Add and implement wayland protocol for pinch gestures

Extends the wl_pointer protocol using the wayland upstream
zwp_pointer_gestures protocol to pass information about pinch gestures.

BUG=b:25668308

Change-Id: I9f90ebebec3f8476181e0426401827a3cf1064e4
Reviewed-on: https://chromium-review.googlesource.com/699017
Commit-Queue: Sean O'Brien <seobrien@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506828}

components/exo/pointer.cc

@@ -8,7 +8,7 @@
 
 #include "ash/public/cpp/shell_window_ids.h"
 #include "components/exo/pointer_delegate.h"
-#include "components/exo/pointer_stylus_delegate.h"
+#include "components/exo/pointer_gesture_pinch_delegate.h"
 #include "components/exo/surface.h"
 #include "components/exo/wm_helper.h"
 #include "components/viz/common/frame_sinks/copy_output_request.h"
@@ -96,6 +96,8 @@ Pointer::~Pointer() {
     focus_surface_->RemoveSurfaceObserver(this);
     focus_surface_->UnregisterCursorProvider(this);
   }
+  if (pinch_delegate_)
+    pinch_delegate_->OnPointerDestroying(this);
   auto* helper = WMHelper::GetInstance();
   helper->RemoveDisplayConfigurationObserver(this);
   helper->RemoveCursorObserver(this);
@@ -151,6 +153,10 @@ gfx::NativeCursor Pointer::GetCursor() {
   return cursor_;
 }
 
+void Pointer::SetGesturePinchDelegate(PointerGesturePinchDelegate* delegate) {
+  pinch_delegate_ = delegate;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // SurfaceDelegate overrides:
 
@@ -293,6 +299,36 @@ void Pointer::OnScrollEvent(ui::ScrollEvent* event) {
   OnMouseEvent(event);
 }
 
+void Pointer::OnGestureEvent(ui::GestureEvent* event) {
+  // We don't want to handle gestures generated from touchscreen events,
+  // we handle touch events in touch.cc
+  if (event->details().device_type() != ui::GestureDeviceType::DEVICE_TOUCHPAD)
+    return;
+
+  if (!focus_surface_ || !pinch_delegate_)
+    return;
+
+  switch (event->type()) {
+    case ui::ET_GESTURE_PINCH_BEGIN:
+      pinch_delegate_->OnPointerPinchBegin(event->unique_touch_event_id(),
+                                           event->time_stamp(), focus_surface_);
+      delegate_->OnPointerFrame();
+      break;
+    case ui::ET_GESTURE_PINCH_UPDATE:
+      pinch_delegate_->OnPointerPinchUpdate(event->time_stamp(),
+                                            event->details().scale());
+      delegate_->OnPointerFrame();
+      break;
+    case ui::ET_GESTURE_PINCH_END:
+      pinch_delegate_->OnPointerPinchEnd(event->unique_touch_event_id(),
+                                         event->time_stamp());
+      delegate_->OnPointerFrame();
+      break;
+    default:
+      break;
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WMHelper::CursorObserver overrides:
 

components/exo/pointer.h

@@ -32,6 +32,7 @@ class MouseEvent;
 
 namespace exo {
 class PointerDelegate;
+class PointerGesturePinchDelegate;
 class Surface;
 class SurfaceTreeHost;
 
@@ -53,6 +54,9 @@ class Pointer : public SurfaceTreeHost,
   // pointer location, in surface local coordinates.
   void SetCursor(Surface* surface, const gfx::Point& hotspot);
 
+  // Set delegate for pinch events.
+  void SetGesturePinchDelegate(PointerGesturePinchDelegate* delegate);
+
   // Returns the current cursor for the pointer.
   gfx::NativeCursor GetCursor();
 
@@ -65,6 +69,7 @@ class Pointer : public SurfaceTreeHost,
   // Overridden from ui::EventHandler:
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnScrollEvent(ui::ScrollEvent* event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
 
   // Overridden from WMHelper::CursorObserver:
   void OnCursorSizeChanged(ui::CursorSize cursor_size) override;
@@ -95,6 +100,9 @@ class Pointer : public SurfaceTreeHost,
   // The delegate instance that all events are dispatched to.
   PointerDelegate* const delegate_;
 
