Support forward and back buttons (#164356)

Based on https://github.com/flutter/flutter/pull/163500 by @2bndy5

engine/src/flutter/shell/platform/linux/fl_pointer_manager.cc

@@ -27,6 +27,35 @@ struct _FlPointerManager {
 
 G_DEFINE_TYPE(FlPointerManager, fl_pointer_manager, G_TYPE_OBJECT);
 
+// 8 corresponds to mouse back button on both x11 and wayland
+static constexpr guint kMouseButtonBack = 8;
+
+// 9 corresponds to mouse forward button on both x11 and wayland
+static constexpr guint kMouseButtonForward = 9;
+
+// Convert a GDK button ID into a Flutter button ID
+static gboolean get_mouse_button(guint gdk_button, int64_t* button) {
+  switch (gdk_button) {
+    case GDK_BUTTON_PRIMARY:
+      *button = kFlutterPointerButtonMousePrimary;
+      return TRUE;
+    case GDK_BUTTON_MIDDLE:
+      *button = kFlutterPointerButtonMouseMiddle;
+      return TRUE;
+    case GDK_BUTTON_SECONDARY:
+      *button = kFlutterPointerButtonMouseSecondary;
+      return TRUE;
+    case kMouseButtonBack:
+      *button = kFlutterPointerButtonMouseBack;
+      return TRUE;
+    case kMouseButtonForward:
+      *button = kFlutterPointerButtonMouseForward;
+      return TRUE;
+    default:
+      return FALSE;
+  }
+}
+
 // Generates a mouse pointer event if the pointer appears inside the window.
 static void ensure_pointer_added(FlPointerManager* self,
                                  guint event_time,
@@ -79,9 +108,14 @@ gboolean fl_pointer_manager_handle_button_press(
     FlutterPointerDeviceKind device_kind,
     gdouble x,
     gdouble y,
-    int64_t button) {
+    guint gdk_button) {
   g_return_val_if_fail(FL_IS_POINTER_MANAGER(self), FALSE);
 
+  int64_t button;
+  if (!get_mouse_button(gdk_button, &button)) {
+    return FALSE;
+  }
+
   ensure_pointer_added(self, event_time, device_kind, x, y);
 
   // Drop the event if Flutter already thinks the button is down.
@@ -112,9 +146,14 @@ gboolean fl_pointer_manager_handle_button_release(
     FlutterPointerDeviceKind device_kind,
     gdouble x,
     gdouble y,
-    int64_t button) {
+    guint gdk_button) {
   g_return_val_if_fail(FL_IS_POINTER_MANAGER(self), FALSE);
 
+  int64_t button;
+  if (!get_mouse_button(gdk_button, &button)) {
+    return FALSE;
+  }
+
   // Drop the event if Flutter already thinks the button is up.
   if ((self->button_state & button) == 0) {
     return FALSE;

engine/src/flutter/shell/platform/linux/fl_pointer_manager.h

@@ -35,7 +35,7 @@ FlPointerManager* fl_pointer_manager_new(FlutterViewId view_id,
  * @device_kind: kind of device generating the event.
  * @x: x co-ordinate of event.
  * @y: y co-ordinate of event.
- * @button: button being pressed.
+ * @gdk_button: button being pressed.
  *
  * Returns %TRUE if this event was handled.
  */
@@ -45,7 +45,7 @@ gboolean fl_pointer_manager_handle_button_press(
     FlutterPointerDeviceKind device_kind,
     gdouble x,
     gdouble y,
-    int64_t button);
+    guint gdk_button);
 
 /**
  * fl_pointer_manager_handle_button_release:
@@ -54,7 +54,7 @@ gboolean fl_pointer_manager_handle_button_press(
  * @device_kind: kind of device generating the event.
  * @x: x co-ordinate of event.
  * @y: y co-ordinate of event.
- * @button: button being released.
+ * @gdk_button: button being released.
  *
  * Returns %TRUE if this event was handled.
  */
@@ -64,7 +64,7 @@ gboolean fl_pointer_manager_handle_button_release(
     FlutterPointerDeviceKind device_kind,
     gdouble x,
     gdouble y,
-    int64_t button);
+    guint gdk_button);
 
