Componentes.Terceros.jvcl/official/3.39/run/JvMessageControl.pas
2010-01-18 16:55:50 +00:00

115 lines
3.4 KiB
ObjectPascal

{-----------------------------------------------------------------------------
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http:{www.mozilla.org/MPL/MPL-1.1.html
Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either expressed or implied. See the License for
the specific language governing rights and limitations under the License.
The Original Code is: JvMessageControl.pas, released on 2004-10-10
The Initial Developer of the Original Code is André Snepvangers [ASnepvangers att users.sourceforge.net]
Portions created by André Snepvangers are Copyright (C) 2004 André Snepvangers.
All Rights Reserved.
Contributor(s):
You may retrieve the latest version of this file at the Project JEDI's JVCL home page,
located at http:{jvcl.sourceforge.net
Known Issues:
It is still possible to move the component in IDE outside the parent.
It could also be called as a feature. Object Treeview shows the
correct parent.
-----------------------------------------------------------------------------}
// $Id: JvMessageControl.pas 12337 2009-06-11 10:42:10Z ahuser $
unit JvMessageControl;
{$I jvcl.inc}
interface
uses
{$IFDEF UNITVERSIONING}
JclUnitVersioning,
{$ENDIF UNITVERSIONING}
SysUtils, Classes, Windows, Messages, Controls, Forms,
JvControlComponent;
type
TJvMessageControl = class(TJvCustomControlComponent)
private
FSavedWinProc: TWndMethod;
FOnMessage: TWndMethod;
protected
procedure SetParent(const Value: TWinControl); override;
procedure ControlWinProc(var Message: TMessage);
public
destructor Destroy; override;
published
property Active;
property OnMessage: TWndMethod read FOnMessage write FOnMessage;
property Parent;
end;
{$IFDEF UNITVERSIONING}
const
UnitVersioning: TUnitVersionInfo = (
RCSfile: '$URL: https://jvcl.svn.sourceforge.net/svnroot/jvcl/tags/JVCL3_39/run/JvMessageControl.pas $';
Revision: '$Revision: 12337 $';
Date: '$Date: 2009-06-11 12:42:10 +0200 (jeu., 11 juin 2009) $';
LogPath: 'JVCL\run'
);
{$ENDIF UNITVERSIONING}
implementation
procedure TJvMessageControl.ControlWinProc(var Message: TMessage);
begin
if Active and Assigned(FOnMessage) then { user message/event handler installed ? }
FOnMessage(Message);
if Message.Result = 0 then
FSavedWinProc(Message); { do the original stuff }
end;
procedure TJvMessageControl.SetParent(const Value: TWinControl);
var
WasActive: Boolean;
begin
if Value <> Parent then
begin
WasActive := Active;
Active := False;
if Assigned(Parent) then
Parent.WindowProc := FSavedWinProc;
inherited SetParent(Value);
if Assigned(Parent) then
begin
FSavedWinProc := Parent.WindowProc;
Parent.WindowProc := ControlWinProc; { intercept messages }
end;
Active := WasActive;
end;
end;
destructor TJvMessageControl.Destroy;
begin
if Assigned(Parent) and not (csDestroying in Parent.ComponentState) then
Parent.WindowProc := FSavedWinProc;
inherited Destroy;
end;
{$IFDEF UNITVERSIONING}
initialization
RegisterUnitVersion(HInstance, UnitVersioning);
finalization
UnregisterUnitVersion(HInstance);
{$ENDIF UNITVERSIONING}
end.