Merge mouse and touch events

Both are handled the very same way on the device.

app/src/control_msg.c

@@ -49,19 +49,15 @@ control_msg_serialize(const struct control_msg *msg, unsigned char *buf) {
                                       CONTROL_MSG_TEXT_MAX_LENGTH, &buf[1]);
             return 1 + len;
         }
-        case CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT:
-            buf[1] = msg->inject_mouse_event.action;
-            buffer_write32be(&buf[2], msg->inject_mouse_event.buttons);
-            write_position(&buf[6], &msg->inject_mouse_event.position);
-            return 18;
         case CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT:
             buf[1] = msg->inject_touch_event.action;
-            buffer_write64be(&buf[2], msg->inject_touch_event.finger_id);
+            buffer_write64be(&buf[2], msg->inject_touch_event.pointer_id);
             write_position(&buf[10], &msg->inject_touch_event.position);
             uint16_t pressure =
                 to_fixed_point_16(msg->inject_touch_event.pressure);
             buffer_write16be(&buf[22], pressure);
-            return 24;
+            buffer_write32be(&buf[24], msg->inject_touch_event.buttons);
+            return 28;
         case CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT:
             write_position(&buf[1], &msg->inject_scroll_event.position);
             buffer_write32be(&buf[13],

app/src/control_msg.h

@@ -15,10 +15,11 @@
 #define CONTROL_MSG_SERIALIZED_MAX_SIZE \
     (3 + CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH)
 
+#define POINTER_ID_MOUSE UINT64_C(-1);
+
 enum control_msg_type {
     CONTROL_MSG_TYPE_INJECT_KEYCODE,
     CONTROL_MSG_TYPE_INJECT_TEXT,
-    CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
     CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
     CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT,
     CONTROL_MSG_TYPE_BACK_OR_SCREEN_ON,
@@ -49,11 +50,7 @@ struct control_msg {
         struct {
             enum android_motionevent_action action;
             enum android_motionevent_buttons buttons;
-            struct position position;
-        } inject_mouse_event;
-        struct {
-            enum android_motionevent_action action;
-            uint64_t finger_id;
+            uint64_t pointer_id;
             struct position position;
             float pressure;
         } inject_touch_event;

app/src/event_converter.c

@@ -128,15 +128,6 @@ convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod) {
     }
 }
 
-static bool
-convert_mouse_action(SDL_EventType from, enum android_motionevent_action *to) {
-    switch (from) {
-        MAP(SDL_MOUSEBUTTONDOWN, AMOTION_EVENT_ACTION_DOWN);
-        MAP(SDL_MOUSEBUTTONUP,   AMOTION_EVENT_ACTION_UP);
-        FAIL;
-    }
-}
-
 static enum android_motionevent_buttons
 convert_mouse_buttons(uint32_t state) {
     enum android_motionevent_buttons buttons = 0;
@@ -176,20 +167,31 @@ convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to) {
     return true;
 }
 
+static bool
+convert_mouse_action(SDL_EventType from, enum android_motionevent_action *to) {
+    switch (from) {
+        MAP(SDL_MOUSEBUTTONDOWN, AMOTION_EVENT_ACTION_DOWN);
+        MAP(SDL_MOUSEBUTTONUP,   AMOTION_EVENT_ACTION_UP);
+        FAIL;
+    }
+}
+
 bool
 convert_mouse_button(const SDL_MouseButtonEvent *from, struct size screen_size,
                      struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT;
+    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
 
-    if (!convert_mouse_action(from->type, &to->inject_mouse_event.action)) {
+    if (!convert_mouse_action(from->type, &to->inject_touch_event.action)) {
         return false;
     }
 
-    to->inject_mouse_event.buttons =
+    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
+    to->inject_touch_event.position.screen_size = screen_size;
+    to->inject_touch_event.position.point.x = from->x;
+    to->inject_touch_event.position.point.y = from->y;
+    to->inject_touch_event.pressure = 1.f;
+    to->inject_touch_event.buttons =
         convert_mouse_buttons(SDL_BUTTON(from->button));
-    to->inject_mouse_event.position.screen_size = screen_size;
-    to->inject_mouse_event.position.point.x = from->x;
-    to->inject_mouse_event.position.point.y = from->y;
 
