Flutter Windows Embedder
flutter_windows_view.h
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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 
5 #ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOWS_VIEW_H_
6 #define FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOWS_VIEW_H_
7 
8 #include <memory>
9 #include <mutex>
10 #include <string>
11 #include <unordered_map>
12 #include <utility>
13 #include <vector>
14 
15 #include "flutter/fml/macros.h"
18 #include "flutter/shell/platform/embedder/embedder.h"
27 
28 namespace flutter {
29 
30 // ID for the window frame buffer.
31 inline constexpr uint32_t kWindowFrameBufferID = 0;
32 
33 // An OS-windowing neutral abstration for flutter
34 // view that works with win32 hwnds and Windows::UI::Composition visuals.
37  public:
38  // Creates a FlutterWindowsView with the given implementor of
39  // WindowBindingHandler.
40  //
41  // In order for object to render Flutter content the SetEngine method must be
42  // called with a valid FlutterWindowsEngine instance.
43  FlutterWindowsView(std::unique_ptr<WindowBindingHandler> window_binding);
44 
45  virtual ~FlutterWindowsView();
46 
47  // Configures the window instance with an instance of a running Flutter
48  // engine.
49  void SetEngine(std::unique_ptr<FlutterWindowsEngine> engine);
50 
51  // Creates rendering surface for Flutter engine to draw into.
52  // Should be called before calling FlutterEngineRun using this view.
53  void CreateRenderSurface();
54 
55  // Destroys current rendering surface if one has been allocated.
56  void DestroyRenderSurface();
57 
58  // Return the currently configured WindowsRenderTarget.
60 
61  // Return the currently configured PlatformWindow.
62  virtual PlatformWindow GetPlatformWindow() const;
63 
64  // Returns the engine backing this view.
66 
67  // Tells the engine to generate a new frame
68  void ForceRedraw();
69 
70  // Callbacks for clearing context, settings context and swapping buffers,
71  // these are typically called on an engine-controlled (non-platform) thread.
72  bool ClearContext();
73  bool MakeCurrent();
74  bool MakeResourceCurrent();
75  bool SwapBuffers();
76 
77  // Callback for presenting a software bitmap.
78  bool PresentSoftwareBitmap(const void* allocation,
79  size_t row_bytes,
80  size_t height);
81 
82  // Send initial bounds to embedder. Must occur after engine has initialized.
83  void SendInitialBounds();
84 
85  // Send the initial accessibility features to the window
87 
88  // Set the text of the alert, and create it if it does not yet exist.
89  void AnnounceAlert(const std::wstring& text);
90 
91  // |WindowBindingHandlerDelegate|
92  void UpdateHighContrastEnabled(bool enabled) override;
93 
94  // Returns the frame buffer id for the engine to render to.
95  uint32_t GetFrameBufferId(size_t width, size_t height);
96 
97  // Sets the cursor that should be used when the mouse is over the Flutter
98  // content. See mouse_cursor.dart for the values and meanings of cursor_name.
99  void UpdateFlutterCursor(const std::string& cursor_name);
100 
101  // Sets the cursor directly from a cursor handle.
102  void SetFlutterCursor(HCURSOR cursor);
103 
104  // |WindowBindingHandlerDelegate|
105  void OnWindowSizeChanged(size_t width, size_t height) override;
106 
107  // |WindowBindingHandlerDelegate|
108  void OnWindowRepaint() override;
109 
110  // |WindowBindingHandlerDelegate|
111  void OnPointerMove(double x,
112  double y,
113  FlutterPointerDeviceKind device_kind,
114  int32_t device_id,
115  int modifiers_state) override;
116 
117  // |WindowBindingHandlerDelegate|
118  void OnPointerDown(double x,
119  double y,
120  FlutterPointerDeviceKind device_kind,
121  int32_t device_id,
122  FlutterPointerMouseButtons button) override;
123 
124  // |WindowBindingHandlerDelegate|
125  void OnPointerUp(double x,
126  double y,
127  FlutterPointerDeviceKind device_kind,
128  int32_t device_id,
129  FlutterPointerMouseButtons button) override;
130 
131  // |WindowBindingHandlerDelegate|
132  void OnPointerLeave(double x,
133  double y,
134  FlutterPointerDeviceKind device_kind,
135  int32_t device_id = 0) override;
136 
137  // |WindowBindingHandlerDelegate|
138  virtual void OnPointerPanZoomStart(int32_t device_id) override;
139 
140  // |WindowBindingHandlerDelegate|
141  virtual void OnPointerPanZoomUpdate(int32_t device_id,
142  double pan_x,
143  double pan_y,
144  double scale,
145  double rotation) override;
146 
147  // |WindowBindingHandlerDelegate|
148  virtual void OnPointerPanZoomEnd(int32_t device_id) override;
149 
