PageSize (Delphi)

Description

The following code sets the thumb tab of a scroll bar so that it represents the proportion of the scrolling range that is visible.

Code

procedure SetThumbTab(wincontrol: TWinControl);
var
  TrackHeight: Integer; { The size of the scroll bar track }
  MinHeight: Integer; { The default size of the thumb tab }
begin
  MinHeight := GetSystemMetrics(SM_CYVTHUMB); { Save the default size. }
  with Form1.ScrollBar1 do
  begin
    TrackHeight := wincontrol.ClientHeight - 2 * GetSystemMetrics(SM_CYVSCROLL);
    PageSize := TrackHeight div (Max - Min + 1);
    if PageSize < MinHeight then PageSize := MinHeight;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
const
  Path = 'OverView.RTF';
begin
  RichEdit1.PlainText := False;
  RichEdit1.Lines.LoadFromFile(Path);
  SetThumbTab(RichEdit1);
end;
procedure TForm1.RichEdit1Change(Sender: TObject);
begin
  SetThumbTab(RichEdit1);
end;

Uses

• Vcl.StdCtrls.TScrollBar.PageSize ( fr | de | ja )