Own resizing area added to stereo wave tracks view and affordance view

(cherry picked from audacity commit 7949a0dc86b6e473ffa7fd41d4fe9ddad1e6ba51)

Signed-off-by: akleja <storspov@gmail.com>

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

@@ -16,6 +16,7 @@
 #include "../../../../TrackPanelMouseEvent.h"
 #include "../../../../TrackArtist.h"
 #include "../../../../TrackPanelDrawingContext.h"
+#include "../../../../TrackPanelResizeHandle.h"
 #include "../../../../ViewInfo.h"
 #include "../../../../WaveTrack.h"
 #include "../../../../WaveClip.h"
@@ -34,14 +35,29 @@ std::vector<UIHandlePtr> WaveTrackAffordanceControls::HitTest(const TrackPanelMo
 
     std::vector<UIHandlePtr> results;
 
-    const auto track = FindTrack();
-
-    const auto waveTrack = std::static_pointer_cast<WaveTrack>(track->SubstitutePendingChangedTrack());
+    auto px = state.state.m_x;
+    auto py = state.state.m_y;
 
     const auto rect = state.rect;
 
-    auto px = state.state.m_x;
-    auto py = state.state.m_y;
+    const auto track = FindTrack();
+
+    auto trackList = track->GetOwner();
+    if ((std::abs(rect.GetTop() - py) <= WaveTrackView::kChannelSeparatorThickness / 2) 
+        && trackList
+        && !track->IsLeader())
+    {
+        //given that track is not a leader there always should be
+        //another track before this one
+        auto prev = --trackList->Find(track.get());
+        auto result = std::static_pointer_cast<UIHandle>(
+            std::make_shared<TrackPanelResizeHandle>((*prev)->shared_from_this(), py)
+        );
+        result = AssignUIHandlePtr(mResizeHandle, result);
+        results.push_back(result);
+    }
+
+    const auto waveTrack = std::static_pointer_cast<WaveTrack>(track->SubstitutePendingChangedTrack());
 
     auto& zoomInfo = ViewInfo::Get(*pProject);
     for (const auto& clip : waveTrack->GetClips())

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

@@ -19,6 +19,7 @@ class TENACITY_DLL_API WaveTrackAffordanceControls : public CommonTrackCell
 {
     std::weak_ptr<WaveClip> mFocusClip;
     std::weak_ptr<AffordanceHandle> mAffordanceHandle;
+    std::weak_ptr<UIHandle> mResizeHandle;
 public:
     WaveTrackAffordanceControls(const std::shared_ptr<Track>& pTrack);
 

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

@@ -31,6 +31,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../../../TrackArtist.h"
 #include "../../../../TrackPanelDrawingContext.h"
 #include "../../../../TrackPanelMouseEvent.h"
+#include "../../../../TrackPanelResizeHandle.h"
 #include "../../../../ViewInfo.h"
 #include "../../../../prefs/TracksPrefs.h"
 
@@ -703,6 +704,49 @@ std::pair<
          mCloseHandle,
          *pWaveTrackView, *this, state ) )
          results.second.push_back( pHandle );
+
+      auto channels = TrackList::Channels(wt.get());
+      if(channels.size() > 1) {
+         // Only one cell is tested and we need to know
+         // which one and it's relative location to the border.
+         auto subviews = pWaveTrackView->GetSubViews();
+         auto currentSubview = std::find_if(subviews.begin(), subviews.end(), 
+            [self = shared_from_this()](const auto& p){
+               return self == p.second;
+         });
+         if (currentSubview != subviews.end())
+         {
+            auto currentSubviewIndex = std::distance(subviews.begin(), currentSubview);
+            
+            const auto py = state.state.GetY();
+            const auto topBorderHit = std::abs(py - state.rect.GetTop())
+               <= WaveTrackView::kChannelSeparatorThickness / 2;
+            const auto bottomBorderHit = std::abs(py - state.rect.GetBottom())
+               <= WaveTrackView::kChannelSeparatorThickness / 2;
+
+            auto currentChannel = channels.find(wt.get());
+            auto currentChannelIndex = std::distance(channels.begin(), currentChannel);
+
+            if (//for not-last-view check the bottom border hit
+               ((currentChannelIndex != channels.size() - 1)
+                  && (currentSubviewIndex == static_cast<int>(subviews.size()) - 1)
+                  && bottomBorderHit)
+               ||
+               //or for not-first-view check the top border hit
+               ((currentChannelIndex != 0) && currentSubviewIndex == 0 && topBorderHit))
+            {
+               //depending on which border hit test succeeded on we
+               //need to choose a proper target for resizing
+               auto it = bottomBorderHit ? currentChannel : currentChannel.advance(-1);
+               auto result = std::static_pointer_cast<UIHandle>(
+                  std::make_shared<TrackPanelResizeHandle>((*it)->shared_from_this(), py)
+               );
+               result = AssignUIHandlePtr(mResizeHandle, result);
+               results.second.push_back(result);
+            }
+         }
+      }
+
       if ( auto pHandle = SubViewAdjustHandle::HitTest(
          mAdjustHandle,
          *pWaveTrackView, *this, state ) )
@@ -964,6 +1008,11 @@ void WaveTrackView::DoSetDisplay(Display display, bool exclusive)
 }
 
 auto WaveTrackView::GetSubViews( const wxRect &rect ) -> Refinement
+{
+   return GetSubViews(&rect);
+}
+
+auto WaveTrackView::GetSubViews(const wxRect* rect) -> Refinement
 {
    BuildSubViews();
 