+  // The delegate instance that all pinch related events are dispatched to.
+  PointerGesturePinchDelegate* pinch_delegate_ = nullptr;
+
   // The current focus surface for the pointer.
   Surface* focus_surface_ = nullptr;
 

components/exo/pointer_gesture_pinch_delegate.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_EXO_POINTER_GESTURE_PINCH_DELEGATE_H_
+#define COMPONENTS_EXO_POINTER_GESTURE_PINCH_DELEGATE_H_
+
+#include "base/time/time.h"
+
+namespace exo {
+class Pointer;
+
+// Handles pinch event details on pointers. Used as an extension to the
+// PointerDelegate.
+class PointerGesturePinchDelegate {
+ public:
+  // Called at the top of the pointer's destructor, to give observers a
+  // chance to remove themselves.
+  virtual void OnPointerDestroying(Pointer* pointer) = 0;
+
+  virtual void OnPointerPinchBegin(uint32_t unique_touch_event_id,
+                                   base::TimeTicks time_stamp,
+                                   Surface* surface) = 0;
+
+  virtual void OnPointerPinchUpdate(base::TimeTicks time_stamp,
+                                    float scale) = 0;
+
+  virtual void OnPointerPinchEnd(uint32_t unique_touch_event_id,
+                                 base::TimeTicks time_stamp) = 0;
+
+ protected:
+  virtual ~PointerGesturePinchDelegate() {}
+};
+
+}  // namespace exo
+
+#endif  // COMPONENTS_EXO_POINTER_GESTURE_PINCH_DELEGATE_H_

components/exo/wayland/BUILD.gn

@@ -64,6 +64,7 @@ source_set("wayland") {
     "//third_party/wayland-protocols:gaming_input_protocol",
     "//third_party/wayland-protocols:keyboard_configuration_protocol",
     "//third_party/wayland-protocols:keyboard_extension_protocol",
+    "//third_party/wayland-protocols:pointer_gestures_protocol",
     "//third_party/wayland-protocols:presentation_time_protocol",
     "//third_party/wayland-protocols:remote_shell_protocol",
     "//third_party/wayland-protocols:secure_output_protocol",

components/exo/wayland/server.cc

@@ -12,6 +12,7 @@
 #include <keyboard-configuration-unstable-v1-server-protocol.h>
 #include <keyboard-extension-unstable-v1-server-protocol.h>
 #include <linux/input.h>
+#include <pointer-gestures-unstable-v1-server-protocol.h>
 #include <presentation-time-server-protocol.h>
 #include <remote-shell-unstable-v1-server-protocol.h>
 #include <secure-output-unstable-v1-server-protocol.h>
@@ -71,6 +72,7 @@
 #include "components/exo/notification_surface_manager.h"
 #include "components/exo/pointer.h"
 #include "components/exo/pointer_delegate.h"
+#include "components/exo/pointer_gesture_pinch_delegate.h"
 #include "components/exo/shared_memory.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/sub_surface.h"
@@ -4093,6 +4095,95 @@ void bind_stylus_v2(wl_client* client,
                                  nullptr);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// pointer_gesture_swipe_v1 interface:
+
+void pointer_gestures_get_swipe_gesture(wl_client* client,
+                                        wl_resource* resource,
+                                        uint32_t id,
+                                        wl_resource* pointer_resource) {
+  NOTIMPLEMENTED();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// pointer_gesture_pinch_v1 interface:
+
+class WaylandPointerGesturePinchDelegate : public PointerGesturePinchDelegate {
+ public:
+  WaylandPointerGesturePinchDelegate(wl_resource* resource, Pointer* pointer)
+      : resource_(resource), pointer_(pointer) {
+    pointer_->SetGesturePinchDelegate(this);
+  }
+
+  ~WaylandPointerGesturePinchDelegate() override {
+    if (pointer_)
+      pointer_->SetGesturePinchDelegate(nullptr);
+  }
+  void OnPointerDestroying(Pointer* pointer) override { pointer_ = nullptr; }
+  void OnPointerPinchBegin(uint32_t unique_touch_event_id,
+                           base::TimeTicks time_stamp,
+                           Surface* surface) override {
+    wl_resource* surface_resource = GetSurfaceResource(surface);
+    DCHECK(surface_resource);
+    zwp_pointer_gesture_pinch_v1_send_begin(resource_, unique_touch_event_id,
+                                            TimeTicksToMilliseconds(time_stamp),
+                                            surface_resource, 2);
+  }
+  void OnPointerPinchUpdate(base::TimeTicks time_stamp, float scale) override {
+    zwp_pointer_gesture_pinch_v1_send_update(
+        resource_, TimeTicksToMilliseconds(time_stamp), 0, 0,
+        wl_fixed_from_double(scale), 0);
+  }
+  void OnPointerPinchEnd(uint32_t unique_touch_event_id,
+                         base::TimeTicks time_stamp) override {
+    zwp_pointer_gesture_pinch_v1_send_end(resource_, unique_touch_event_id,
+                                          TimeTicksToMilliseconds(time_stamp),
+                                          0);
+  }
+
+ private:
+  wl_resource* const resource_;
+  Pointer* pointer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaylandPointerGesturePinchDelegate);
+};
+
+void pointer_gesture_pinch_destroy(wl_client* client, wl_resource* resource) {
+  wl_resource_destroy(resource);
+}
+
+const struct zwp_pointer_gesture_pinch_v1_interface
+    pointer_gesture_pinch_implementation = {pointer_gesture_pinch_destroy};
+
+void pointer_gestures_get_pinch_gesture(wl_client* client,
+                                        wl_resource* resource,
+                                        uint32_t id,
+                                        wl_resource* pointer_resource) {
+  Pointer* pointer = GetUserDataAs<Pointer>(pointer_resource);
+  wl_resource* pointer_gesture_pinch_resource = wl_resource_create(
+      client, &zwp_pointer_gesture_pinch_v1_interface, 1, id);
+  SetImplementation(pointer_gesture_pinch_resource,
+                    &pointer_gesture_pinch_implementation,
+                    base::MakeUnique<WaylandPointerGesturePinchDelegate>(
+                        pointer_gesture_pinch_resource, pointer));
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// pointer_gestures_v1 interface:
+
+const struct zwp_pointer_gestures_v1_interface pointer_gestures_implementation =
+    {pointer_gestures_get_swipe_gesture, pointer_gestures_get_pinch_gesture};
+
+void bind_pointer_gestures(wl_client* client,
+                           void* data,
+                           uint32_t version,
+                           uint32_t id) {
+  wl_resource* resource = wl_resource_create(
+      client, &zwp_pointer_gestures_v1_interface, version, id);
+  wl_resource_set_implementation(resource, &pointer_gestures_implementation,
+                                 data, nullptr);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // pointer_stylus interface (deprecated)
 // TODO(denniskempin): Remove once client no longer depends on this interface.
@@ -4440,6 +4531,8 @@ Server::Server(Display* display)
                    bind_stylus_v1_DEPRECATED);
   wl_global_create(wl_display_.get(), &zcr_stylus_v2_interface, 1, display_,
                    bind_stylus_v2);
+  wl_global_create(wl_display_.get(), &zwp_pointer_gestures_v1_interface, 1,
+                   display_, bind_pointer_gestures);
   wl_global_create(wl_display_.get(), &zcr_keyboard_configuration_v1_interface,
                    2, display_, bind_keyboard_configuration);
   wl_global_create(wl_display_.get(), &zcr_stylus_tools_v1_interface, 1,