150  // |WindowBindingHandlerDelegate|
151  void OnText(const std::u16string&) override;
152 
153  // |WindowBindingHandlerDelegate|
154  void OnKey(int key,
155  int scancode,
156  int action,
157  char32_t character,
158  bool extended,
159  bool was_down,
160  KeyEventCallback callback) override;
161 
162  // |WindowBindingHandlerDelegate|
163  void OnComposeBegin() override;
164 
165  // |WindowBindingHandlerDelegate|
166  void OnComposeCommit() override;
167 
168  // |WindowBindingHandlerDelegate|
169  void OnComposeEnd() override;
170 
171  // |WindowBindingHandlerDelegate|
172  void OnComposeChange(const std::u16string& text, int cursor_pos) override;
173 
174  // |WindowBindingHandlerDelegate|
175  void OnScroll(double x,
176  double y,
177  double delta_x,
178  double delta_y,
179  int scroll_offset_multiplier,
180  FlutterPointerDeviceKind device_kind,
181  int32_t device_id) override;
182 
183  // |WindowBindingHandlerDelegate|
184  void OnScrollInertiaCancel(int32_t device_id) override;
185 
186  // |WindowBindingHandlerDelegate|
187  virtual void OnUpdateSemanticsEnabled(bool enabled) override;
188 
189  // |WindowBindingHandlerDelegate|
190  virtual gfx::NativeViewAccessible GetNativeViewAccessible() override;
191 
192  // |TextInputPluginDelegate|
193  void OnCursorRectUpdated(const Rect& rect) override;
194 
195  // |TextInputPluginDelegate|
196  void OnResetImeComposing() override;
197 
198  // Called when a WM_ONCOMPOSITIONCHANGED message is received.
200 
201  // Get a pointer to the alert node for this view.
202  ui::AXPlatformNodeWin* AlertNode() const;
203 
204  // |WindowBindingHandlerDelegate|
205  virtual ui::AXFragmentRootDelegateWin* GetAxFragmentRootDelegate() override;
206 
207  // Called to re/set the accessibility bridge pointer.
208  virtual void UpdateSemanticsEnabled(bool enabled);
209 
210  std::weak_ptr<AccessibilityBridgeWindows> accessibility_bridge() {
211  return accessibility_bridge_;
212  }
213 
214  // |WindowBindingHandlerDelegate|
215  void OnWindowStateEvent(HWND hwnd, WindowStateEvent event) override;
216 
217  protected:
218  virtual void NotifyWinEventWrapper(ui::AXPlatformNodeWin* node,
219  ax::mojom::Event event);
220 
221  // Create an AccessibilityBridgeWindows using this view.
222  virtual std::shared_ptr<AccessibilityBridgeWindows>
224 
225  private:
226  // Struct holding the state of an individual pointer. The engine doesn't keep
227  // track of which buttons have been pressed, so it's the embedding's
228  // responsibility.
229  struct PointerState {
230  // The device kind.
231  FlutterPointerDeviceKind device_kind = kFlutterPointerDeviceKindMouse;
232 
233  // A virtual pointer ID that is unique across all device kinds.
234  int32_t pointer_id = 0;
235 
236  // True if the last event sent to Flutter had at least one button pressed.
237  bool flutter_state_is_down = false;
238 
239  // True if kAdd has been sent to Flutter. Used to determine whether
240  // to send a kAdd event before sending an incoming pointer event, since
241  // Flutter expects pointers to be added before events are sent for them.
242  bool flutter_state_is_added = false;
243 
244  // The currently pressed buttons, as represented in FlutterPointerEvent.
245  uint64_t buttons = 0;
246 
247  // The x position where the last pan/zoom started.
248  double pan_zoom_start_x = 0;
249 
250  // The y position where the last pan/zoom started.
251  double pan_zoom_start_y = 0;
252  };
253 
254  // States a resize event can be in.
255  enum class ResizeState {
256  // When a resize event has started but is in progress.
257  kResizeStarted,
258  // After a resize event starts and the framework has been notified to
259  // generate a frame for the right size.
260  kFrameGenerated,
261  // Default state for when no resize is in progress. Also used to indicate
262  // that during a resize event, a frame with the right size has been rendered
263  // and the buffers have been swapped.
264  kDone,
265  };
266 
267  // Sends a window metrics update to the Flutter engine using current window
268  // dimensions in physical
269  void SendWindowMetrics(size_t width, size_t height, double dpiscale) const;
270 
271  // Reports a mouse movement to Flutter engine.
272  void SendPointerMove(double x, double y, PointerState* state);
273 
274  // Reports mouse press to Flutter engine.
275  void SendPointerDown(double x, double y, PointerState* state);
276 
277  // Reports mouse release to Flutter engine.
278  void SendPointerUp(double x, double y, PointerState* state);
279 
280  // Reports mouse left the window client area.
