lazarus/lcl/include/dragobject.inc

{%MainUnit ../controls.pp}

{******************************************************************************
                                     TDragObject
 ******************************************************************************

 *****************************************************************************
 *                                                                           *
 *  This file is part of the Lazarus Component Library (LCL)                 *
 *                                                                           *
 *  See the file COPYING.modifiedLGPL.txt, included in this distribution,    *
 *  for details about the copyright.                                         *
 *                                                                           *
 *  This program is distributed in the hope that it will be useful,          *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                     *
 *                                                                           *
 *****************************************************************************
}

{ TDragObject }

constructor TDragObject.Create(AControl : TControl);
begin
  FControl := AControl;
end;

constructor TDragObject.AutoCreate(AControl: TControl);
begin
  Create(AControl);
  FAutoCreated := True;
  FAutoFree := True;
end;

procedure TDragObject.EndDrag(Target: TObject; X, Y: Integer);
begin
  if FControl <> nil then
    FControl.DoEndDrag(Target, X, Y);
end;

function TDragObject.GetDragImages: TDragImageList;
begin
  Result := nil;
end;

function TDragObject.GetDragCursor(Accepted: Boolean; X, Y: Integer): TCursor;
begin
  if Accepted then
    Result := crDrag
  else
    Result := crNoDrop;
end;

procedure TDragObject.HideDragImage;
begin
  if GetDragImages <> nil then
    GetDragImages.HideDragImage;
end;

procedure TDragObject.ShowDragImage;
begin
  if GetDragImages <> nil then
    GetDragImages.ShowDragImage;
end;

{ TDragObjectEx }

constructor TDragObjectEx.Create(AControl: TControl);
begin
  inherited Create(AControl);
  FAutoFree := True;
end;

{ TDragControlObject }

function TDragControlObject.GetDragCursor(Accepted: Boolean; X, Y: Integer): TCursor;
begin
  if Accepted then
    Result := Control.DragCursor
  else
    Result := crNoDrop;
end;

function TDragControlObject.GetDragImages: TDragImageList;
begin
  Result := Control.GetDragImages;
end;

{ TDragControlObjectEx }

constructor TDragControlObjectEx.Create(AControl: TControl);
begin
  inherited Create(AControl);
  FAutoFree := True;
end;

{ TDragDockObject }

procedure TDragDockObject.AdjustDockRect(ARect: TRect);
begin
  with DockOffset do
    OffsetRect(FDockRect, -X, -Y);
end;

function TDragDockObject.GetDragCursor(Accepted: Boolean; X, Y: Integer): TCursor;
begin
  Result := crDefault;
end;

procedure TDragDockObject.EndDrag(Target: TObject; X, Y: Integer);
begin
  if FControl <> nil then
    FControl.DoEndDock(Target, X, Y);
end;

procedure TDragDockObject.InitDock(APosition: TPoint);
begin
  // Determine hotspot scale for adjusting the undocked rectangle.
  // Since the undocked extent of the control doesn't change, we fix the hotspot offset.
  // Usage: OffsetRect(DockRect, FDockOffset);

  DragPos := APosition; //should have been done before
  Control.CalculateDockSizes;
  // mouse click offset from control TopLeft in screen coordinates
  with FDockRect do
  begin
    TopLeft := Control.ClientToScreen(Point(0, 0));
    Right := Left + Control.Width;
    Bottom := Top + Control.Height;
  end;
  if Control.Width > 0 then
    FDockOffset.x := Round((APosition.x - FDockRect.Left) / Control.Width * Control.UndockWidth)
  else
    FDockOffset.X := 0;
  if Control.Height > 0 then
    FDockOffset.Y := Round((APosition.y - FDockRect.Top) / Control.Height * Control.UndockHeight)
  else
    FDockOffset.Y := 0;
  FEraseDockRect := Rect(MaxInt, 0, MaxInt, 0);
end;

procedure TDragDockObject.ShowDockImage;
begin
  WidgetSet.DrawDefaultDockImage(EraseDockRect, DockRect, disShow);
  EraseDockRect := DockRect;
end;

procedure TDragDockObject.HideDockImage;
begin
  WidgetSet.DrawDefaultDockImage(EraseDockRect, DockRect, disHide);
  FEraseDockRect := Rect(MaxInt, 0, MaxInt, 0);
end;

procedure TDragDockObject.MoveDockImage;
begin
  //Draw the form outlines when the position has changed
  if not CompareMem(@DockRect, @EraseDockRect, SizeOf(TRect)) then
  begin
    WidgetSet.DrawDefaultDockImage(EraseDockRect, DockRect, disMove);
    EraseDockRect := DockRect;
  end;
end;

{ TDragDockObjectEx }

constructor TDragDockObjectEx.Create(AControl: TControl);
begin
  inherited Create(AControl);
  FAutoFree := True;
end;

// included by controls.pp