Add shortcuts to switch the camera torch

MOD+l turns on the camera torch, MOD+Shift+l turns it off.

TODO ref 6243

Co-authored-by: Tommie <teh420@gmail.com>

app/scrcpy.1

@@ -819,6 +819,14 @@ Install APK from computer
 .B Drag & drop non-APK file
 Push file to device (see \fB\-\-push\-target\fR)
 
+.TP
+.B MOD+l
+Turn on the camera torch (camera mode only)
+
+.TP
+.B MOD+Shift+l
+Turn off the camera torch (camera mode only)
+
 
 .SH Environment variables
 

app/src/cli.c

@@ -1213,6 +1213,14 @@ static const struct sc_shortcut shortcuts[] = {
         .shortcuts = { "Drag & drop non-APK file" },
         .text = "Push file to device (see --push-target)",
     },
+    {
+        .shortcuts = { "MOD+l" },
+        .text = "Turn on the camera torch (camera mode only)",
+    },
+    {
+        .shortcuts = { "MOD+Shift+l" },
+        .text = "Turn off the camera torch (camera mode only)",
+    },
 };
 
 static const struct sc_envvar envvars[] = {

app/src/control_msg.c

@@ -182,6 +182,9 @@ sc_control_msg_serialize(const struct sc_control_msg *msg, uint8_t *buf) {
             size_t len = write_string_tiny(&buf[1], msg->start_app.name, 255);
             return 1 + len;
         }
+        case SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH:
+            buf[1] = msg->camera_set_torch.on ? 1 : 0;
+            return 2;
         case SC_CONTROL_MSG_TYPE_EXPAND_NOTIFICATION_PANEL:
         case SC_CONTROL_MSG_TYPE_EXPAND_SETTINGS_PANEL:
         case SC_CONTROL_MSG_TYPE_COLLAPSE_PANELS:
@@ -318,6 +321,10 @@ sc_control_msg_log(const struct sc_control_msg *msg) {
         case SC_CONTROL_MSG_TYPE_RESET_VIDEO:
             LOG_CMSG("reset video");
             break;
+        case SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH:
+            LOG_CMSG("camera set torch %s",
+                     msg->camera_set_torch.on ? "on" : "off");
+            break;
         default:
             LOG_CMSG("unknown type: %u", (unsigned) msg->type);
             break;

app/src/control_msg.h

@@ -43,6 +43,7 @@ enum sc_control_msg_type {
     SC_CONTROL_MSG_TYPE_OPEN_HARD_KEYBOARD_SETTINGS,
     SC_CONTROL_MSG_TYPE_START_APP,
     SC_CONTROL_MSG_TYPE_RESET_VIDEO,
+    SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH,
 };
 
 enum sc_copy_key {
@@ -111,6 +112,9 @@ struct sc_control_msg {
         struct {
             char *name;
         } start_app;
+        struct {
+            bool on;
+        } camera_set_torch;
     };
 };
 

app/src/input_manager.c

@@ -302,6 +302,19 @@ reset_video(struct sc_input_manager *im) {
     }
 }
 
+static void
+camera_set_torch(struct sc_input_manager *im, bool on) {
+    assert(im->controller && im->camera);
+
+    struct sc_control_msg msg;
+    msg.type = SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH;
+    msg.camera_set_torch.on = on;
+
+    if (!sc_controller_push_msg(im->controller, &msg)) {
+        LOGW("Could not request setting camera torch");
+    }
+}
+
 static void
 apply_orientation_transform(struct sc_input_manager *im,
                             enum sc_orientation transform) {
@@ -581,6 +594,16 @@ sc_input_manager_process_key(struct sc_input_manager *im,
             }
         }
 
+        if (control && im->camera) {
+            switch (sdl_keycode) {
+                case SDLK_L:
+                    if (!repeat && down) {
+                        camera_set_torch(im, !shift);
+                    }
+                    return;
+            }
+        }
+
         return;
     }
 

app/tests/test_control_msg_serialize.c

@@ -446,6 +446,25 @@ static void test_serialize_reset_video(void) {
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
 
