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{
*****************************************************************************
See the file COPYING.modifiedLGPL.txt, included in this distribution,
for details about the license.
*****************************************************************************
Author: Mattias Gaertner
Abstract:
Example for RTTI controls.
Demonstrates how to write your own property editors to access readonly
properties.
}
unit Example3;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs, RTTICtrls,
StdCtrls, PropEdits;
type
{ TBall - a class with some readonly properties and a procedure to set the
properties. }
TBall = class(TPersistent)
private
FX: integer;
FY: integer;
FSize: word;
public
procedure SetBall(const NewX, NewY: integer; const NewSize: word);
published
// published readonly properties
property X: integer read FX;
property Y: integer read FY;
property Size: word read FSize;
end;
{ TBallPropertyEditor - a property editor for the TBall properties }
TBallPropertyEditor = class(TIntegerPropertyEditor)
public
procedure SetValue(const NewValue: string); override;
end;
{ TForm1 }
TForm1 = class(TForm)
SizeTIEdit: TTIEdit;
XLabel: TLabel;
YLabel: TLabel;
SizeLabel: TLabel;
XTIEdit: TTIEdit;
YTIEdit: TTIEdit;
procedure Form1Create(Sender: TObject);
procedure Form1Destroy(Sender: TObject);
procedure Form1Paint(Sender: TObject);
private
{ private declarations }
public
{ public declarations }
Ball1: TBall;
end;
var
Form1: TForm1;
implementation
{$R example3.lfm}
{ TBall }
procedure TBall.SetBall(const NewX, NewY: integer; const NewSize: word);
begin
if (FX=NewX) and (FY=NewY) and (FSize=NewSize) then exit;
FX:=NewX;
FY:=NewY;
FSize:=NewSize;
Form1.Invalidate;
end;
{ TForm1 }
procedure TForm1.Form1Create(Sender: TObject);
begin
Ball1:=TBall.Create;
Ball1.SetBall(200,100,20);
XTIEdit.Link.SetObjectAndProperty(Ball1,'X');
YTIEdit.Link.SetObjectAndProperty(Ball1,'Y');
SizeTIEdit.Link.SetObjectAndProperty(Ball1,'Size');
end;
procedure TForm1.Form1Destroy(Sender: TObject);
begin
// unlink properties
XTIEdit.Link.TIObject:=nil;
YTIEdit.Link.TIObject:=nil;
SizeTIEdit.Link.TIObject:=nil;
Ball1.Free;
end;
procedure TForm1.Form1Paint(Sender: TObject);
begin
with Canvas do begin
Brush.Color:=clBlue;
Ellipse(Ball1.X-Ball1.Size,Ball1.Y-Ball1.Size,
Ball1.X+Ball1.Size,Ball1.Y+Ball1.Size);
end;
end;
{ TBallPropertyEditor }
procedure TBallPropertyEditor.SetValue(const NewValue: string);
var
L: integer;
Ball: TBall;
X: integer;
Y: integer;
Size: word;
PropName: String;
begin
L := StrToIntDef(NewValue,0);
Ball:=GetComponent(0) as TBall;
PropName:=GetName;
if CompareText(PropName,'X')=0 then X:=L else X:=Ball.X;
if CompareText(PropName,'Y')=0 then Y:=L else Y:=Ball.Y;
if CompareText(PropName,'Size')=0 then Size:=Word(L) else Size:=Ball.Size;
Ball.SetBall(X,Y,Size);
end;
initialization
RegisterPropertyEditor(TypeInfo(integer),TBall,'X',TBallPropertyEditor);
RegisterPropertyEditor(TypeInfo(integer),TBall,'Y',TBallPropertyEditor);
RegisterPropertyEditor(TypeInfo(word),TBall,'Size',TBallPropertyEditor);
end.
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