lazarus/components/jcf2/Utils/Delay.pas

167 lines
3.5 KiB
ObjectPascal

unit Delay;
{ AFS 14 Jan 2K
abstraction of timer mechanism
Use this to call a proc after a short delay
Needed for IDE regiestering
See delayed reg. technique from sample code by Mike Remec
http://www.miharemec.com/doc/ota-nmi.html
usage:
lcMyDelay := TDelay.Create;
lcMyDelay.ObjectProc := lcSomeObject.Proc;
lcMyDelay.DoItSoon;
....
lcMyDelay.Free;
or
lcMyDelay := TDelay.Create;
lcMyDelay.Proc := SomeProc;
lcMyDelay.DoItSoon;
....
lcMyDelay.Free;
}
{(*}
(*------------------------------------------------------------------------------
Delphi Code formatter source code
The Original Code is Delay, released May 2003.
The Initial Developer of the Original Code is Anthony Steele.
Portions created by Anthony Steele are Copyright (C) 1999-2000 Anthony Steele.
All Rights Reserved.
Contributor(s): Anthony Steele.
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/NPL/
Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied.
See the License for the specific language governing rights and limitations
under the License.
Alternatively, the contents of this file may be used under the terms of
the GNU General Public License Version 2 or later (the "GPL")
See http://www.gnu.org/licenses/gpl.html
------------------------------------------------------------------------------*)
{*)}
{$I JcfGlobal.inc}
interface
uses ExtCtrls;
type
TProcedure = procedure(var pbTryAgain: boolean);
TObjectProcedure = procedure(var pbTryAgain: boolean) of object;
TDelay = class(TObject)
private
fiDelay: integer;
// can call a proc, or a proc on an object (or both)
fcProc: TProcedure;
fcObjectProc: TObjectProcedure;
fcTimer: TTimer;
fbDone: boolean;
procedure DoItNow(Sender: TObject);
public
constructor Create;
destructor Destroy; override;
procedure DoItSoon;
{ how long to delay in Miliseconds}
property Delay: integer Read fiDelay Write fiDelay;
{ done yet? }
property Done: boolean Read fbDone;
{ proc to call }
property Proc: TProcedure Read fcProc Write fcProc;
property objectProc: TobjectProcedure Read fcObjectProc Write fcObjectProc;
end;
implementation
uses SysUtils;
const
// default of 100ms = 1/0 second
DEFAULT_DELAY = 100;
{ TDelay }
constructor TDelay.Create;
begin
inherited;
fcTimer := nil; // create the timer when needed
fcProc := nil;
fcObjectProc := nil;
fiDelay := DEFAULT_DELAY; // default 1/2 sec
fbDone := False;
end;
destructor TDelay.Destroy;
begin
FreeAndNil(fcTimer);
inherited;
end;
procedure TDelay.DoItNow(Sender: TObject);
var
lbDoAgain: boolean;
begin
Assert(fcTimer <> nil);
lbDoAgain := False;
// disable until finished
fcTimer.Enabled := False;
if Assigned(fcProc) then
fcProc(lbDoAgain);
if assigned(fcObjectProc) then
fcObjectProc(lbDoAgain);
//FreeAndNil(fcTimer); this causes problems in IDE plug-ins
// stop unless the proc called raised the falg
if lbDoAgain then
begin
// restart
fcTimer.Enabled := True;
end
else
begin
fbDone := True;
{ no longer timing }
fcTimer.OnTimer := nil;
end;
end;
procedure TDelay.DoItSoon;
begin
// need a timer now
if fcTimer = nil then
fcTimer := TTimer.Create(nil);
fcTimer.Interval := fiDelay;
fcTimer.OnTimer := DoItNow;
fcTimer.Enabled := True;
fbDone := False;
end;
end.