From 3c9900948e31c76cc7b6ba3062b97b847f72e369 Mon Sep 17 00:00:00 2001
From: martin <laz.git@mfriebe.de>
Date: Sun, 8 Sep 2013 19:34:22 +0000
Subject: [PATCH] LCL: PageControl, changing (moving) the tab position of a
 page, would sometimes (but not always) trigger OnChanging. OnChanging could
 prevent the change, while it must always be allowed during moving tabs.

git-svn-id: trunk@42682 -
---
 lcl/comctrls.pp                |  1 +
 lcl/include/customnotebook.inc | 13 +++++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/lcl/comctrls.pp b/lcl/comctrls.pp
index 31f4afa997..343cba519b 100644
--- a/lcl/comctrls.pp
+++ b/lcl/comctrls.pp
@@ -416,6 +416,7 @@ type
     procedure KeyDown(var Key: Word; Shift: TShiftState); override;
     procedure ReadState(Reader: TReader); override;
     function  DialogChar(var Message: TLMKey): boolean; override;
+    procedure InternalSetPageIndex(AValue: Integer); // No OnChange
     procedure ShowControl(APage: TControl); override;
     procedure UpdateTabProperties; virtual;
     class function GetControlClassDefaultSize: TSize; override;
diff --git a/lcl/include/customnotebook.inc b/lcl/include/customnotebook.inc
index 5e619f5d68..c116128d76 100644
--- a/lcl/include/customnotebook.inc
+++ b/lcl/include/customnotebook.inc
@@ -206,7 +206,7 @@ begin
 
     // update PageIndex
     if ActivePage <> nil then
-      FNotebook.PageIndex := IndexOfPage(ActivePage)
+      FNotebook.InternalSetPageIndex(IndexOfPage(ActivePage))
     else // Can not restore an invalid page index.
     if FNotebook.PageIndex >= 0 then // keep if -1
       FNotebook.PageIndex := NewIndex;
@@ -578,9 +578,7 @@ begin
   if not CanChangePageIndex then exit;
   //debugln('TCustomTabControl.SetPageIndex B ',dbgsName(Self),' AValue=',dbgs(AValue),' fPageIndex=',dbgs(fPageIndex),' PageCount=',dbgs(PageCount),' HandleAllocated=',dbgs(HandleAllocated));
 
-  FPageIndex := AValue;
-  UpdateAllDesignerFlags;
-  DoSendPageIndex;
+  InternalSetPageIndex(AValue);
   if ([csDesigning, csLoading, csDestroying] * ComponentState = []) then
     DoChange;
 end;
@@ -977,6 +975,13 @@ begin
     Result := destPage.DialogChar(Message);
 end;
 
+procedure TCustomTabControl.InternalSetPageIndex(AValue: Integer);
+begin
+  FPageIndex := AValue;
+  UpdateAllDesignerFlags;
+  DoSendPageIndex;
+end;
+
 {------------------------------------------------------------------------------
   TCustomTabControl CNNotify
  ------------------------------------------------------------------------------}