     return true;
 }
@@ -197,12 +199,14 @@ convert_mouse_button(const SDL_MouseButtonEvent *from, struct size screen_size,
 bool
 convert_mouse_motion(const SDL_MouseMotionEvent *from, struct size screen_size,
                      struct control_msg *to) {
-    to->type = CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT;
-    to->inject_mouse_event.action = AMOTION_EVENT_ACTION_MOVE;
-    to->inject_mouse_event.buttons = convert_mouse_buttons(from->state);
-    to->inject_mouse_event.position.screen_size = screen_size;
-    to->inject_mouse_event.position.point.x = from->x;
-    to->inject_mouse_event.position.point.y = from->y;
+    to->type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT;
+    to->inject_touch_event.action = AMOTION_EVENT_ACTION_MOVE;
+    to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
+    to->inject_touch_event.position.screen_size = screen_size;
+    to->inject_touch_event.position.point.x = from->x;
+    to->inject_touch_event.position.point.y = from->y;
+    to->inject_touch_event.pressure = 1.f;
+    to->inject_touch_event.buttons = convert_mouse_buttons(from->state);
 
     return true;
 }
@@ -226,12 +230,13 @@ convert_touch(const SDL_TouchFingerEvent *from, struct size screen_size,
         return false;
     }
 
-    to->inject_touch_event.finger_id = from->fingerId;
+    to->inject_touch_event.pointer_id = from->fingerId;
     to->inject_touch_event.position.screen_size = screen_size;
     // SDL touch event coordinates are normalized in the range [0; 1]
     to->inject_touch_event.position.point.x = from->x * screen_size.width;
     to->inject_touch_event.position.point.y = from->y * screen_size.height;
     to->inject_touch_event.pressure = from->pressure;
+    to->inject_touch_event.buttons = 0;
     return true;
 }
 

app/src/input_manager.c

@@ -423,6 +423,10 @@ void
 input_manager_process_mouse_button(struct input_manager *input_manager,
                                    const SDL_MouseButtonEvent *event,
                                    bool control) {
+    if (event->which == SDL_TOUCH_MOUSEID) {
+        // simulated from touch events, so it's a duplicate
+        return;
+    }
     if (event->type == SDL_MOUSEBUTTONDOWN) {
         if (control && event->button == SDL_BUTTON_RIGHT) {
             press_back_or_turn_screen_on(input_manager->controller);

app/tests/test_control_msg_serialize.c

@@ -67,45 +67,12 @@ static void test_serialize_inject_text_long(void) {
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
 
-static void test_serialize_inject_mouse_event(void) {
-    struct control_msg msg = {
-        .type = CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
-        .inject_mouse_event = {
-            .action = AMOTION_EVENT_ACTION_DOWN,
-            .buttons = AMOTION_EVENT_BUTTON_PRIMARY,
-            .position = {
-                .point = {
-                    .x = 260,
-                    .y = 1026,
-                },
-                .screen_size = {
-                    .width = 1080,
-                    .height = 1920,
-                },
-            },
-        },
-    };
-
-    unsigned char buf[CONTROL_MSG_SERIALIZED_MAX_SIZE];
-    int size = control_msg_serialize(&msg, buf);
-    assert(size == 18);
-
-    const unsigned char expected[] = {
-        CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
-        0x00, // AKEY_EVENT_ACTION_DOWN
-        0x00, 0x00, 0x00, 0x01, // AMOTION_EVENT_BUTTON_PRIMARY
-        0x00, 0x00, 0x01, 0x04, 0x00, 0x00, 0x04, 0x02, // 260 1026
-        0x04, 0x38, 0x07, 0x80, // 1080 1920
-    };
-    assert(!memcmp(buf, expected, sizeof(expected)));
-}
-#include <stdio.h>
 static void test_serialize_inject_touch_event(void) {
     struct control_msg msg = {
         .type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
         .inject_touch_event = {
             .action = AMOTION_EVENT_ACTION_DOWN,
-            .finger_id = 0x1234567887654321L,
+            .pointer_id = 0x1234567887654321L,
             .position = {
                 .point = {
                     .x = 100,
@@ -117,20 +84,22 @@ static void test_serialize_inject_touch_event(void) {
                 },
             },
             .pressure = 1.0f,
+            .buttons = AMOTION_EVENT_BUTTON_PRIMARY,
         },
     };
 
     unsigned char buf[CONTROL_MSG_SERIALIZED_MAX_SIZE];
     int size = control_msg_serialize(&msg, buf);
-    assert(size == 24);
+    assert(size == 28);
 
