newprogressbar.pas

源代码

unit NewProgressBar;

{
  Inno Setup
  Copyright (C) 1997-2004 Jordan Russell
  Portions by Martijn Laan
  For conditions of distribution and use, see LICENSE.TXT.

  TNewProgressBar component - a smooth TProgressBar for Delphi 2 and a 32 bit
  TProgressBar for Delphi 2 and all platforms

  $jrsoftware: issrc/Components/NewProgressBar.pas,v 1.4 2004/06/26 04:52:06 jr Exp $
}

interface

uses
  Classes, Controls, ComCtrls;

type
  TNewProgressBar = class(TWinControl)
  private
    FMin: LongInt;
    FMax: LongInt;
    FPosition: LongInt;
    procedure SetMin(Value: LongInt);
    procedure SetMax(Value: LongInt);
    procedure SetPosition(Value: LongInt);
  protected
    procedure CreateParams(var Params: TCreateParams); override;
    procedure CreateWnd; override;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property Min: LongInt read FMin write SetMin;
    property Max: LongInt read FMax write SetMax;
    property Position: LongInt read FPosition write SetPosition default 0;
  end;

procedure Register;

implementation

uses
  Windows, CommCtrl;

procedure Register;
begin
  RegisterComponents('JR', [TNewProgressBar]);
end;

constructor TNewProgressBar.Create(AOwner: TComponent);
begin
  inherited;
  Width := 150;
  Height := GetSystemMetrics(SM_CYVSCROLL);
  FMin := 0;
  FMax := 100;
end;

procedure TNewProgressBar.CreateParams(var Params: TCreateParams);
const
  PBS_SMOOTH = 1;
begin
  InitCommonControls;
  inherited;
  CreateSubClass(Params, PROGRESS_CLASS);
  Params.Style := Params.Style or PBS_SMOOTH;
end;

procedure TNewProgressBar.CreateWnd;
begin
  inherited CreateWnd;
  SendMessage(Handle, PBM_SETRANGE, 0, MAKELPARAM(0, 65535));
  SetPosition(FPosition);
end;

procedure TNewProgressBar.SetMin(Value: LongInt);
begin
  FMin := Value;
  SetPosition(FPosition);
end;

procedure TNewProgressBar.SetMax(Value: LongInt);
begin
  FMax := Value;
  SetPosition(FPosition);
end;

procedure TNewProgressBar.SetPosition(Value: LongInt);
begin
  if Value < FMin then
    Value := FMin
  else if Value > FMax then
    Value := FMax;
  FPosition := Value;
  if HandleAllocated then
    SendMessage(Handle, PBM_SETPOS, MulDiv(Value - FMin, 65535, FMax - FMin), 0);
end;

end.