# osgGA::GUIActionAdapter Class Reference

Abstract base class defining the interface by which GUIEventHandlers may request actions of the GUI system in use. More...

Inheritance diagram for osgGA::GUIActionAdapter:

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List of all members.

## Public Member Functions

virtual void | requestRedraw ()=0
| requestRedraw() requests a single redraw.
virtual void | requestContinuousUpdate (bool needed=true)=0
| requestContinousUpdate(bool) is for en/disabling a throw or idle callback to be requested by a GUIEventHandler (typically a MatrixManipulator, though other GUIEventHandler's may also provide functionality).
virtual void | requestWarpPointer (float x, float y)=0
| requestWarpPointer(int,int) is requesting a repositioning of the mouse pointer to a specified x,y location on the window.

## Detailed Description

Abstract base class defining the interface by which GUIEventHandlers may request actions of the GUI system in use.

These requests for actions should then be honoured by the GUI toolkit of the user's application.

To provide more detail, when a GUIEventHandler (e.g. a TrackballManipulator) handles an incoming event, such as a mouse event, it may wish to make a request of the GUI. E.g. if a model is 'thrown', the trackball manipulator may wish to start a timer, and be repeatedly called, to continuously refresh the camera's position and orientation. However, it has no way of doing this, as it knows nothing of the window system in which it's operating. Instead, the GUIEventHandler issues it's request via a GUIActionAdapter, and the viewer in use should honour the request, using the GUI system in play.

There is more than one way of using the GUIActionAdapter. E.g. it may be inherited into a Viewer class, as is done with osgGLUT::Viewer. Alternatively, a simple subclass of GUIActionAdapter (e.g. osgQt::QtActionAdapter) may be passed to the GUIEventHandler::handle() function; once the function has returned, the viewer will then unpack the results and work out what to do to respond to the requests.

Also there are several ways to run your app and handle the updating of the window. osgGLUT::Viewer always has a idle callback registered which does a redraw all the time. osgGLUT::Viewer can safely ignore both requestRedraw() and requestContinousUpdate() as these are happening all the time anyway.

Other apps will probably want to respond to the requestRedraw() and requestContinousUpdate(bool) and again there is more than one way to handle it. You can override requestRedraw() and implement to call your own window redraw straight away. Or you can implement so that a flag is set and then you then respond the flag being set in your own leisure.

## Member Function Documentation

virtual void osgGA::GUIActionAdapter::requestContinuousUpdate | ( | bool | needed = `true` | ) | `[pure virtual]`

| requestContinousUpdate(bool) is for en/disabling a throw or idle callback to be requested by a GUIEventHandler (typically a MatrixManipulator, though other GUIEventHandler's may also provide functionality). GUI toolkits can respond to this immediately by registering an idle/timed callback, or can delay setting the callback and update at their own leisure. Implemented in osgProducer::Viewer.

virtual void osgGA::GUIActionAdapter::requestRedraw | ( |  | ) | `[pure virtual]`

| requestRedraw() requests a single redraw. Implemented in osgProducer::Viewer.

virtual void osgGA::GUIActionAdapter::requestWarpPointer | ( | float | x,
|  | float | y
| ) | `[pure virtual]`

| requestWarpPointer(int,int) is requesting a repositioning of the mouse pointer to a specified x,y location on the window. This is used by some camera manipulators to initialise the mouse pointer when mouse position relative to a controls neutral mouse position is required, i.e when mimicking a aircrafts joystick. Implemented in osgProducer::Viewer.

The documentation for this class was generated from the following file:

- GUIActionAdapter