Bug1665: Pan, Gain, Velocity were unresponsive except on last track

src/tracks/playabletrack/notetrack/ui/NoteTrackSliderHandles.cpp

@@ -79,12 +79,15 @@ HitTestResult VelocitySliderHandle::HitTest
    if ( TrackInfo::HideTopItem( rect, sliderRect, kTrackInfoSliderAllowance ) )
       return {};
    if (sliderRect.Contains(event.m_x, event.m_y)) {
-      NoteTrack *const notetrack = static_cast<NoteTrack*>(pTrack);
-      auto slider = TrackInfo::VelocitySlider
-         (sliderRect, notetrack, true,
+      Instance().mSliderFn =
+      []( AudacityProject *pProject, const wxRect &sliderRect, Track *pTrack ) {
+         return TrackInfo::VelocitySlider
+            (sliderRect, static_cast<NoteTrack*>( pTrack ), true,
              const_cast<TrackPanel*>(pProject->GetTrackPanel()));
-      Instance().mpSlider = slider;
-      Instance().mpTrack = notetrack;
+      };
+      Instance().mRect = sliderRect;
+      Instance().mpTrack = pTrack;
+
       return { HitPreview(), &Instance() };
    }
    else

src/tracks/playabletrack/wavetrack/ui/WaveTrackSliderHandles.cpp

@@ -72,7 +72,7 @@ UIHandle::Result GainSliderHandle::CommitChanges
 
 HitTestResult GainSliderHandle::HitTest
 (const wxMouseEvent &event, const wxRect &rect,
- const AudacityProject *pProject, Track *pTrack)
+ const AudacityProject *, Track *pTrack)
 {
    if (!event.Button(wxMOUSE_BTN_LEFT))
       return {};
@@ -82,14 +82,18 @@ HitTestResult GainSliderHandle::HitTest
    if ( TrackInfo::HideTopItem( rect, sliderRect, kTrackInfoSliderAllowance ) )
       return {};
    if (sliderRect.Contains(event.m_x, event.m_y)) {
-      WaveTrack *const wavetrack = static_cast<WaveTrack*>(pTrack);
       wxRect sliderRect;
       TrackInfo::GetGainRect(rect.GetTopLeft(), sliderRect);
-      auto slider = TrackInfo::GainSlider
-         (sliderRect, wavetrack, true,
+
+      Instance().mSliderFn =
+      []( AudacityProject *pProject, const wxRect &sliderRect, Track *pTrack ) {
+         return TrackInfo::GainSlider
+            (sliderRect, static_cast<WaveTrack*>( pTrack ), true,
              const_cast<TrackPanel*>(pProject->GetTrackPanel()));
-      Instance().mpSlider = slider;
-      Instance().mpTrack = wavetrack;
+      };
+      Instance().mRect = sliderRect;
+      Instance().mpTrack = pTrack;
+
       return {
          HitPreview(),
          &Instance()
@@ -174,12 +178,15 @@ HitTestResult PanSliderHandle::HitTest
    if ( TrackInfo::HideTopItem( rect, sliderRect, kTrackInfoSliderAllowance ) )
       return {};
    if (sliderRect.Contains(event.m_x, event.m_y)) {
-      WaveTrack *const wavetrack = static_cast<WaveTrack*>(pTrack);
-      auto slider = TrackInfo::PanSlider
-         (sliderRect, wavetrack, true,
+      Instance().mSliderFn =
+      []( AudacityProject *pProject, const wxRect &sliderRect, Track *pTrack ) {
+         return TrackInfo::PanSlider
+            (sliderRect, static_cast<WaveTrack*>( pTrack ), true,
              const_cast<TrackPanel*>(pProject->GetTrackPanel()));
-      Instance().mpSlider = slider;
-      Instance().mpTrack = wavetrack;
+      };
+      Instance().mRect = sliderRect;
+      Instance().mpTrack = pTrack;
+
       return {
          HitPreview(),
          &Instance()

src/tracks/ui/SliderHandle.cpp

@@ -30,7 +30,7 @@ HitTestPreview SliderHandle::HitPreview()
 }
 
 UIHandle::Result SliderHandle::Click
-(const TrackPanelMouseEvent &evt, AudacityProject *)
+(const TrackPanelMouseEvent &evt, AudacityProject *pProject)
 {
    wxMouseEvent &event = evt.event;
    using namespace RefreshCode;
@@ -39,8 +39,8 @@ UIHandle::Result SliderHandle::Click
 
    // Come here for left click or double click
    mStartingValue = GetValue();
-   mpSlider->Set(mStartingValue);
-   mpSlider->OnMouseEvent(event);
+   GetSlider( pProject )->Set(mStartingValue);
+   GetSlider( pProject )->OnMouseEvent(event);
 
    if (event.ButtonDClick())
       // Just did a modal dialog in OnMouseEvent
@@ -55,8 +55,8 @@ UIHandle::Result SliderHandle::Drag
 {
    wxMouseEvent &event = evt.event;
    using namespace RefreshCode;
-   mpSlider->OnMouseEvent(event);
-   const float newValue = mpSlider->Get();
+   GetSlider( pProject )->OnMouseEvent(event);
+   const float newValue = GetSlider( pProject )->Get();
 
    // Make a non-permanent change to the project data:
    return RefreshCell | SetValue(pProject, newValue);
@@ -75,22 +75,26 @@ UIHandle::Result SliderHandle::Release
 {
    using namespace RefreshCode;
    wxMouseEvent &event = evt.event;
-   mpSlider->OnMouseEvent(event);
-   const float newValue = mpSlider->Get();
+   GetSlider( pProject )->OnMouseEvent(event);
+   const float newValue = GetSlider( pProject )->Get();
 
    Result result = RefreshCell;
 
    // Commit changes to the project data:
    result |= SetValue(pProject, newValue);
    result |= CommitChanges(event, pProject);
+
+   mpTrack = nullptr;
    return result;
 }
 
 UIHandle::Result SliderHandle::Cancel(AudacityProject *pProject)
 {
    wxMouseEvent event(wxEVT_LEFT_UP);
-   mpSlider->OnMouseEvent(event);
+   GetSlider( pProject )->OnMouseEvent(event);
 
    // Undo un-committed changes to project data:
-   return RefreshCode::RefreshCell | SetValue(pProject, mStartingValue);
+   auto result = SetValue(pProject, mStartingValue);
+   mpTrack = nullptr;
+   return RefreshCode::RefreshCell | result;
 }

src/tracks/ui/SliderHandle.h

@@ -12,6 +12,7 @@ Paul Licameli
 #define __AUDACITY_SLIDER_HANDLE__
 
 #include "../../UIHandle.h"
+#include <wx/gdicmn.h>
 
 class wxMouseEvent;
 class LWSlider;
@@ -56,7 +57,11 @@ protected:
 
    // Derived track is expected to set these two before Click():
    Track *mpTrack {};
-   LWSlider *mpSlider {};
+   wxRect mRect{};
+   using SliderFn = LWSlider *(*)( AudacityProject*, const wxRect&, Track* );
+   SliderFn mSliderFn;
+   LWSlider *GetSlider( AudacityProject *pProject )
+   { return mSliderFn( pProject, mRect, mpTrack ); }
 
    float mStartingValue {};
 };