 /**
  * fl_pointer_manager_handle_motion:

engine/src/flutter/shell/platform/linux/fl_pointer_manager_test.cc

@@ -157,9 +157,9 @@ TEST(FlPointerManagerTest, EnterButtonPress) {
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
   fl_pointer_manager_handle_enter(manager, 1234, kFlutterPointerDeviceKindMouse,
                                   1.0, 2.0);
-  fl_pointer_manager_handle_button_press(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 4.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1235,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 2u);
 
@@ -199,9 +199,9 @@ TEST(FlPointerManagerTest, NoEnterButtonPress) {
       }));
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 2u);
 
@@ -221,7 +221,7 @@ TEST(FlPointerManagerTest, NoEnterButtonPress) {
   EXPECT_EQ(pointer_events[1].view_id, 42);
 }
 
-TEST(FlPointerManagerTest, ButtonPressButtonRelease) {
+TEST(FlPointerManagerTest, ButtonPressButtonReleasePrimary) {
   g_autoptr(FlDartProject) project = fl_dart_project_new();
   g_autoptr(FlEngine) engine = fl_engine_new(project);
 
@@ -242,12 +242,12 @@ TEST(FlPointerManagerTest, ButtonPressButtonRelease) {
       }));
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
-  fl_pointer_manager_handle_button_release(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_PRIMARY);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 3u);
 
@@ -266,6 +266,184 @@ TEST(FlPointerManagerTest, ButtonPressButtonRelease) {
   EXPECT_EQ(pointer_events[2].view_id, 42);
 }
 
