Enhanced StatusBar Component

by Kevin S. Gallagher - gallaghe@teleport.com

I developed this component as a jumping off point to investigate other enhancements to the status bar component in general. In case you haven't worked with StatusBar's much, the sizegrip may appear in certain circumstances where you don't want it. This component corrects that behavior and also adds the interesting effect that you can drop other components (i.e. buttons) onto the status bar. It generates some interesting possibilities.

Please email me if you have comments or ideas about further enhancements!

 unit NoSizeGripBar;
{*****************************************************************}
{                                                                 }
{ Enhanced freeware StatusBar component                           }
{ By Kevin S. Gallagher                                           }
{                                                                 }
{ Accepts other components, i.e. buttons                          }
{ Removes SizeGrip on non-sizable forms                           }
{                                                                 }
{ abnormalities                                                   }
{ 1. You can not toggle the SizeGrip property                     }
{ 2. If you attempt to change the SizeGrip property in the Object }
{    Inspector on a non-sizeable form, the SizeGrip may appear.   }
{    This does not alter runtime behavior, it still works.        }
{=================================================================}
{ USE TDialogStatusbar AT YOUR OWN RISK.                          }
{ I AM NOT RESPONSIBLE FOR ANY HARM THIS COMPONENT MIGHT CAUSE!!  }
{                                                                 }
{ Kevin S. Gallagher                                              }
{ E-Mail : Gallaghe@teleport.com                                  }
{                                                                 }
{*****************************************************************}
interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, DsgnIntf;

type
  TAbout = class(TPropertyEditor)
  public
    procedure Edit; override;
    function GetAttributes: TPropertyAttributes; override;
    function GetValue: string; override;
  end;

  TDialogStatusbar = class(TStatusBar)
  private
    FAbout: TAbout;
    FSizeGrip: Boolean;
    procedure SetUpSizeGrip;
  protected
    procedure CreateParams(var Params: TCreateParams); override;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property About: TAbout read FAbout write FAbout;
  end;

procedure Register;

implementation

uses Commctrl;

procedure TAbout.Edit;
begin
  Application.MessageBox('TDialogStatusbar component'  + #13 +
  '© 1998 Kevin S. Gallagher - This component is freeware.',
  'About TDialogStatusbar Component', MB_OK + MB_ICONINFORMATION);
end;

function TAbout.GetAttributes: TPropertyAttributes;
begin
  Result:= [paMultiSelect, paDialog, paReadOnly];
end;

function TAbout.GetValue: string;
begin
  Result:= '(about)';
end;

constructor TDialogStatusbar.Create(AOwner: TComponent);
begin
  { Try dropping onto a data form }
  if not(AOwner is TForm) then
    raise EInvalidOperation.Create('Must be owned by a standard form');

  inherited Create(AOwner);

  FSizeGrip := False;

  { This allows you to drop things like labels, editboxes, gauges, button etc
    onto the StatusBar }
  ControlStyle := ControlStyle + [csAcceptsControls];

  SetUpSizeGrip;
end;

procedure TDialogStatusbar.SetUpSizeGrip;
begin
  { Check to see if this is a sizeable form or not }
  with Owner as TForm do
    FSizeGrip :=  not(BorderStyle in [bsToolWindow,
                                      bsDialog,
                                      bsNone,
                                      bsSingle]);
  SizeGrip := FSizeGrip;
end;

{ Must setup the SizeGrip here }
procedure TDialogStatusbar.CreateParams(var Params: TCreateParams);
begin
  inherited CreateParams(Params);
  CreateSubClass(Params, STATUSCLASSNAME);

  with Params do begin
    { This is needed to finalize our task }
    SetUpSizeGrip;
    if FSizeGrip then
      Style := Style or SBARS_SIZEGRIP
    else
      Style := Style or CCS_TOP;
    WindowClass.style := WindowClass.style and not CS_HREDRAW;
  end;
end;

procedure Register;
begin
  RegisterComponents('Win32', [TDialogStatusbar]);
  RegisterPropertyEditor(TypeInfo(TAbout), TDialogStatusbar, 'ABOUT', TAbout);
end;
end.