Avoid additional copy on Java text parsing

Directly pass the buffer range to the String constructor.

README.md

@@ -490,17 +490,15 @@ requested orientation.
 
 #### Copy-paste
 
-It is possible to synchronize clipboards between the computer and the device, in
-both directions:
+Any time the Android clipboard changes, it is automatically synchronized to the
+computer clipboard.
 
- - `RCtrl`+`c` copies the device clipboard to the computer clipboard;
- - `RCtrl`+`Shift`+`v` copies the computer clipboard to the device clipboard
-   (and pastes if the device runs Android >= 7);
- - `RCtrl`+`v` _pastes_ the computer clipboard as a sequence of text events (but
-   breaks non-ASCII characters).
+`Ctrl`+`c` (copy), `Ctrl`+`x` (cut) and `LCtrl`+`v` (paste) work as you expect.
+
+In addition, `RCtrl`+`v` allows to inject the computer clipboard content as a
+sequence of text event. Even if it can break non-ASCII content, this is
+sometimes necessary when pasting directly is not possible.
 
-Moreover, any time the Android clipboard changes, it is automatically
-synchronized to the computer clipboard.
 
 #### Text injection preference
 
@@ -563,13 +561,16 @@ Also see [issue #14].
 `RCtrl` is the right `Ctrl` key (the left `Ctrl` key is forwarded to the
 device).
 
+On macOS, `Cmd` also works (for shortcuts which are not already captured by the
+system).
+
  | Action                                      |   Shortcut
  | ------------------------------------------- |:-----------------------------
  | Switch fullscreen mode                      | `RCtrl`+`f`
  | Rotate display left                         | `RCtrl`+`←`
  | Rotate display right                        | `RCtrl`+`→`
  | Resize window to 1:1 (pixel-perfect)        | `RCtrl`+`g`
- | Resize window to remove black borders       | `RCtrl`+`x` \| _Double-click¹_
+ | Resize window to remove black borders       | `RCtrl`+`w` \| _Double-click¹_
  | Click on `HOME`                             | `RCtrl`+`h` \| _Middle-click_
  | Click on `BACK`                             | `RCtrl`+`b` \| _Right-click²_
  | Click on `APP_SWITCH`                       | `RCtrl`+`s`
@@ -583,9 +584,7 @@ device).
  | Rotate device screen                        | `RCtrl`+`r`
  | Expand notification panel                   | `RCtrl`+`n`
  | Collapse notification panel                 | `RCtrl`+`Shift`+`n`
- | Copy device clipboard to computer           | `RCtrl`+`c`
- | Paste computer clipboard to device          | `RCtrl`+`v`
- | Copy computer clipboard to device and paste | `RCtrl`+`Shift`+`v`
+ | Inject computer clipboard text              | `RCtrl`+`v`
  | Enable/disable FPS counter (on stdout)      | `RCtrl`+`i`
 
 _¹Double-click on black borders to remove them._  

app/scrcpy.1

@@ -222,7 +222,7 @@ Rotate display right
 Resize window to 1:1 (pixel\-perfect)
 
 .TP
-.B RCtrl+x, Double\-click on black borders
+.B RCtrl+w, Double\-click on black borders
 Resize window to remove black borders
 
 .TP
@@ -277,17 +277,9 @@ Expand notification panel
 .B RCtrl+Shift+n
 Collapse notification panel
 
-.TP
-.B RCtrl+c
-Copy device clipboard to computer
-
 .TP
 .B RCtrl+v
-Paste computer clipboard to device
-
-.TP
-.B RCtrl+Shift+v
-Copy computer clipboard to device (and paste if the device runs Android >= 7)
+Inject computer clipboard text
 
 .TP
 .B RCtrl+i

app/src/cli.c

@@ -196,7 +196,7 @@ scrcpy_print_usage(const char *arg0) {
         "    RCtrl+g\n"
         "        Resize window to 1:1 (pixel-perfect)\n"
         "\n"
-        "    RCtrl+x\n"
+        "    RCtrl+w\n"
         "    Double-click on black borders\n"
         "        Resize window to remove black borders\n"
         "\n"
@@ -242,15 +242,8 @@ scrcpy_print_usage(const char *arg0) {
         "    RCtrl+Shift+n\n"
         "        Collapse notification panel\n"
         "\n"
-        "    RCtrl+c\n"
-        "        Copy device clipboard to computer\n"
-        "\n"
         "    RCtrl+v\n"
-        "        Paste computer clipboard to device\n"
-        "\n"
-        "    RCtrl+Shift+v\n"
-        "        Copy computer clipboard to device (and paste if the device\n"
-        "        runs Android >= 7)\n"
+        "        Inject computer clipboard text\n"
         "\n"
         "    RCtrl+i\n"
         "        Enable/disable FPS counter (print frames/second in logs)\n"

app/src/input_manager.c

@@ -101,16 +101,6 @@ collapse_notification_panel(struct controller *controller) {
     }
 }
 