     const unsigned char expected[] = {
         CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
         0x00, // AKEY_EVENT_ACTION_DOWN
-        0x12, 0x34, 0x56, 0x78, 0x87, 0x65, 0x43, 0x21, // finger id
+        0x12, 0x34, 0x56, 0x78, 0x87, 0x65, 0x43, 0x21, // pointer id
         0x00, 0x00, 0x00, 0x64, 0x00, 0x00, 0x00, 0xc8, // 100 200
         0x04, 0x38, 0x07, 0x80, // 1080 1920
         0xff, 0xff, // pressure
+        0x00, 0x00, 0x00, 0x01 // AMOTION_EVENT_BUTTON_PRIMARY
     };
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
@@ -271,7 +240,6 @@ int main(void) {
     test_serialize_inject_keycode();
     test_serialize_inject_text();
     test_serialize_inject_text_long();
-    test_serialize_inject_mouse_event();
     test_serialize_inject_touch_event();
     test_serialize_inject_scroll_event();
     test_serialize_back_or_screen_on();

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

@@ -7,15 +7,14 @@ public final class ControlMessage {
 
     public static final int TYPE_INJECT_KEYCODE = 0;
     public static final int TYPE_INJECT_TEXT = 1;
-    public static final int TYPE_INJECT_MOUSE_EVENT = 2;
-    public static final int TYPE_INJECT_TOUCH_EVENT = 3;
-    public static final int TYPE_INJECT_SCROLL_EVENT = 4;
-    public static final int TYPE_BACK_OR_SCREEN_ON = 5;
-    public static final int TYPE_EXPAND_NOTIFICATION_PANEL = 6;
-    public static final int TYPE_COLLAPSE_NOTIFICATION_PANEL = 7;
-    public static final int TYPE_GET_CLIPBOARD = 8;
-    public static final int TYPE_SET_CLIPBOARD = 9;
-    public static final int TYPE_SET_SCREEN_POWER_MODE = 10;
+    public static final int TYPE_INJECT_TOUCH_EVENT = 2;
+    public static final int TYPE_INJECT_SCROLL_EVENT = 3;
+    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;
+    public static final int TYPE_SET_CLIPBOARD = 8;
+    public static final int TYPE_SET_SCREEN_POWER_MODE = 9;
 
     private int type;
     private String text;
@@ -23,7 +22,7 @@ public final class ControlMessage {
     private int action; // KeyEvent.ACTION_* or MotionEvent.ACTION_* or POWER_MODE_*
     private int keycode; // KeyEvent.KEYCODE_*
     private int buttons; // MotionEvent.BUTTON_*
-    private long fingerId;
+    private long pointerId;
     private float pressure;
     private Position position;
     private int hScroll;
@@ -48,22 +47,15 @@ public final class ControlMessage {
         return msg;
     }
 
-    public static ControlMessage createInjectMouseEvent(int action, int buttons, Position position) {
-        ControlMessage msg = new ControlMessage();
-        msg.type = TYPE_INJECT_MOUSE_EVENT;
-        msg.action = action;
-        msg.buttons = buttons;
-        msg.position = position;
-        return msg;
-    }
-
-    public static ControlMessage createInjectTouchEvent(int action, long fingerId, Position position, float pressure) {
+    public static ControlMessage createInjectTouchEvent(int action, long pointerId, Position position, float pressure,
+            int buttons) {
         ControlMessage msg = new ControlMessage();
         msg.type = TYPE_INJECT_TOUCH_EVENT;
         msg.action = action;
-        msg.fingerId = fingerId;
+        msg.pointerId = pointerId;
         msg.pressure = pressure;
         msg.position = position;
+        msg.buttons = buttons;
         return msg;
     }
 
@@ -123,8 +115,8 @@ public final class ControlMessage {
         return buttons;
     }
 
-    public long getFingerId() {
-        return fingerId;
+    public long getPointerId() {
+        return pointerId;
     }
 
     public float getPressure() {

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

@@ -60,9 +60,6 @@ public class ControlMessageReader {
             case ControlMessage.TYPE_INJECT_TEXT:
                 msg = parseInjectText();
                 break;
-            case ControlMessage.TYPE_INJECT_MOUSE_EVENT:
-                msg = parseInjectMouseEvent();
-                break;
             case ControlMessage.TYPE_INJECT_TOUCH_EVENT:
                 msg = parseInjectTouchEvent();
                 break;
@@ -124,28 +121,20 @@ public class ControlMessageReader {
         return ControlMessage.createInjectText(text);
     }
 
