* Fixed some memory leaks in TfpgComboBox.

* Fixed the destruction order of TfpgComboBox.
* Introduced DoRemoveWindowLookup() in gfxbase.pas so that we
  can offload some of the responsibility from DoReleaseWindowHandle()
* Add two new debug methods to help debug fpGUI and fpGUI based
  applications. They are PrintCallTrace() and PrintCallTraceDbgln().
* Fixed 'Index out of bounds' error when quiting your application.
* I included lots of debug output in this revision, so I can test
  under Windows. As soon as I confirmed everything works, I'll
  remove the debug output again.

6 files changed, 81 insertions, 41 deletions

diff --git a/src/gui/fpgui_package.lpk b/src/gui/fpgui_package.lpk
index a9716935..54ded6b2 100644
--- a/src/gui/fpgui_package.lpk
+++ b/src/gui/fpgui_package.lpk
@@ -17,6 +17,11 @@
       <CodeGeneration>
         <Generate Value="Faster"/>
       </CodeGeneration>
+      <Linking>
+        <Debugging>
+          <GenerateDebugInfo Value="True"/>
+        </Debugging>
+      </Linking>
       <Other>
         <CompilerPath Value="$(CompPath)"/>
       </Other>
@@ -143,12 +148,12 @@
     <LazDoc Paths="../../docs/xml/gui/"/>
     <RequiredPkgs Count="2">
       <Item1>
-        <PackageName Value="FCL"/>
-        <MinVersion Major="1" Valid="True"/>
-      </Item1>
-      <Item2>
         <PackageName Value="fpgfx_package"/>
         <MinVersion Minor="5" Valid="True"/>
+      </Item1>
+      <Item2>
+        <PackageName Value="FCL"/>
+        <MinVersion Major="1" Valid="True"/>
       </Item2>
     </RequiredPkgs>
     <UsageOptions>
diff --git a/src/gui/gui_combobox.pas b/src/gui/gui_combobox.pas
index 0c9b4282..cfe2c966 100644
--- a/src/gui/gui_combobox.pas
+++ b/src/gui/gui_combobox.pas
@@ -1,7 +1,7 @@
 {
     fpGUI  -  Free Pascal GUI Library
 
-    Copyright (C) 2006 - 2007 See the file AUTHORS.txt, included in this
+    Copyright (C) 2006 - 2008 See the file AUTHORS.txt, included in this
     distribution, for details of the copyright.
 
     See the file COPYING.modifiedLGPL, included in this distribution,
@@ -19,6 +19,8 @@ unit gui_combobox;
 
 {$mode objfpc}{$H+}
 
+{.$Define DEBUG}
+
 { TODO: When combobox Items changes, the combobox needs to refresh. We need a
       custom StringItems class to notify us of changes. See TfpgListBox for
       an example. }
@@ -56,6 +58,7 @@ type
     procedure   SetFocusItem(const AValue: integer);
     procedure   SetFontDesc(const AValue: string);
     procedure   CalculateInternalButtonRect;
+    procedure   MsgPopupClose(var msg: TfpgMessageRec); message FPGM_POPUPCLOSE;
   protected
     FMargin: integer;
     FBtnPressed: Boolean;
@@ -114,7 +117,6 @@ var
   OriginalFocusRoot: TfpgWidget;
 
 type
-
   { This is the class representing the dropdown window of the combo box. }
   TDropDownWindow = class(TfpgPopupWindow)
   private
@@ -131,12 +133,13 @@ type
     property    CallerWidget: TfpgWidget read FCallerWidget write FCallerWidget;
   end;
 
+
 { TDropDownWindow }
 
 procedure TDropDownWindow.HandlePaint;
 begin
   Canvas.BeginDraw;
-  inherited HandlePaint;
+//  inherited HandlePaint;
   Canvas.Clear(clWhite);
   Canvas.EndDraw;
 end;
@@ -186,8 +189,10 @@ begin
 end;
 
 destructor TDropDownWindow.Destroy;
+var
+  tmp: IInterface;
 begin
-  ListBox.Free;
+  tmp := PrintCallTrace(ClassName, 'Destroy');
   inherited Destroy;
 end;
 
