Resizing panels?

Here's the source code for a resizable panel. Give the panel an align property of alClient, throw some controls on it, and watch them resize at run time when you resize the form. There is some code that prohibits resizing during design time, but this can be taken out. This may not be perfect, because I threw it together in a few minutes, but it's worked for me so far.

unit Elastic;

interface

uses

SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,

Forms, Dialogs, ExtCtrls;

type

TElasticPanel = class( TPanel )

private

FHorz, FVert: boolean;

nOldWidth, nOldHeight: integer;

bResized: boolean;

protected

procedure WMSize( var message: TWMSize ); message WM_SIZE;

public

nCount: integer;

constructor Create( AOwner: TComponent ); override;

published

property ElasticHorizontal: boolean read FHorz write FHorz default

TRUE;

property ElasticVertical: boolean read FVert write FVert default

TRUE;

end;

procedure Register;

implementation

constructor TElasticPanel.Create( AOwner: TComponent );

begin

inherited Create( AOwner );

FHorz := TRUE;

FVert := TRUE;

nOldWidth := Width;

nOldHeight := Height;

bResized := FALSE;

end;

procedure TElasticPanel.WMSize( var message: TWMSize );

var

bResize: boolean;

xRatio: real;

i: integer;

ctl: TWinControl;

begin

Inc( nCount );

if Align = alNone then

bResize := TRUE

else

bResize := bResized;

if not ( csDesigning in ComponentState ) and bResize then

begin

if FHorz then

begin

xRatio := Width / nOldWidth;

for i := 0 to ControlCount - 1 do

begin

ctl := TWinControl( Controls[i] );

ctl.Left := Round( ctl.Left * xRatio );

ctl.Width := Round( ctl.Width * xRatio );

end;

if FVert then

begin

xRatio := Height / nOldHeight;

for i := 0 to ControlCount - 1 do

begin

ctl := TWinControl( Controls[i] );

ctl.Top := Round( ctl.Top * xRatio );

ctl.Height := Round( ctl.Height * xRatio );

end;

end

else

begin

nOldWidth := Width;

nOldHeight := Height;

end;

bResized := TRUE;

nOldWidth := Width;

nOldHeight := Height;

end;

procedure Register;

begin

RegisterComponents('Additional', [TElasticPanel]);

end;

end.