public class Fade extends Visibility
View.setVisibility(int)
state of the view as well as whether it
is parented in the current view hierarchy.
The ability of this transition to fade out a particular view, and the
way that that fading operation takes place, is based on
the situation of the view in the view hierarchy. For example, if a view was
simply removed from its parent, then the view will be added into a ViewGroupOverlay
while fading. If a visible view is
changed to be View.GONE
or View.INVISIBLE
, then the
visibility will be changed to View.VISIBLE
for the duration of
the animation. However, if a view is in a hierarchy which is also altering
its visibility, the situation can be more complicated. In general, if a
view that is no longer in the hierarchy in the end scene still has a
parent (so its parent hierarchy was removed, but it was not removed from
its parent), then it will be left alone to avoid side-effects from
improperly removing it from its parent. The only exception to this is if
the previous Scene
was
created from a layout resource file
, then it is considered safe to un-parent
the starting scene view in order to fade it out.
Unlike the platform version, this does not support use in XML resources.
Transition.TransitionListener
Modifier and Type | Field and Description |
---|---|
static int |
IN
Fading mode used in
Fade(int) to make the transition
operate on targets that are appearing. |
static int |
OUT
Fading mode used in
Fade(int) to make the transition
operate on targets that are disappearing. |
Constructor and Description |
---|
Fade()
Constructs a Fade transition that will fade targets in and out.
|
Fade(int fadingMode)
Constructs a Fade transition that will fade targets in
and/or out, according to the value of fadingMode.
|
Modifier and Type | Method and Description |
---|---|
void |
captureEndValues(TransitionValues transitionValues)
Captures the values in the end scene for the properties that this
transition monitors.
|
void |
captureStartValues(TransitionValues transitionValues)
Captures the values in the start scene for the properties that this
transition monitors.
|
Animator |
createAnimator(ViewGroup sceneRoot,
TransitionValues startValues,
TransitionValues endValues)
This method creates an animation that will be run for this transition
given the information in the startValues and endValues structures captured
earlier for the start and end scenes.
|
isVisible, onAppear, onDisappear
addListener, addTarget, addTarget, excludeChildren, excludeChildren, excludeChildren, excludeTarget, excludeTarget, excludeTarget, getDuration, getInterpolator, getName, getStartDelay, getTargetIds, getTargets, getTransitionProperties, getTransitionValues, removeListener, removeTarget, removeTarget, setDuration, setInterpolator, setStartDelay, toString
public static final int IN
Fade(int)
to make the transition
operate on targets that are appearing. Maybe be combined with
OUT
to fade both in and out.public static final int OUT
Fade(int)
to make the transition
operate on targets that are disappearing. Maybe be combined with
IN
to fade both in and out.public Fade(int fadingMode)
public Fade()
public void captureEndValues(@NonNull TransitionValues transitionValues)
Transition
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
.
The main concern for an implementation is what the
properties are that the transition cares about and what the values are
for all of those properties. The start and end values will be compared
later during the
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
method to determine what, if any, animations, should be run.
Subclasses must implement this method. The method should only be called by the transition system; it is not intended to be called from external classes.
captureEndValues
in class Visibility
transitionValues
- The holder for any values that the Transition
wishes to store. Values are stored in the values
field
of this TransitionValues object and are keyed from
a String value. For example, to store a view's rotation value,
a transition might call
transitionValues.values.put("appname:transitionname:rotation",
view.getRotation())
. The target view will already be stored
in
the transitionValues structure when this method is called.Transition.captureStartValues(TransitionValues)
,
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
public void captureStartValues(@NonNull TransitionValues transitionValues)
Transition
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
.
The main concern for an implementation is what the
properties are that the transition cares about and what the values are
for all of those properties. The start and end values will be compared
later during the
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
method to determine what, if any, animations, should be run.
Subclasses must implement this method. The method should only be called by the transition system; it is not intended to be called from external classes.
captureStartValues
in class Visibility
transitionValues
- The holder for any values that the Transition
wishes to store. Values are stored in the values
field
of this TransitionValues object and are keyed from
a String value. For example, to store a view's rotation value,
a transition might call
transitionValues.values.put("appname:transitionname:rotation",
view.getRotation())
. The target view will already be stored
in
the transitionValues structure when this method is called.Transition.captureEndValues(TransitionValues)
,
Transition.createAnimator(ViewGroup, TransitionValues, TransitionValues)
@Nullable public Animator createAnimator(@NonNull ViewGroup sceneRoot, @NonNull TransitionValues startValues, @NonNull TransitionValues endValues)
Transition
This method is called by the transition's parent (all the way up to the
topmost Transition in the hierarchy) with the sceneRoot and start/end
values that the transition may need to set up initial target values
and construct an appropriate animation. For example, if an overall
Transition is a TransitionSet
consisting of several
child transitions in sequence, then some of the child transitions may
want to set initial values on target views prior to the overall
Transition commencing, to put them in an appropriate state for the
delay between that start and the child Transition start time. For
example, a transition that fades an item in may wish to set the starting
alpha value to 0, to avoid it blinking in prior to the transition
actually starting the animation. This is necessary because the scene
change that triggers the Transition will automatically set the end-scene
on all target views, so a Transition that wants to animate from a
different value should set that value prior to returning from this method.
Additionally, a Transition can perform logic to determine whether the transition needs to run on the given target and start/end values. For example, a transition that resizes objects on the screen may wish to avoid running for views which are not present in either the start or end scenes.
If there is an animator created and returned from this method, the
transition mechanism will apply any applicable duration, startDelay,
and interpolator to that animation and start it. A return value of
null
indicates that no animation should run. The default
implementation returns null.
The method is called for every applicable target object, which is
stored in the TransitionValues.view
field.
createAnimator
in class Transition
sceneRoot
- The root of the transition hierarchy.startValues
- The values for a specific target in the start scene.endValues
- The values for the target in the end scene.