third_party/wayland-protocols/BUILD.gn

@@ -221,6 +221,27 @@ source_set("stylus_protocol") {
   public_configs = [ ":stylus_protocol_config" ]
 }
 
+config("pointer_gestures_protocol_config") {
+  include_dirs = [ "include/protocol" ]
+}
+
+source_set("pointer_gestures_protocol") {
+  sources = [
+    "include/protocol/pointer-gestures-unstable-v1-client-protocol.h",
+    "include/protocol/pointer-gestures-unstable-v1-server-protocol.h",
+    "protocol/pointer-gestures-v1-protocol.c",
+  ]
+
+  deps = [
+    "//third_party/wayland:wayland_util",
+  ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+
+  public_configs = [ ":pointer_gestures_protocol_config" ]
+}
+
 config("keyboard_configuration_protocol_config") {
   include_dirs = [ "include/protocol" ]
 }

third_party/wayland-protocols/README.chromium

@@ -64,4 +64,6 @@ To import a new snapshot of wayland-protocols:
     wayland-scanner code < unstable/keyboard/keyboard-extension-unstable-v1.xml > protocol/keyboard-extension-protocol.c
     wayland-scanner server-header < unstable/keyboard/keyboard-extension-unstable-v1.xml > include/protocol/keyboard-extension-unstable-v1-server-protocol.h
     wayland-scanner client-header < unstable/keyboard/keyboard-extension-unstable-v1.xml > include/protocol/keyboard-extension-unstable-v1-client-protocol.h
+    wayland-scanner client-header < src/unstable/pointer-gestures/pointer-gestures-unstable-v1.xml > include/protocol/pointer-gestures-unstable-v1-client-protocol.h
+    wayland-scanner server-header < src/unstable/pointer-gestures/pointer-gestures-unstable-v1.xml > include/protocol/pointer-gestures-unstable-v1-server-protocol.h
 - Update this README to reflect the new version number.

