OnMouseMove (Delphi)

Description

The following example requires a form with a four-paneled status bar.

Note: Set the Width of the status panels to 150 before running this example. When you press a mouse button, move the mouse, and release the mouse button, a rectangle is drawn on the form. When the mouse button is released, the rectangle appears on the form's canvas. Its upper-left and lower-right corners are defined by the location of the mouse pointer when you pressed and released the mouse button. While you drag the mouse, the location of the top, left, bottom, and right sides of the rectangle is displayed in the status bar.

Code

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  StartX := X;
  StartY := Y;
end;

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  Form1.Canvas.Rectangle(StartX, StartY, X, Y);
  StatusBar1.Panels[0].Text := '';
  StatusBar1.Panels[1].Text := '';
  StatusBar1.Panels[2].Text := '';
  StatusBar1.Panels[3].Text := '';
end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
  if ssLeft in Shift then { Make sure the button is down. }
  begin
    if Y > StartY then
      begin
      StatusBar1.Panels[0].Text := 'Top: ' + IntToStr(StartY);
      StatusBar1.Panels[2].Text := 'Bottom: ' + IntToStr(Y);
      end
    else
      begin
      StatusBar1.Panels[0].Text := 'Top: ' + IntToStr(Y);
      StatusBar1.Panels[2].Text := 'Bottom: ' + IntToStr(StartY);
      end;
    if X > StartX then
      begin
      StatusBar1.Panels[1].Text := 'Left: ' + IntToStr(StartX);
      StatusBar1.Panels[3].Text := 'Right: ' + IntToStr(X);
      end
    else
      begin
      StatusBar1.Panels[1].Text := 'Left: ' + IntToStr(X);
      StatusBar1.Panels[3].Text := 'Right: ' + IntToStr(StartX);
      end;
  end;
end;

Uses

• Vcl.Controls.TControl.OnMouseDown ( fr | de | ja )
• Vcl.Controls.TControl.OnMouseMove ( fr | de | ja )
• Vcl.Controls.TControl.OnMouseUp ( fr | de | ja )
• Vcl.ComCtrls.TCustomStatusBar.Panels ( fr | de | ja )
• Vcl.ComCtrls.TStatusPanel.Text ( fr | de | ja )