Implement computer-to-device clipboard copy

It was already possible to _paste_ (with Ctrl+v) the content of the
computer clipboard on the device. Technically, it injects a sequence of
events to generate the text.

Add a new feature (Ctrl+Shift+v) to copy to the device clipboard
instead, without injecting the content. Contrary to events injection,
this preserves the UTF-8 content exactly, so the text is not broken by
special characters.

<https://github.com/Genymobile/scrcpy/issues/413>

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

@@ -13,6 +13,7 @@ public final class ControlEvent {
     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;
+    public static final int TYPE_SET_CLIPBOARD = 8;
 
     private int type;
     private String text;
@@ -61,6 +62,13 @@ public final class ControlEvent {
         return event;
     }
 
+    public static ControlEvent createSetClipboardControlEvent(String text) {
+        ControlEvent event = new ControlEvent();
+        event.type = TYPE_SET_CLIPBOARD;
+        event.text = text;
+        return event;
+    }
+
     public static ControlEvent createSimpleControlEvent(int type) {
         ControlEvent event = new ControlEvent();
         event.type = type;

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

@@ -13,11 +13,12 @@ public class ControlEventReader {
     private static final int SCROLL_PAYLOAD_LENGTH = 20;
 
     public static final int TEXT_MAX_LENGTH = 300;
+    public static final int CLIPBOARD_TEXT_MAX_LENGTH = 4093;
     private static final int RAW_BUFFER_SIZE = 1024;
 
     private final byte[] rawBuffer = new byte[RAW_BUFFER_SIZE];
     private final ByteBuffer buffer = ByteBuffer.wrap(rawBuffer);
-    private final byte[] textBuffer = new byte[TEXT_MAX_LENGTH];
+    private final byte[] textBuffer = new byte[CLIPBOARD_TEXT_MAX_LENGTH];
 
     public ControlEventReader() {
         // invariant: the buffer is always in "get" mode
@@ -63,6 +64,9 @@ public class ControlEventReader {
             case ControlEvent.TYPE_SCROLL:
                 controlEvent = parseScrollControlEvent();
                 break;
+            case ControlEvent.TYPE_SET_CLIPBOARD:
+                controlEvent = parseSetClipboardEvent();
+                break;
             case ControlEvent.TYPE_BACK_OR_SCREEN_ON:
             case ControlEvent.TYPE_EXPAND_NOTIFICATION_PANEL:
             case ControlEvent.TYPE_COLLAPSE_NOTIFICATION_PANEL:
@@ -132,6 +136,14 @@ public class ControlEventReader {
         return ControlEvent.createScrollControlEvent(position, hScroll, vScroll);
     }
 
+    private ControlEvent parseSetClipboardEvent() {
+        String text = parseString();
+        if (text == null) {
+            return null;
+        }
+        return ControlEvent.createSetClipboardControlEvent(text);
+    }
+
     private static Position readPosition(ByteBuffer buffer) {
         int x = buffer.getInt();
         int y = buffer.getInt();

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

@@ -147,6 +147,10 @@ public final class Device {
         return s.toString();
     }
 
+    public void setClipboardText(String text) {
+        serviceManager.getClipboardManager().setText(text);
+    }
+
     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

@@ -94,6 +94,9 @@ public class EventController {
                 String clipboardText = device.getClipboardText();
                 sender.pushClipboardText(clipboardText);
                 break;
+            case ControlEvent.TYPE_SET_CLIPBOARD:
+                device.setClipboardText(controlEvent.getText());
+                break;
             default:
                 // do nothing
         }

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

@@ -9,11 +9,13 @@ import java.lang.reflect.Method;
 public class ClipboardManager {
     private final IInterface manager;
     private final Method getPrimaryClipMethod;
+    private final Method setPrimaryClipMethod;
 
     public ClipboardManager(IInterface manager) {
         this.manager = manager;
         try {
             getPrimaryClipMethod = manager.getClass().getMethod("getPrimaryClip", String.class);
+            setPrimaryClipMethod = manager.getClass().getMethod("setPrimaryClip", ClipData.class, String.class);
         } catch (NoSuchMethodException e) {
             throw new AssertionError(e);
         }
@@ -30,4 +32,13 @@ public class ClipboardManager {
             throw new AssertionError(e);
         }
     }
+
+    public void setText(CharSequence text) {
+        ClipData clipData = ClipData.newPlainText(null, text);
+        try {
+            setPrimaryClipMethod.invoke(manager, clipData, "com.android.shell");
+        } catch (InvocationTargetException | IllegalAccessException e) {
+            throw new AssertionError(e);
+        }
+    }
 }

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

@@ -190,6 +190,26 @@ public class ControlEventReaderTest {
         Assert.assertEquals(ControlEvent.TYPE_GET_CLIPBOARD, event.getType());
     }
 
+    @Test
+    public void testParseSetClipboardEvent() throws IOException {
+        ControlEventReader reader = new ControlEventReader();
+
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutputStream dos = new DataOutputStream(bos);
+        dos.writeByte(ControlEvent.TYPE_SET_CLIPBOARD);
+        byte[] text = "testé".getBytes(StandardCharsets.UTF_8);
+        dos.writeShort(text.length);
+        dos.write(text);
+
+        byte[] packet = bos.toByteArray();
+
+        reader.readFrom(new ByteArrayInputStream(packet));
+        ControlEvent event = reader.next();
+
+        Assert.assertEquals(ControlEvent.TYPE_SET_CLIPBOARD, event.getType());
+        Assert.assertEquals("testé", event.getText());
+    }
+
     @Test
     public void testMultiEvents() throws IOException {
         ControlEventReader reader = new ControlEventReader();