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fl_scrolling_manager.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
6 #include "flutter/shell/platform/embedder/embedder.h"
8 
9 static constexpr int kMicrosecondsPerMillisecond = 1000;
10 
12  GObject parent_instance;
13 
14  GWeakRef engine;
15 
16  FlutterViewId view_id;
17 
18  gdouble last_x;
19  gdouble last_y;
20 
21  gboolean pan_started;
22  gdouble pan_x;
23  gdouble pan_y;
24 
25  gboolean zoom_started;
26  gboolean rotate_started;
27  gdouble scale;
28  gdouble rotation;
29 };
30 
31 G_DEFINE_TYPE(FlScrollingManager, fl_scrolling_manager, G_TYPE_OBJECT);
32 
33 static void fl_scrolling_manager_dispose(GObject* object) {
34  FlScrollingManager* self = FL_SCROLLING_MANAGER(object);
35 
36  g_weak_ref_clear(&self->engine);
37 
38  G_OBJECT_CLASS(fl_scrolling_manager_parent_class)->dispose(object);
39 }
40 
41 static void fl_scrolling_manager_class_init(FlScrollingManagerClass* klass) {
42  G_OBJECT_CLASS(klass)->dispose = fl_scrolling_manager_dispose;
43 }
44 
45 static void fl_scrolling_manager_init(FlScrollingManager* self) {}
46 
47 FlScrollingManager* fl_scrolling_manager_new(FlEngine* engine,
48  FlutterViewId view_id) {
49  g_return_val_if_fail(FL_IS_ENGINE(engine), nullptr);
50 
51  FlScrollingManager* self = FL_SCROLLING_MANAGER(
52  g_object_new(fl_scrolling_manager_get_type(), nullptr));
53 
54  g_weak_ref_init(&self->engine, engine);
55  self->view_id = view_id;
56  self->pan_started = FALSE;
57  self->zoom_started = FALSE;
58  self->rotate_started = FALSE;
59 
60  return self;
61 }
62 
63 void fl_scrolling_manager_set_last_mouse_position(FlScrollingManager* self,
64  gdouble x,
65  gdouble y) {
66  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
67  self->last_x = x;
68  self->last_y = y;
69 }
70 
71 void fl_scrolling_manager_handle_scroll_event(FlScrollingManager* self,
72  GdkEventScroll* scroll_event,
73  gint scale_factor) {
74  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
75 
76  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
77  if (engine == nullptr) {
78  return;
79  }
80 
81  GdkEvent* event = reinterpret_cast<GdkEvent*>(scroll_event);
82 
83  guint event_time = gdk_event_get_time(event);
84  gdouble event_x = 0.0, event_y = 0.0;
85  gdk_event_get_coords(event, &event_x, &event_y);
86  gdouble scroll_delta_x = 0.0, scroll_delta_y = 0.0;
87  GdkScrollDirection event_direction = GDK_SCROLL_SMOOTH;
88  if (gdk_event_get_scroll_direction(event, &event_direction)) {
89  if (event_direction == GDK_SCROLL_UP) {
90  scroll_delta_x = 0;
91  scroll_delta_y = -1;
92  } else if (event_direction == GDK_SCROLL_DOWN) {
93  scroll_delta_x = 0;
94  scroll_delta_y = 1;
95  } else if (event_direction == GDK_SCROLL_LEFT) {
96  scroll_delta_x = -1;
97  scroll_delta_y = 0;
98  } else if (event_direction == GDK_SCROLL_RIGHT) {
99  scroll_delta_x = 1;
100  scroll_delta_y = 0;
101  }
102  } else {
103  gdk_event_get_scroll_deltas(event, &scroll_delta_x, &scroll_delta_y);
104  }
105 
106  // The multiplier is taken from the Chromium source
107  // (ui/events/x/events_x_utils.cc).