+static void test_serialize_camera_set_torch(void) {
+    struct sc_control_msg msg = {
+        .type = SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH,
+        .camera_set_torch = {
+            .on = true,
+        },
+    };
+
+    uint8_t buf[SC_CONTROL_MSG_MAX_SIZE];
+    size_t size = sc_control_msg_serialize(&msg, buf);
+    assert(size == 2);
+
+    const uint8_t expected[] = {
+        SC_CONTROL_MSG_TYPE_CAMERA_SET_TORCH,
+        0x01, // true
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
 int main(int argc, char *argv[]) {
     (void) argc;
     (void) argv;
@@ -470,5 +489,6 @@ int main(int argc, char *argv[]) {
     test_serialize_open_hard_keyboard();
     test_serialize_start_app();
     test_serialize_reset_video();
+    test_serialize_camera_set_torch();
     return 0;
 }

server/src/main/java/com/genymobile/scrcpy/control/ControlMessage.java

@@ -25,6 +25,7 @@ public final class ControlMessage {
     public static final int TYPE_OPEN_HARD_KEYBOARD_SETTINGS = 15;
     public static final int TYPE_START_APP = 16;
     public static final int TYPE_RESET_VIDEO = 17;
+    public static final int TYPE_CAMERA_SET_TORCH = 18;
 
     public static final long SEQUENCE_INVALID = 0;
 
@@ -166,6 +167,13 @@ public final class ControlMessage {
         return msg;
     }
 
+    public static ControlMessage createCameraSetTorch(boolean on) {
+        ControlMessage msg = new ControlMessage();
+        msg.type = TYPE_CAMERA_SET_TORCH;
+        msg.on = on;
+        return msg;
+    }
+
     public int getType() {
         return type;
     }

server/src/main/java/com/genymobile/scrcpy/control/ControlMessageReader.java

@@ -56,6 +56,8 @@ public class ControlMessageReader {
                 return parseUhidDestroy();
             case ControlMessage.TYPE_START_APP:
                 return parseStartApp();
+            case ControlMessage.TYPE_CAMERA_SET_TORCH:
+                return parseCameraSetTorch();
             default:
                 throw new ControlProtocolException("Unknown event type: " + type);
         }
@@ -166,6 +168,11 @@ public class ControlMessageReader {
         return ControlMessage.createStartApp(name);
     }
 
+    private ControlMessage parseCameraSetTorch() throws IOException {
+        boolean on = dis.readBoolean();
+        return ControlMessage.createCameraSetTorch(on);
+    }
+
     private Position parsePosition() throws IOException {
         int x = dis.readInt();
         int y = dis.readInt();

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

@@ -12,6 +12,7 @@ import com.genymobile.scrcpy.device.Position;
 import com.genymobile.scrcpy.device.Size;
 import com.genymobile.scrcpy.util.Ln;
 import com.genymobile.scrcpy.util.LogUtils;
+import com.genymobile.scrcpy.video.CameraCapture;
 import com.genymobile.scrcpy.video.SurfaceCapture;
 import com.genymobile.scrcpy.video.VideoSource;
 import com.genymobile.scrcpy.video.VirtualDisplayListener;
@@ -99,7 +100,7 @@ public class Controller implements AsyncProcessor, VirtualDisplayListener {
 
     private boolean keepDisplayPowerOff;
 