third_party/wayland-protocols/include/protocol/pointer-gestures-unstable-v1-client-protocol.h

+#ifndef POINTER_GESTURES_UNSTABLE_V1_CLIENT_PROTOCOL_H
+#define POINTER_GESTURES_UNSTABLE_V1_CLIENT_PROTOCOL_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stddef.h>
+#include "wayland-client.h"
+
+struct wl_client;
+struct wl_resource;
+
+struct zwp_pointer_gestures_v1;
+struct zwp_pointer_gesture_swipe_v1;
+struct zwp_pointer_gesture_pinch_v1;
+
+extern const struct wl_interface zwp_pointer_gestures_v1_interface;
+extern const struct wl_interface zwp_pointer_gesture_swipe_v1_interface;
+extern const struct wl_interface zwp_pointer_gesture_pinch_v1_interface;
+
+#define ZWP_POINTER_GESTURES_V1_GET_SWIPE_GESTURE	0
+#define ZWP_POINTER_GESTURES_V1_GET_PINCH_GESTURE	1
+
+static inline void
+zwp_pointer_gestures_v1_set_user_data(struct zwp_pointer_gestures_v1 *zwp_pointer_gestures_v1, void *user_data)
+{
+	wl_proxy_set_user_data((struct wl_proxy *) zwp_pointer_gestures_v1, user_data);
+}
+
+static inline void *
+zwp_pointer_gestures_v1_get_user_data(struct zwp_pointer_gestures_v1 *zwp_pointer_gestures_v1)
+{
+	return wl_proxy_get_user_data((struct wl_proxy *) zwp_pointer_gestures_v1);
+}
+
+static inline void
+zwp_pointer_gestures_v1_destroy(struct zwp_pointer_gestures_v1 *zwp_pointer_gestures_v1)
+{
+	wl_proxy_destroy((struct wl_proxy *) zwp_pointer_gestures_v1);
+}
+
+static inline struct zwp_pointer_gesture_swipe_v1 *
+zwp_pointer_gestures_v1_get_swipe_gesture(struct zwp_pointer_gestures_v1 *zwp_pointer_gestures_v1, struct wl_pointer *pointer)
+{
+	struct wl_proxy *id;
+
+	id = wl_proxy_marshal_constructor((struct wl_proxy *) zwp_pointer_gestures_v1,
+			 ZWP_POINTER_GESTURES_V1_GET_SWIPE_GESTURE, &zwp_pointer_gesture_swipe_v1_interface, NULL, pointer);
+
+	return (struct zwp_pointer_gesture_swipe_v1 *) id;
+}
+
+static inline struct zwp_pointer_gesture_pinch_v1 *
+zwp_pointer_gestures_v1_get_pinch_gesture(struct zwp_pointer_gestures_v1 *zwp_pointer_gestures_v1, struct wl_pointer *pointer)
+{
+	struct wl_proxy *id;
+
+	id = wl_proxy_marshal_constructor((struct wl_proxy *) zwp_pointer_gestures_v1,
+			 ZWP_POINTER_GESTURES_V1_GET_PINCH_GESTURE, &zwp_pointer_gesture_pinch_v1_interface, NULL, pointer);
+
+	return (struct zwp_pointer_gesture_pinch_v1 *) id;
+}
+
+/**
+ * zwp_pointer_gesture_swipe_v1 - a swipe gesture object
+ * @begin: multi-finger swipe begin
+ * @update: multi-finger swipe motion
+ * @end: multi-finger swipe end
+ *
+ * A swipe gesture object notifies a client about a multi-finger swipe
+ * gesture detected on an indirect input device such as a touchpad. The
+ * gesture is usually initiated by multiple fingers moving in the same
+ * direction but once initiated the direction may change. The precise
+ * conditions of when such a gesture is detected are
+ * implementation-dependent.
+ *
+ * A gesture consists of three stages: begin, update (optional) and end.
+ * There cannot be multiple simultaneous pinch or swipe gestures on a same
+ * pointer/seat, how compositors prevent these situations is
+ * implementation-dependent.
+ *
+ * A gesture may be cancelled by the compositor or the hardware. Clients
+ * should not consider performing permanent or irreversible actions until
+ * the end of a gesture has been received.
+ */
+struct zwp_pointer_gesture_swipe_v1_listener {
+	/**
+	 * begin - multi-finger swipe begin
+	 * @serial: (none)
+	 * @time: timestamp with millisecond granularity
+	 * @surface: (none)
+	 * @fingers: number of fingers
+	 *
+	 * This event is sent when a multi-finger swipe gesture is
+	 * detected on the device.
+	 */
+	void (*begin)(void *data,
+		      struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1,