108  const int kScrollOffsetMultiplier = 53;
109  scroll_delta_x *= kScrollOffsetMultiplier * scale_factor;
110  scroll_delta_y *= kScrollOffsetMultiplier * scale_factor;
111 
112  if (gdk_device_get_source(gdk_event_get_source_device(event)) ==
113  GDK_SOURCE_TOUCHPAD) {
114  scroll_delta_x *= -1;
115  scroll_delta_y *= -1;
116  if (gdk_event_is_scroll_stop_event(event)) {
118  engine, self->view_id, event_time * kMicrosecondsPerMillisecond,
119  event_x * scale_factor, event_y * scale_factor, kPanZoomEnd,
120  self->pan_x, self->pan_y, 0, 0);
121  self->pan_started = FALSE;
122  } else {
123  if (!self->pan_started) {
124  self->pan_x = 0;
125  self->pan_y = 0;
127  engine, self->view_id, event_time * kMicrosecondsPerMillisecond,
128  event_x * scale_factor, event_y * scale_factor, kPanZoomStart, 0, 0,
129  0, 0);
130  self->pan_started = TRUE;
131  }
132  self->pan_x += scroll_delta_x;
133  self->pan_y += scroll_delta_y;
135  engine, self->view_id, event_time * kMicrosecondsPerMillisecond,
136  event_x * scale_factor, event_y * scale_factor, kPanZoomUpdate,
137  self->pan_x, self->pan_y, 1, 0);
138  }
139  } else {
140  self->last_x = event_x * scale_factor;
141  self->last_y = event_y * scale_factor;
143  engine, self->view_id,
144  FlutterPointerPhase::kMove /* arbitrary value, phase will be ignored as
145  this is a discrete scroll event */
146  ,
147  event_time * kMicrosecondsPerMillisecond, event_x * scale_factor,
148  event_y * scale_factor, kFlutterPointerDeviceKindMouse, scroll_delta_x,
149  scroll_delta_y, 0);
150  }
151 }
152 
153 void fl_scrolling_manager_handle_rotation_begin(FlScrollingManager* self) {
154  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
155 
156  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
157  if (engine == nullptr) {
158  return;
159  }
160 
161  self->rotate_started = TRUE;
162  if (!self->zoom_started) {
163  self->scale = 1;
164  self->rotation = 0;
166  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
167  kPanZoomStart, 0, 0, 0, 0);
168  }
169 }
170 
171 void fl_scrolling_manager_handle_rotation_update(FlScrollingManager* self,
172  gdouble rotation) {
173  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
174 
175  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
176  if (engine == nullptr) {
177  return;
178  }
179 
180  self->rotation = rotation;
182  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
183  kPanZoomUpdate, 0, 0, self->scale, self->rotation);
184 }
185 
186 void fl_scrolling_manager_handle_rotation_end(FlScrollingManager* self) {
187  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
188 
189  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
190  if (engine == nullptr) {
191  return;
192  }
193 
194  self->rotate_started = FALSE;
195  if (!self->zoom_started) {
197  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
198  kPanZoomEnd, 0, 0, 0, 0);
199  }
200 }
201 
202 void fl_scrolling_manager_handle_zoom_begin(FlScrollingManager* self) {
203  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
204 
205  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
206  if (engine == nullptr) {
207  return;
208  }
209 
210  self->zoom_started = TRUE;
211  if (!self->rotate_started) {
212  self->scale = 1;
213  self->rotation = 0;
215  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
216  kPanZoomStart, 0, 0, 0, 0);
217  }
218 }
219 
220 void fl_scrolling_manager_handle_zoom_update(FlScrollingManager* self,
221  gdouble scale) {
222  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
223 
224  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
225  if (engine == nullptr) {
226  return;
227  }
228 
229  self->scale = scale;
231  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
232  kPanZoomUpdate, 0, 0, self->scale, self->rotation);
233 }
234 
235 void fl_scrolling_manager_handle_zoom_end(FlScrollingManager* self) {
236  g_return_if_fail(FL_IS_SCROLLING_MANAGER(self));
237 
238  g_autoptr(FlEngine) engine = FL_ENGINE(g_weak_ref_get(&self->engine));
239  if (engine == nullptr) {
