Componentes.Terceros.jvcl/official/3.32/run/JvScreenSaveSuppress.pas

125 lines
3.5 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: JvAppCommand.PAS, released on 2005-09-02.
The Initial Developer of the Original Code is Robert Marquardt [robert_marquardt att dmx dott de]
Portions created by Robert Marquardt are Copyright (C) 2001 Robert Marquardt.
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:
-----------------------------------------------------------------------------}
// $Id: JvScreenSaveSuppress.pas 10612 2006-05-19 19:04:09Z jfudickar $
unit JvScreenSaveSuppress;
{$I jvcl.inc}
interface
uses
{$IFDEF UNITVERSIONING}
JclUnitVersioning,
{$ENDIF UNITVERSIONING}
Windows, Messages, SysUtils, Classes, Controls, Forms,
JvComponentBase;
const
// from JwaWinUser.pas
SC_SCREENSAVE = $F140;
{$EXTERNALSYM SC_SCREENSAVE}
type
TJvScreenSaveEvent = procedure(var Handled: Boolean) of object;
TJvScreenSaveSuppressor = class(TJvComponent)
private
FActive: Boolean;
FOnScreenSave: TJvScreenSaveEvent;
FForm: TCustomForm;
function NewWndProc(var Msg: TMessage): Boolean;
procedure SetActive(Value: Boolean);
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property Active: Boolean read FActive write SetActive default True;
property OnScreenSave: TJvScreenSaveEvent read FOnScreenSave write FOnScreenSave;
end;
{$IFDEF UNITVERSIONING}
const
UnitVersioning: TUnitVersionInfo = (
RCSfile: '$URL: https://jvcl.svn.sourceforge.net/svnroot/jvcl/tags/JVCL3_32/run/JvScreenSaveSuppress.pas $';
Revision: '$Revision: 10612 $';
Date: '$Date: 2006-05-19 21:04:09 +0200 (ven., 19 mai 2006) $';
LogPath: 'JVCL\run'
);
{$ENDIF UNITVERSIONING}
implementation
uses
JvWndProcHook;
constructor TJvScreenSaveSuppressor.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FForm := GetParentForm(TControl(AOwner));
Active := True;
end;
destructor TJvScreenSaveSuppressor.Destroy;
begin
Active := False;
inherited Destroy;
end;
procedure TJvScreenSaveSuppressor.SetActive(Value: Boolean);
begin
if FActive <> Value then
begin
FActive := Value;
if (FForm <> nil) and not (csDesigning in ComponentState) then
if Value then
RegisterWndProcHook(FForm, NewWndProc, hoBeforeMsg)
else
UnregisterWndProcHook(FForm, NewWndProc, hoBeforeMsg);
end;
end;
function TJvScreenSaveSuppressor.NewWndProc(var Msg: TMessage): Boolean;
begin
Result := False;
if (Msg.Msg = WM_SYSCOMMAND) and (Msg.WParam = SC_SCREENSAVE) and Active then
begin
Result := True;
if Assigned(FOnScreenSave) then
FOnScreenSave(Result);
Msg.Result := Ord(Result);
end;
end;
{$IFDEF UNITVERSIONING}
initialization
RegisterUnitVersion(HInstance, UnitVersioning);
finalization
UnregisterUnitVersion(HInstance);
{$ENDIF UNITVERSIONING}
end.