Implement clipboard paste

Paste computer clipboard to the device on Ctrl+v.

The other direction (pasting the device clipboard to the computer) is
not implemented. It would require a communication channel from the
device to the computer, other than the socket used by the video stream.

README.md

@@ -182,6 +182,7 @@ If several devices are listed in `adb devices`, you must specify the _serial_:
  | click on `VOLUME_DOWN`                 | `Ctrl`+`-`    |
  | click on `POWER`                       | `Ctrl`+`p`    |
  | turn screen on                         | _Right-click_ |
+ | paste computer clipboard to device     | `Ctrl`+`v`    |
  | enable/disable FPS counter (on stdout) | `Ctrl`+`i`    |
 
 

app/src/controlevent.c

@@ -36,10 +36,11 @@ int control_event_serialize(const struct control_event *event, unsigned char *bu
             // write length (1 byte) + date (non nul-terminated)
             size_t len = strlen(event->text_event.text);
             if (len > TEXT_MAX_LENGTH) {
+                // injecting a text takes time, so limit the text length
                 len = TEXT_MAX_LENGTH;
             }
             buf[1] = (Uint8) len;
-            memcpy(&buf[2], &event->text_event.text, len);
+            memcpy(&buf[2], event->text_event.text, len);
             return 2 + len;
         }
         case CONTROL_EVENT_TYPE_MOUSE:
@@ -61,6 +62,12 @@ int control_event_serialize(const struct control_event *event, unsigned char *bu
     }
 }
 
+void control_event_destroy(struct control_event *event) {
+    if (event->type == CONTROL_EVENT_TYPE_TEXT) {
+        SDL_free(event->text_event.text);
+    }
+}
+
 SDL_bool control_event_queue_is_empty(const struct control_event_queue *queue) {
     return queue->head == queue->tail;
 }
@@ -77,7 +84,11 @@ SDL_bool control_event_queue_init(struct control_event_queue *queue) {
 }
 
 void control_event_queue_destroy(struct control_event_queue *queue) {
-    // nothing to do in the current implementation
+    int i = queue->tail;
+    while (i != queue->head) {
+        control_event_destroy(&queue->data[i]);
+        i = (i + 1) % CONTROL_EVENT_QUEUE_SIZE;
+    }
 }
 
 SDL_bool control_event_queue_push(struct control_event_queue *queue, const struct control_event *event) {

app/src/controlevent.h

@@ -10,7 +10,7 @@
 
 #define CONTROL_EVENT_QUEUE_SIZE 64
 #define SERIALIZED_EVENT_MAX_SIZE 33
-#define TEXT_MAX_LENGTH 31
+#define TEXT_MAX_LENGTH 256
 
 enum control_event_type {
     CONTROL_EVENT_TYPE_KEYCODE,
@@ -31,7 +31,7 @@ struct control_event {
             enum android_metastate metastate;
         } keycode_event;
         struct {
-            char text[TEXT_MAX_LENGTH + 1]; // nul-terminated string
+            char *text; // owned, to be freed by SDL_free()
         } text_event;
         struct {
             enum android_motionevent_action action;
@@ -68,4 +68,6 @@ SDL_bool control_event_queue_is_full(const struct control_event_queue *queue);
 SDL_bool control_event_queue_push(struct control_event_queue *queue, const struct control_event *event);
 SDL_bool control_event_queue_take(struct control_event_queue *queue, struct control_event *event);
 
+void control_event_destroy(struct control_event *event);
+
 #endif

app/src/controller.c

@@ -65,7 +65,9 @@ static int run_controller(void *data) {
         }
         struct control_event event;
         while (control_event_queue_take(&controller->queue, &event)) {
-            if (!process_event(controller, &event)) {
+            SDL_bool ok = process_event(controller, &event);
+            control_event_destroy(&event);
+            if (!ok) {
                 LOGD("Cannot write event to socket");
                 goto end;
             }

app/src/inputmanager.c

@@ -100,6 +100,27 @@ static void switch_fps_counter_state(struct frames *frames) {
     mutex_unlock(frames->mutex);
 }
 