-static void
-request_device_clipboard(struct controller *controller) {
-    struct control_msg msg;
-    msg.type = CONTROL_MSG_TYPE_GET_CLIPBOARD;
-
-    if (!controller_push_msg(controller, &msg)) {
-        LOGW("Could not request device clipboard");
-    }
-}
-
 static void
 set_device_clipboard(struct controller *controller, bool paste) {
     char *text = SDL_GetClipboardText();
@@ -252,6 +242,25 @@ convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to,
     return true;
 }
 
+static void
+inject_as_ctrl(struct input_manager *im, const SDL_KeyboardEvent *event) {
+    struct control_msg msg;
+
+    if (!convert_input_key(event, &msg, false)) {
+        return;
+    }
+
+    // Disable RCtrl and Meta
+    msg.inject_keycode.metastate &=
+        ~(AMETA_CTRL_RIGHT_ON | AMETA_META_LEFT_ON | AMETA_META_RIGHT_ON);
+    // Enable LCtrl
+    msg.inject_keycode.metastate |= AMETA_CTRL_LEFT_ON;
+
+    if (!controller_push_msg(im->controller, &msg)) {
+        LOGW("Could not request 'inject keycode'");
+    }
+}
+
 void
 input_manager_process_key(struct input_manager *im,
                           const SDL_KeyboardEvent *event,
@@ -259,25 +268,36 @@ input_manager_process_key(struct input_manager *im,
     // control: indicates the state of the command-line option --no-control
     // ctrl: the Ctrl key
 
+    bool lctrl = event->keysym.mod & KMOD_LCTRL;
     bool rctrl = event->keysym.mod & KMOD_RCTRL;
     bool alt = event->keysym.mod & (KMOD_LALT | KMOD_RALT);
     bool meta = event->keysym.mod & (KMOD_LGUI | KMOD_RGUI);
+    bool shift = event->keysym.mod & (KMOD_LSHIFT | KMOD_RSHIFT);
 
-    if (alt || meta) {
-        // No shortcuts involve Alt or Meta, and they are not forwarded to the
-        // device
+    bool shortcut_key = rctrl;
+#ifdef __APPLE__
+    shortcut_key |= meta;
+#else
+    if (meta) {
+        // No shortcut involve Meta, and it is not forwarded to the device
+        return;
+    }
+#endif
+
+    if (alt) {
+        // No shortcuts involve Alt, and it is not forwarded to the device
         return;
     }
 
     struct controller *controller = im->controller;
 
+    SDL_Keycode keycode = event->keysym.sym;
+    bool down = event->type == SDL_KEYDOWN;
+
     // Capture all RCtrl events
-    if (rctrl) {
-        SDL_Keycode keycode = event->keysym.sym;
-        bool down = event->type == SDL_KEYDOWN;
+    if (shortcut_key) {
         int action = down ? ACTION_DOWN : ACTION_UP;
         bool repeat = event->repeat;
-        bool shift = event->keysym.mod & (KMOD_LSHIFT | KMOD_RSHIFT);
         switch (keycode) {
             case SDLK_h:
                 // Ctrl+h on all platform, since Cmd+h is already captured by
@@ -339,20 +359,10 @@ input_manager_process_key(struct input_manager *im,
                     rotate_client_right(im->screen);
                 }
                 return;
-            case SDLK_c:
-                if (control && !shift && !repeat && down) {
-                    request_device_clipboard(controller);
-                }
-                return;
             case SDLK_v:
-                if (control && !repeat && down) {
-                    if (shift) {
-                        // store the text in the device clipboard and paste
-                        set_device_clipboard(controller, true);
-                    } else {
-                        // inject the text as input events
-                        clipboard_paste(controller);
-                    }
+                if (control && !shift && !repeat && down) {
+                    // Inject the text as input events
+                    clipboard_paste(controller);
                 }
                 return;
             case SDLK_f:
@@ -360,7 +370,7 @@ input_manager_process_key(struct input_manager *im,
                     screen_switch_fullscreen(im->screen);
                 }
                 return;
-            case SDLK_x:
+            case SDLK_w:
                 if (!shift && !repeat && down) {
                     screen_resize_to_fit(im->screen);
                 }
@@ -391,6 +401,15 @@ input_manager_process_key(struct input_manager *im,
                     rotate_device(controller);
                 }
                 return;
+            case SDLK_c:
+            case SDLK_x:
+                if (control && !shift) {
+                    // For convenience, forward shortcut_key+c and
+                    // shortcut_key+x as Ctrl+c and Ctrl+x (typically "copy" and
+                    // "cut", but not always) to the device
+                    inject_as_ctrl(im, event);
+                }
+                return;
         }
 
         return;
@@ -400,6 +419,12 @@ input_manager_process_key(struct input_manager *im,
         return;
     }
 