281  //
282  // Win32 api doesn't have "mouse enter" event. Therefore, there is no
283  // SendPointerEnter method. A mouse enter event is tracked then the "move"
284  // event is called.
285  void SendPointerLeave(double x, double y, PointerState* state);
286 
287  void SendPointerPanZoomStart(int32_t device_id, double x, double y);
288 
289  void SendPointerPanZoomUpdate(int32_t device_id,
290  double pan_x,
291  double pan_y,
292  double scale,
293  double rotation);
294 
295  void SendPointerPanZoomEnd(int32_t device_id);
296 
297  // Reports a keyboard character to Flutter engine.
298  void SendText(const std::u16string&);
299 
300  // Reports a raw keyboard message to Flutter engine.
301  void SendKey(int key,
302  int scancode,
303  int action,
304  char32_t character,
305  bool extended,
306  bool was_down,
308 
309  // Reports an IME compose begin event.
310  //
311  // Triggered when the user begins editing composing text using a multi-step
312  // input method such as in CJK text input.
313  void SendComposeBegin();
314 
315  // Reports an IME compose commit event.
316  //
317  // Triggered when the user commits the current composing text while using a
318  // multi-step input method such as in CJK text input. Composing continues with
319  // the next keypress.
320  void SendComposeCommit();
321 
322  // Reports an IME compose end event.
323  //
324  // Triggered when the user commits the composing text while using a multi-step
325  // input method such as in CJK text input.
326  void SendComposeEnd();
327 
328  // Reports an IME composing region change event.
329  //
330  // Triggered when the user edits the composing text while using a multi-step
331  // input method such as in CJK text input.
332  void SendComposeChange(const std::u16string& text, int cursor_pos);
333 
334  // Reports scroll wheel events to Flutter engine.
335  void SendScroll(double x,
336  double y,
337  double delta_x,
338  double delta_y,
339  int scroll_offset_multiplier,
340  FlutterPointerDeviceKind device_kind,
341  int32_t device_id);
342 
343  // Reports scroll inertia cancel events to Flutter engine.
344  void SendScrollInertiaCancel(int32_t device_id, double x, double y);
345 
346  // Creates a PointerState object unless it already exists.
347  PointerState* GetOrCreatePointerState(FlutterPointerDeviceKind device_kind,
348  int32_t device_id);
349 
350  // Sets |event_data|'s phase to either kMove or kHover depending on the
351  // current primary mouse button state.
352  void SetEventPhaseFromCursorButtonState(FlutterPointerEvent* event_data,
353  const PointerState* state) const;
354 
355  // Sends a pointer event to the Flutter engine based on given data. Since
356  // all input messages are passed in physical pixel values, no translation is
357  // needed before passing on to engine.
358  void SendPointerEventWithData(const FlutterPointerEvent& event_data,
359  PointerState* state);
360 
361  // Currently configured WindowsRenderTarget for this view used by
362  // surface_manager for creation of render surfaces and bound to the physical
363  // os window.
364  std::unique_ptr<WindowsRenderTarget> render_target_;
365 
366  // The engine associated with this view.
367  std::unique_ptr<FlutterWindowsEngine> engine_;
368 
369  // Keeps track of pointer states in relation to the window.
370  std::unordered_map<int32_t, std::unique_ptr<PointerState>> pointer_states_;
371 
372  // Currently configured WindowBindingHandler for view.
373  std::unique_ptr<WindowBindingHandler> binding_handler_;
374 
375  // Resize events are synchronized using this mutex and the corresponding
376  // condition variable.
377  std::mutex resize_mutex_;
378  std::condition_variable resize_cv_;
379 
380  // Indicates the state of a window resize event. Platform thread will be
381  // blocked while this is not done. Guarded by resize_mutex_.
382  ResizeState resize_status_ = ResizeState::kDone;
383 
384  // Target for the window width. Valid when resize_pending_ is set. Guarded by
385  // resize_mutex_.
386  size_t resize_target_width_ = 0;
387 
388  // Target for the window width. Valid when resize_pending_ is set. Guarded by
389  // resize_mutex_.
390  size_t resize_target_height_ = 0;
391 
392  // True when flutter's semantics tree is enabled.
393  bool semantics_enabled_ = false;
394 
395  // The accessibility bridge associated with this view.
396  std::shared_ptr<AccessibilityBridgeWindows> accessibility_bridge_;
397 
398  FML_DISALLOW_COPY_AND_ASSIGN(FlutterWindowsView);
399 };
400 
401 } // namespace flutter
402 
403 #endif // FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOWS_VIEW_H_
flutter::FlutterWindowsView::OnPointerMove
void OnPointerMove(double x, double y, FlutterPointerDeviceKind device_kind, int32_t device_id, int modifiers_state) override
Definition: flutter_windows_view.cc:145
flutter::FlutterWindowsView::OnPointerUp
void OnPointerUp(double x, double y, FlutterPointerDeviceKind device_kind, int32_t device_id, FlutterPointerMouseButtons button) override
Definition: flutter_windows_view.cc:167
flutter::WindowStateEvent
WindowStateEvent
An event representing a change in window state that may update the.
