SliderHandle.h

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/**********************************************************************
 
Audacity: A Digital Audio Editor
 
SliderHandle.h
 
Paul Licameli
 
**********************************************************************/
 
#ifndef __AUDACITY_SLIDER_HANDLE__
#define __AUDACITY_SLIDER_HANDLE__
 
#include "../../UIHandle.h"
 
class wxMouseEvent;
class wxMouseState;
class LWSlider;
class Track;
class TranslatableString;
 
class AUDACITY_DLL_API SliderHandle /* not final */ : public UIHandle
{
   SliderHandle(const SliderHandle&) = delete;
 
public:
   using SliderFn = LWSlider *(*)( AudacityProject*, const wxRect&, Track* );
 
   explicit SliderHandle
      ( SliderFn sliderFn, const wxRect &rect,
        const std::shared_ptr<Track> &pTrack );
 
   SliderHandle &operator=(const SliderHandle&) = default;
 
   std::shared_ptr<const Track> FindTrack() const override;
   std::shared_ptr<Track> GetTrack() const { return mpTrack.lock(); }
   bool IsDragging() const override;
 
protected:
   virtual ~SliderHandle();
 
   // These NEW abstract virtuals simplify the duties of further subclasses.
   // This class will decide whether to refresh the clicked cell for slider state
   // change.
   // Subclass can decide to refresh other things and the results will be ORed.
   virtual float GetValue() = 0;
   virtual Result SetValue(AudacityProject *pProject, float newValue) = 0;
   virtual Result CommitChanges
      (const wxMouseEvent &event, AudacityProject *pProject) = 0;
 
   // Define a message for the status bar and tooltip.
   virtual TranslatableString Tip(
      const wxMouseState &state, AudacityProject &project) const = 0;
 
   void Enter(bool forward, AudacityProject *) override;
 
   Result Click
      (const TrackPanelMouseEvent &event, AudacityProject *pProject)
      final override;
 
   Result Drag
      (const TrackPanelMouseEvent &event, AudacityProject *pProject)
      final override;
 
   HitTestPreview Preview
      (const TrackPanelMouseState &state, AudacityProject *pProject)
      final override;
 
   Result Release
      (const TrackPanelMouseEvent &event, AudacityProject *pProject,
       wxWindow *pParent) final override;
 
   Result Cancel(AudacityProject *pProject) final override;
 
   // Derived class is expected to set these two before Click():
   std::weak_ptr<Track> mpTrack;
   wxRect mRect{};
   SliderFn mSliderFn;
   LWSlider *GetSlider( AudacityProject *pProject );
 
   float mStartingValue {};
 
   bool mIsDragging{};
};
 
#endif