From bf30c6198cd51966f9415181c7281ffd8a91793f Mon Sep 17 00:00:00 2001
From: James Crook <james.k.crook@gmail.com>
Date: Sun, 7 Jan 2018 18:27:40 +0000
Subject: [PATCH] Improve mouse wheel zooming

Zooming with mouse was virtually unusable before this fix, as the location of interest would move
around too much on a zoom in.
---
 src/tracks/ui/CommonTrackPanelCell.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/tracks/ui/CommonTrackPanelCell.cpp b/src/tracks/ui/CommonTrackPanelCell.cpp
index 644fe9d12..ecdf26856 100644
--- a/src/tracks/ui/CommonTrackPanelCell.cpp
+++ b/src/tracks/ui/CommonTrackPanelCell.cpp
@@ -79,6 +79,12 @@ unsigned CommonTrackPanelCell::HandleWheelRotation
          center_h = viewInfo.h + (pProject->GetScreenEndTime() - viewInfo.h) / 2.0;
          xx = viewInfo.TimeToPosition(center_h, trackLeftEdge);
       }
+      else if( steps > 0 ){
+         // When zooming in, keep the selection start where it was.
+         // This is particularly helpful for a point selection.
+         center_h = viewInfo.selectedRegion.t0();
+         xx = viewInfo.TimeToPosition( center_h, trackLeftEdge);
+      }
       else
       {
          xx = event.m_x;