From cf4f4331003f9ab4ab04953c144e9fcf70ac8691 Mon Sep 17 00:00:00 2001
From: paul <paul@lazarus-ide.org>
Date: Mon, 26 Jan 2009 03:41:21 +0000
Subject: [PATCH] lcl: - skip forms which does not share application taskbar
 item from TApplication.UpdateVisible (bug #0013042) - don't perform any
 visual actions when we change ShowInTaskBar property in the design time

git-svn-id: trunk@18445 -
---
 lcl/include/application.inc | 15 ++++++++++++---
 lcl/include/customform.inc  |  2 +-
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/lcl/include/application.inc b/lcl/include/application.inc
index 85127364b6..4caddcf4ea 100644
--- a/lcl/include/application.inc
+++ b/lcl/include/application.inc
@@ -825,22 +825,31 @@ end;
  ------------------------------------------------------------------------------}
 procedure TApplication.UpdateVisible;
 
+  function UseAppTaskbarItem(AForm: TCustomForm): Boolean; inline;
+  begin
+    Result := (AForm = MainForm) or (AForm.ShowInTaskBar in [stNever, stDefault]);
+  end;
+
   function HasVisibleForms: Boolean;
   var
     i: integer;
+    AForm: TCustomForm;
   begin
     Result := False;
     for i := 0 to Screen.CustomFormCount - 1 do
-      if Screen.CustomForms[i].Visible and (Screen.CustomForms[i].Parent = nil) then
+    begin
+      AForm := Screen.CustomForms[i];
+      if AForm.Visible and (AForm.Parent = nil) and UseAppTaskbarItem(AForm) then
       begin
         Result := True;
         break;
       end;
+    end;
   end;
 
 begin
-  // if there are visible forms then application task bar item must be visible too
-  // else hide it
+  // if there are visible forms wich shares application taskbar item then application
+  // task bar item must be visible too else hide it
   WidgetSet.AppSetVisible(HasVisibleForms);
 end;
 
diff --git a/lcl/include/customform.inc b/lcl/include/customform.inc
index 75f96abb8a..8001971a10 100644
--- a/lcl/include/customform.inc
+++ b/lcl/include/customform.inc
@@ -1418,7 +1418,7 @@ procedure TCustomForm.SetShowInTaskbar(Value: TShowInTaskbar);
 begin
   if Value = FShowInTaskbar then exit;
   FShowInTaskbar := Value;
-  if HandleAllocated then
+  if not (csDesigning in ComponentState) and HandleAllocated then
     TWSCustomFormClass(WidgetSetClass).SetShowInTaskbar(Self, Value);
 end;