directly in ShareReceiver.
PendingIntent shareAction = PendingIntent.getBroadcast(context, 0,
new Intent(context, GlobalScreenshot.ShareReceiver.class)
.putExtra(SHARING_INTENT, sharingIntent),
PendingIntent.FLAG_CANCEL_CURRENT);
Notification.Action.Builder shareActionBuilder = new Notification.Action.Builder(
R.drawable.ic_screenshot_share,
r.getString(com.android.internal.R.string.share), shareAction);
mNotificationBuilder.addAction(shareActionBuilder.build());
// Create a delete action for the notification
PendingIntent deleteAction = PendingIntent.getBroadcast(context, 0,
new Intent(context, GlobalScreenshot.DeleteScreenshotReceiver.class)
.putExtra(GlobalScreenshot.SCREENSHOT_URI_ID, uri.toString()),
PendingIntent.FLAG_CANCEL_CURRENT | PendingIntent.FLAG_ONE_SHOT);
Notification.Action.Builder deleteActionBuilder = new Notification.Action.Builder(
R.drawable.ic_screenshot_delete,
r.getString(com.android.internal.R.string.delete), deleteAction);
mNotificationBuilder.addAction(deleteActionBuilder.build());
mParams.imageUri = uri;
mParams.image = null;
mParams.errorMsgResId = 0;
} catch (Exception e) {
// IOException/UnsupportedOperationException may be thrown if external storage is not
// mounted
Slog.e(TAG, "unable to save screenshot", e);
mParams.clearImage();
mParams.errorMsgResId = R.string.screenshot_failed_to_save_text;
}
// Recycle the bitmap data
if (image != null) {
image.recycle();
}
return null;
}
@Override
protected void onPostExecute(Void params) {
if (mParams.errorMsgResId != 0) {
// Show a message that we've failed to save the image to disk
GlobalScreenshot.notifyScreenshotError(mParams.context, mNotificationManager,
mParams.errorMsgResId);
} else {
// Show the final notification to indicate screenshot saved
Context context = mParams.context;
Resources r = context.getResources();
// Create the intent to show the screenshot in gallery
Intent launchIntent = new Intent(Intent.ACTION_VIEW);
launchIntent.setDataAndType(mParams.imageUri, "image/png");
launchIntent.setFlags(
Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_GRANT_READ_URI_PERMISSION);
final long now = System.currentTimeMillis();
// Update the text and the icon for the existing notification
mPublicNotificationBuilder
.setContentTitle(r.getString(R.string.screenshot_saved_title))
.setContentText(r.getString(R.string.screenshot_saved_text))
.setContentIntent(PendingIntent.getActivity(mParams.context, 0, launchIntent, 0))
.setWhen(now)
.setAutoCancel(true)
.setColor(context.getColor(
com.android.internal.R.color.system_notification_accent_color));
mNotificationBuilder
.setContentTitle(r.getString(R.string.screenshot_saved_title))
.setContentText(r.getString(R.string.screenshot_saved_text))
.setContentIntent(PendingIntent.getActivity(mParams.context, 0, launchIntent, 0))
.setWhen(now)
.setAutoCancel(true)
.setColor(context.getColor(
com.android.internal.R.color.system_notification_accent_color))
.setPublicVersion(mPublicNotificationBuilder.build())
.setFlag(Notification.FLAG_NO_CLEAR, false);
mNotificationManager.notify(SystemMessage.NOTE_GLOBAL_SCREENSHOT,
mNotificationBuilder.build());
}
mParams.finisher.run();
mParams.clearContext();
}
@Override
protected void onCancelled(Void params) {
// If we are cancelled while the task is running in the background, we may get null params.
// The finisher is expected to always be called back, so just use the baked-in params from
// the ctor in any case.
mParams.finisher.run();
mParams.clearImage();
mParams.clearContext();
// Cancel the posted notification
mNotificationManager.cancel(SystemMessage.NOTE_GLOBAL_SCREENSHOT);
}
}Under Simply put, SaveImageInBackgroundTask constructor lot of preparation work, cut the picture screen time naming format, screenshots notification object is created, the screenshots will doInBackground by ContentResolver storage to MediaStore, create two PendingIntent, for sharing, and deleting screenshots, send Notification to statuBar just created is displayed in onPostExecute, a screenshot of this process is over.
other
We go back to PhoneWindowManager in look, we know that to cut through the above screen simply by following two lines of code
mScreenshotRunnable.setScreenshotType(TAKE_SCREENSHOT_FULLSCREEN);
mHandler.post(mScreenshotRunnable);By searching the key code above, we find that there is another two also call code screenshots, look at together
@Override
public long interceptKeyBeforeDispatching(WindowState win, KeyEvent event, int policyFlags) {
final boolean keyguardOn = keyguardOn();
final int keyCode = event.getKeyCode();
.....
else if (keyCode == KeyEvent.KEYCODE_S && event.isMetaPressed()
&& event.isCtrlPressed()) {
if (down && repeatCount == 0) {
int type = event.isShiftPressed() ? TAKE_SCREENSHOT_SELECTED_REGION
: TAKE_SCREENSHOT_FULLSCREEN;
mScreenshotRunnable.setScreenshotType(type);
mHandler.post(mScreenshotRunnable);
return -1;
}
}
....
else if (keyCode == KeyEvent.KEYCODE_SYSRQ) {
if (down && repeatCount == 0) {
mScreenshotRunnable.setScreenshotType(TAKE_SCREENSHOT_FULLSCREEN);
mHandler.post(mScreenshotRunnable);
}
return -1;
}
......
}Also in previous methods to intercept the key message distribution, review KeyEvent source, probably the first case under the online search, it should be when you attach peripherals, and press S + Meta key + Ctrl key to screenshots, about Meta Description refer Meta key beginning and end when the second case is a screen shot button is pressed, the corresponding keyCode 120, 120 may be an analog adb shell input keyevent screenshots can be found
/** Key code constant: 'S' key. */
public static final int KEYCODE_S = 47;
/** Key code constant: System Request / Print Screen key. */
public static final int KEYCODE_SYSRQ = 120;
Common key corresponding value
Three-finger two lines of code to the screenshots, we can add in PhoneWindowManager, when the gesture listener to get three fingers, simply call the screenshots of this at the beginning of the article mentioned
to sum up
App not processed in the processing method PhoneWindowManager dispatchUnhandledKey of key events, including of course the power button and the volume down key combination key
Start TakeScreenshotService service through a series of calls, and perform operations through its screenshots.
Specific screenshot native code is implemented layer.
Screenshots operating time, if the screenshots failed to send notification directly inform screenshot failure.
After following screenshots, screenshots if successful, to perform a screen shot of animation, and the animation is finished, send a screenshot of the notification of the successful notification.
Reference article