flutter_flutter/shell/platform/windows/win32_flutter_window.h

// Copyright 2013 The Flutter 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 FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOW_H_
#define FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOW_H_

#include <windowsx.h>

#include <string>
#include <vector>

#include "flutter/shell/platform/common/cpp/client_wrapper/include/flutter/plugin_registrar.h"
#include "flutter/shell/platform/common/cpp/incoming_message_dispatcher.h"
#include "flutter/shell/platform/embedder/embedder.h"
#include "flutter/shell/platform/windows/angle_surface_manager.h"
#include "flutter/shell/platform/windows/key_event_handler.h"
#include "flutter/shell/platform/windows/keyboard_hook_handler.h"
#include "flutter/shell/platform/windows/platform_handler.h"
#include "flutter/shell/platform/windows/public/flutter_windows.h"
#include "flutter/shell/platform/windows/text_input_plugin.h"
#include "flutter/shell/platform/windows/win32_window.h"
#include "flutter/shell/platform/windows/window_state.h"

namespace flutter {

// A win32 flutter child window used as implementatin for flutter view.  In the
// future, there will likely be a CoreWindow-based FlutterWindow as well.  At
// the point may make sense to dependency inject the native window rather than
// inherit.
class Win32FlutterWindow : public Win32Window {
 public:
  // Create flutter Window for use as child window
  Win32FlutterWindow(int width, int height);

  virtual ~Win32FlutterWindow();

  static FlutterDesktopViewControllerRef CreateWin32FlutterWindow(int width,
                                                                  int height);

  // |Win32Window|
  void OnDpiScale(unsigned int dpi) override;

  // |Win32Window|
  void OnResize(unsigned int width, unsigned int height) override;

  // |Win32Window|
  void OnPointerMove(double x, double y) override;

  // |Win32Window|
  void OnPointerDown(double x, double y, UINT button) override;

  // |Win32Window|
  void OnPointerUp(double x, double y, UINT button) override;

  // |Win32Window|
  void OnPointerLeave() override;

  // |Win32Window|
  void OnText(const std::u16string& text) override;

  // |Win32Window|
  void OnKey(int key, int scancode, int action, char32_t character) override;

  // |Win32Window|
  void OnScroll(double delta_x, double delta_y) override;

  // |Win32Window|
  void OnFontChange() override;

  // Configures the window instance with an instance of a running Flutter engine
  // returning a configured FlutterDesktopWindowControllerRef.
  void SetState(FLUTTER_API_SYMBOL(FlutterEngine) state);

  // Returns the currently configured Plugin Registrar.
  FlutterDesktopPluginRegistrarRef GetRegistrar();

  // Callback passed to Flutter engine for notifying window of platform
  // messages.
  void HandlePlatformMessage(const FlutterPlatformMessage*);

  // Create a surface for Flutter engine to render into.
  void CreateRenderSurface();

  // Callbacks for clearing context, settings context and swapping buffers.
  bool ClearContext();
  bool MakeCurrent();
  bool MakeResourceCurrent();
  bool SwapBuffers();

  // Sends a window metrics update to the Flutter engine using current window
  // dimensions in physical
  void SendWindowMetrics();

 private:
  // Destroy current rendering surface if one has been allocated.
  void DestroyRenderSurface();

  // Reports a mouse movement to Flutter engine.
  void SendPointerMove(double x, double y);

  // Reports mouse press to Flutter engine.
  void SendPointerDown(double x, double y);

  // Reports mouse release to Flutter engine.
  void SendPointerUp(double x, double y);

  // Reports mouse left the window client area.
  //
  // Win32 api doesn't have "mouse enter" event. Therefore, there is no
  // SendPointerEnter method. A mouse enter event is tracked then the "move"
  // event is called.
  void SendPointerLeave();

  // Reports text input to Flutter engine.
  void SendText(const std::u16string& text);

  // Reports a raw keyboard message to Flutter engine.
  void SendKey(int key, int scancode, int action, char32_t character);

  // Reports scroll wheel events to Flutter engine.
  void SendScroll(double delta_x, double delta_y);

  // Updates |event_data| with the current location of the mouse cursor.
  void SetEventLocationFromCursorPosition(FlutterPointerEvent* event_data);

  // Set's |event_data|'s phase to either kMove or kHover depending on the
  // current
  // primary mouse button state.
  void SetEventPhaseFromCursorButtonState(FlutterPointerEvent* event_data);

  // Sends a pointer event to the Flutter engine based on givern data.  Since
  // all input messages are passed in physical pixel values, no translation is
  // needed before passing on to engine.
  void SendPointerEventWithData(const FlutterPointerEvent& event_data);

  std::unique_ptr<AngleSurfaceManager> surface_manager = nullptr;
  EGLSurface render_surface = EGL_NO_SURFACE;

  // state of the mouse button
  bool pointer_is_down_ = false;

  // The handle to the Flutter engine instance.
  FLUTTER_API_SYMBOL(FlutterEngine) engine_ = nullptr;

  // Whether or not to track mouse movements to send kHover events.
  bool hover_tracking_is_enabled_ = false;

  // Whether or not the pointer has been added (or if tracking is enabled, has
  // been added since it was last removed).
  bool pointer_currently_added_ = false;

  // The window handle given to API clients.
  std::unique_ptr<FlutterDesktopView> window_wrapper_;

  // The plugin registrar handle given to API clients.
  std::unique_ptr<FlutterDesktopPluginRegistrar> plugin_registrar_;

  // Message dispatch manager for messages from the Flutter engine.
  std::unique_ptr<flutter::IncomingMessageDispatcher> message_dispatcher_;

  // The plugin registrar managing internal plugins.
  std::unique_ptr<flutter::PluginRegistrar> internal_plugin_registrar_;

  // Handlers for keyboard events from Windows.
  std::vector<std::unique_ptr<flutter::KeyboardHookHandler>>
      keyboard_hook_handlers_;

  // Handler for the flutter/platform channel.
  std::unique_ptr<flutter::PlatformHandler> platform_handler_;

  // should we forword input messages or not
  bool process_events_ = false;
};

}  // namespace flutter

#endif  // FLUTTER_SHELL_PLATFORM_WINDOWS_FLUTTER_WINDOW_H_