GHOST_TrackpadWin32.hh

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/* SPDX-FileCopyrightText: 2022-2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#pragma once
 
#ifndef WIN32
#  error WIN32 only!
#endif  // WIN32
 
#include "GHOST_Types.h"
 
#include <directmanipulation.h>
#include <wrl.h>
 
#define PINCH_SCALE_FACTOR 125.0f
 
typedef struct {
  int32_t x, y, scale;
  bool isScrollDirectionInverted;
} GHOST_TTrackpadInfo;
 
class GHOST_DirectManipulationHelper;
 
class GHOST_DirectManipulationViewportEventHandler
    : public Microsoft::WRL::RuntimeClass<
          Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::RuntimeClassType::ClassicCom>,
          Microsoft::WRL::Implements<
              Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::RuntimeClassType::ClassicCom>,
              Microsoft::WRL::FtmBase,
              IDirectManipulationViewportEventHandler>> {
 public:
  GHOST_DirectManipulationViewportEventHandler(uint16_t dpi);
 
  /*
   * Resets viewport and tracked touchpad state.
   */
  void resetViewport(IDirectManipulationViewport *viewport);
 
  /* DirectManipulation callbacks. */
  HRESULT STDMETHODCALLTYPE OnViewportStatusChanged(IDirectManipulationViewport *viewport,
                                                    DIRECTMANIPULATION_STATUS current,
                                                    DIRECTMANIPULATION_STATUS previous) override;
 
  HRESULT STDMETHODCALLTYPE OnViewportUpdated(IDirectManipulationViewport *viewport) override;
 
  HRESULT STDMETHODCALLTYPE OnContentUpdated(IDirectManipulationViewport *viewport,
                                             IDirectManipulationContent *content) override;
 
 private:
  enum { GESTURE_NONE, GESTURE_PAN, GESTURE_PINCH } gesture_state;
 
  int32_t last_x, last_y, last_scale;
  GHOST_TTrackpadInfo accumulated_values;
  uint16_t dpi;
  DIRECTMANIPULATION_STATUS dm_status;
 
  friend class GHOST_DirectManipulationHelper;
};
 
class GHOST_DirectManipulationHelper {
 public:
  /*
   * Creates a GHOST_DirectManipulationHelper for the provided window.
   * \param hWnd: The window receiving DirectManipulation events.
   * \param dpi: The current DPI.
   * \return Pointer to the new GHOST_DirectManipulationHelper if created, nullptr if there was an
   * error.
   */
  static GHOST_DirectManipulationHelper *create(HWND hWnd, uint16_t dpi);
 
  ~GHOST_DirectManipulationHelper();
 
  /*
   * Drives the DirectManipulation context.
   * DirectManipulation's intended use is to tie user input into DirectComposition's compositor
   * scaling and translating. We are not using DirectComposition and therefore must drive
   * DirectManipulation manually.
   */
  void update();
 
  /*
   * Sets pointer in contact with the DirectManipulation context.
   * \param pointerId: ID of the pointer in contact.
   */
  void onPointerHitTest(UINT32 pointerId);
 
  /*
   * Updates DPI information for touchpad scaling.
   * \param dpi: The new DPI.
   */
  void setDPI(uint16_t dpi);
 
  /*
   * Retrieves trackpad input.
   * \return The accumulated trackpad translation and scale since last call.
   */
  GHOST_TTrackpadInfo getTrackpadInfo();
 
 private:
  GHOST_DirectManipulationHelper(
      HWND hWnd,
      Microsoft::WRL::ComPtr<IDirectManipulationManager> directManipulationManager,
      Microsoft::WRL::ComPtr<IDirectManipulationUpdateManager> directManipulationUpdateManager,
      Microsoft::WRL::ComPtr<IDirectManipulationViewport> directManipulationViewport,
      Microsoft::WRL::ComPtr<GHOST_DirectManipulationViewportEventHandler>
          directManipulationEventHandler,
      DWORD directManipulationViewportHandlerCookie,
      bool isScrollDirectionInverted);
 
  /*
   * Retrieves the scroll direction from the registry.
   * \return True if scroll direction is inverted.
   */
  static bool getScrollDirectionFromReg();
 
  /*
   * Registers listener for registry scroll direction entry changes.
   */
  void registerScrollDirectionChangeListener();
 
  HWND m_hWnd;
 
  HKEY m_scrollDirectionRegKey;
  HANDLE m_scrollDirectionChangeEvent;
 
  Microsoft::WRL::ComPtr<IDirectManipulationManager> m_directManipulationManager;
  Microsoft::WRL::ComPtr<IDirectManipulationUpdateManager> m_directManipulationUpdateManager;
  Microsoft::WRL::ComPtr<IDirectManipulationViewport> m_directManipulationViewport;
  Microsoft::WRL::ComPtr<GHOST_DirectManipulationViewportEventHandler>
      m_directManipulationEventHandler;
  DWORD m_directManipulationViewportHandlerCookie;
 
  bool m_isScrollDirectionInverted;
};