Difference between revisions of "Application full screen mode"

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==Introduction==
 
==Introduction==
  
Some applications like some web browsers allow show in full screen mode using key F11. In full screen mode window haven't border and title bar and use entire screen space. Task bar is hidden too.
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Some applications like some web browsers allow show in full screen mode using key {{keypress|F11}}. In full screen mode window haven't border and title bar and use entire screen space. Task bar is hidden too.
  
  

Revision as of 07:01, 17 April 2012

Introduction

Some applications like some web browsers allow show in full screen mode using key F11. In full screen mode window haven't border and title bar and use entire screen space. Task bar is hidden too.


To be able to switch to fullscreen mode you will need:

  • Remember previous form state as position and size and window state
  • Be able to determine screen size
  • Capture some key and perform operation


Best way to capture desired key is using Actions. Simply define new action in action manager and assign key shortcut. Than shortcut will work even if main form would lost focus.

Example program

unit Unit1; 

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls,
  Menus;

type

  { TForm1 }

  TForm1 = class(TForm)
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
  private
  public
    OriginalBounds: TRect;
    OriginalWindowState: TWindowState;
    ScreenBounds: TRect;
    procedure SwitchFullScreen;
  end; 

var
  Form1: TForm1; 

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
  );
const
  KeyF11 = 122;
begin
  if Key = KeyF11 then SwitchFullScreen;
end;

procedure TForm1.SwitchFullScreen;
begin
  if BorderStyle <> bsNone then begin
    // To full screen
    OriginalWindowState := WindowState;
    OriginalBounds := BoundsRect;

    BorderStyle := bsNone;
    ScreenBounds := Screen.MonitorFromWindow(Handle).BoundsRect;
    with ScreenBounds do
      SetBounds(Left, Top, Right - Left, Bottom - Top) ;
  end else begin
    // From full screen
    {$IFDEF MSWINDOWS}
    BorderStyle := bsSizeable;
    {$ENDIF}      
    if OriginalWindowState = wsMaximized then
      WindowState := wsMaximized
    else
      with OriginalBounds do
        SetBounds(Left, Top, Right - Left, Bottom - Top) ;
    {$IFDEF LINUX}
    BorderStyle := bsSizeable;
    {$ENDIF}  
  end;
end;

end.

Get task bar size

If you want to have task bar visible you have to adjust size according task bar position and size.

For Windows:

function GetTaskBarSize: TRect;
begin
  SystemParametersInfo(SPI_GETWORKAREA, 0, @Result, 0);
end;

GTK way to switch to fullscreen mode

To switch form to full screen dimensions:

gdk_window_fullscreen(PGtkWidget(Handle)^.window);

To roll back to normal mode:

gdk_window_unfullscreen(PGtkWidget(Handle)^.window);

This is GTK2 only. You must add to uses section such modules as gtk2, gdk2, glib2. You can do it by the directive {$IFDEF LCLGTK2}, gtk2, gdk2, glib2{$ENDIF}.

Changing screen resolution

There is no OS independent way to switch screen resolution now.

For Windows you can find information in article for Delphi Get and Set Screen Resolution (Display Device Modes)

See also

External links