@@ -974,41 +1023,51 @@ auto WaveTrackView::GetSubViews( const wxRect &rect ) -> Refinement
    std::vector< Item > items;
    size_t ii = 0;
    float total = 0;
-   WaveTrackSubViews::ForEach( [&]( WaveTrackSubView &subView ){
-      auto &placement = mPlacements[ii];
+   WaveTrackSubViews::ForEach([&](WaveTrackSubView& subView) {
+      auto& placement = mPlacements[ii];
       auto index = placement.index;
       auto fraction = placement.fraction;
-      if ( index >= 0 && fraction > 0.0 )
+      if (index >= 0 && fraction > 0.0)
          total += fraction,
-         items.push_back( { index, fraction, subView.shared_from_this() } );
+         items.push_back({ index, fraction, subView.shared_from_this() });
       ++ii;
-   } );
-   std::sort( items.begin(), items.end(), [](const Item &a, const Item &b){
+   });
+   std::sort(items.begin(), items.end(), [](const Item& a, const Item& b) {
       return a.index < b.index;
-   } );
+   });
 
    // Remove views we don't need
    auto begin = items.begin(), end = items.end(),
-     newEnd = std::remove_if( begin, end,
-        []( const Item &item ){ return !item.pView; } );
-   items.erase( newEnd, end );
+        newEnd = std::remove_if(begin, end,
+            [](const Item& item) { return !item.pView; });
+   items.erase(newEnd, end);
 
-   // Assign coordinates, redenominating to the total height,
-   // storing integer values
    Refinement results;
-   results.reserve( items.size() );
-   const auto top = rect.GetTop();
-   const auto height = rect.GetHeight();
-   float partial = 0;
-   wxCoord lastCoord = 0;
-   for ( const auto &item : items ) {
-      wxCoord newCoord = top + (partial / total) * height;
-      results.emplace_back( newCoord, item.pView );
-      partial += item.fraction;
-   }
 
-   // Cache for the use of sub-view dragging
-   mLastHeight = height;
+   if (rect != nullptr)
+   {
+      // Assign coordinates, redenominating to the total height,
+      // storing integer values
+      results.reserve(items.size());
+      const auto top = rect->GetTop();
+      const auto height = rect->GetHeight();
+      float partial = 0;
+      wxCoord lastCoord = 0;
+      for (const auto& item : items) {
+         wxCoord newCoord = top + (partial / total) * height;
+         results.emplace_back(newCoord, item.pView);
+         partial += item.fraction;
+      }
+
+      // Cache for the use of sub-view dragging
+      mLastHeight = height;
+   }
+   else
+   {
+      std::transform(items.begin(), items.end(), std::back_inserter(results), [](const auto& item) {
+         return std::make_pair(0, item.pView);
+      });
+   }
 
    return results;
 }

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

@@ -52,6 +52,7 @@ protected:
 
 private:
    std::weak_ptr<UIHandle> mCloseHandle;
+   std::weak_ptr<UIHandle> mResizeHandle;
    std::weak_ptr<UIHandle> mAdjustHandle;
    std::weak_ptr<UIHandle> mRearrangeHandle;
    std::weak_ptr<CutlineHandle> mCutlineHandle;
@@ -77,6 +78,8 @@ class TENACITY_DLL_API WaveTrackView final
    WaveTrackView &operator=( const WaveTrackView& ) = delete;
 
 public:
+   static constexpr int kChannelSeparatorThickness{ 8 };
+
    using Display = WaveTrackViewConstants::Display;
 
    static WaveTrackView &Get( WaveTrack &track );
@@ -128,6 +131,15 @@ public:
 
    std::weak_ptr<WaveClip> GetSelectedClip();
 
+   // Returns a visible subset of subviews, sorted in the same 
+   // order as they are supposed to be displayed
+   
+
+   // Get the visible sub-views,
+   // if rect is provided then result will contain
+   // y coordinate for each subview within this rect
+   Refinement GetSubViews(const wxRect* rect = nullptr);
+
 private:
    void BuildSubViews() const;
    void DoSetDisplay(Display display, bool exclusive = true);
@@ -143,8 +155,7 @@ private:
       override;
 
    // TrackView implementation
-   // Get the visible sub-views with top y coordinates
-   Refinement GetSubViews( const wxRect &rect ) override;
+   Refinement GetSubViews(const wxRect& rect) override;
 
 protected:
    std::shared_ptr<CommonTrackCell> DoGetAffordanceControls() override;