@@ -228,6 +233,7 @@ end;
 
 function TfpgAbstractComboBox.GetText: string;
 begin
+  PrintCallTraceDbgLn('FocusItem = ' + IntToStr(FocusItem));
   if (FocusItem > 0) and (FocusItem <= FItems.Count) then
     Result := FItems.Strings[FocusItem-1]
   else
@@ -241,15 +247,19 @@ end;
 
 procedure TfpgAbstractComboBox.DoDropDown;
 var
+  tmp: IInterface;
   ddw: TDropDownWindow;
   rowcount: integer;
 begin
+  tmp := PrintCallTrace(Classname, 'DoDropDown');
   if (not Assigned(FDropDown)) or (not FDropDown.HasHandle) then
   begin
+    PrintCallTraceDbgLn('DoDropDown - Part 1');
+    FreeAndNil(FDropDown);
     OriginalFocusRoot := FocusRootWidget;
-    FDropDown     := TDropDownWindow.Create(nil);
-    ddw           := TDropDownWindow(FDropDown);
-    ddw.Width     := Width;
+    FDropDown       := TDropDownWindow.Create(nil);
+    ddw := TDropDownWindow(FDropDown);
+    ddw.Width := Width;
     // adjust the height of the dropdown
     rowcount := FItems.Count;
     if rowcount > FDropDownCount then
@@ -264,15 +274,16 @@ begin
     ddw.ListBox.Items.Assign(FItems);
     ddw.ListBox.FocusItem := FFocusItem;
 
-    FDropDown.ShowAt(Parent, Left, Top+Height);
-    FDropDown.DontCloseWidget := self;  // now we can control when the popup window closes
-//    FDropDown.ActiveWidget := ddw.ListBox;
+//    ddw.DontCloseWidget := self;  // now we can control when the popup window closes
+    ddw.ShowAt(Parent, Left, Top+Height);
     ddw.ListBox.SetFocus;
   end
   else
   begin
+    PrintCallTraceDbgLn('DoDropDown - Part 2');
     FBtnPressed := False;
-    FDropDown.Close;
+    ddw := TDropDownWindow(FDropDown);
+    ddw.Close;
     FreeAndNil(FDropDown);
   end;
 end;
@@ -285,13 +296,16 @@ end;
 procedure TfpgAbstractComboBox.InternalListBoxSelect(Sender: TObject);
 var
   msgp: TfpgMessageParams;
+  tmp: IInterface;
 begin
+  tmp := PrintCallTrace(ClassName, 'InternalListBoxSelect');
   FFocusItem := TDropDownWindow(FDropDown).ListBox.FocusItem;
 
   { Don't use .Close because this method is called by FDropDown.ListBox and
-    causes issues if it's freed to quickly. }
-//  FDropDown.Close;
-  fpgSendMessage(self, FDropDown, FPGM_CLOSE, msgp);
+    causes issues if it's freed to quickly. We can't destroy the ListBox while
+    it's still executing it's event handler - instead we send a message to self. }
+  FDropDown.Close;
+//  fpgSendMessage(self, self, FPGM_POPUPCLOSE, msgp); // request to close the dropdown.
 
   if HasHandle then
     Repaint;
@@ -357,6 +371,14 @@ begin
   FInternalBtnRect.SetRect(Width - Min(Height, 20), 2, Min(Height, 20)-2, Height-4);
 end;
 
