From f2e1d9f50bf65e08fba0c52034db79c784c603f0 Mon Sep 17 00:00:00 2001
From: zeljko <zeljko@lazarus-ide.org>
Date: Sat, 4 Sep 2010 17:14:49 +0000
Subject: [PATCH] Gtk2: fixed TGtk2WSWinControl.SetChildZPosition(). fixes
 #17298

git-svn-id: trunk@27269 -
---
 lcl/interfaces/gtk2/gtk2wscontrols.pp | 30 ++++++++++++++-------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/lcl/interfaces/gtk2/gtk2wscontrols.pp b/lcl/interfaces/gtk2/gtk2wscontrols.pp
index 1722ebf602..f2213ae71c 100644
--- a/lcl/interfaces/gtk2/gtk2wscontrols.pp
+++ b/lcl/interfaces/gtk2/gtk2wscontrols.pp
@@ -617,25 +617,27 @@ begin
   if not WSCheckHandleAllocated(AWincontrol, 'SetChildZPosition')
   then Exit;
 
-  if ANewPos < AChildren.Count div 2 then
+  if not WSCheckHandleAllocated(AChild, 'SetChildZPosition (child)') then
+    Exit;
+
+  if (ANewPos <= 0) or (ANewPos >= AChildren.Count - 1) then
   begin
-    // move down (and others below us)
-    for n := ANewPos downto 0 do
-    begin
-      child := TWinControlHack(AChildren[n]);
-      if child.HandleAllocated then
-        TGtkPrivateWidgetClass(
-          child.WidgetSetClass.WSPrivate).SetZPosition(child, wszpBack);
-    end;
+    // simple
+    Child := TWinControlHack(AChild);
+    if ANewPos <= 0 then // bottom
+      TGtkPrivateWidgetClass(
+          Child.WidgetSetClass.WSPrivate).SetZPosition(Child, wszpBack)
+    else
+      TGtkPrivateWidgetClass(
+          Child.WidgetSetClass.WSPrivate).SetZPosition(Child, wszpFront);
   end else
   begin
-    // move up (and others above us)
-    for n := ANewPos to AChildren.Count - 1 do
+    for n := 1 to AChildren.Count - 1 do
     begin
-      child := TWinControlHack(AChildren[n]);
-      if child.HandleAllocated then
+      Child := TWinControlHack(AChildren[n]);
+      if Child.HandleAllocated then
         TGtkPrivateWidgetClass(
-          child.WidgetSetClass.WSPrivate).SetZPosition(child, wszpFront);
+          Child.WidgetSetClass.WSPrivate).SetZPosition(Child, wszpBack);
     end;
   end;
 end;