Bug 2279 - Multi-view: turning it on does not cause a split Multi-view to be displayed

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

@@ -770,16 +770,18 @@ void WaveTrackMenuTable::OnMultiView(wxCommandEvent & event)
 {
    const auto pTrack = static_cast<WaveTrack*>(mpData->pTrack);
    const auto &view = WaveTrackView::Get( *pTrack );
+   const int nViewTypes = 2;
    bool multi = !view.GetMultiView();
    WaveTrackView::WaveTrackDisplay display;
-   if ( !multi )
-      display = *view.GetDisplays().begin();
+   display = *view.GetDisplays().begin();
    for (const auto channel : TrackList::Channels(pTrack)) {
       auto &channelView = WaveTrackView::Get( *channel );
       channelView.SetMultiView( multi );
-      if ( !multi )
-         // Whichever sub-view was on top will take up all
-         channelView.SetDisplay( display );
+
+      // Whichever sub-view was on top stays on top
+      // If going into Multi-view, it will be 1/nth the height.
+      // If exiting multi-view, it will be full height.
+      channelView.SetDisplay(display, multi ? 1.0/nViewTypes :1.0);
    }
 }
 

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

@@ -540,10 +540,10 @@ auto WaveTrackView::GetDisplays() const -> std::vector<WaveTrackDisplay>
    return results;
 }
 
-void WaveTrackView::SetDisplay(WaveTrackDisplay display)
+void WaveTrackView::SetDisplay(WaveTrackDisplay display, float frac)
 {
    BuildSubViews();
-   DoSetDisplay( display );
+   DoSetDisplay( display, frac );
 }
 
 void WaveTrackView::ToggleSubView(WaveTrackDisplay display)
@@ -587,15 +587,31 @@ void WaveTrackView::ToggleSubView(WaveTrackDisplay display)
    }
 }
 
-void WaveTrackView::DoSetDisplay(WaveTrackDisplay display)
+// frac sets proportion/height of the chosen display, which will be first.
+//   use 1.0 to take up entire space
+//   use some fraction to take up that proportion, leaving the rest for 
+//       one each of the other types.
+//   use 1.0/number-of-types for equal spacing.
+void WaveTrackView::DoSetDisplay(WaveTrackDisplay display,float frac)
 {
    size_t ii = 0;
+   size_t jj = 1;
+   const int nViewTypes = 2;
    WaveTrackSubViews::ForEach( [&,display]( WaveTrackSubView &subView ){
-      if ( subView.SubViewType() == display )
-         mPlacements[ii] = {  0, 1.0 };
-      else
+      auto viewType = subView.SubViewType();
+      if (viewType == display) {
+         // 0 for first view
+         mPlacements[ii] = { 0, frac };
+         --jj;
+      }
+      else if( frac > 0.999)
+         // -1 for not displayed
          mPlacements[ii] = { -1, 0.0 };
+      else
+         // jj for positions excluding the first.
+         mPlacements[ii] = { (int)jj, (1.0f-frac)/(nViewTypes-1) };
       ++ii;
+      ++jj;
    } );
 }
 
@@ -904,7 +920,7 @@ void WaveTrackView::BuildSubViews() const
             settings.scaleType = WaveformSettings::stLogarithmic;
          }
          
-         pThis->DoSetDisplay( display );
+         pThis->DoSetDisplay( display, 1.0 );
       }
    }
 }

src/tracks/playabletrack/wavetrack/ui/WaveTrackView.h

@@ -84,7 +84,7 @@ public:
    using WaveTrackDisplay = WaveTrackViewConstants::Display;
 
    std::vector<WaveTrackDisplay> GetDisplays() const;
-   void SetDisplay(WaveTrackDisplay display);
+   void SetDisplay(WaveTrackDisplay display, float frac=1.0);
 
    const WaveTrackSubViewPlacements &SavePlacements() const
       { return mPlacements; }
@@ -105,7 +105,7 @@ public:
 
 private:
    void BuildSubViews() const;
-   void DoSetDisplay(WaveTrackDisplay display);
+   void DoSetDisplay(WaveTrackDisplay display, float frac);
 
    // TrackPanelDrawable implementation
    void Draw(