Method Drag

src/tracks/ui/SelectHandle.cpp:809–901

}

UIHandle::Result SelectHandle::Drag(const TrackPanelMouseEvent &evt,
   AudacityProject *pProject)
{
   using namespace RefreshCode;

   const auto pView = mpView.lock();
   if ( !pView )
      return Cancelled;
   auto &view = *pView;

   auto &viewInfo = ViewInfo::Get( *pProject );
   const wxMouseEvent &event = evt.event;

   int x = mAutoScrolling ? mMostRecentX : event.m_x;
   int y = mAutoScrolling ? mMostRecentY : event.m_y;
   mMostRecentX = x;
   mMostRecentY = y;

   /// AS: If we're dragging to adjust a selection (or actually,
   ///  if the screen is scrolling while you're selecting), we
   ///  handle it here.

   // Fuhggeddaboudit if we're not dragging and not autoscrolling.
   if (!event.Dragging() && !mAutoScrolling)
      return RefreshNone;

   if (event.CmdDown()) {
      // Ctrl-drag has no meaning, fuhggeddaboudit
      // JKC YES it has meaning.
      //return RefreshNone;
   }

   // Also fuhggeddaboudit if not in a track.
   const auto pChannel = view.FindChannel();
   if (!pChannel)
      return RefreshNone;

   // JKC: Logic to prevent a selection smaller than 5 pixels to
   // prevent accidental dragging when selecting.
   // (if user really wants a tiny selection, they should zoom in).
   // Can someone make this value of '5' configurable in
   // preferences?
   enum { minimumSizedSelection = 5 }; //measured in pixels

   // Might be dragging frequency bounds only, test
   if (mSelStartValid) {
      wxInt64 SelStart = viewInfo.TimeToPosition(mSelStart, mRect.x); //cvt time to pixels.
      // Abandon this drag if selecting < 5 pixels.
      if (wxLongLong(SelStart - x).Abs() < minimumSizedSelection)
         return RefreshNone;
   }

   if (evt.pCell) {
      if ( auto clickedTrack =
          static_cast<CommonTrackPanelCell*>(evt.pCell.get())->FindTrack() ) {
         // Handle which tracks are selected
         Track *sTrack = FindTrack();
         Track *eTrack = clickedTrack.get();