+TEST(FlPointerManagerTest, ButtonPressButtonReleaseSecondary) {
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  g_autoptr(FlEngine) engine = fl_engine_new(project);
+
+  g_autoptr(GError) error = nullptr;
+  EXPECT_TRUE(fl_engine_start(engine, &error));
+  EXPECT_EQ(error, nullptr);
+
+  std::vector<FlutterPointerEvent> pointer_events;
+  fl_engine_get_embedder_api(engine)->SendPointerEvent = MOCK_ENGINE_PROC(
+      SendPointerEvent,
+      ([&pointer_events](auto engine, const FlutterPointerEvent* events,
+                         size_t events_count) {
+        for (size_t i = 0; i < events_count; i++) {
+          pointer_events.push_back(events[i]);
+        }
+
+        return kSuccess;
+      }));
+
+  g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_SECONDARY);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_SECONDARY);
+
+  EXPECT_EQ(pointer_events.size(), 3u);
+
+  // Ignore first synthetic enter event
+  EXPECT_EQ(pointer_events[1].timestamp, 1234000u);
+  EXPECT_EQ(pointer_events[1].x, 4.0);
+  EXPECT_EQ(pointer_events[1].y, 8.0);
+  EXPECT_EQ(pointer_events[1].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[1].buttons, kFlutterPointerButtonMouseSecondary);
+  EXPECT_EQ(pointer_events[1].view_id, 42);
+  EXPECT_EQ(pointer_events[2].timestamp, 1235000u);
+  EXPECT_EQ(pointer_events[2].x, 5.0);
+  EXPECT_EQ(pointer_events[2].y, 9.0);
+  EXPECT_EQ(pointer_events[2].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[2].buttons, 0);
+  EXPECT_EQ(pointer_events[2].view_id, 42);
+}
+
+TEST(FlPointerManagerTest, ButtonPressButtonReleaseMiddle) {
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  g_autoptr(FlEngine) engine = fl_engine_new(project);
+
+  g_autoptr(GError) error = nullptr;
+  EXPECT_TRUE(fl_engine_start(engine, &error));
+  EXPECT_EQ(error, nullptr);
+
+  std::vector<FlutterPointerEvent> pointer_events;
+  fl_engine_get_embedder_api(engine)->SendPointerEvent = MOCK_ENGINE_PROC(
+      SendPointerEvent,
+      ([&pointer_events](auto engine, const FlutterPointerEvent* events,
+                         size_t events_count) {
+        for (size_t i = 0; i < events_count; i++) {
+          pointer_events.push_back(events[i]);
+        }
+
+        return kSuccess;
+      }));
+
+  g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_MIDDLE);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_MIDDLE);
+
+  EXPECT_EQ(pointer_events.size(), 3u);
+
+  // Ignore first synthetic enter event
+  EXPECT_EQ(pointer_events[1].timestamp, 1234000u);
+  EXPECT_EQ(pointer_events[1].x, 4.0);
+  EXPECT_EQ(pointer_events[1].y, 8.0);
+  EXPECT_EQ(pointer_events[1].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[1].buttons, kFlutterPointerButtonMouseMiddle);
+  EXPECT_EQ(pointer_events[1].view_id, 42);
+  EXPECT_EQ(pointer_events[2].timestamp, 1235000u);
+  EXPECT_EQ(pointer_events[2].x, 5.0);
+  EXPECT_EQ(pointer_events[2].y, 9.0);
+  EXPECT_EQ(pointer_events[2].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[2].buttons, 0);
+  EXPECT_EQ(pointer_events[2].view_id, 42);
+}
+
+TEST(FlPointerManagerTest, ButtonPressButtonReleaseBack) {
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  g_autoptr(FlEngine) engine = fl_engine_new(project);
+
+  g_autoptr(GError) error = nullptr;
+  EXPECT_TRUE(fl_engine_start(engine, &error));
+  EXPECT_EQ(error, nullptr);
+
+  std::vector<FlutterPointerEvent> pointer_events;
+  fl_engine_get_embedder_api(engine)->SendPointerEvent = MOCK_ENGINE_PROC(
+      SendPointerEvent,
+      ([&pointer_events](auto engine, const FlutterPointerEvent* events,
+                         size_t events_count) {
+        for (size_t i = 0; i < events_count; i++) {
+          pointer_events.push_back(events[i]);
+        }
+
+        return kSuccess;
+      }));
+
+  // Forward button is 8 (no GDK define).
+  g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
+  fl_pointer_manager_handle_button_press(
+      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0, 8);
+  fl_pointer_manager_handle_button_release(
+      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0, 8);
+
+  EXPECT_EQ(pointer_events.size(), 3u);
+
+  // Ignore first synthetic enter event
+  EXPECT_EQ(pointer_events[1].timestamp, 1234000u);
+  EXPECT_EQ(pointer_events[1].x, 4.0);
+  EXPECT_EQ(pointer_events[1].y, 8.0);
+  EXPECT_EQ(pointer_events[1].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[1].buttons, kFlutterPointerButtonMouseBack);
+  EXPECT_EQ(pointer_events[1].view_id, 42);
+  EXPECT_EQ(pointer_events[2].timestamp, 1235000u);
+  EXPECT_EQ(pointer_events[2].x, 5.0);
