WCPositionEH.h
Classes
- WCPositionEH -- Base class for handling WorldCanvas position events. (full description)
Interface
- Public Members
- WCPositionEH()
- virtual void operator()(const WCPositionEvent & ev)
- virtual ~WCPositionEH()
Prerequisite
- WCPositionEvent
- Understanding of Display library event-handling methodology
Etymology
WCPositionEH : WorldCanvas Position Event-Handler
Synopsis
WCPositionEH is a base class. Its operator() function is called by mechanisms within
the Display Library when a keyboard key or mouse button is pressed while within the
area of the world canvas.
Users must derive from this class and override the op () function to catch key
and button presses. Positions in world, linear, and pixel coordinates are
returned.
This base class does have a concrete implementation, namely to report
to stdout events it receives. To effect this behaviour, create an instance
this class and register it as an event-handler on a WorldCanvas.
Motivation
Provide the user with an object-oriented approach to event handling and
include world-coordinate position information.
Example
see the test programs in Display/test.
Member Description
Default Constructor Required
Default just prints the event to cout
Destructor