Title: How to draw buttons with rounded corners
unit RVButton;
interface
uses
SysUtils, Classes, Controls, Messages, Graphics, Windows;
const
iOffset = 3;
type
TRVButton = class(TGraphicControl)
private
FCaption : string;
FButtonColor: TColor;
FLButtonDown: boolean;
FBtnPoints : array[1..2] of TPoint;
FKRgn : HRgn;
procedure SetCaption(Value: string);
procedure SetButtonColor(Value: TColor);
procedure FreeRegion;
protected
procedure Paint; override;
procedure DrawCircle;
procedure MoveButton;
procedure WMLButtonDown(var Message: TWMLButtonDown); message WM_LBUTTONDOWN;
procedure WMLButtonUp(var Message: TWMLButtonUp); message WM_LBUTTONUP;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property ButtonColor: TColor read FButtonColor write SetButtonColor;
property Caption: string read FCaption write SetCaption;
property Enabled;
property Font;
property ParentFont;
property ParentShowHint;
property ShowHint;
property Visible;
property OnClick;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [TRVButton]);
end;
{ TRVButton }
constructor TRVButton.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
ControlStyle := [csClickEvents,csCaptureMouse];
Width := 50;
Height := 50;
FButtonColor := clBtnFace;
FKRgn := 0;
FLButtonDown := False;
end;
destructor TRVButton.Destroy;
begin
if FKRgn 0 then FreeRegion;
inherited Destroy;
end;
procedure TRVButton.DrawCircle;
begin
FBtnPoints[1] := Point(iOffset,iOffset);
FBtnPoints[2] := Point(Width - iOffset,Height - iOffset);
FKRgn := CreateEllipticRgn(FBtnPoints[1].x,FBtnPoints[1].y,FBtnPoints[2].x,FBtnPoints[2].y);
Canvas.Brush.Color := FButtonColor;
FillRgn(Canvas.Handle,FKRgn,Canvas.Brush.Handle);
MoveButton;
end;
procedure TRVButton.FreeRegion;
begin
if FKRgn 0 then DeleteObject(FKRgn);
FKRgn := 0;
end;
procedure TRVButton.MoveButton;
var
Color1: TColor;
Color2: TColor;
begin
with Canvas do
begin
if not FLButtonDown then
begin
Color1 := clBtnHighlight;
Color2 := clBtnShadow;
end
else
begin
Color1 := clBtnShadow;
Color2 := clBtnHighLight;
end;
Pen.Width := 1;
if FLButtonDown then Pen.Color := clBlack
else Pen.Color := Color2;
Ellipse(FBtnPoints[1].x - 2,FBtnPoints[1].y - 2,FBtnPoints[2].x + 2,FBtnPoints[2].y + 2);
if not FLButtonDown then Pen.Width := 2
else Pen.Width := 1;
Pen.Color := Color1;
Arc(FBtnPoints[1].x,FBtnPoints[1].y,FBtnPoints[2].x,FBtnPoints[2].y,
FBtnPoints[2].x,FBtnPoints[1].y,FBtnPoints[1].x,FBtnPoints[2].y);
Pen.Color := Color2;
Arc(FBtnPoints[1].x,FBtnPoints[1].y,FBtnPoints[2].x,FBtnPoints[2].y,
FBtnPoints[1].x,FBtnPoints[2].y,FBtnPoints[2].x,FBtnPoints[1].y);
end;
SetCaption('');
end;
procedure TRVButton.Paint;
begin
inherited Paint;
FreeRegion;
DrawCircle;
end;
procedure TRVButton.SetButtonColor(Value: TColor);
begin
if Value FButtonColor then
begin
FButtonColor := Value;
Invalidate;
end;
end;
procedure TRVButton.SetCaption(Value: string);
var
X: Integer;
Y: Integer;
begin
if ((Value FCaption) and (Value '')) then
begin
FCaption := Value;
end;
with Canvas.Font do
begin
Name := Font.Name;
Size := Font.Size;
Style := Font.Style;
if Self.Enabled then Color := Font.Color
else
Color := clDkGray;
end;
X := (Width div 2) - (Canvas.TextWidth(FCaption) div 2);
Y := (Height div 2) - (Canvas.TextHeight(FCaption) div 2);
Canvas.TextOut(X, Y, FCaption);
// Invalidate;
end;
procedure TRVButton.WMLButtonDown(var Message: TWMLButtonDown);
begin
if not PtInRegion(FKRgn,Message.xPos,Message.yPos) then exit;
FLButtonDown := True;
MoveButton;
inherited;
end;
procedure TRVButton.WMLButtonUp(var Message: TWMLButtonUp);
begin
if not FLButtonDown then exit;
FLButtonDown := False;
MoveButton;
inherited;
end;