-    private ControlMessage parseInjectMouseEvent() {
-        if (buffer.remaining() < INJECT_MOUSE_EVENT_PAYLOAD_LENGTH) {
-            return null;
-        }
-        int action = toUnsigned(buffer.get());
-        int buttons = buffer.getInt();
-        Position position = readPosition(buffer);
-        return ControlMessage.createInjectMouseEvent(action, buttons, position);
-    }
-
+    @SuppressWarnings("checkstyle:MagicNumber")
     private ControlMessage parseInjectTouchEvent() {
         if (buffer.remaining() < INJECT_TOUCH_EVENT_PAYLOAD_LENGTH) {
             return null;
         }
         int action = toUnsigned(buffer.get());
-        long fingerId = buffer.getLong();
+        long pointerId = buffer.getLong();
         Position position = readPosition(buffer);
         // 16 bits fixed-point
         int pressureInt = toUnsigned(buffer.getShort());
         // convert it to a float between 0 and 1 (0x1p16f is 2^16 as float)
         float pressure = pressureInt == 0xffff ? 1f : (pressureInt / 0x1p16f);
-        return ControlMessage.createInjectTouchEvent(action, fingerId, position, pressure);
+        int buttons = buffer.getInt();
+        return ControlMessage.createInjectTouchEvent(action, pointerId, position, pressure, buttons);
     }
 
     private ControlMessage parseInjectScrollEvent() {

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

@@ -13,44 +13,28 @@ import java.io.IOException;
 
 public class Controller {
 
-    private static final int MAX_FINGERS = 10;
-
     private final Device device;
     private final DesktopConnection connection;
     private final DeviceMessageSender sender;
 
     private final KeyCharacterMap charMap = KeyCharacterMap.load(KeyCharacterMap.VIRTUAL_KEYBOARD);
 
-    private long lastMouseDown;
-    private final MotionEvent.PointerProperties[] mousePointerProperties = {new MotionEvent.PointerProperties()};
-    private final MotionEvent.PointerCoords[] mousePointerCoords = {new MotionEvent.PointerCoords()};
-
     private long lastTouchDown;
-    private final FingersState fingersState = new FingersState(MAX_FINGERS);
-    private final MotionEvent.PointerProperties[] touchPointerProperties = new MotionEvent.PointerProperties[MAX_FINGERS];
-    private final MotionEvent.PointerCoords[] touchPointerCoords = new MotionEvent.PointerCoords[MAX_FINGERS];
+    private final PointersState pointersState = new PointersState();
+    private final MotionEvent.PointerProperties[] pointerProperties =
+            new MotionEvent.PointerProperties[PointersState.MAX_POINTERS];
+    private final MotionEvent.PointerCoords[] pointerCoords =
+            new MotionEvent.PointerCoords[PointersState.MAX_POINTERS];
 
     public Controller(Device device, DesktopConnection connection) {
         this.device = device;
         this.connection = connection;
-        initMousePointer();
-        initTouchPointers();
+        initPointers();
         sender = new DeviceMessageSender(connection);
     }
 
-    private void initMousePointer() {
-        MotionEvent.PointerProperties props = mousePointerProperties[0];
-        props.id = 0;
-        props.toolType = MotionEvent.TOOL_TYPE_FINGER;
-
-        MotionEvent.PointerCoords coords = mousePointerCoords[0];
-        coords.orientation = 0;
-        coords.pressure = 1;
-        coords.size = 1;
-    }
-
-    private void initTouchPointers() {
-        for (int i = 0; i < MAX_FINGERS; ++i) {
+    private void initPointers() {
+        for (int i = 0; i < PointersState.MAX_POINTERS; ++i) {
             MotionEvent.PointerProperties props = new MotionEvent.PointerProperties();
             props.toolType = MotionEvent.TOOL_TYPE_FINGER;
 
@@ -58,23 +42,11 @@ public class Controller {
             coords.orientation = 0;
             coords.size = 1;
 
-            touchPointerProperties[i] = props;
-            touchPointerCoords[i] = coords;
+            pointerProperties[i] = props;
+            pointerCoords[i] = coords;
         }
     }
 
