Keep the screen off on powering on

PR #1577 <https://github.com/Genymobile/scrcpy/pull/1577>
Fixes #1573 <https://github.com/Genymobile/scrcpy/issues/1573>

Signed-off-by: Romain Vimont <rom@rom1v.com>

README.md

@@ -440,8 +440,12 @@ scrcpy -S
 
 Or by pressing <kbd>MOD</kbd>+<kbd>o</kbd> at any time.
 
-To turn it back on, press <kbd>MOD</kbd>+<kbd>Shift</kbd>+<kbd>o</kbd> (or
-`POWER`, <kbd>MOD</kbd>+<kbd>p</kbd>).
+To turn it back on, press <kbd>MOD</kbd>+<kbd>Shift</kbd>+<kbd>o</kbd>.
+
+On Android, the `POWER` button always turns the screen on. For convenience, if
+`POWER` is sent via scrcpy (via right-click or <kbd>Ctrl</kbd>+<kbd>p</kbd>), it
+will force to turn the screen off after a small delay (on a best effort basis).
+The physical `POWER` button will still cause the screen to be turned on.
 
 It can be useful to also prevent the device to sleep:
 

server/src/main/java/com/genymobile/scrcpy/Controller.java

@@ -8,11 +8,16 @@ import android.view.KeyEvent;
 import android.view.MotionEvent;
 
 import java.io.IOException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 
 public class Controller {
 
     private static final int DEVICE_ID_VIRTUAL = -1;
 
+    private static final ScheduledExecutorService EXECUTOR = Executors.newSingleThreadScheduledExecutor();
+
     private final Device device;
     private final DesktopConnection connection;
     private final DeviceMessageSender sender;
@@ -24,6 +29,8 @@ public class Controller {
     private final MotionEvent.PointerProperties[] pointerProperties = new MotionEvent.PointerProperties[PointersState.MAX_POINTERS];
     private final MotionEvent.PointerCoords[] pointerCoords = new MotionEvent.PointerCoords[PointersState.MAX_POINTERS];
 
+    private boolean keepPowerModeOff;
+
     public Controller(Device device, DesktopConnection connection) {
         this.device = device;
         this.connection = connection;
@@ -117,6 +124,7 @@ public class Controller {
                     int mode = msg.getAction();
                     boolean setPowerModeOk = Device.setScreenPowerMode(mode);
                     if (setPowerModeOk) {
+                        keepPowerModeOff = mode == Device.POWER_MODE_OFF;
                         Ln.i("Device screen turned " + (mode == Device.POWER_MODE_OFF ? "off" : "on"));
                     }
                 }
@@ -130,6 +138,9 @@ public class Controller {
     }
 
     private boolean injectKeycode(int action, int keycode, int repeat, int metaState) {
+        if (keepPowerModeOff && action == KeyEvent.ACTION_UP && (keycode == KeyEvent.KEYCODE_POWER || keycode == KeyEvent.KEYCODE_WAKEUP)) {
+            schedulePowerModeOff();
+        }
         return device.injectKeyEvent(action, keycode, repeat, metaState);
     }
 
@@ -223,8 +234,24 @@ public class Controller {
         return device.injectEvent(event);
     }
 
+    /**
+     * Schedule a call to set power mode to off after a small delay.
+     */
+    private static void schedulePowerModeOff() {
+        EXECUTOR.schedule(new Runnable() {
+            @Override
+            public void run() {
+                Ln.i("Forcing screen off");
+                Device.setScreenPowerMode(Device.POWER_MODE_OFF);
+            }
+        }, 200, TimeUnit.MILLISECONDS);
+    }
+
     private boolean pressBackOrTurnScreenOn() {
         int keycode = device.isScreenOn() ? KeyEvent.KEYCODE_BACK : KeyEvent.KEYCODE_WAKEUP;
+        if (keepPowerModeOff && keycode == KeyEvent.KEYCODE_WAKEUP) {
+            schedulePowerModeOff();
+        }
         return device.injectKeycode(keycode);
     }