From 0ea4366163cb7ff02e3cdc7a8c0513a8036a9f80 Mon Sep 17 00:00:00 2001
From: wangqr <wangqr@wangqr.tk>
Date: Sun, 25 Aug 2019 21:34:58 -0400
Subject: [PATCH] Fix the width of expander in wxDataViewCtrl

In 8f386265dc0db1b96d435c83cd1aaca5c2e9cdaa, the width of a tree
expander is changed to the native value on the platform. But some
calculations still use guessed value (m_lineHeight) as the width. This
fixes the value, by retrieving the width using the same method as in
OnPaint().

Closes https://github.com/wxWidgets/wxWidgets/pull/1508

Closes #18473.
---
 src/generic/datavgen.cpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/generic/datavgen.cpp b/src/generic/datavgen.cpp
index 0a2d50c8c2..dcb6792ca5 100644
--- a/src/generic/datavgen.cpp
+++ b/src/generic/datavgen.cpp
@@ -2153,8 +2153,7 @@ wxBitmap wxDataViewMainWindow::CreateItemBitmap( unsigned int row, int &indent )
     {
         wxDataViewTreeNode *node = GetTreeNodeByRow(row);
         indent = GetOwner()->GetIndent() * node->GetIndentLevel();
-        indent = indent + m_lineHeight;
-            // try to use the m_lineHeight as the expander space
+        indent += wxRendererNative::Get().GetExpanderSize(this).GetWidth();
     }
     width -= indent;
 
@@ -3879,7 +3878,7 @@ wxRect wxDataViewMainWindow::GetItemRect( const wxDataViewItem & item,
     {
         wxDataViewTreeNode* node = GetTreeNodeByRow(row);
         indent = GetOwner()->GetIndent() * node->GetIndentLevel();
-        indent = indent + m_lineHeight; // use m_lineHeight as the width of the expander
+        indent += wxRendererNative::Get().GetExpanderSize(this).GetWidth();
     }
 
     wxRect itemRect( xpos + indent,
@@ -4708,6 +4707,7 @@ void wxDataViewMainWindow::OnMouse( wxMouseEvent &event )
 
         int indent = node->GetIndentLevel();
         itemOffset = GetOwner()->GetIndent()*indent;
+        const int expWidth = wxRendererNative::Get().GetExpanderSize(this).GetWidth();
 
         if ( node->HasChildren() )
         {
@@ -4715,7 +4715,7 @@ void wxDataViewMainWindow::OnMouse( wxMouseEvent &event )
             // visual expander so the user can hit that little thing reliably
             wxRect rect(xpos + itemOffset,
                         GetLineStart( current ) + (GetLineHeight(current) - m_lineHeight)/2,
-                        m_lineHeight, m_lineHeight);
+                        expWidth, m_lineHeight);
 
             if( rect.Contains(x, y) )
             {
@@ -4737,7 +4737,7 @@ void wxDataViewMainWindow::OnMouse( wxMouseEvent &event )
 
         // Account for the expander as well, even if this item doesn't have it,
         // its parent does so it still counts for the offset.
-        itemOffset += m_lineHeight;
+        itemOffset += expWidth;
     }
     if (!hoverOverExpander)
     {