-    private void setMousePointerCoords(Point point) {
-        MotionEvent.PointerCoords coords = mousePointerCoords[0];
-        coords.x = point.getX();
-        coords.y = point.getY();
-    }
-
-    private void setScroll(int hScroll, int vScroll) {
-        MotionEvent.PointerCoords coords = mousePointerCoords[0];
-        coords.setAxisValue(MotionEvent.AXIS_HSCROLL, hScroll);
-        coords.setAxisValue(MotionEvent.AXIS_VSCROLL, vScroll);
-    }
-
     @SuppressWarnings("checkstyle:MagicNumber")
     public void control() throws IOException {
         // on start, power on the device
@@ -109,11 +81,8 @@ public class Controller {
             case ControlMessage.TYPE_INJECT_TEXT:
                 injectText(msg.getText());
                 break;
-            case ControlMessage.TYPE_INJECT_MOUSE_EVENT:
-                injectMouse(msg.getAction(), msg.getButtons(), msg.getPosition());
-                break;
             case ControlMessage.TYPE_INJECT_TOUCH_EVENT:
-                injectTouch(msg.getAction(), msg.getFingerId(), msg.getPosition(), msg.getPressure());
+                injectTouch(msg.getAction(), msg.getPointerId(), msg.getPosition(), msg.getPressure(), 0);
                 break;
             case ControlMessage.TYPE_INJECT_SCROLL_EVENT:
                 injectScroll(msg.getPosition(), msg.getHScroll(), msg.getVScroll());
@@ -173,23 +142,7 @@ public class Controller {
         return successCount;
     }
 
-    private boolean injectMouse(int action, int buttons, Position position) {
-        long now = SystemClock.uptimeMillis();
-        if (action == MotionEvent.ACTION_DOWN) {
-            lastMouseDown = now;
-        }
-        Point point = device.getPhysicalPoint(position);
-        if (point == null) {
-            // ignore event
-            return false;
-        }
-        setMousePointerCoords(point);
-        MotionEvent event = MotionEvent.obtain(lastMouseDown, now, action, 1, mousePointerProperties, mousePointerCoords, 0, buttons, 1f, 1f, 0, 0,
-                InputDevice.SOURCE_TOUCHSCREEN, 0);
-        return injectEvent(event);
-    }
-
-    private boolean injectTouch(int action, long fingerId, Position position, float pressure) {
+    private boolean injectTouch(int action, long pointerId, Position position, float pressure, int buttons) {
         long now = SystemClock.uptimeMillis();
 
         Point point = device.getPhysicalPoint(position);
@@ -198,38 +151,33 @@ public class Controller {
             return false;
         }
 
-        int fingerIndex = fingersState.getFingerIndex(fingerId);
-        if (fingerIndex == -1) {
-            Ln.w("Too many fingers for touch event");
+        int pointerIndex = pointersState.getPointerIndex(pointerId);
+        if (pointerIndex == -1) {
+            Ln.w("Too many pointers for touch event");
             return false;
         }
-        Finger finger = fingersState.get(fingerIndex);
-        finger.setPoint(point);
-        finger.setPressure(pressure);
-        finger.setUp(action == MotionEvent.ACTION_UP);
+        Pointer pointer = pointersState.get(pointerIndex);
+        pointer.setPoint(point);
+        pointer.setPressure(pressure);
+        pointer.setUp(action == MotionEvent.ACTION_UP);
 
-        // FAIL: action_up will always remove the finger, and the event will not be written!
-        int pointerCount = fingersState.update(touchPointerProperties, touchPointerCoords);
-        fingersState.cleanUp();
+        int pointerCount = pointersState.update(pointerProperties, pointerCoords);
 
