Manager View Hooks

A manager view hook is an instance of the IlvManagerViewHook class. To be active, it must be associated with a manager view. Each manager view handles a list of view hooks. To connect and disconnect view hooks from a manager view, use the following IlvManager member functions:

• IlvManager::installViewHook

• IlvManager::removeViewHook

The IlvManagerViewHook class has a number of virtual member functions that are automatically called by the manager when certain predefined operations occur. Here is the list of these member functions and the circumstances under which they are called:

• beforeDraw

Called before the manager draws in the manager view. Applications often overload this member function to perform additional drawings before the manager displays its graphic objects.

• afterDraw

Called after the manager has drawn in the manager view. Applications often overload this member function to perform additional drawings on top of the graphic objects displayed by the manager.

• afterExpose

Called after the manager has received an Expose event in the view.

• interactorChanged

Called when the interactor of the manager view changes.

• transformerChanged

Called when the transformer of the manager view changes.

• viewResized

Called when the manager view is resized.

• viewRemoved

Called when the manager view is detached from the manager.

• contentsChanged

Called when the contents of the manager change, that is, graphic objects have been added, removed, or their geometry has changed.

When an event occurs in view, the manager calls the corresponding member functions of all the hooks attached to this view.