-    // Used for resetting video encoding on RESET_VIDEO message
+    // Used for resetting video encoding on RESET_VIDEO message or for sending camera controls
     private SurfaceCapture surfaceCapture;
 
     public Controller(ControlChannel controlChannel, CleanUp cleanUp, Options options) {
@@ -368,6 +369,16 @@ public class Controller implements AsyncProcessor, VirtualDisplayListener {
                 default:
                     // fall through
             }
+        } else {
+            assert surfaceCapture instanceof CameraCapture;
+            CameraCapture cameraCapture = (CameraCapture) surfaceCapture;
+            switch (type) {
+                case ControlMessage.TYPE_CAMERA_SET_TORCH:
+                    cameraCapture.setTorchEnabled(msg.getOn());
+                    return true;
+                default:
+                    // fall through
+            }
         }
 
         throw new AssertionError("Unexpected message type: " + type);

server/src/main/java/com/genymobile/scrcpy/video/CameraCapture.java

@@ -80,8 +80,10 @@ public class CameraCapture extends SurfaceCapture {
 
     private final AtomicBoolean disconnected = new AtomicBoolean();
 
-    // Must be accessed only from the camera thread
+    // The following fields must be accessed only from the camera thread
     private boolean started;
+    private CaptureRequest.Builder requestBuilder;
+    private CameraCaptureSession currentSession;
 
     public CameraCapture(Options options) {
         this.explicitCameraId = options.getCameraId();
@@ -287,7 +289,7 @@ public class CameraCapture extends SurfaceCapture {
                 }
 
                 try {
-                    CaptureRequest.Builder requestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_RECORD);
+                    requestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_RECORD);
                     requestBuilder.addTarget(captureSurface);
 
                     if (fps > 0) {
@@ -300,6 +302,7 @@ public class CameraCapture extends SurfaceCapture {
 
                     CaptureRequest request = requestBuilder.build();
                     setRepeatingRequest(session, request);
+                    currentSession = session;
                 } catch (CameraAccessException e) {
                     Ln.e("Camera error", e);
                     invalidate();
@@ -325,6 +328,8 @@ public class CameraCapture extends SurfaceCapture {
     public void stop() {
         cameraHandler.post(() -> {
             assertCameraThread();
+            currentSession = null;
+            requestBuilder = null;
             started = false;
         });
 
@@ -435,6 +440,22 @@ public class CameraCapture extends SurfaceCapture {
         return disconnected.get();
     }
 
+    public void setTorchEnabled(boolean enabled) {
+        cameraHandler.post(() -> {
+            assertCameraThread();
+            if (currentSession != null && requestBuilder != null) {
+                try {
+                    Ln.i("Turn camera torch " + (enabled ? "on" : "off"));
+                    requestBuilder.set(CaptureRequest.FLASH_MODE, enabled ? CaptureRequest.FLASH_MODE_TORCH : CaptureRequest.FLASH_MODE_OFF);
+                    CaptureRequest request = requestBuilder.build();
+                    setRepeatingRequest(currentSession, request);
+                } catch (CameraAccessException e) {
+                    Ln.e("Camera error", e);
+                }
+            }
+        });
+    }
+
     private void assertCameraThread() {
         assert Thread.currentThread() == cameraThread;
     }

server/src/test/java/com/genymobile/scrcpy/control/ControlMessageReaderTest.java

@@ -422,6 +422,24 @@ public class ControlMessageReaderTest {
         Assert.assertEquals(-1, bis.read()); // EOS
     }
 
+    @Test
+    public void testParseCameraSetTorch() throws IOException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutputStream dos = new DataOutputStream(bos);
+        dos.writeByte(ControlMessage.TYPE_CAMERA_SET_TORCH);
+        dos.writeBoolean(true);
+        byte[] packet = bos.toByteArray();
+
+        ByteArrayInputStream bis = new ByteArrayInputStream(packet);
+        ControlMessageReader reader = new ControlMessageReader(bis);
+
+        ControlMessage event = reader.read();
+        Assert.assertEquals(ControlMessage.TYPE_CAMERA_SET_TORCH, event.getType());
+        Assert.assertTrue(event.getOn());
+
+        Assert.assertEquals(-1, bis.read()); // EOS
+    }
+
     @Test
     public void testMultiEvents() throws IOException {
         ByteArrayOutputStream bos = new ByteArrayOutputStream();