Copy on "get clipboard" if possible

Ctrl+c synchronizes the Android device clipboard to the computer
clipboard.

To make the copy more straightforward, if the device runs at least
Android 7, also send a COPY keycode before copying the clipboard.

<https://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_COPY>

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

@@ -18,6 +18,7 @@ public final class ControlMessage {
     public static final int TYPE_ROTATE_DEVICE = 10;
 
     public static final int FLAGS_PASTE = 1;
+    public static final int FLAGS_COPY = 2;
 
     private int type;
     private String text;
@@ -81,6 +82,15 @@ public final class ControlMessage {
         return msg;
     }
 
+    public static ControlMessage createGetClipboard(boolean copy) {
+        ControlMessage msg = new ControlMessage();
+        msg.type = TYPE_GET_CLIPBOARD;
+        if (copy) {
+            msg.flags = FLAGS_COPY;
+        }
+        return msg;
+    }
+
     /**
      * @param mode one of the {@code Device.SCREEN_POWER_MODE_*} constants
      */

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

@@ -12,6 +12,7 @@ public class ControlMessageReader {
     static final int INJECT_TOUCH_EVENT_PAYLOAD_LENGTH = 27;
     static final int INJECT_SCROLL_EVENT_PAYLOAD_LENGTH = 20;
     static final int SET_SCREEN_POWER_MODE_PAYLOAD_LENGTH = 1;
+    static final int GET_CLIPBOARD_PAYLOAD_LENGTH = 1;
     static final int SET_CLIPBOARD_FIXED_PAYLOAD_LENGTH = 1;
 
     public static final int CLIPBOARD_TEXT_MAX_LENGTH = 4092; // 4096 - 1 (type) - 1 (parse flag) - 2 (length)
@@ -67,6 +68,9 @@ public class ControlMessageReader {
             case ControlMessage.TYPE_INJECT_SCROLL_EVENT:
                 msg = parseInjectScrollEvent();
                 break;
+            case ControlMessage.TYPE_GET_CLIPBOARD:
+                msg = parseGetClipboard();
+                break;
             case ControlMessage.TYPE_SET_CLIPBOARD:
                 msg = parseSetClipboard();
                 break;
@@ -76,7 +80,6 @@ public class ControlMessageReader {
             case ControlMessage.TYPE_BACK_OR_SCREEN_ON:
             case ControlMessage.TYPE_EXPAND_NOTIFICATION_PANEL:
             case ControlMessage.TYPE_COLLAPSE_NOTIFICATION_PANEL:
-            case ControlMessage.TYPE_GET_CLIPBOARD:
             case ControlMessage.TYPE_ROTATE_DEVICE:
                 msg = ControlMessage.createEmpty(type);
                 break;
@@ -148,6 +151,14 @@ public class ControlMessageReader {
         return ControlMessage.createInjectScrollEvent(position, hScroll, vScroll);
     }
 
+    private ControlMessage parseGetClipboard() {
+        if (buffer.remaining() < GET_CLIPBOARD_PAYLOAD_LENGTH) {
+            return null;
+        }
+        boolean copy = buffer.get() != 0;
+        return ControlMessage.createGetClipboard(copy);
+    }
+
     private ControlMessage parseSetClipboard() {
         if (buffer.remaining() < SET_CLIPBOARD_FIXED_PAYLOAD_LENGTH) {
             return null;

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

@@ -104,10 +104,8 @@ public class Controller {
                 device.collapsePanels();
                 break;
             case ControlMessage.TYPE_GET_CLIPBOARD:
-                String clipboardText = device.getClipboardText();
-                if (clipboardText != null) {
-                    sender.pushClipboardText(clipboardText);
-                }
+                boolean copy = (msg.getFlags() & ControlMessage.FLAGS_COPY) != 0;
+                getClipboard(copy);
                 break;
             case ControlMessage.TYPE_SET_CLIPBOARD:
                 boolean paste = (msg.getFlags() & ControlMessage.FLAGS_PASTE) != 0;
@@ -229,6 +227,19 @@ public class Controller {
         return device.injectKeycode(keycode);
     }
 
+    private void getClipboard(boolean copy) {
+        // On Android >= 7, also press the COPY key if requested
+        if (copy && Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && device.supportsInputEvents()) {
+            // Must wait until the COPY has been executed
+            device.injectCopyKeycode();
+        }
+
+        String clipboardText = device.getClipboardText();
+        if (clipboardText != null) {
+            sender.pushClipboardText(clipboardText);
+        }
+    }
+
     private boolean setClipboard(String text, boolean paste) {
         boolean ok = device.setClipboardText(text);
         if (ok) {

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

@@ -186,6 +186,14 @@ public final class Device {
         return injectKeycode(keyCode, InputManager.INJECT_INPUT_EVENT_MODE_ASYNC);
     }
 
+    public boolean injectCopyKeycode() {
+        isSettingClipboard.set(true);
+        // Must wait until the COPY has been executed
+        boolean ret = injectKeycode(KeyEvent.KEYCODE_COPY, InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH);
+        isSettingClipboard.set(false);
+        return ret;
+    }
+
     public boolean injectPasteKeycode() {
         return injectKeycode(KeyEvent.KEYCODE_PASTE);
     }

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

@@ -200,6 +200,7 @@ public class ControlMessageReaderTest {
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         DataOutputStream dos = new DataOutputStream(bos);
         dos.writeByte(ControlMessage.TYPE_GET_CLIPBOARD);
+        dos.writeByte(1); // copy
 
         byte[] packet = bos.toByteArray();
 
@@ -207,6 +208,7 @@ public class ControlMessageReaderTest {
         ControlMessage event = reader.next();
 
         Assert.assertEquals(ControlMessage.TYPE_GET_CLIPBOARD, event.getType());
+        Assert.assertEquals(1, (event.getFlags() & ControlMessage.FLAGS_COPY));
     }
 
     @Test