Title: Resizable forms and size grip
Question: How do I supply a visual cue that a form is resizable without using a status bar?
Answer:
When a form has a sizable border, ther is no default way to supply a visual cue but using a status bar. Luckily a window API may help us. The API in question is DrawFrameControl.
How the name suggests, this API is used to draw the frame of various controls such as buttons, check boxes, menus and, yes, size grips just by supplying a display context and the proper flags.
Here is a sample code on how to use this API in a regular Deplhi form with sizable border.
unit TestForm;
interface
uses
Windows, Forms;
type
TfrmTest = class(TForm)
procedure FormResize(Sender: TObject);
procedure FormPaint(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
frmTest: TfrmTest;
implementation
{$R *.DFM}
procedure TfrmTest.FormResize(Sender: TObject);
begin
Self.Repaint;
end;
procedure TfrmTest.FormPaint(Sender: TObject);
var
rectBounds: TRect;
begin
rectBounds := Self.ClientRect;
with rectBounds do
begin
Left := Right - GetSystemMetrics(SM_CXVSCROLL);
Top := Bottom - GetSystemMetrics(SM_CYVSCROLL);
end;
{Here is the magic!!}
DrawFrameControl(Self.Canvas.Handle,
rectBounds,
DFC_SCROLL,
DFCS_SCROLLSIZEGRIP);
end;
end.