-        Ln.d("pointerCount = " + pointerCount);
-        for (int i = 0; i < pointerCount; ++i) {
-            Ln.d("props = " + touchPointerProperties[i].id);
-            Ln.d("coords = " + touchPointerCoords[i].x + "," + touchPointerCoords[i].y);
-        }
-
-        if (pointerCount > 1) {
-            if (action == MotionEvent.ACTION_UP) {
-                action = MotionEvent.ACTION_POINTER_UP | (fingerIndex << MotionEvent.ACTION_POINTER_INDEX_SHIFT);
-            } else if (action == MotionEvent.ACTION_DOWN) {
-                action = MotionEvent.ACTION_POINTER_DOWN | (fingerIndex << MotionEvent.ACTION_POINTER_INDEX_SHIFT);
+        if (pointerCount == 1) {
+            if (action == MotionEvent.ACTION_DOWN) {
+                lastTouchDown = now;
+            }
+        } else {
+            // secondary pointers must use ACTION_POINTER_* ORed with the pointerIndex
+            if (action == MotionEvent.ACTION_UP) {
+                action = MotionEvent.ACTION_POINTER_UP | (pointerIndex << MotionEvent.ACTION_POINTER_INDEX_SHIFT);
+            } else if (action == MotionEvent.ACTION_DOWN) {
+                action = MotionEvent.ACTION_POINTER_DOWN | (pointerIndex << MotionEvent.ACTION_POINTER_INDEX_SHIFT);
             }
-        } else if (action == MotionEvent.ACTION_DOWN) {
-            lastTouchDown = now;
         }
 
-        MotionEvent event = MotionEvent.obtain(lastTouchDown, now, action, pointerCount, touchPointerProperties, touchPointerCoords, 0, 0, 1f, 1f, 0, 0,
-                InputDevice.SOURCE_TOUCHSCREEN, 0);
+        MotionEvent event = MotionEvent.obtain(lastTouchDown, now, action, pointerCount, pointerProperties,
+                pointerCoords, 0, 0, 1f, 1f, 0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);
         return injectEvent(event);
     }
 
@@ -240,23 +188,30 @@ public class Controller {
             // ignore event
             return false;
         }
-        setMousePointerCoords(point);
-        setScroll(hScroll, vScroll);
-        MotionEvent event = MotionEvent.obtain(lastMouseDown, now, MotionEvent.ACTION_SCROLL, 1, mousePointerProperties, mousePointerCoords, 0, 0, 1f, 1f, 0,
-                0, InputDevice.SOURCE_MOUSE, 0);
+
+        MotionEvent.PointerProperties props = pointerProperties[0];
+        props.id = 0;
+
+        MotionEvent.PointerCoords coords = pointerCoords[0];
+        coords.x = point.getX();
+        coords.y = point.getY();
+        coords.setAxisValue(MotionEvent.AXIS_HSCROLL, hScroll);
+        coords.setAxisValue(MotionEvent.AXIS_VSCROLL, vScroll);
+
+        MotionEvent event = MotionEvent.obtain(lastTouchDown, now, MotionEvent.ACTION_SCROLL, 1, pointerProperties,
+                pointerCoords, 0, 0, 1f, 1f, 0, 0, InputDevice.SOURCE_MOUSE, 0);
         return injectEvent(event);
     }
 
     private boolean injectKeyEvent(int action, int keyCode, int repeat, int metaState) {
         long now = SystemClock.uptimeMillis();
-        KeyEvent event = new KeyEvent(now, now, action, keyCode, repeat, metaState, KeyCharacterMap.VIRTUAL_KEYBOARD, 0, 0,
-                InputDevice.SOURCE_KEYBOARD);
+        KeyEvent event = new KeyEvent(now, now, action, keyCode, repeat, metaState, KeyCharacterMap.VIRTUAL_KEYBOARD,
+                0, 0, InputDevice.SOURCE_KEYBOARD);
         return injectEvent(event);
     }
 
     private boolean injectKeycode(int keyCode) {
-        return injectKeyEvent(KeyEvent.ACTION_DOWN, keyCode, 0, 0)
-                && injectKeyEvent(KeyEvent.ACTION_UP, keyCode, 0, 0);
+        return injectKeyEvent(KeyEvent.ACTION_DOWN, keyCode, 0, 0) && injectKeyEvent(KeyEvent.ACTION_UP, keyCode, 0, 0);
     }
 
