InputDevice.ViewBehavior
public
static
final
class
InputDevice.ViewBehavior
extends Object
java.lang.Object | |
↳ | android.view.InputDevice.ViewBehavior |
Provides information on how views processing MotionEvent
s generated by this input
device should respond to the events. Use InputManager#getInputDeviceViewBehavior(int)
to get an instance of the view behavior for an input device.
See an example below how a View
can use this class to determine and apply the
scrolling behavior for a generic MotionEvent
.
public boolean onGenericMotionEvent(MotionEvent event) {
InputManager manager = context.getSystemService(InputManager.class);
ViewBehavior viewBehavior = manager.getInputDeviceViewBehavior(event.getDeviceId());
// Assume a helper function that tells us which axis to use for scrolling purpose.
int axis = getScrollAxisForGenericMotionEvent(event);
int source = event.getSource();
boolean shouldSmoothScroll =
viewBehavior != null && viewBehavior.shouldSmoothScroll(axis, source);
// Proceed to running the scrolling logic...
}
Summary
Public methods | |
---|---|
boolean
|
shouldSmoothScroll(int axis, int source)
Returns whether a view should smooth scroll when scrolling due to a |
Inherited methods | |
---|---|
Public methods
shouldSmoothScroll
public boolean shouldSmoothScroll (int axis, int source)
Returns whether a view should smooth scroll when scrolling due to a MotionEvent
generated by the input device.
Smooth scroll in this case refers to a scroll that animates the transition between
the starting and ending positions of the scroll. When this method returns true
,
views should try to animate a scroll generated by this device at the given axis and with
the given source to produce a good scroll user experience. If this method returns
false
, animating scrolls is not necessary.
If the input device does not have a MotionRange
with the provided axis and
source, this method returns false
.
Parameters | |
---|---|
axis |
int : the MotionEvent axis whose value is used to get the scroll extent. |
source |
int : the InputDevice source from which the MotionEvent that
triggers the scroll came. |
Returns | |
---|---|
boolean |
true if smooth scrolling should be used for the scroll, or false
if smooth scrolling is not necessary, or if the provided axis and source combination
is not available for the input device. |