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{%MainUnit ../controls.pp}
{******************************************************************************
TCustomControl
******************************************************************************
*****************************************************************************
This file is part of the Lazarus Component Library (LCL)
See the file COPYING.modifiedLGPL.txt, included in this distribution,
for details about the license.
*****************************************************************************
}
{------------------------------------------------------------------------------
Method: TCustomControl.Create
Params: none
Returns: Nothing
Constructor for the class.
------------------------------------------------------------------------------}
constructor TCustomControl.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FCanvas := TControlCanvas.Create;
TControlCanvas(FCanvas).Control := Self;
end;
{------------------------------------------------------------------------------
Method: TCustomControl.Destroy
Params: None
Returns: Nothing
Destructor for the class.
------------------------------------------------------------------------------}
destructor TCustomControl.Destroy;
begin
FreeAndNil(FCanvas);
inherited Destroy;
end;
procedure TCustomControl.DestroyWnd;
begin
if FCanvas <> nil then
TControlCanvas(FCanvas).FreeHandle;
inherited DestroyWnd;
end;
{------------------------------------------------------------------------------
Method: TCustomControl.Paint
Params: none
Returns: nothing
Default paint handler. Derived classed should paint themselves
------------------------------------------------------------------------------}
procedure TCustomControl.Paint;
begin
if Assigned(FOnPaint) then FOnPaint(Self);
end;
procedure TCustomControl.FontChanged(Sender: TObject);
begin
Canvas.Font.BeginUpdate;
try
Canvas.Font.PixelsPerInch := Font.PixelsPerInch;
Canvas.Font := Font;
finally
Canvas.Font.EndUpdate;
end;
inherited FontChanged(Sender);
end;
procedure TCustomControl.SetColor(Value: TColor);
begin
if Value = Color then Exit;
inherited SetColor(Value);
Canvas.Brush.Color := Color;
end;
class procedure TCustomControl.WSRegisterClass;
const
Registered : boolean = False;
begin
if Registered then
Exit;
inherited WSRegisterClass;
RegisterCustomControl;
Registered := True;
end;
{------------------------------------------------------------------------------
Method: TCustomControl.LMPaint
Params: Msg: The paint message
Returns: nothing
Paint event handler.
------------------------------------------------------------------------------}
procedure TCustomControl.WMPaint(var Message: TLMPaint);
begin
if (csDestroying in ComponentState) or (not HandleAllocated) then exit;
Include(FControlState, csCustomPaint);
inherited WMPaint(Message);
Exclude(FControlState, csCustomPaint);
end;
{------------------------------------------------------------------------------
Method: TCustomControl.PaintWindow
Params: DC: The device context to paint on
Returns: nothing
This is a plug-in in TWinControl to get the DC, assign it to our canvas and
call the paint method for descendents to do the actual painting
------------------------------------------------------------------------------}
procedure TCustomControl.PaintWindow(DC: HDC);
var
DCChanged: boolean;
begin
DCChanged := (not FCanvas.HandleAllocated) or (FCanvas.Handle <> DC);
if DCChanged then
FCanvas.Handle := DC;
try
Paint;
finally
if DCChanged then FCanvas.Handle := 0;
end;
end;
// included by controls.pp
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