+		      uint32_t serial,
+		      uint32_t time,
+		      struct wl_surface *surface,
+		      uint32_t fingers);
+	/**
+	 * update - multi-finger swipe motion
+	 * @time: timestamp with millisecond granularity
+	 * @dx: delta x coordinate in surface coordinate space
+	 * @dy: delta y coordinate in surface coordinate space
+	 *
+	 * This event is sent when a multi-finger swipe gesture changes
+	 * the position of the logical center.
+	 *
+	 * The dx and dy coordinates are relative coordinates of the
+	 * logical center of the gesture compared to the previous event.
+	 */
+	void (*update)(void *data,
+		       struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1,
+		       uint32_t time,
+		       wl_fixed_t dx,
+		       wl_fixed_t dy);
+	/**
+	 * end - multi-finger swipe end
+	 * @serial: (none)
+	 * @time: timestamp with millisecond granularity
+	 * @cancelled: 1 if the gesture was cancelled, 0 otherwise
+	 *
+	 * This event is sent when a multi-finger swipe gesture ceases to
+	 * be valid. This may happen when one or more fingers are lifted or
+	 * the gesture is cancelled.
+	 *
+	 * When a gesture is cancelled, the client should undo state
+	 * changes caused by this gesture. What causes a gesture to be
+	 * cancelled is implementation-dependent.
+	 */
+	void (*end)(void *data,
+		    struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1,
+		    uint32_t serial,
+		    uint32_t time,
+		    int32_t cancelled);
+};
+
+static inline int
+zwp_pointer_gesture_swipe_v1_add_listener(struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1,
+					  const struct zwp_pointer_gesture_swipe_v1_listener *listener, void *data)
+{
+	return wl_proxy_add_listener((struct wl_proxy *) zwp_pointer_gesture_swipe_v1,
+				     (void (**)(void)) listener, data);
+}
+
+#define ZWP_POINTER_GESTURE_SWIPE_V1_DESTROY	0
+
+static inline void
+zwp_pointer_gesture_swipe_v1_set_user_data(struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1, void *user_data)
+{
+	wl_proxy_set_user_data((struct wl_proxy *) zwp_pointer_gesture_swipe_v1, user_data);
+}
+
+static inline void *
+zwp_pointer_gesture_swipe_v1_get_user_data(struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1)
+{
+	return wl_proxy_get_user_data((struct wl_proxy *) zwp_pointer_gesture_swipe_v1);
+}
+
+static inline void
+zwp_pointer_gesture_swipe_v1_destroy(struct zwp_pointer_gesture_swipe_v1 *zwp_pointer_gesture_swipe_v1)
+{
+	wl_proxy_marshal((struct wl_proxy *) zwp_pointer_gesture_swipe_v1,
+			 ZWP_POINTER_GESTURE_SWIPE_V1_DESTROY);
+
+	wl_proxy_destroy((struct wl_proxy *) zwp_pointer_gesture_swipe_v1);
+}
+
+/**
+ * zwp_pointer_gesture_pinch_v1 - a pinch gesture object
+ * @begin: multi-finger pinch begin
+ * @update: multi-finger pinch motion
+ * @end: multi-finger pinch end
+ *
+ * A pinch gesture object notifies a client about a multi-finger pinch
+ * gesture detected on an indirect input device such as a touchpad. The
+ * gesture is usually initiated by multiple fingers moving towards each
+ * other or away from each other, or by two or more fingers rotating around
+ * a logical center of gravity. The precise conditions of when such a
+ * gesture is detected are implementation-dependent.
+ *
+ * A gesture consists of three stages: begin, update (optional) and end.
+ * There cannot be multiple simultaneous pinch or swipe gestures on a same
+ * pointer/seat, how compositors prevent these situations is
+ * implementation-dependent.
+ *
+ * A gesture may be cancelled by the compositor or the hardware. Clients
+ * should not consider performing permanent or irreversible actions until
+ * the end of a gesture has been received.
+ */
