Implement device-to-computer clipboard copy

On Ctrl+C:
 - the client sends a GET_CLIPBOARD command to the device;
 - the device retrieve its current clipboard text and sends it in a
   GET_CLIPBOARD device event;
 - the client sets this text as the system clipboard text, so that it
   can be pasted in another application.

Fixes <https://github.com/Genymobile/scrcpy/issues/145>

README.md

@@ -287,6 +287,7 @@ you are interested, see [issue 14].
  | turn screen on                         | _Right-click²_                |
  | expand notification panel              | `Ctrl`+`n`                    |
  | collapse notification panel            | `Ctrl`+`Shift`+`n`            |
+ | copy device clipboard to computer      | `Ctrl`+`c`                    |
  | paste computer clipboard to device     | `Ctrl`+`v`                    |
  | enable/disable FPS counter (on stdout) | `Ctrl`+`i`                    |
 

app/src/control_event.c

@@ -50,6 +50,7 @@ control_event_serialize(const struct control_event *event, unsigned char *buf) {
         case CONTROL_EVENT_TYPE_BACK_OR_SCREEN_ON:
         case CONTROL_EVENT_TYPE_EXPAND_NOTIFICATION_PANEL:
         case CONTROL_EVENT_TYPE_COLLAPSE_NOTIFICATION_PANEL:
+        case CONTROL_EVENT_TYPE_GET_CLIPBOARD:
             // no additional data
             return 1;
         default:

app/src/control_event.h

@@ -20,6 +20,7 @@ enum control_event_type {
     CONTROL_EVENT_TYPE_BACK_OR_SCREEN_ON,
     CONTROL_EVENT_TYPE_EXPAND_NOTIFICATION_PANEL,
     CONTROL_EVENT_TYPE_COLLAPSE_NOTIFICATION_PANEL,
+    CONTROL_EVENT_TYPE_GET_CLIPBOARD,
 };
 
 struct control_event {

app/src/input_manager.c

@@ -126,6 +126,16 @@ collapse_notification_panel(struct controller *controller) {
     }
 }
 
+static void
+request_device_clipboard(struct controller *controller) {
+    struct control_event control_event;
+    control_event.type = CONTROL_EVENT_TYPE_GET_CLIPBOARD;
+
+    if (!controller_push_event(controller, &control_event)) {
+        LOGW("Cannot get device clipboard");
+    }
+}
+
 static void
 switch_fps_counter_state(struct video_buffer *vb) {
     mutex_lock(vb->mutex);
@@ -250,6 +260,12 @@ input_manager_process_key(struct input_manager *input_manager,
                     action_volume_up(input_manager->controller, action);
                 }
                 return;
+            case SDLK_c:
+                if (control && ctrl && !meta && !shift && !repeat
+                        && event->type == SDL_KEYDOWN) {
+                    request_device_clipboard(input_manager->controller);
+                }
+                return;
             case SDLK_v:
                 if (control && ctrl && !meta && !shift && !repeat
                         && event->type == SDL_KEYDOWN) {

app/src/main.c

@@ -137,6 +137,9 @@ static void usage(const char *arg0) {
         "    Ctrl+Shift+n\n"
         "       collapse notification panel\n"
         "\n"
+        "    Ctrl+c\n"
+        "        copy device clipboard to computer\n"
+        "\n"
         "    Ctrl+v\n"
         "        paste computer clipboard to device\n"
         "\n"

app/tests/test_control_event_serialize.c

@@ -178,6 +178,21 @@ static void test_serialize_collapse_notification_panel_event(void) {
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
 
+static void test_serialize_get_clipboard_event(void) {
+    struct control_event event = {
+        .type = CONTROL_EVENT_TYPE_GET_CLIPBOARD,
+    };
+
+    unsigned char buf[CONTROL_EVENT_SERIALIZED_MAX_SIZE];
+    int size = control_event_serialize(&event, buf);
+    assert(size == 1);
+
+    const unsigned char expected[] = {
+        0x07, // CONTROL_EVENT_TYPE_GET_CLIPBOARD
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
 int main(void) {
     test_serialize_keycode_event();
     test_serialize_text_event();
@@ -187,5 +202,6 @@ int main(void) {
     test_serialize_back_or_screen_on_event();
     test_serialize_expand_notification_panel_event();
     test_serialize_collapse_notification_panel_event();
+    test_serialize_get_clipboard_event();
     return 0;
 }

