Color the selected region on a TPanel

write Your own component based on TCustomPanel, where You can move Canvas property to public section, then use Canvas' to draw anything You want.

ziolko.

Hello Sir,

  I did find a solution for my question. I shall post it soon.

with regards,
padmaja.

Hello Sir,

  Here is the solution.


unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    procedure FormMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    { Private declarations }
    Capturing : bool;
    Captured : bool;
    StartPlace : TPoint;
    EndPlace : TPoint;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
implementation

{$R *.DFM}

function MakeRect(Pt1 : TPoint;
                  Pt2 : TPoint) : TRect;
begin
  if pt1.x < pt2.x then begin
    Result.Left := pt1.x;
    Result.Right := pt2.x;
  end else begin
    Result.Left := pt2.x;
    Result.Right := pt1.x;
  end;
  if pt1.y < pt2.y then begin
    Result.Top := pt1.y;
    Result.Bottom := pt2.y;
  end else begin
    Result.Top := pt2.y;
    Result.Bottom := pt1.y;
  end;
end;
procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Captured then
  StartPlace.x := X;
  StartPlace.y := Y;
  EndPlace.x := X;
  EndPlace.y := Y;
  Capturing := true;
  Captured := true;
end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var
  S : TRect;
  tmpi,tmpj,tmpk1,tmpk2 : Integer;
begin
  if Capturing then
  begin
    EndPlace.x := X;
    EndPlace.y := Y;
    tmpk1:=4;
    tmpk2:=24;
    tmpi:=0;
    repeat
    tmpj:=0;
    repeat
      if PtInRect(rect(tmpj*Form1.Width div tmpk1,tmpi*Form1.Height div tmpk2,(tmpj+1)*Form1.Width div tmpk1,(tmpi+1)*Form1.Height div tmpk2),Point(EndPlace.X,EndPlace.Y)) then
      begin
        S.Left := tmpj*Form1.Width div tmpk1;
        S.Top := tmpi*Form1.Height div tmpk2;
        S.Right := (tmpj+1)*Form1.Width div tmpk1;
        S.Bottom := (tmpi+1)*Form1.Height div tmpk2;
        Form1.Canvas.Brush.Color := CLyELLOW;
        Form1.Canvas.FillRect(S);
      end;
    tmpj := tmpj+1;
    until tmpj>=tmpk1;
    tmpi := tmpi+1;
    until tmpi>=tmpk2;
  end;
end;

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  Capturing := false;
end;
end.

with regards,
padmaja.