     private boolean injectEvent(InputEvent event) {

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

@@ -1,101 +0,0 @@
-package com.genymobile.scrcpy;
-
-import android.view.MotionEvent;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class FingersState {
-
-    private final List<Finger> fingers = new ArrayList<>();
-    private int maxFingers;
-
-    public FingersState(int maxFingers) {
-        this.maxFingers = maxFingers;
-    }
-
-    private int indexOf(long id) {
-        for (int i = 0; i < fingers.size(); ++i) {
-            Finger finger = fingers.get(i);
-            if (finger.getId() == id) {
-                return i;
-            }
-        }
-        return -1;
-    }
-
-    private boolean isLocalIdAvailable(int localId) {
-        for (int i = 0; i < fingers.size(); ++i) {
-            Finger finger = fingers.get(i);
-            if (finger.getLocalId() == localId) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    private int nextUnusedLocalId() {
-        for (int localId = 0; localId < maxFingers; ++localId) {
-            if (isLocalIdAvailable(localId)) {
-                return localId;
-            }
-        }
-        return -1;
-    }
-
-    public Finger get(int index) {
-        return fingers.get(index);
-    }
-
-    public int getFingerIndex(long id) {
-        int index = indexOf(id);
-        if (index != -1) {
-            // already exists, return it
-            return index;
-        }
-        if (fingers.size() >= maxFingers) {
-            // it's full
-            return -1;
-        }
-        // id 0 is reserved for mouse events
-        int localId = nextUnusedLocalId();
-        if (localId == -1) {
-            throw new AssertionError("fingers.size() < maxFingers implies that a local id is available");
-        }
-        Finger finger = new Finger(id, localId);
-        fingers.add(finger);
-        // return the index of the finger
-        return fingers.size() - 1;
-    }
-
-    /**
-     * Initialize the motion event parameters.
-     *
-     * @param props  the pointer properties
-     * @param coords the pointer coordinates
-     * @return The number of items initialized (the number of fingers).
-     */
-    public int update(MotionEvent.PointerProperties[] props, MotionEvent.PointerCoords[] coords) {
-        for (int i = 0; i < fingers.size(); ++i) {
-            Finger finger = fingers.get(i);
-
-            // id 0 is reserved for mouse events
-            props[i].id = finger.getLocalId();
-
-            Point point = finger.getPoint();
-            coords[i].x = point.getX();
-            coords[i].y = point.getY();
-            coords[i].pressure = finger.getPressure();
-        }
-        return fingers.size();
-    }
-
-    public void cleanUp() {
-        for (int i = fingers.size() - 1; i >= 0; --i) {
-            Finger finger = fingers.get(i);
-            if (finger.isUp()) {
-                fingers.remove(i);
-            }
-        }
-    }
-}

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

@@ -1,14 +1,22 @@
 package com.genymobile.scrcpy;
 
-public class Finger {
+public class Pointer {
 
+    /**
+     * Pointer id as received from the client.
+     */
     private final long id;
+
+    /**
+     * Local pointer id, using the lowest possible values to fill the {@link android.view.MotionEvent.PointerProperties PointerProperties}.
+     */
     private final int localId;
+
     private Point point;
     private float pressure;
     private boolean up;
 
-    public Finger(long id, int localId) {
+    public Pointer(long id, int localId) {
         this.id = id;
         this.localId = localId;
     }

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

@@ -0,0 +1,103 @@
+package com.genymobile.scrcpy;
+
+import android.view.MotionEvent;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PointersState {
+
+    public static final int MAX_POINTERS = 10;
+
+    private final List<Pointer> pointers = new ArrayList<>();
+
+    private int indexOf(long id) {
+        for (int i = 0; i < pointers.size(); ++i) {
+            Pointer pointer = pointers.get(i);
+            if (pointer.getId() == id) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    private boolean isLocalIdAvailable(int localId) {
+        for (int i = 0; i < pointers.size(); ++i) {
+            Pointer pointer = pointers.get(i);
+            if (pointer.getLocalId() == localId) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private int nextUnusedLocalId() {
+        for (int localId = 0; localId < MAX_POINTERS; ++localId) {
+            if (isLocalIdAvailable(localId)) {
+                return localId;
+            }
+        }
+        return -1;
+    }
+
+    public Pointer get(int index) {
+        return pointers.get(index);
+    }
+
+    public int getPointerIndex(long id) {
+        int index = indexOf(id);
+        if (index != -1) {
+            // already exists, return it
+            return index;
+        }
+        if (pointers.size() >= MAX_POINTERS) {
+            // it's full
+            return -1;
+        }
+        // id 0 is reserved for mouse events
+        int localId = nextUnusedLocalId();
+        if (localId == -1) {
+            throw new AssertionError("pointers.size() < maxFingers implies that a local id is available");
+        }
+        Pointer pointer = new Pointer(id, localId);
+        pointers.add(pointer);
+        // return the index of the pointer
+        return pointers.size() - 1;
+    }
+
+    /**
+     * Initialize the motion event parameters.
+     *
+     * @param props  the pointer properties
+     * @param coords the pointer coordinates
+     * @return The number of items initialized (the number of pointers).
+     */
+    public int update(MotionEvent.PointerProperties[] props, MotionEvent.PointerCoords[] coords) {
+        int count = pointers.size();
+        for (int i = 0; i < count; ++i) {
+            Pointer pointer = pointers.get(i);
+
+            // id 0 is reserved for mouse events
+            props[i].id = pointer.getLocalId();
+
+            Point point = pointer.getPoint();
+            coords[i].x = point.getX();
+            coords[i].y = point.getY();
+            coords[i].pressure = pointer.getPressure();
+        }
+        cleanUp();
+        return count;
+    }
+
+    /**
+     * Remove all pointers which are UP.
+     */
+    private void cleanUp() {
+        for (int i = pointers.size() - 1; i >= 0; --i) {
+            Pointer pointer = pointers.get(i);
+            if (pointer.isUp()) {
+                pointers.remove(i);
+            }
+        }
+    }
+}