+procedure TfpgAbstractComboBox.MsgPopupClose(var msg: TfpgMessageRec);
+var
+  tmp: IInterface;
+begin
+  tmp := PrintCallTrace(Classname, 'MsgPopupClose');
+  DoDropDown;
+end;
+
 procedure TfpgAbstractComboBox.SetHeight(const AValue: TfpgCoord);
 begin
   inherited;
@@ -365,10 +387,10 @@ begin
 end;
 
 procedure TfpgAbstractComboBox.HandleLMouseDown(x, y: integer; shiftstate: TShiftState);
+var
+  tmp: IInterface;
 begin
-  {$IFDEF DEBUG}
-  writeln('TfpgAbstractComboBox.HandleLMouseDown [', Classname, ']');
-  {$ENDIF}
+  tmp := PrintCallTrace(Classname, 'HandleLMouseDown');
   inherited HandleLMouseDown(x, y, shiftstate);
   // button state is down only if user clicked in the button rectangle.
   if PtInRect(FInternalBtnRect, Point(x, y)) then
@@ -377,10 +399,10 @@ begin
 end;
 
 procedure TfpgAbstractComboBox.HandleLMouseUp(x, y: integer; shiftstate: TShiftState);
+var
+  tmp: IInterface;
 begin
-  {$IFDEF DEBUG}
-  writeln('TfpgAbstractComboBox.HandleLMouseUp [', Classname, ']');
-  {$ENDIF}
+  tmp := PrintCallTrace(Classname, 'HandleLMouseUp');
   inherited HandleLMouseUp(x, y, shiftstate);
   FBtnPressed := False;
   DoDropDown;
@@ -495,11 +517,12 @@ begin
 end;
 
 destructor TfpgAbstractComboBox.Destroy;
+var
+  tmp: IInterface;
 begin
-  { Todo: Double check FDropDown.Free call, because we are closing FDropDown
-    via a fpgSendMessage call. This needs improving. }
-  if Assigned(FDropDown) and (FDropDown.HasHandle) then
-    FDropDown.Free;
+  tmp := PrintCallTrace(ClassName, 'Destroy');
+  FDropDown.Free;
+  PrintCallTraceDbgLn('**** Freeing off the ComboBox items');
   FItems.Free;
   FFont.Free;
   inherited Destroy;
@@ -507,7 +530,7 @@ end;
 
 procedure TfpgAbstractComboBox.Update;
 begin
-  FFocusItem := 1;
+  FFocusItem := 0;
   Repaint;
 end;
 
diff --git a/src/gui/gui_form.pas b/src/gui/gui_form.pas
index bf2ae6bc..0828c927 100644
--- a/src/gui/gui_form.pas
+++ b/src/gui/gui_form.pas
@@ -1,7 +1,7 @@
 {
     fpGUI  -  Free Pascal GUI Library
 
-    Copyright (C) 2006 - 2007 See the file AUTHORS.txt, included in this
+    Copyright (C) 2006 - 2008 See the file AUTHORS.txt, included in this
     distribution, for details of the copyright.
 
     See the file COPYING.modifiedLGPL, included in this distribution,
@@ -244,10 +244,13 @@ begin
 end;
 
 procedure TfpgForm.MsgClose(var msg: TfpgMessageRec);
+var
+  tmp: IInterface;
 begin
-  HandleClose;
+  tmp := PrintCallTrace(Classname, 'MsgClose');
   if Assigned(FOnClose) then
     FOnClose(self);
+  HandleClose;
 end;
 
 procedure TfpgForm.HandleClose;
@@ -257,9 +260,9 @@ end;
 
 procedure TfpgForm.HandleHide;
 begin
-  inherited HandleHide;
   if Assigned(FOnHide) then
     FOnHide(self);
+  inherited HandleHide;
 end;
 