+struct zwp_pointer_gesture_pinch_v1_listener {
+	/**
+	 * begin - multi-finger pinch begin
+	 * @serial: (none)
+	 * @time: timestamp with millisecond granularity
+	 * @surface: (none)
+	 * @fingers: number of fingers
+	 *
+	 * This event is sent when a multi-finger pinch gesture is
+	 * detected on the device.
+	 */
+	void (*begin)(void *data,
+		      struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1,
+		      uint32_t serial,
+		      uint32_t time,
+		      struct wl_surface *surface,
+		      uint32_t fingers);
+	/**
+	 * update - multi-finger pinch motion
+	 * @time: timestamp with millisecond granularity
+	 * @dx: delta x coordinate in surface coordinate space
+	 * @dy: delta y coordinate in surface coordinate space
+	 * @scale: scale relative to the initial finger position
+	 * @rotation: angle in degrees cw relative to the previous event
+	 *
+	 * This event is sent when a multi-finger pinch gesture changes
+	 * the position of the logical center, the rotation or the relative
+	 * scale.
+	 *
+	 * The dx and dy coordinates are relative coordinates in the
+	 * surface coordinate space of the logical center of the gesture.
+	 *
+	 * The scale factor is an absolute scale compared to the
+	 * pointer_gesture_pinch.begin event, e.g. a scale of 2 means the
+	 * fingers are now twice as far apart as on
+	 * pointer_gesture_pinch.begin.
+	 *
+	 * The rotation is the relative angle in degrees clockwise compared
+	 * to the previous pointer_gesture_pinch.begin or
+	 * pointer_gesture_pinch.update event.
+	 */
+	void (*update)(void *data,
+		       struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1,
+		       uint32_t time,
+		       wl_fixed_t dx,
+		       wl_fixed_t dy,
+		       wl_fixed_t scale,
+		       wl_fixed_t rotation);
+	/**
+	 * end - multi-finger pinch end
+	 * @serial: (none)
+	 * @time: timestamp with millisecond granularity
+	 * @cancelled: 1 if the gesture was cancelled, 0 otherwise
+	 *
+	 * This event is sent when a multi-finger pinch gesture ceases to
+	 * be valid. This may happen when one or more fingers are lifted or
+	 * the gesture is cancelled.
+	 *
+	 * When a gesture is cancelled, the client should undo state
+	 * changes caused by this gesture. What causes a gesture to be
+	 * cancelled is implementation-dependent.
+	 */
+	void (*end)(void *data,
+		    struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1,
+		    uint32_t serial,
+		    uint32_t time,
+		    int32_t cancelled);
+};
+
+static inline int
+zwp_pointer_gesture_pinch_v1_add_listener(struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1,
+					  const struct zwp_pointer_gesture_pinch_v1_listener *listener, void *data)
+{
+	return wl_proxy_add_listener((struct wl_proxy *) zwp_pointer_gesture_pinch_v1,
+				     (void (**)(void)) listener, data);
+}
+
+#define ZWP_POINTER_GESTURE_PINCH_V1_DESTROY	0
+
+static inline void
+zwp_pointer_gesture_pinch_v1_set_user_data(struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1, void *user_data)
+{
+	wl_proxy_set_user_data((struct wl_proxy *) zwp_pointer_gesture_pinch_v1, user_data);
+}
+
+static inline void *
+zwp_pointer_gesture_pinch_v1_get_user_data(struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1)
+{
+	return wl_proxy_get_user_data((struct wl_proxy *) zwp_pointer_gesture_pinch_v1);
+}
+
+static inline void
+zwp_pointer_gesture_pinch_v1_destroy(struct zwp_pointer_gesture_pinch_v1 *zwp_pointer_gesture_pinch_v1)
+{
+	wl_proxy_marshal((struct wl_proxy *) zwp_pointer_gesture_pinch_v1,
+			 ZWP_POINTER_GESTURE_PINCH_V1_DESTROY);
+
+	wl_proxy_destroy((struct wl_proxy *) zwp_pointer_gesture_pinch_v1);
+}
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif

