[Overview][Types][Classes][Procedures and functions][Index] Reference for unit 'DrawnControl' (#HMI)

TElement

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

base class for elements, that can be added to a TDrawing object

Declaration

Source position: drawncontrol.pas line 20

type TElement = class(TComponent) end;

protected

  class function GetVectorDirection();

  

calculates the angle of a vector being given in screen coordinates.

  class function GetVectorLength();

  

calculates the absolute value (length) of the given vector

  class procedure SetVectorDirection();

  class procedure SetVectorLength();

  class procedure VectorRotate();

  class procedure VectorZoom();

  procedure Notification(); override;

  procedure Shift(); virtual; abstract;

  procedure Rotate(); virtual; abstract;

  procedure Zoom(); virtual; abstract;

public

  destructor Destroy; override;

  property Brush: TBrush; [r]

  property Pen: TPen; [r]

  property Control: TGraphicControl; [rw]

Inheritance

TElement

  

base class for elements, that can be added to a TDrawing object

|

TComponent

?

TObject

Description

Objects of this class are usually placed on a TDrawing object. Because TElement is abstract, it is necessary to derive concrete element classes from it first. You can use the protected methods, especially class methods for vector handling, to design. The design has to happen by overriding the abstract and other virtual methods.

See also

#HMI.drawncontrol.TLine

  

straight line that starts at SP and ends at EP

#HMI.drawncontrol.TRectangle

  

TElement descendant to add a rectangle to a drawing

#HMI.drawncontrol.TRotativePointer

  

pointer rotating around the point CP by changing the value of Angle