+static void clipboard_paste(struct controller *controller) {
+    char *text = SDL_GetClipboardText();
+    if (!text) {
+        LOGW("Cannot get clipboard text: %s", SDL_GetError());
+        return;
+    }
+    if (!*text) {
+        // empty text
+        SDL_free(text);
+        return;
+    }
+
+    struct control_event control_event;
+    control_event.type = CONTROL_EVENT_TYPE_TEXT;
+    control_event.text_event.text = text;
+    if (!controller_push_event(controller, &control_event)) {
+        SDL_free(text);
+        LOGW("Cannot send clipboard paste event");
+    }
+}
+
 void input_manager_process_text_input(struct input_manager *input_manager,
                                       const SDL_TextInputEvent *event) {
     if (is_ctrl_down()) {
@@ -116,8 +137,11 @@ void input_manager_process_text_input(struct input_manager *input_manager,
 
     struct control_event control_event;
     control_event.type = CONTROL_EVENT_TYPE_TEXT;
-    strncpy(control_event.text_event.text, event->text, TEXT_MAX_LENGTH);
-    control_event.text_event.text[TEXT_MAX_LENGTH] = '\0';
+    control_event.text_event.text = SDL_strdup(event->text);
+    if (!control_event.text_event.text) {
+        LOGW("Cannot strdup input text");
+        return;
+    }
     if (!controller_push_event(input_manager->controller, &control_event)) {
         LOGW("Cannot send text event");
     }
@@ -157,6 +181,9 @@ void input_manager_process_key(struct input_manager *input_manager,
             case SDLK_p:
                 action_power(input_manager->controller);
                 return;
+            case SDLK_v:
+                clipboard_paste(input_manager->controller);
+                return;
             case SDLK_f:
                 screen_switch_fullscreen(input_manager->screen);
                 return;

app/src/main.c

@@ -82,6 +82,9 @@ static void usage(const char *arg0) {
         "    Right-click\n"
         "        turn screen on\n"
         "\n"
+        "    Ctrl+v\n"
+        "        paste computer clipboard to device\n"
+        "\n"
         "    Ctrl+i\n"
         "        enable/disable FPS counter (print frames/second in logs)\n"
         "\n",

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

@@ -13,12 +13,12 @@ public class ControlEventReader {
     private static final int SCROLL_PAYLOAD_LENGTH = 16;
     private static final int COMMAND_PAYLOAD_LENGTH = 1;
 
-    private static final int MAX_TEXT_LENGTH = 32;
+    private static final int TEXT_MAX_LENGTH = 256;
     private static final int RAW_BUFFER_SIZE = 128;
 
     private final byte[] rawBuffer = new byte[RAW_BUFFER_SIZE];
     private final ByteBuffer buffer = ByteBuffer.wrap(rawBuffer);
-    private final byte[] textBuffer = new byte[MAX_TEXT_LENGTH];
+    private final byte[] textBuffer = new byte[TEXT_MAX_LENGTH];
 
     public ControlEventReader() {
         // invariant: the buffer is always in "get" mode

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

@@ -93,14 +93,12 @@ public class EventController {
         return injectKeyEvent(action, keycode, 0, metaState);
     }
 
-    private boolean injectText(String text) {
-        return injectText(text, true);
-    }
-
-    private boolean injectText(String text, boolean decomposeOnFailure) {
-        KeyEvent[] events = charMap.getEvents(text.toCharArray());
+    private boolean injectChar(char c) {
+        String decomposed = KeyComposition.decompose(c);
+        char[] chars = decomposed != null ? decomposed.toCharArray() : new char[] {c};
+        KeyEvent[] events = charMap.getEvents(chars);
         if (events == null) {
-            return decomposeOnFailure ? injectDecomposition(text) : false;
+            return false;
         }
         for (KeyEvent event : events) {
             if (!injectEvent(event)) {
@@ -110,10 +108,9 @@ public class EventController {
         return true;
     }
 
-    private boolean injectDecomposition(String text) {
+    private boolean injectText(String text) {
         for (char c : text.toCharArray()) {
-            String composedText = KeyComposition.decompose(c);
-            if (composedText == null || !injectText(composedText, false)) {
+            if (!injectChar(c)) {
                 return false;
             }
         }