In ViewInfo, remove GetLabelWidth() and add comments

(cherry picked from audacity commit cef8e228f9)

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

src/TrackPanel.cpp

@@ -26,7 +26,7 @@
   TrackInfo class to draw the controls area on the left of a track,
   and the TrackArtist class to draw the actual waveforms.
 
-  Note that in some of the older code here, e.g., GetLabelWidth(),
+  Note that in some of the older code here,
   "Label" means the TrackInfo plus the vertical ruler.
   Confusing relative to LabelTrack labels.
 
@@ -118,8 +118,8 @@ controls, and is a constant.
 GetVRulerWidth() is variable -- all tracks have the same ruler width at any
 time, but that width may be adjusted when tracks change their vertical scales.
 
-GetLabelWidth() counts columns up to and including the VRuler.
-GetLeftOffset() is yet one more -- it counts the "one pixel" column.
+GetLeftOffset() counts columns up to and including the VRuler and one more,
+the "one pixel" column.
 
 Cell for label has a rectangle that OMITS left, top, and bottom
 margins

src/TrackPanelResizerCell.cpp

@@ -74,7 +74,7 @@ void TrackPanelResizerCell::Draw(
             
             // Paint the left part of the background
             const auto artist = TrackArtist::Get( context );
-            auto labelw = artist->pZoomInfo->GetLabelWidth();
+            auto labelw = artist->pZoomInfo->GetLeftOffset() - 1;
             AColor::MediumTrackInfo( dc, pTrack->GetSelected() );
             dc->DrawRectangle(
                rect.GetX(), rect.GetY(), labelw, rect.GetHeight() );

src/ZoomInfo.h

@@ -98,9 +98,11 @@ public:
    int GetVRulerWidth() const { return mVRulerWidth; }
    void SetVRulerWidth( int width ) { mVRulerWidth = width; }
    int GetVRulerOffset() const { return kTrackInfoWidth + kLeftMargin; }
-   int GetLabelWidth() const { return GetVRulerOffset() + GetVRulerWidth(); }
-   int GetLeftOffset() const { return GetLabelWidth() + 1;}
 
+   // The x-coordinate of the start of the displayed track data
+   int GetLeftOffset() const
+      { return GetVRulerOffset() + GetVRulerWidth() + 1; }
+   // The number of pixel columns for display of track data
    int GetTracksUsableWidth() const
    {
       return

src/tracks/labeltrack/ui/LabelTrackView.cpp

@@ -2253,9 +2253,10 @@ int LabelTrackView::DialogForLabelName(
       trackPanel.FindTrackRect( trackFocus.Get() ).GetBottomLeft();
    // The start of the text in the text box will be roughly in line with the label's position
    // if it's a point label, or the start of its region if it's a region label.
-   position.x += viewInfo.GetLabelWidth()
-      + std::max(0, static_cast<int>(viewInfo.TimeToPosition(region.t0())))
-      -40;
+   position.x +=
+      + std::max(0, static_cast<int>(viewInfo.TimeToPosition(
+         viewInfo.GetLeftOffset(), region.t0())))
+      - 39;
    position.y += 2;  // just below the bottom of the track
    position = trackPanel.ClientToScreen(position);
    auto &window = GetProjectFrame( project );