Add option to turn device screen off

In addition to the shortcut (Ctrl+o) to turn the device screen off, add
a command-line argument to turn it off on start.

app/src/main.c

@@ -28,6 +28,7 @@ struct args {
     uint16_t max_size;
     uint32_t bit_rate;
     bool always_on_top;
+    bool turn_screen_off;
 };
 
 static void usage(const char *arg0) {
@@ -82,6 +83,9 @@ static void usage(const char *arg0) {
         "        The device serial number. Mandatory only if several devices\n"
         "        are connected to adb.\n"
         "\n"
+        "    -S, --turn-screen-off\n"
+        "        Turn the device screen off immediately.\n"
+        "\n"
         "    -t, --show-touches\n"
         "        Enable \"show touches\" on start, disable on quit.\n"
         "        It only shows physical touches (not clicks from scrcpy).\n"
@@ -299,11 +303,12 @@ parse_args(struct args *args, int argc, char *argv[]) {
         {"record-format",   required_argument, NULL, 'f'},
         {"serial",          required_argument, NULL, 's'},
         {"show-touches",    no_argument,       NULL, 't'},
+        {"turn-screen-off", no_argument,       NULL, 'S'},
         {"version",         no_argument,       NULL, 'v'},
         {NULL,              0,                 NULL, 0  },
     };
     int c;
-    while ((c = getopt_long(argc, argv, "b:c:fF:hm:nNp:r:s:tTv", long_options,
+    while ((c = getopt_long(argc, argv, "b:c:fF:hm:nNp:r:s:StTv", long_options,
                             NULL)) != -1) {
         switch (c) {
             case 'b':
@@ -347,6 +352,9 @@ parse_args(struct args *args, int argc, char *argv[]) {
             case 's':
                 args->serial = optarg;
                 break;
+            case 'S':
+                args->turn_screen_off = true;
+                break;
             case 't':
                 args->show_touches = true;
                 break;
@@ -417,6 +425,7 @@ main(int argc, char *argv[]) {
         .always_on_top = false,
         .no_control = false,
         .no_display = false,
+        .turn_screen_off = false,
     };
     if (!parse_args(&args, argc, argv)) {
         return 1;
@@ -457,6 +466,7 @@ main(int argc, char *argv[]) {
         .always_on_top = args.always_on_top,
         .control = !args.no_control,
         .display = !args.no_display,
+        .turn_screen_off = args.turn_screen_off,
     };
     int res = scrcpy(&options) ? 0 : 1;
 

app/src/scrcpy.c

@@ -375,6 +375,16 @@ scrcpy(const struct scrcpy_options *options) {
             goto end;
         }
 
+        if (options->turn_screen_off) {
+            struct control_msg msg;
+            msg.type = CONTROL_MSG_TYPE_SET_SCREEN_POWER_MODE;
+            msg.set_screen_power_mode.mode = SCREEN_POWER_MODE_OFF;
+
+            if (!controller_push_msg(&controller, &msg)) {
+                LOGW("Cannot request 'set screen power mode'");
+            }
+        }
+
         if (options->fullscreen) {
             screen_switch_fullscreen(&screen);
         }

app/src/scrcpy.h

@@ -18,6 +18,7 @@ struct scrcpy_options {
     bool always_on_top;
     bool control;
     bool display;
+    bool turn_screen_off;
 };
 
 bool

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

@@ -53,9 +53,21 @@ public class Controller {
         coords.setAxisValue(MotionEvent.AXIS_VSCROLL, vScroll);
     }
 
+    @SuppressWarnings("checkstyle:MagicNumber")
     public void control() throws IOException {
         // on start, power on the device
-        powerOn();
+        if (!device.isScreenOn()) {
+            injectKeycode(KeyEvent.KEYCODE_POWER);
+
+            // dirty hack
+            // After POWER is injected, the device is powered on asynchronously.
+            // To turn the device screen off while mirroring, the client will send a message that
+            // would be handled before the device is actually powered on, so its effect would
+            // be "canceled" once the device is turned back on.
+            // Adding this delay prevents to handle the message before the device is actually
+            // powered on.
+            SystemClock.sleep(500);
+        }
 
         while (true) {
             handleEvent();
@@ -182,10 +194,6 @@ public class Controller {
         return device.injectInputEvent(event, InputManager.INJECT_INPUT_EVENT_MODE_ASYNC);
     }
 
-    private boolean powerOn() {
-        return device.isScreenOn() || injectKeycode(KeyEvent.KEYCODE_POWER);
-    }
-
     private boolean pressBackOrTurnScreenOn() {
         int keycode = device.isScreenOn() ? KeyEvent.KEYCODE_BACK : KeyEvent.KEYCODE_POWER;
         return injectKeycode(keycode);