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

@@ -12,6 +12,7 @@ public final class ControlEvent {
     public static final int TYPE_BACK_OR_SCREEN_ON = 4;
     public static final int TYPE_EXPAND_NOTIFICATION_PANEL = 5;
     public static final int TYPE_COLLAPSE_NOTIFICATION_PANEL = 6;
+    public static final int TYPE_GET_CLIPBOARD = 7;
 
     private int type;
     private String text;

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

@@ -66,6 +66,7 @@ public class ControlEventReader {
             case ControlEvent.TYPE_BACK_OR_SCREEN_ON:
             case ControlEvent.TYPE_EXPAND_NOTIFICATION_PANEL:
             case ControlEvent.TYPE_COLLAPSE_NOTIFICATION_PANEL:
+            case ControlEvent.TYPE_GET_CLIPBOARD:
                 controlEvent = ControlEvent.createSimpleControlEvent(type);
                 break;
             default:

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

@@ -139,6 +139,14 @@ public final class Device {
         serviceManager.getStatusBarManager().collapsePanels();
     }
 
+    public String getClipboardText() {
+        CharSequence s = serviceManager.getClipboardManager().getText();
+        if (s == null) {
+            return null;
+        }
+        return s.toString();
+    }
+
     static Rect flipRect(Rect crop) {
         return new Rect(crop.top, crop.left, crop.bottom, crop.right);
     }

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

@@ -90,6 +90,10 @@ public class EventController {
             case ControlEvent.TYPE_COLLAPSE_NOTIFICATION_PANEL:
                 device.collapsePanels();
                 break;
+            case ControlEvent.TYPE_GET_CLIPBOARD:
+                String clipboardText = device.getClipboardText();
+                sender.pushClipboardText(clipboardText);
+                break;
             default:
                 // do nothing
         }

server/src/main/java/com/genymobile/scrcpy/wrappers/ClipboardManager.java

@@ -0,0 +1,33 @@
+package com.genymobile.scrcpy.wrappers;
+
+import android.content.ClipData;
+import android.os.IInterface;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public class ClipboardManager {
+    private final IInterface manager;
+    private final Method getPrimaryClipMethod;
+
+    public ClipboardManager(IInterface manager) {
+        this.manager = manager;
+        try {
+            getPrimaryClipMethod = manager.getClass().getMethod("getPrimaryClip", String.class);
+        } catch (NoSuchMethodException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    public CharSequence getText() {
+        try {
+            ClipData clipData = (ClipData) getPrimaryClipMethod.invoke(manager, "com.android.shell");
+            if (clipData == null || clipData.getItemCount() == 0) {
+                return null;
+            }
+            return clipData.getItemAt(0).getText();
+        } catch (InvocationTargetException | IllegalAccessException e) {
+            throw new AssertionError(e);
+        }
+    }
+}

server/src/main/java/com/genymobile/scrcpy/wrappers/ServiceManager.java

@@ -15,6 +15,7 @@ public final class ServiceManager {
     private InputManager inputManager;
     private PowerManager powerManager;
     private StatusBarManager statusBarManager;
+    private ClipboardManager clipboardManager;
 
     public ServiceManager() {
         try {
@@ -68,4 +69,11 @@ public final class ServiceManager {
         }
         return statusBarManager;
     }
+
+    public ClipboardManager getClipboardManager() {
+        if (clipboardManager == null) {
+            clipboardManager = new ClipboardManager(getService("clipboard", "android.content.IClipboard"));
+        }
+        return clipboardManager;
+    }
 }

server/src/test/java/com/genymobile/scrcpy/ControlEventReaderTest.java

@@ -174,6 +174,22 @@ public class ControlEventReaderTest {
         Assert.assertEquals(ControlEvent.TYPE_COLLAPSE_NOTIFICATION_PANEL, event.getType());
     }
 
+    @Test
+    public void testParseGetClipboardEvent() throws IOException {
+        ControlEventReader reader = new ControlEventReader();
+
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutputStream dos = new DataOutputStream(bos);
+        dos.writeByte(ControlEvent.TYPE_GET_CLIPBOARD);
+
+        byte[] packet = bos.toByteArray();
+
+        reader.readFrom(new ByteArrayInputStream(packet));
+        ControlEvent event = reader.next();
+
+        Assert.assertEquals(ControlEvent.TYPE_GET_CLIPBOARD, event.getType());
+    }
+
     @Test
     public void testMultiEvents() throws IOException {
         ControlEventReader reader = new ControlEventReader();