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>

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();