third_party/wayland-protocols/include/protocol/pointer-gestures-unstable-v1-server-protocol.h

+#ifndef POINTER_GESTURES_UNSTABLE_V1_SERVER_PROTOCOL_H
+#define POINTER_GESTURES_UNSTABLE_V1_SERVER_PROTOCOL_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stddef.h>
+#include "wayland-util.h"
+
+struct wl_client;
+struct wl_resource;
+
+struct zwp_pointer_gestures_v1;
+struct zwp_pointer_gesture_swipe_v1;
+struct zwp_pointer_gesture_pinch_v1;
+
+extern const struct wl_interface zwp_pointer_gestures_v1_interface;
+extern const struct wl_interface zwp_pointer_gesture_swipe_v1_interface;
+extern const struct wl_interface zwp_pointer_gesture_pinch_v1_interface;
+
+/**
+ * zwp_pointer_gestures_v1 - touchpad gestures
+ * @get_swipe_gesture: get swipe gesture
+ * @get_pinch_gesture: get pinch gesture
+ *
+ * A global interface to provide semantic touchpad gestures for a given
+ * pointer.
+ *
+ * Two gestures are currently supported: swipe and zoom/rotate. All
+ * gestures follow a three-stage cycle: begin, update, end and are
+ * identified by a unique id.
+ *
+ * Warning! The protocol described in this file is experimental and
+ * backward incompatible changes may be made. Backward compatible changes
+ * may be added together with the corresponding interface version bump.
+ * Backward incompatible changes are done by bumping the version number in
+ * the protocol and interface names and resetting the interface version.
+ * Once the protocol is to be declared stable, the 'z' prefix and the
+ * version number in the protocol and interface names are removed and the
+ * interface version number is reset.
+ */
+struct zwp_pointer_gestures_v1_interface {
+	/**
+	 * get_swipe_gesture - get swipe gesture
+	 * @id: (none)
+	 * @pointer: (none)
+	 *
+	 * Create a swipe gesture object. See the
+	 * wl_pointer_gesture_swipe interface for details.
+	 */
+	void (*get_swipe_gesture)(struct wl_client *client,
+				  struct wl_resource *resource,
+				  uint32_t id,
+				  struct wl_resource *pointer);
+	/**
+	 * get_pinch_gesture - get pinch gesture
+	 * @id: (none)
+	 * @pointer: (none)
+	 *
+	 * Create a pinch gesture object. See the
+	 * wl_pointer_gesture_pinch interface for details.
+	 */
+	void (*get_pinch_gesture)(struct wl_client *client,
+				  struct wl_resource *resource,
+				  uint32_t id,
+				  struct wl_resource *pointer);
+};
+
+/**
+ * zwp_pointer_gesture_swipe_v1 - a swipe gesture object
+ * @destroy: destroy the pointer swipe gesture object
+ *
+ * A swipe gesture object notifies a client about a multi-finger swipe
+ * gesture detected on an indirect input device such as a touchpad. The
+ * gesture is usually initiated by multiple fingers moving in the same
+ * direction but once initiated the direction may change. The precise
+ * conditions of when such a gesture is detected are
+ * implementation-dependent.
+ *
+ * A gesture consists of three stages: begin, update (optional) and end.
+ * There cannot be multiple simultaneous pinch or swipe gestures on a same
+ * pointer/seat, how compositors prevent these situations is
+ * implementation-dependent.
+ *
+ * A gesture may be cancelled by the compositor or the hardware. Clients
+ * should not consider performing permanent or irreversible actions until
+ * the end of a gesture has been received.
+ */
+struct zwp_pointer_gesture_swipe_v1_interface {
+	/**
+	 * destroy - destroy the pointer swipe gesture object
+	 *
+	 * 
+	 */
+	void (*destroy)(struct wl_client *client,
+			struct wl_resource *resource);
+};
+
+#define ZWP_POINTER_GESTURE_SWIPE_V1_BEGIN	0
+#define ZWP_POINTER_GESTURE_SWIPE_V1_UPDATE	1
+#define ZWP_POINTER_GESTURE_SWIPE_V1_END	2
+
+static inline void
+zwp_pointer_gesture_swipe_v1_send_begin(struct wl_resource *resource_, uint32_t serial, uint32_t time, struct wl_resource *surface, uint32_t fingers)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_SWIPE_V1_BEGIN, serial, time, surface, fingers);
+}
+
+static inline void
+zwp_pointer_gesture_swipe_v1_send_update(struct wl_resource *resource_, uint32_t time, wl_fixed_t dx, wl_fixed_t dy)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_SWIPE_V1_UPDATE, time, dx, dy);
+}
+
+static inline void
+zwp_pointer_gesture_swipe_v1_send_end(struct wl_resource *resource_, uint32_t serial, uint32_t time, int32_t cancelled)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_SWIPE_V1_END, serial, time, cancelled);
+}
+
+/**
+ * zwp_pointer_gesture_pinch_v1 - a pinch gesture object
+ * @destroy: destroy the pinch gesture object
+ *
+ * A pinch gesture object notifies a client about a multi-finger pinch
+ * gesture detected on an indirect input device such as a touchpad. The
+ * gesture is usually initiated by multiple fingers moving towards each
+ * other or away from each other, or by two or more fingers rotating around
+ * a logical center of gravity. The precise conditions of when such a
+ * gesture is detected are implementation-dependent.
+ *
+ * A gesture consists of three stages: begin, update (optional) and end.
+ * There cannot be multiple simultaneous pinch or swipe gestures on a same
+ * pointer/seat, how compositors prevent these situations is
+ * implementation-dependent.
+ *
+ * A gesture may be cancelled by the compositor or the hardware. Clients
+ * should not consider performing permanent or irreversible actions until
+ * the end of a gesture has been received.
+ */
+struct zwp_pointer_gesture_pinch_v1_interface {
+	/**
+	 * destroy - destroy the pinch gesture object
+	 *
+	 * 
+	 */
+	void (*destroy)(struct wl_client *client,
+			struct wl_resource *resource);
+};
+
+#define ZWP_POINTER_GESTURE_PINCH_V1_BEGIN	0
+#define ZWP_POINTER_GESTURE_PINCH_V1_UPDATE	1
+#define ZWP_POINTER_GESTURE_PINCH_V1_END	2
+
+static inline void
+zwp_pointer_gesture_pinch_v1_send_begin(struct wl_resource *resource_, uint32_t serial, uint32_t time, struct wl_resource *surface, uint32_t fingers)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_PINCH_V1_BEGIN, serial, time, surface, fingers);
+}
+
+static inline void
+zwp_pointer_gesture_pinch_v1_send_update(struct wl_resource *resource_, uint32_t time, wl_fixed_t dx, wl_fixed_t dy, wl_fixed_t scale, wl_fixed_t rotation)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_PINCH_V1_UPDATE, time, dx, dy, scale, rotation);
+}
+
+static inline void
+zwp_pointer_gesture_pinch_v1_send_end(struct wl_resource *resource_, uint32_t serial, uint32_t time, int32_t cancelled)
+{
+	wl_resource_post_event(resource_, ZWP_POINTER_GESTURE_PINCH_V1_END, serial, time, cancelled);
+}
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif

