ExposeEvent Class

Provide information about an ExposeEvent, used to notify a window that it may need to be repainted.

Inheritance Hierarchy

Object
Event
ExposeEvent

Namespace: VO
Assembly: VOGUIClasses (in VOGUIClasses.dll) Version: 2.21

Syntax

Copy

 CLASS ExposeEvent INHERIT Event

public class ExposeEvent : Event

Request Example View Source

The ExposeEvent type exposes the following members.

Constructors

	Name	Description
	ExposeEvent	Initializes a new instance of the ExposeEvent class

Top

Properties

	Name	Description
	ExposedArea	A bounding box—in canvas coordinates—representing the exposed area that caused this expose event. Use this method to optimize your repainting routines so that they paint only the area which requires refreshing.
	Handle	The pointer to the window where the event occurred (Inherited from Event.)
	Message	A dword representing the Windows API message associated with the given event. (Inherited from Event.)
	Window	An object indicating the window or control in which the event occurred. This is helpful, for example, for distinguishing between similar menu events coming from the same context menu attached to different controls. (Inherited from Event.)

Top

Fields

	Name	Description
	hWnd	(Inherited from Event.)
	lParam	(Inherited from Event.)
	oWindow	(Inherited from Event.)
	uMsg	(Inherited from Event.)
	wParam	(Inherited from Event.)

Top

Remarks

An ExposeEvent occurs when a window is: First shown Moved or closed Moving or closing a window exposes the area underneath the window; if any other windows are in this newly exposed area, they need to be repainted. The system automatically sends these window(s) an ExposeEvent to notify them that they must repaint the area that was uncovered. Resized The ExposeEvent goes to the Window:Expose() event handler with the responsibility for repainting the exposed area. You should place your own code in this event handler if you want your application to do something when its window is exposed.

Examples

The following example prints different messages, depending on what part of the window has been exposed:

Copy

1METHOD Expose(oEE) CLASS MyWindow
2LOCAL oBB AS BOUNDINGBOX
3oBB := oEE:ExposedArea
4IF oBB:Bottom() < 20
5SELF:TextPrint("In the 20's",Point{0,20})
6ENDIF
7IF oBB:Bottom() > 40
8SELF:TextPrint("In the 40's",Point{0,40})
9ENDIF

Reference

VO Namespace