Flutter Linux Embedder
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 
7 static constexpr int kMicrosecondsPerMillisecond = 1000;
8 
10  GObject parent_instance;
11 
12  FlScrollingViewDelegate* view_delegate;
13 
14  gdouble last_x;
15  gdouble last_y;
16 
17  gboolean pan_started;
18  gdouble pan_x;
19  gdouble pan_y;
20 
21  gboolean zoom_started;
22  gboolean rotate_started;
23  gdouble scale;
24  gdouble rotation;
25 };
26 
27 G_DEFINE_TYPE(FlScrollingManager, fl_scrolling_manager, G_TYPE_OBJECT);
28 
29 static void fl_scrolling_manager_dispose(GObject* object);
30 
31 static void fl_scrolling_manager_class_init(FlScrollingManagerClass* klass) {
32  G_OBJECT_CLASS(klass)->dispose = fl_scrolling_manager_dispose;
33 }
34 
35 static void fl_scrolling_manager_init(FlScrollingManager* self) {}
36 
37 static void fl_scrolling_manager_dispose(GObject* object) {
38  G_OBJECT_CLASS(fl_scrolling_manager_parent_class)->dispose(object);
39 }
40 
41 FlScrollingManager* fl_scrolling_manager_new(
42  FlScrollingViewDelegate* view_delegate) {
43  g_return_val_if_fail(FL_IS_SCROLLING_VIEW_DELEGATE(view_delegate), nullptr);
44 
45  FlScrollingManager* self = FL_SCROLLING_MANAGER(
46  g_object_new(fl_scrolling_manager_get_type(), nullptr));
47 
48  self->view_delegate = view_delegate;
50  G_OBJECT(view_delegate),
51  reinterpret_cast<gpointer*>(&(self->view_delegate)));
52 
53  self->pan_started = false;
54  self->zoom_started = false;
55  self->rotate_started = false;
56 
57  return self;
58 }
59 
60 void fl_scrolling_manager_set_last_mouse_position(FlScrollingManager* self,
61  gdouble x,
62  gdouble y) {
63  self->last_x = x;
64  self->last_y = y;
65 }
66 
67 void fl_scrolling_manager_handle_scroll_event(FlScrollingManager* self,
68  GdkEventScroll* event,
69  gint scale_factor) {
70  gdouble scroll_delta_x = 0.0, scroll_delta_y = 0.0;
71  if (event->direction == GDK_SCROLL_SMOOTH) {
72  scroll_delta_x = event->delta_x;
73  scroll_delta_y = event->delta_y;
74  } else if (event->direction == GDK_SCROLL_UP) {
75  scroll_delta_y = -1;
76  } else if (event->direction == GDK_SCROLL_DOWN) {
77  scroll_delta_y = 1;
78  } else if (event->direction == GDK_SCROLL_LEFT) {
79  scroll_delta_x = -1;
80  } else if (event->direction == GDK_SCROLL_RIGHT) {
81  scroll_delta_x = 1;
82  }
83 
84  // The multiplier is taken from the Chromium source
85  // (ui/events/x/events_x_utils.cc).
86  const int kScrollOffsetMultiplier = 53;
87  scroll_delta_x *= kScrollOffsetMultiplier * scale_factor;
88  scroll_delta_y *= kScrollOffsetMultiplier * scale_factor;
89 
90  if (gdk_device_get_source(gdk_event_get_source_device(
91  reinterpret_cast<GdkEvent*>(event))) == GDK_SOURCE_TOUCHPAD) {
92  scroll_delta_x *= -1;
93  scroll_delta_y *= -1;
94  if (event->is_stop) {
96  self->view_delegate, event->time * kMicrosecondsPerMillisecond,
97  event->x * scale_factor, event->y * scale_factor, kPanZoomEnd,
98  self->pan_x, self->pan_y, 0, 0);
99  self->pan_started = FALSE;
100  } else {
101  if (!self->pan_started) {
102  self->pan_x = 0;
103  self->pan_y = 0;
105  self->view_delegate, event->time * kMicrosecondsPerMillisecond,
106  event->x * scale_factor, event->y * scale_factor, kPanZoomStart, 0,
107  0, 0, 0);
108  self->pan_started = TRUE;
109  }
110  self->pan_x += scroll_delta_x;
111  self->pan_y += scroll_delta_y;
113  self->view_delegate, event->time * kMicrosecondsPerMillisecond,
114  event->x * scale_factor, event->y * scale_factor, kPanZoomUpdate,
115  self->pan_x, self->pan_y, 1, 0);
116  }
117  } else {
118  self->last_x = event->x * scale_factor;
119  self->last_y = event->y * scale_factor;
121  self->view_delegate,
122  FlutterPointerPhase::kMove /* arbitrary value, phase will be ignored as
123  this is a discrete scroll event */
124  ,
125  event->time * kMicrosecondsPerMillisecond, event->x * scale_factor,
126  event->y * scale_factor, scroll_delta_x, scroll_delta_y, 0);
127  }
128 }
129 
130 void fl_scrolling_manager_handle_rotation_begin(FlScrollingManager* self) {
131  self->rotate_started = true;
132  if (!self->zoom_started) {
133  self->scale = 1;
134  self->rotation = 0;
136  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
137  kPanZoomStart, 0, 0, 0, 0);
138  }
139 }
140 
141 void fl_scrolling_manager_handle_rotation_update(FlScrollingManager* self,
142  gdouble rotation) {
143  self->rotation = rotation;
145  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
146  kPanZoomUpdate, 0, 0, self->scale, self->rotation);
147 }
148 void fl_scrolling_manager_handle_rotation_end(FlScrollingManager* self) {
149  self->rotate_started = false;
