Interface IEventDelegate
interface IEventDelegate
Extends com.amazon.apmf.IStandard
This interface provides functionality to customize the behaviour of pointer/key events. This is different
from key/pointer event listener, as the default implementation does many things in addition to calling the listener,
but if the user wants to modify the behaviour of how the event is dispatched and handled among the receiving view and its
children, then the user can implement this interface and provides its instance. Each function of this delegate provides
an additional parameter which holds a pointer to the default implementation of this delegate. This enables the
user to call the base implementation of the function as per the use-case (similar to calling the parent class
function from the overriden function in child class).
See also- IViewModule::makeViewWithDelegate.
Methods
dispatchPointerEvent()
This function is called for the view which will get the pointer event after performing hit test. Hit testing will return a list of views which are in range for receiving the pointer event. The framework will iterate over all the views returned by hit test and call this function for each of the views. We will pass the pointer event to each of these views until a view is found which returns true (meaning that view has consumed the pointer event). For each of the remaining views, this function will be called with the pointer event argument in cancelled state, to allow for cleanup. By default, it will call the pointer event listeners added to this view and mark the pointer event as consumed, so that it is not propagated any more.booldispatchPointerEvent(IView*view,IUIPointerEvent*pointerEvent,IEventDelegate*defaultDelegate)
Parameters
view
IView* — Required
IView Instance of the view which is receiving the pointer event.
pointerEvent
IUIPointerEvent* — Required
IUIPointerEvent Instance of pointer event which contains information about
the pointer data.
defaultDelegate
IEventDelegate* — Required
IEventDelegate Pointer to the default implementation of IEventDelegate.
Returns
bool
bool True if the view has consumed the pointer event and vice-versa.
dispatchKeyEvent()
This function is called for the view to allow for consumption of key event. This function will be called one by one for each of the views starting from the root view. By default, this function will call the key listeners if this view is focused, else it will call this function for the focused child. If both of these conditions return false, then the next child of the root view will receive this callback. If all the views return false, then focus change if performed for this key event.booldispatchKeyEvent(IView*view,IUIKeyEvent*key,IEventDelegate*defaultDelegate)
Parameters
view
IView* — Required
IView Instance of the view which is receiving the key event.
key
IUIKeyEvent* — Required
IUIKeyEvent Instance of key event which contains information about the key data.
defaultDelegate
IEventDelegate* — Required
IEventDelegate Pointer to the default implementation of IEventDelegate.
Returns
bool
bool True if the view has consumed key event and vice-versa.
dispatchAxisEvent()
This function is called for the view to allow for consumption of axis event. This function will be called one by one for each of the views starting from the root view. By default, this function will call the event listeners if this view is focused, else it will call this function for the focused child. If both of these conditions return false, then the next child of the root view will receive this callback. If all the views return false, then focus change is performed for this event.booldispatchAxisEvent(IView*view,IUIAxisEvent*axisEvent,IEventDelegate*defaultDelegate)
Parameters
view
IView* — Required
IView Instance of the view which is receiving the axis event.
axisEvent
IUIAxisEvent* — Required
IUIAxisEvent instance which contains information about the axis data.
defaultDelegate
IEventDelegate* — Required
IEventDelegate Pointer to the default implementation of IEventDelegate.
Returns
bool
bool True if the view has consumed key event and vice-versa.