third_party/wayland-protocols/protocol/pointer-gestures-v1-protocol.c

+#include <stdlib.h>
+#include <stdint.h>
+#include "wayland-util.h"
+
+extern const struct wl_interface zwp_pointer_gesture_swipe_v1_interface;
+extern const struct wl_interface wl_pointer_interface;
+extern const struct wl_interface zwp_pointer_gesture_pinch_v1_interface;
+extern const struct wl_interface wl_pointer_interface;
+extern const struct wl_interface wl_surface_interface;
+extern const struct wl_interface wl_surface_interface;
+
+static const struct wl_interface *types[] = {
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	&zwp_pointer_gesture_swipe_v1_interface,
+	&wl_pointer_interface,
+	&zwp_pointer_gesture_pinch_v1_interface,
+	&wl_pointer_interface,
+	NULL,
+	NULL,
+	&wl_surface_interface,
+	NULL,
+	NULL,
+	NULL,
+	&wl_surface_interface,
+	NULL,
+};
+
+static const struct wl_message zwp_pointer_gestures_v1_requests[] = {
+	{ "get_swipe_gesture", "no", types + 5 },
+	{ "get_pinch_gesture", "no", types + 7 },
+};
+
+WL_EXPORT const struct wl_interface zwp_pointer_gestures_v1_interface = {
+	"zwp_pointer_gestures_v1", 1,
+	2, zwp_pointer_gestures_v1_requests,
+	0, NULL,
+};
+
+static const struct wl_message zwp_pointer_gesture_swipe_v1_requests[] = {
+	{ "destroy", "", types + 0 },
+};
+
+static const struct wl_message zwp_pointer_gesture_swipe_v1_events[] = {
+	{ "begin", "uuou", types + 9 },
+	{ "update", "uff", types + 0 },
+	{ "end", "uui", types + 0 },
+};
+
+WL_EXPORT const struct wl_interface zwp_pointer_gesture_swipe_v1_interface = {
+	"zwp_pointer_gesture_swipe_v1", 1,
+	1, zwp_pointer_gesture_swipe_v1_requests,
+	3, zwp_pointer_gesture_swipe_v1_events,
+};
+
+static const struct wl_message zwp_pointer_gesture_pinch_v1_requests[] = {
+	{ "destroy", "", types + 0 },
+};
+
+static const struct wl_message zwp_pointer_gesture_pinch_v1_events[] = {
+	{ "begin", "uuou", types + 13 },
+	{ "update", "uffff", types + 0 },
+	{ "end", "uui", types + 0 },
+};
+
+WL_EXPORT const struct wl_interface zwp_pointer_gesture_pinch_v1_interface = {
+	"zwp_pointer_gesture_pinch_v1", 1,
+	1, zwp_pointer_gesture_pinch_v1_requests,
+	3, zwp_pointer_gesture_pinch_v1_events,
+};
+