 procedure TfpgForm.HandleShow;
diff --git a/src/gui/gui_gauge.pas b/src/gui/gui_gauge.pas
index 3d0317c8..52ac9df3 100644
--- a/src/gui/gui_gauge.pas
+++ b/src/gui/gui_gauge.pas
@@ -45,7 +45,7 @@ type
     FPosition: Longint;
     FKind: TGaugeKind;
     FShowText: Boolean;
-    {TODO _ Implement Border style }
+    { TODO: Implement Border style }
     FBorderStyle: TBorderStyle;
     FColor: TfpgColor; // Background color
     { Currently little used colors, should be derived from style and possibly
@@ -53,7 +53,7 @@ type
     or give pair? }
     FFirstColor: TfpgColor; // Text and Needle color
     FSecondColor: TfpgColor; // Bar, Pie etc. main color
-    { Currently unused - TODO - Implement Low Watermark and High Watermark }
+    { TODO: Currently unused. Implement Low Watermark and High Watermark }
     FLWMColor: TfpgColor; // Low Watermark Color
     FLWMValue: Longint;   //  Low Watermark Value
     FHWMColor: TfpgColor; // High Watermark Color
@@ -448,7 +448,7 @@ begin
   if AValue <> FBorderStyle then
   begin
     FBorderStyle := AValue;
-    {TODO - Implement Border style }
+    { TODO: Implement Border style }
     // Graeme:  Wouldn't descending from TfpgBevel give you this functionality already?
     //          It could be a option.
     //RePaint;
@@ -460,7 +460,7 @@ begin
   if AValue <> FFirstColor then
   begin
     FFirstColor := AValue;
-    {TODO - allow user colors}
+    { TODO: allow user colors}
     //RePaint;
   end;
 end;
@@ -470,7 +470,7 @@ begin
   if AValue <> FSecondColor then
   begin
     FSecondColor := AValue;
-    {TODO - allow user colors}
+    { TODO: allow user colors}
     //RePaint;
   end;
 end;
@@ -525,7 +525,7 @@ begin
     FPosition := AValue;
     if CurrPercentage <> Percentage then  // Visible value has changed
       MustRepaint := True;
-    { TODO Check against low and high watermarks }
+    { TODO: Check against low and high watermarks }
     end;
   if MustRepaint then
     RePaint;
diff --git a/src/gui/gui_listbox.pas b/src/gui/gui_listbox.pas
index a7c7e740..4e2a2f39 100644
--- a/src/gui/gui_listbox.pas
+++ b/src/gui/gui_listbox.pas
@@ -388,7 +388,10 @@ begin
 end;
 
 procedure TfpgBaseListBox.HandleLMouseDown(x, y: integer; shiftstate: TShiftState);
+var
+  tmp: IInterface;
 begin
+  tmp := PrintCallTrace(ClassName, 'HandleLMouseDown');
   inherited HandleLMouseDown(x, y, shiftstate);
 
   if ItemCount < 1 then
@@ -593,7 +596,7 @@ begin
   
   FScrollBar          := TfpgScrollBar.Create(self);
   FScrollBar.OnScroll := @ScrollBarMove;
-  FScrollBar.Visible  := False;
+//  FScrollBar.Visible  := False;
 
   FFocusable      := True;
   FFocusItem      := 1;
@@ -659,7 +662,11 @@ begin
 end;
 
 destructor TfpgTextListBox.Destroy;
+var
+  tmp: IInterface;
 begin
+  tmp := PrintCallTrace(ClassName, 'Destroy');
+  PrintCallTraceDbgLn('**** Freeing off the listbox items');
   TfpgListBoxStrings(FItems).Free;
   inherited Destroy;
 end;
@@ -670,7 +677,10 @@ begin
 end;
 
 function TfpgTextListBox.Text: string;
+var
+  tmp: IInterface;
 begin
+  tmp := PrintCallTrace(Classname, 'Text');
   if (FocusItem > 0) and (FocusItem <= FItems.Count) then
     result := FItems.Strings[FocusItem-1]
   else
diff --git a/src/gui/gui_listview.pas b/src/gui/gui_listview.pas
index a3eaba43..0a2ff4f8 100644
--- a/src/gui/gui_listview.pas
+++ b/src/gui/gui_listview.pas
@@ -572,7 +572,6 @@ procedure TfpgListView.ItemChanged(AIndex: Integer);
 begin
   if FUpdateCount = 0 then
     DoRePaint;
-  // TODO
 end;
 
 procedure TfpgListView.ItemsUpdated;
@@ -1374,7 +1373,7 @@ begin
 
     if lvppIcon in PaintPart then
     begin
-      // TODO paint icon
+      { TODO: paint icon }
     end;
     
     if lvppFocused in PaintPart then