From c03557f0beea824e046f57ea8e85a82113a9c776 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sun, 4 May 2014 22:12:57 +0000
Subject: [PATCH] Fix position of the column after drag-move operation in
 wxGrid.

Fix the logic for finding the correct position to drop the column at when
ending a drag move operation. The old code dropped it one position too far to
the left when it was dropped on the "far" (i.e. right with LTR layout) part of
the target column.

See #16110.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76453 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 src/generic/grid.cpp | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/src/generic/grid.cpp b/src/generic/grid.cpp
index b324ac86c5..17cae6e47e 100644
--- a/src/generic/grid.cpp
+++ b/src/generic/grid.cpp
@@ -3712,29 +3712,31 @@ void wxGrid::ProcessColLabelMouseEvent( wxMouseEvent& event )
                     // get the position of the column we're over
                     int pos = XToPos(x);
 
-                    // we may need to adjust the drop position but don't bother
-                    // checking for it if we can't anyhow
-                    if ( pos > 1 )
-                    {
-                        // also find the index of the column we're over: notice
-                        // that the existing "col" variable may be invalid but
-                        // we need a valid one here
-                        const int colValid = GetColAt(pos);
+                    // insert the column being dragged either before or after
+                    // it, depending on where exactly it was dropped, so
+                    // find the index of the column we're over: notice
+                    // that the existing "col" variable may be invalid but
+                    // we need a valid one here
+                    const int colValid = GetColAt(pos);
 
-                        // if we're on the "near" (usually left but right in
-                        // RTL case) part of the column, the actual position we
-                        // should be placed in is actually the one before it
-                        bool onNearPart;
-                        const int middle = GetColLeft(colValid) +
-                                                GetColWidth(colValid)/2;
-                        if ( GetLayoutDirection() == wxLayout_LeftToRight )
-                            onNearPart = (x <= middle);
-                        else // wxLayout_RightToLeft
-                            onNearPart = (x > middle);
+                    // and check if we're on the "near" (usually left but right
+                    // in RTL case) part of the column
+                    bool onNearPart;
+                    const int middle = GetColLeft(colValid) +
+                                            GetColWidth(colValid)/2;
+                    if ( GetLayoutDirection() == wxLayout_LeftToRight )
+                        onNearPart = (x <= middle);
+                    else // wxLayout_RightToLeft
+                        onNearPart = (x > middle);
 
-                        if ( onNearPart )
-                            pos--;
-                    }
+                    // adjust for the column being dragged itself
+                    if ( pos < GetColPos(m_dragRowOrCol) )
+                        pos++;
+
+                    // and if it's on the near part of the target column,
+                    // insert it before it, not after
+                    if ( onNearPart )
+                        pos--;
 
                     DoEndMoveCol(pos);
                 }