150  if (!self->zoom_started) {
152  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
153  kPanZoomEnd, 0, 0, 0, 0);
154  }
155 }
156 
157 void fl_scrolling_manager_handle_zoom_begin(FlScrollingManager* self) {
158  self->zoom_started = true;
159  if (!self->rotate_started) {
160  self->scale = 1;
161  self->rotation = 0;
163  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
164  kPanZoomStart, 0, 0, 0, 0);
165  }
166 }
167 void fl_scrolling_manager_handle_zoom_update(FlScrollingManager* self,
168  gdouble scale) {
169  self->scale = scale;
171  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
172  kPanZoomUpdate, 0, 0, self->scale, self->rotation);
173 }
174 void fl_scrolling_manager_handle_zoom_end(FlScrollingManager* self) {
175  self->zoom_started = false;
176  if (!self->rotate_started) {
178  self->view_delegate, g_get_real_time(), self->last_x, self->last_y,
179  kPanZoomEnd, 0, 0, 0, 0);
180  }
181 }
_FlKeyEvent::time
guint32 time
Definition: fl_key_event.h:33
event
FlKeyEvent * event
Definition: fl_key_channel_responder.cc:118
_FlScrollingManager
Definition: fl_scrolling_manager.cc:9
fl_scrolling_manager_handle_zoom_end
void fl_scrolling_manager_handle_zoom_end(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:174
_FlScrollingManager::pan_x
gdouble pan_x
Definition: fl_scrolling_manager.cc:18
_FlScrollingManager::pan_y
gdouble pan_y
Definition: fl_scrolling_manager.cc:19
_FlScrollingManager::zoom_started
gboolean zoom_started
Definition: fl_scrolling_manager.cc:21
fl_scrolling_manager_class_init
static void fl_scrolling_manager_class_init(FlScrollingManagerClass *klass)
Definition: fl_scrolling_manager.cc:31
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:37
fl_scrolling_manager_new
FlScrollingManager * fl_scrolling_manager_new(FlScrollingViewDelegate *view_delegate)
Definition: fl_scrolling_manager.cc:41
_FlScrollingManager::scale
gdouble scale
Definition: fl_scrolling_manager.cc:23
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:60
_FlScrollingManager::pan_started
gboolean pan_started
Definition: fl_scrolling_manager.cc:17
_FlScrollingManager::rotation
gdouble rotation
Definition: fl_scrolling_manager.cc:24
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:167
_FlScrollingManager::view_delegate
FlScrollingViewDelegate * view_delegate
Definition: fl_scrolling_manager.cc:12
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g_object_add_weak_pointer(G_OBJECT(self), reinterpret_cast< gpointer * >(&self->engine))
fl_scrolling_manager_init
static void fl_scrolling_manager_init(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:35
fl_scrolling_manager_handle_rotation_update
void fl_scrolling_manager_handle_rotation_update(FlScrollingManager *self, gdouble rotation)
Definition: fl_scrolling_manager.cc:141
_FlScrollingManager::parent_instance
GObject parent_instance
Definition: fl_scrolling_manager.cc:10
fl_scrolling_view_delegate_send_mouse_pointer_event
void fl_scrolling_view_delegate_send_mouse_pointer_event(FlScrollingViewDelegate *self, FlutterPointerPhase phase, size_t timestamp, double x, double y, double scroll_delta_x, double scroll_delta_y, int64_t buttons)
Definition: fl_scrolling_view_delegate.cc:14
_FlScrollingManager::last_x
gdouble last_x
Definition: fl_scrolling_manager.cc:14
self
GdkEvent FlView * self
Definition: fl_view.cc:100
fl_scrolling_manager_handle_scroll_event
void fl_scrolling_manager_handle_scroll_event(FlScrollingManager *self, GdkEventScroll *event, gint scale_factor)
Definition: fl_scrolling_manager.cc:67
_FlScrollingManager::rotate_started
gboolean rotate_started
Definition: fl_scrolling_manager.cc:22
kMicrosecondsPerMillisecond
static constexpr int kMicrosecondsPerMillisecond
Definition: fl_scrolling_manager.cc:7
fl_scrolling_manager_handle_rotation_end
void fl_scrolling_manager_handle_rotation_end(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:148
fl_scrolling_manager_handle_rotation_begin
void fl_scrolling_manager_handle_rotation_begin(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:130
_FlScrollingManager::last_y
gdouble last_y
Definition: fl_scrolling_manager.cc:15
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void fl_scrolling_manager_handle_zoom_begin(FlScrollingManager *self)
Definition: fl_scrolling_manager.cc:157
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void fl_scrolling_view_delegate_send_pointer_pan_zoom_event(FlScrollingViewDelegate *self, size_t timestamp, double x, double y, FlutterPointerPhase phase, double pan_x, double pan_y, double scale, double rotation)
Definition: fl_scrolling_view_delegate.cc:28