Definition: windows_lifecycle_manager.h:24
flutter::FlutterWindowsView::OnWindowStateEvent
void OnWindowStateEvent(HWND hwnd, WindowStateEvent event) override
Definition: flutter_windows_view.cc:697
flutter::FlutterWindowsView::FlutterWindowsView
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Definition: flutter_windows_view.cc:41
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void CreateRenderSurface()
Definition: flutter_windows_view.cc:590
flutter::FlutterWindowsView::OnWindowSizeChanged
void OnWindowSizeChanged(size_t width, size_t height) override
Definition: flutter_windows_view.cc:107
flutter::FlutterWindowsView::OnUpdateSemanticsEnabled
virtual void OnUpdateSemanticsEnabled(bool enabled) override
Definition: flutter_windows_view.cc:251
flutter::FlutterWindowsView::OnComposeCommit
void OnComposeCommit() override
Definition: flutter_windows_view.cc:222
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Definition: flutter_windows_view.h:35
scancode
int scancode
Definition: keyboard_key_handler_unittests.cc:115
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Definition: flutter_windows_view.cc:622
flutter::FlutterWindowsView::~FlutterWindowsView
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Definition: flutter_windows_view.cc:51
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Definition: flutter_windows_view.cc:544
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Definition: keyboard_key_handler_unittests.cc:119
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Definition: keyboard_key_handler_unittests.cc:118
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Definition: flutter_windows_view.cc:154
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Definition: flutter_windows_engine.h:78
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char32_t character
Definition: keyboard_key_handler_unittests.cc:117
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void OnComposeChange(const std::u16string &text, int cursor_pos) override
Definition: flutter_windows_view.cc:230
flutter::FlutterWindowsView::accessibility_bridge
std::weak_ptr< AccessibilityBridgeWindows > accessibility_bridge()
Definition: flutter_windows_view.h:210
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void OnScrollInertiaCancel(int32_t device_id) override
Definition: flutter_windows_view.cc:246
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Definition: flutter_windows_view.cc:100
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Definition: flutter_windows_view.cc:608
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Definition: window_binding_handler.h:44
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Definition: flutter_windows_view.cc:187
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Definition: window_binding_handler_delegate.h:18
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Definition: geometry.h:56
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Definition: flutter_windows_view.cc:540
flutter::FlutterWindowsView::OnCursorRectUpdated
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Definition: flutter_windows_view.cc:263
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Definition: flutter_windows_view.cc:634
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Definition: text_input_plugin_delegate.h:13
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constexpr uint32_t kWindowFrameBufferID
Definition: flutter_windows_view.h:31
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virtual void OnPointerPanZoomUpdate(int32_t device_id, double pan_x, double pan_y, double scale, double rotation) override
Definition: flutter_windows_view.cc:192
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Definition: flutter_windows_view.cc:141
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Definition: window_binding_handler_delegate.h:20
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Definition: flutter_windows_view.cc:226
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Definition: window_binding_handler.h:40
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Definition: keyboard_unittests.cc:332
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Definition: flutter_windows_view.cc:61
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Definition: flutter_windows_view.cc:548
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Definition: flutter_windows_view.cc:92
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Definition: flutter_windows_view.cc:96
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Definition: flutter_windows_view.cc:180
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Definition: flutter_windows_view.cc:204
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Definition: flutter_windows_view.cc:583
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Definition: flutter_windows_view.cc:655
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Definition: flutter_windows_view.cc:536
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Definition: flutter_windows_view.cc:200
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Definition: flutter_windows_view.cc:676
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Definition: flutter_windows_view.cc:644
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Definition: flutter_windows_view.cc:664
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Definition: flutter_windows_view.cc:218
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Definition: flutter_windows_view.cc:618
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Definition: flutter_windows_view.cc:283
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Definition: flutter_windows_view.cc:660
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Definition: keyboard_key_handler_unittests.cc:116
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Definition: flutter_windows_view.cc:235
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Definition: flutter_windows_view.cc:267
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Definition: flutter_windows_view.cc:651
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Definition: flutter_windows_view.cc:626
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Definition: keyboard_key_handler_unittests.cc:114
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Definition: flutter_windows_view.cc:208
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Definition: flutter_windows_view.cc:255
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Definition: flutter_windows_view.cc:630
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Definition: flutter_windows_view.cc:73
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Definition: flutter_windows_view.cc:614
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Definition: flutter_windows_view_unittests.cc:46