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TSelectionPoint = class(TStyledControl)


class PASCALIMPLEMENTATION TSelectionPoint : public Fmx::Controls::TStyledControl


Type Visibility Source Unit Parent
class public
FMX.Objects FMX.Objects


TSelectionPoint defines a 2D point object that can be moved. It inherits TControl and can be used in styles to create controls.

The TSelectionPoint class implements operations of moving of a 2D point object with a mouse or another pointing device.

The behavior of selection point objects depends upon the existence of a corresponding style-resource in an application style book:

  • When an application style book does not contain a style-resource for selection points:
    • A selection point in this application is drawn as a circle having a radius equal to GripSize.
    • The used GripSize is truncated to 1<= GripSize<=20.
    • A selection point is drawn as a white circle having the blue circumference.
    • When a selection point is selected, its circle is shown red.
    • To select a selection point, place the mouse pointer over the circle shape or the bounds rectangle of the selection point (having the Width and Height dimensions).
  • When an application style book contains a style-resource for selection points, then all selection point properties are loaded from the style-resource; property values are set in the Form Designer or are ignored programmatically. On some platforms, selection points use predefined platform-specific values. For example, on some mobile platforms GripSize is 16 or 17 and this value cannot be changed programmatically.

Notice that the GripCenter property has the following implementation. The X and Y values of GripCenter define an offset between the mouse pointer position and the shown selection point when the pressed mouse pointer is moved.

You can use scaling factors Scale of the TSelectionPoint object to proportionally change a selection point and a grip sizes along coordinate axes. The rotation axis RotationCenter and rotation angle RotationAngle of the selection point object can also be used to modify the position of the selection point.

See Also

Code Examples