+  EXPECT_EQ(pointer_events[2].y, 9.0);
+  EXPECT_EQ(pointer_events[2].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[2].buttons, 0);
+  EXPECT_EQ(pointer_events[2].view_id, 42);
+}
+
+TEST(FlPointerManagerTest, ButtonPressButtonReleaseForward) {
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  g_autoptr(FlEngine) engine = fl_engine_new(project);
+
+  g_autoptr(GError) error = nullptr;
+  EXPECT_TRUE(fl_engine_start(engine, &error));
+  EXPECT_EQ(error, nullptr);
+
+  std::vector<FlutterPointerEvent> pointer_events;
+  fl_engine_get_embedder_api(engine)->SendPointerEvent = MOCK_ENGINE_PROC(
+      SendPointerEvent,
+      ([&pointer_events](auto engine, const FlutterPointerEvent* events,
+                         size_t events_count) {
+        for (size_t i = 0; i < events_count; i++) {
+          pointer_events.push_back(events[i]);
+        }
+
+        return kSuccess;
+      }));
+
+  // Forward button is 9 (no GDK define).
+  g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
+  fl_pointer_manager_handle_button_press(
+      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0, 9);
+  fl_pointer_manager_handle_button_release(
+      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0, 9);
+
+  EXPECT_EQ(pointer_events.size(), 3u);
+
+  // Ignore first synthetic enter event
+  EXPECT_EQ(pointer_events[1].timestamp, 1234000u);
+  EXPECT_EQ(pointer_events[1].x, 4.0);
+  EXPECT_EQ(pointer_events[1].y, 8.0);
+  EXPECT_EQ(pointer_events[1].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[1].buttons, kFlutterPointerButtonMouseForward);
+  EXPECT_EQ(pointer_events[1].view_id, 42);
+  EXPECT_EQ(pointer_events[2].timestamp, 1235000u);
+  EXPECT_EQ(pointer_events[2].x, 5.0);
+  EXPECT_EQ(pointer_events[2].y, 9.0);
+  EXPECT_EQ(pointer_events[2].device_kind, kFlutterPointerDeviceKindMouse);
+  EXPECT_EQ(pointer_events[2].buttons, 0);
+  EXPECT_EQ(pointer_events[2].view_id, 42);
+}
+
 TEST(FlPointerManagerTest, ButtonPressButtonReleaseThreeButtons) {
   g_autoptr(FlDartProject) project = fl_dart_project_new();
   g_autoptr(FlEngine) engine = fl_engine_new(project);
@@ -288,21 +466,21 @@ TEST(FlPointerManagerTest, ButtonPressButtonReleaseThreeButtons) {
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
   // Press buttons 1-2-3, release 3-2-1
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 1.0, 2.0,
-      kFlutterPointerButtonMousePrimary);
-  fl_pointer_manager_handle_button_press(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 3.0, 4.0,
-      kFlutterPointerButtonMouseSecondary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 1.0,
+                                         2.0, GDK_BUTTON_PRIMARY);
+  fl_pointer_manager_handle_button_press(manager, 1235,
+                                         kFlutterPointerDeviceKindMouse, 3.0,
+                                         4.0, GDK_BUTTON_SECONDARY);
   fl_pointer_manager_handle_button_press(manager, 1236,
                                          kFlutterPointerDeviceKindMouse, 5.0,
-                                         6.0, kFlutterPointerButtonMouseMiddle);
-  fl_pointer_manager_handle_button_release(
-      manager, 1237, kFlutterPointerDeviceKindMouse, 7.0, 8.0,
-      kFlutterPointerButtonMouseMiddle);
-  fl_pointer_manager_handle_button_release(
-      manager, 1238, kFlutterPointerDeviceKindMouse, 9.0, 10.0,
-      kFlutterPointerButtonMouseSecondary);
+                                         6.0, GDK_BUTTON_MIDDLE);
+  fl_pointer_manager_handle_button_release(manager, 1237,
+                                           kFlutterPointerDeviceKindMouse, 7.0,
+                                           8.0, GDK_BUTTON_MIDDLE);
+  fl_pointer_manager_handle_button_release(manager, 1238,
+                                           kFlutterPointerDeviceKindMouse, 9.0,
+                                           10.0, GDK_BUTTON_SECONDARY);
   fl_pointer_manager_handle_button_release(
       manager, 1239, kFlutterPointerDeviceKindMouse, 11.0, 12.0,
       kFlutterPointerButtonMousePrimary);
@@ -361,16 +539,16 @@ TEST(FlPointerManagerTest, ButtonPressButtonPressButtonRelease) {
       }));
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_PRIMARY);
   // Ignore duplicate press
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 6.0, 10.0,
-      kFlutterPointerButtonMousePrimary);
-  fl_pointer_manager_handle_button_release(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 6.0,
+                                         10.0, GDK_BUTTON_PRIMARY);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 3u);
 