240  return;
241  }
242 
243  self->zoom_started = FALSE;
244  if (!self->rotate_started) {
246  engine, self->view_id, g_get_real_time(), self->last_x, self->last_y,
247  kPanZoomEnd, 0, 0, 0, 0);
248  }
249 }
_FlScrollingManager
Definition: fl_scrolling_manager.cc:11
fl_scrolling_manager_handle_zoom_end
void fl_scrolling_manager_handle_zoom_end(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:235
fl_scrolling_manager_handle_scroll_event
void fl_scrolling_manager_handle_scroll_event(FlScrollingManager *self, GdkEventScroll *scroll_event, gint scale_factor)
Definition: fl_scrolling_manager.cc:71
_FlScrollingManager::pan_x
gdouble pan_x
Definition: fl_scrolling_manager.cc:22
_FlScrollingManager::view_id
FlutterViewId view_id
Definition: fl_scrolling_manager.cc:16
_FlScrollingManager::pan_y
gdouble pan_y
Definition: fl_scrolling_manager.cc:23
_FlScrollingManager::zoom_started
gboolean zoom_started
Definition: fl_scrolling_manager.cc:25
fl_scrolling_manager_class_init
static void fl_scrolling_manager_class_init(FlScrollingManagerClass *klass)
Definition: fl_scrolling_manager.cc:41
G_DEFINE_TYPE
G_DEFINE_TYPE(FlScrollingManager, fl_scrolling_manager, G_TYPE_OBJECT)
fl_scrolling_manager_dispose
static void fl_scrolling_manager_dispose(GObject *object)
Definition: fl_scrolling_manager.cc:33
_FlScrollingManager::scale
gdouble scale
Definition: fl_scrolling_manager.cc:27
fl_scrolling_manager_set_last_mouse_position
void fl_scrolling_manager_set_last_mouse_position(FlScrollingManager *self, gdouble x, gdouble y)
Definition: fl_scrolling_manager.cc:63
_FlScrollingManager::pan_started
gboolean pan_started
Definition: fl_scrolling_manager.cc:21
_FlScrollingManager::rotation
gdouble rotation
Definition: fl_scrolling_manager.cc:28
fl_engine_private.h
fl_scrolling_manager.h
TRUE
return TRUE
Definition: fl_pixel_buffer_texture_test.cc:53
fl_scrolling_manager_handle_zoom_update
void fl_scrolling_manager_handle_zoom_update(FlScrollingManager *self, gdouble scale)
Definition: fl_scrolling_manager.cc:220
fl_scrolling_manager_init
static void fl_scrolling_manager_init(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:45
fl_scrolling_manager_handle_rotation_update
void fl_scrolling_manager_handle_rotation_update(FlScrollingManager *self, gdouble rotation)
Definition: fl_scrolling_manager.cc:171
_FlScrollingManager::parent_instance
GObject parent_instance
Definition: fl_scrolling_manager.cc:12
_FlScrollingManager::last_x
gdouble last_x
Definition: fl_scrolling_manager.cc:18
_FlScrollingManager::rotate_started
gboolean rotate_started
Definition: fl_scrolling_manager.cc:26
kMicrosecondsPerMillisecond
static constexpr int kMicrosecondsPerMillisecond
Definition: fl_scrolling_manager.cc:9
fl_engine_send_pointer_pan_zoom_event
void fl_engine_send_pointer_pan_zoom_event(FlEngine *self, FlutterViewId view_id, size_t timestamp, double x, double y, FlutterPointerPhase phase, double pan_x, double pan_y, double scale, double rotation)
Definition: fl_engine.cc:1082
fl_scrolling_manager_handle_rotation_end
void fl_scrolling_manager_handle_rotation_end(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:186
fl_scrolling_manager_handle_rotation_begin
void fl_scrolling_manager_handle_rotation_begin(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:153
fl_scrolling_manager_new
FlScrollingManager * fl_scrolling_manager_new(FlEngine *engine, FlutterViewId view_id)
Definition: fl_scrolling_manager.cc:47
_FlScrollingManager::last_y
gdouble last_y
Definition: fl_scrolling_manager.cc:19
fl_scrolling_manager_handle_zoom_begin
void fl_scrolling_manager_handle_zoom_begin(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:202
_FlScrollingManager::engine
GWeakRef engine
Definition: fl_scrolling_manager.cc:14
fl_engine_send_mouse_pointer_event
void fl_engine_send_mouse_pointer_event(FlEngine *self, FlutterViewId view_id, FlutterPointerPhase phase, size_t timestamp, double x, double y, FlutterPointerDeviceKind device_kind, double scroll_delta_x, double scroll_delta_y, int64_t buttons)
Definition: fl_engine.cc:918