+    if (lctrl && !shift && keycode == SDLK_v && down) {
+        // Synchronize the computer clipboard to the device clipboard before
+        // sending Ctrl+V, to allow seamless copy-paste.
+        set_device_clipboard(controller, false);
+    }
+
     struct control_msg msg;
     if (convert_input_key(event, &msg, im->prefer_text)) {
         if (!controller_push_msg(controller, &msg)) {

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

@@ -17,8 +17,6 @@ public final class ControlMessage {
     public static final int TYPE_SET_SCREEN_POWER_MODE = 9;
     public static final int TYPE_ROTATE_DEVICE = 10;
 
-    public static final int FLAGS_PASTE = 1;
-
     private int type;
     private String text;
     private int metaState; // KeyEvent.META_*
@@ -30,7 +28,7 @@ public final class ControlMessage {
     private Position position;
     private int hScroll;
     private int vScroll;
-    private int flags;
+    private boolean paste;
 
     private ControlMessage() {
     }
@@ -75,9 +73,7 @@ public final class ControlMessage {
         ControlMessage msg = new ControlMessage();
         msg.type = TYPE_SET_CLIPBOARD;
         msg.text = text;
-        if (paste) {
-            msg.flags = FLAGS_PASTE;
-        }
+        msg.paste = paste;
         return msg;
     }
 
@@ -141,7 +137,7 @@ public final class ControlMessage {
         return vScroll;
     }
 
-    public int getFlags() {
-        return flags;
+    public boolean getPaste() {
+        return paste;
     }
 }

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

@@ -21,7 +21,6 @@ public class ControlMessageReader {
 
     private final byte[] rawBuffer = new byte[RAW_BUFFER_SIZE];
     private final ByteBuffer buffer = ByteBuffer.wrap(rawBuffer);
-    private final byte[] textBuffer = new byte[CLIPBOARD_TEXT_MAX_LENGTH];
 
     public ControlMessageReader() {
         // invariant: the buffer is always in "get" mode
@@ -111,8 +110,10 @@ public class ControlMessageReader {
         if (buffer.remaining() < len) {
             return null;
         }
-        buffer.get(textBuffer, 0, len);
-        return new String(textBuffer, 0, len, StandardCharsets.UTF_8);
+        int position = buffer.position();
+        // Move the buffer position to consume the text
+        buffer.position(position + len);
+        return new String(rawBuffer, position, len, StandardCharsets.UTF_8);
     }
 
     private ControlMessage parseInjectText() {

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

@@ -110,8 +110,7 @@ public class Controller {
                 }
                 break;
             case ControlMessage.TYPE_SET_CLIPBOARD:
-                boolean paste = (msg.getFlags() & ControlMessage.FLAGS_PASTE) != 0;
-                setClipboard(msg.getText(), paste);
+                setClipboard(msg.getText(), msg.getPaste());
                 break;
             case ControlMessage.TYPE_SET_SCREEN_POWER_MODE:
                 if (device.supportsInputEvents()) {

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

@@ -207,6 +207,14 @@ public final class Device {
     }
 
     public boolean setClipboardText(String text) {
+        String currentClipboard = getClipboardText();
+        if (currentClipboard == null || currentClipboard.equals(text)) {
+            // The clipboard already contains the requested text.
+            // Since pasting text from the computer involves setting the device clipboard, it could be set twice on a copy-paste. This would cause
+            // the clipboard listeners to be notified twice, and that would flood the Android keyboard clipboard history. To workaround this
+            // problem, do not explicitly set the clipboard text if it already contains the expected content.
+            return false;
+        }
         isSettingClipboard.set(true);
         boolean ok = serviceManager.getClipboardManager().setText(text);
         isSettingClipboard.set(false);

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

@@ -228,9 +228,7 @@ public class ControlMessageReaderTest {
 
         Assert.assertEquals(ControlMessage.TYPE_SET_CLIPBOARD, event.getType());
         Assert.assertEquals("testé", event.getText());
-
-        boolean parse = (event.getFlags() & ControlMessage.FLAGS_PASTE) != 0;
-        Assert.assertTrue(parse);
+        Assert.assertTrue(event.getPaste());
     }
 
     @Test
@@ -256,9 +254,7 @@ public class ControlMessageReaderTest {
 
         Assert.assertEquals(ControlMessage.TYPE_SET_CLIPBOARD, event.getType());
         Assert.assertEquals(text, event.getText());
-
-        boolean parse = (event.getFlags() & ControlMessage.FLAGS_PASTE) != 0;
-        Assert.assertTrue(parse);
+        Assert.assertTrue(event.getPaste());
     }
 
     @Test