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

@@ -76,35 +76,6 @@ public class ControlMessageReaderTest {
         Assert.assertEquals(new String(text, StandardCharsets.US_ASCII), event.getText());
     }
 
-    @Test
-    @SuppressWarnings("checkstyle:MagicNumber")
-    public void testParseMouseEvent() throws IOException {
-        ControlMessageReader reader = new ControlMessageReader();
-
-        ByteArrayOutputStream bos = new ByteArrayOutputStream();
-        DataOutputStream dos = new DataOutputStream(bos);
-        dos.writeByte(ControlMessage.TYPE_INJECT_MOUSE_EVENT);
-        dos.writeByte(MotionEvent.ACTION_DOWN);
-        dos.writeInt(MotionEvent.BUTTON_PRIMARY);
-        dos.writeInt(100);
-        dos.writeInt(200);
-        dos.writeShort(1080);
-        dos.writeShort(1920);
-
-        byte[] packet = bos.toByteArray();
-
-        reader.readFrom(new ByteArrayInputStream(packet));
-        ControlMessage event = reader.next();
-
-        Assert.assertEquals(ControlMessage.TYPE_INJECT_MOUSE_EVENT, event.getType());
-        Assert.assertEquals(MotionEvent.ACTION_DOWN, event.getAction());
-        Assert.assertEquals(MotionEvent.BUTTON_PRIMARY, event.getButtons());
-        Assert.assertEquals(100, event.getPosition().getPoint().getX());
-        Assert.assertEquals(200, event.getPosition().getPoint().getY());
-        Assert.assertEquals(1080, event.getPosition().getScreenSize().getWidth());
-        Assert.assertEquals(1920, event.getPosition().getScreenSize().getHeight());
-    }
-
     @Test
     @SuppressWarnings("checkstyle:MagicNumber")
     public void testParseTouchEvent() throws IOException {
@@ -114,12 +85,13 @@ public class ControlMessageReaderTest {
         DataOutputStream dos = new DataOutputStream(bos);
         dos.writeByte(ControlMessage.TYPE_INJECT_TOUCH_EVENT);
         dos.writeByte(MotionEvent.ACTION_DOWN);
-        dos.writeLong(-42); // fingerId
+        dos.writeLong(-42); // pointerId
         dos.writeInt(100);
         dos.writeInt(200);
         dos.writeShort(1080);
         dos.writeShort(1920);
         dos.writeShort(0xffff); // pressure
+        dos.writeInt(MotionEvent.BUTTON_PRIMARY);
 
         byte[] packet = bos.toByteArray();
 
@@ -128,12 +100,13 @@ public class ControlMessageReaderTest {
 
         Assert.assertEquals(ControlMessage.TYPE_INJECT_TOUCH_EVENT, event.getType());
         Assert.assertEquals(MotionEvent.ACTION_DOWN, event.getAction());
-        Assert.assertEquals(-42, event.getFingerId());
+        Assert.assertEquals(-42, event.getPointerId());
         Assert.assertEquals(100, event.getPosition().getPoint().getX());
         Assert.assertEquals(200, event.getPosition().getPoint().getY());
         Assert.assertEquals(1080, event.getPosition().getScreenSize().getWidth());
         Assert.assertEquals(1920, event.getPosition().getScreenSize().getHeight());
         Assert.assertEquals(1f, event.getPressure(), 0f); // must be exact
+        Assert.assertEquals(MotionEvent.BUTTON_PRIMARY, event.getButtons());
     }
 
     @Test