@@ -410,16 +588,16 @@ TEST(FlPointerManagerTest, ButtonPressButtonReleaseButtonRelease) {
       }));
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
-  fl_pointer_manager_handle_button_press(
-      manager, 1234, kFlutterPointerDeviceKindMouse, 4.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
-  fl_pointer_manager_handle_button_release(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1234,
+                                         kFlutterPointerDeviceKindMouse, 4.0,
+                                         8.0, GDK_BUTTON_PRIMARY);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_PRIMARY);
   // Ignore duplicate release
-  fl_pointer_manager_handle_button_release(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 6.0, 10.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 6.0,
+                                           10.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 3u);
 
@@ -460,9 +638,9 @@ TEST(FlPointerManagerTest, NoButtonPressButtonRelease) {
 
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
   // Release without associated press, will be ignored
-  fl_pointer_manager_handle_button_release(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 5.0, 9.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_release(manager, 1235,
+                                           kFlutterPointerDeviceKindMouse, 5.0,
+                                           9.0, GDK_BUTTON_PRIMARY);
 
   EXPECT_EQ(pointer_events.size(), 0u);
 }
@@ -541,14 +719,14 @@ TEST(FlPointerManagerTest, Drag) {
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
   fl_pointer_manager_handle_motion(manager, 1234,
                                    kFlutterPointerDeviceKindMouse, 1.0, 2.0);
-  fl_pointer_manager_handle_button_press(
-      manager, 1235, kFlutterPointerDeviceKindMouse, 3.0, 4.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1235,
+                                         kFlutterPointerDeviceKindMouse, 3.0,
+                                         4.0, GDK_BUTTON_PRIMARY);
   fl_pointer_manager_handle_motion(manager, 1236,
                                    kFlutterPointerDeviceKindMouse, 5.0, 6.0);
-  fl_pointer_manager_handle_button_release(
-      manager, 1237, kFlutterPointerDeviceKindMouse, 7.0, 8.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_release(manager, 1237,
+                                           kFlutterPointerDeviceKindMouse, 7.0,
+                                           8.0, GDK_BUTTON_PRIMARY);
   fl_pointer_manager_handle_motion(manager, 1238,
                                    kFlutterPointerDeviceKindMouse, 9.0, 10.0);
 
@@ -605,14 +783,14 @@ TEST(FlPointerManagerTest, DeviceKind) {
   g_autoptr(FlPointerManager) manager = fl_pointer_manager_new(42, engine);
   fl_pointer_manager_handle_enter(manager, 1234,
                                   kFlutterPointerDeviceKindTrackpad, 1.0, 2.0);
-  fl_pointer_manager_handle_button_press(
-      manager, 1235, kFlutterPointerDeviceKindTrackpad, 1.0, 2.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_press(manager, 1235,
+                                         kFlutterPointerDeviceKindTrackpad, 1.0,
+                                         2.0, GDK_BUTTON_PRIMARY);
   fl_pointer_manager_handle_motion(manager, 1238,
                                    kFlutterPointerDeviceKindTrackpad, 3.0, 4.0);
-  fl_pointer_manager_handle_button_release(
-      manager, 1237, kFlutterPointerDeviceKindTrackpad, 3.0, 4.0,
-      kFlutterPointerButtonMousePrimary);
+  fl_pointer_manager_handle_button_release(manager, 1237,
+                                           kFlutterPointerDeviceKindTrackpad,
+                                           3.0, 4.0, GDK_BUTTON_PRIMARY);
   fl_pointer_manager_handle_leave(manager, 1235,
                                   kFlutterPointerDeviceKindTrackpad, 3.0, 4.0);
 

engine/src/flutter/shell/platform/linux/fl_view.cc

@@ -135,25 +135,6 @@ static FlutterPointerDeviceKind get_device_kind(GdkEvent* event) {
   }
 }
 
-static gboolean get_mouse_button(GdkEvent* event, int64_t* button) {
-  guint event_button = 0;
-  gdk_event_get_button(event, &event_button);
-
-  switch (event_button) {
-    case GDK_BUTTON_PRIMARY:
-      *button = kFlutterPointerButtonMousePrimary;
-      return TRUE;
-    case GDK_BUTTON_MIDDLE:
-      *button = kFlutterPointerButtonMouseMiddle;
-      return TRUE;
-    case GDK_BUTTON_SECONDARY:
-      *button = kFlutterPointerButtonMouseSecondary;
-      return TRUE;
-    default:
-      return FALSE;
-  }
-}
-
 // Called when the mouse cursor changes.
 static void cursor_changed_cb(FlView* self) {
   FlMouseCursorHandler* handler =
@@ -323,10 +304,8 @@ static gboolean button_press_event_cb(FlView* self,
     return FALSE;
   }
 
-  int64_t button;
-  if (!get_mouse_button(event, &button)) {
-    return FALSE;
-  }
+  guint button = 0;
+  gdk_event_get_button(event, &button);
 
   gdouble x = 0.0, y = 0.0;
   gdk_event_get_coords(event, &x, &y);
@@ -345,10 +324,8 @@ static gboolean button_release_event_cb(FlView* self,
                                         GdkEventButton* button_event) {
   GdkEvent* event = reinterpret_cast<GdkEvent*>(button_event);
 
-  int64_t button;
-  if (!get_mouse_button(event, &button)) {
-    return FALSE;
-  }
+  guint button = 0;
+  gdk_event_get_button(event, &button);
 
   gdouble x = 0.0, y = 0.0;
   gdk_event_get_coords(event, &x, &y);