Fade
public
class
Fade
extends Visibility
java.lang.Object | |||
↳ | android.transition.Transition | ||
↳ | android.transition.Visibility | ||
↳ | android.transition.Fade |
This transition tracks changes to the visibility of target views in the
start and end scenes and fades views in or out when they become visible
or non-visible. Visibility is determined by both the
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.
A Fade transition can be described in a resource file by using the
tag fade
, along with the standard
attributes of R.styleable.Fade
and
R.styleable.Transition
.
Summary
Inherited XML attributes | |
---|---|
Constants | |
---|---|
int |
IN
Fading mode used in |
int |
OUT
Fading mode used in |
Inherited constants |
---|
Public constructors | |
---|---|
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. |
|
Fade(Context context, AttributeSet attrs)
|
Public methods | |
---|---|
void
|
captureStartValues(TransitionValues transitionValues)
Captures the values in the start scene for the properties that this transition monitors. |
Animator
|
onAppear(ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues)
The default implementation of this method returns a null Animator. |
Animator
|
onDisappear(ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues)
The default implementation of this method returns a null Animator. |
Inherited methods | |
---|---|
Constants
IN
public static final int IN
Fading mode used in Fade(int)
to make the transition
operate on targets that are appearing. Maybe be combined with
OUT
to fade both in and out. Equivalent to
Visibility#MODE_IN
.
Constant Value: 1 (0x00000001)
OUT
public static final int OUT
Fading mode used in Fade(int)
to make the transition
operate on targets that are disappearing. Maybe be combined with
IN
to fade both in and out. Equivalent to
Visibility#MODE_OUT
.
Constant Value: 2 (0x00000002)
Public constructors
Fade
public Fade ()
Constructs a Fade transition that will fade targets in and out.
Fade
public Fade (int fadingMode)
Constructs a Fade transition that will fade targets in and/or out, according to the value of fadingMode.
Parameters | |
---|---|
fadingMode |
int : The behavior of this transition, a combination of
IN and OUT .
Value is either 0 or a combination of Visibility.MODE_IN , Visibility.MODE_OUT , IN , and OUT |
Fade
public Fade (Context context, AttributeSet attrs)
Parameters | |
---|---|
context |
Context |
attrs |
AttributeSet |
Public methods
captureStartValues
public void captureStartValues (TransitionValues transitionValues)
Captures the values in the start scene for the properties that this
transition monitors. These values are then passed as the startValues
structure in a later call to
createAnimator(android.view.ViewGroup, android.transition.TransitionValues, android.transition.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
createAnimator(android.view.ViewGroup, android.transition.TransitionValues, android.transition.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.
Parameters | |
---|---|
transitionValues |
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. |
onAppear
public Animator onAppear (ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues)
The default implementation of this method returns a null Animator. Subclasses should
override this method to make targets appear with the desired transition. The
method should only be called from
onAppear(android.view.ViewGroup, android.transition.TransitionValues, int, android.transition.TransitionValues, int)
.
Parameters | |
---|---|
sceneRoot |
ViewGroup : The root of the transition hierarchy |
view |
View : The View to make appear. This will be in the target scene's View hierarchy and
will be VISIBLE. |
startValues |
TransitionValues : The target values in the start scene |
endValues |
TransitionValues : The target values in the end scene |
Returns | |
---|---|
Animator |
An Animator to be started at the appropriate time in the overall transition for this scene change. A null value means no animation should be run. |
onDisappear
public Animator onDisappear (ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues)
The default implementation of this method returns a null Animator. Subclasses should
override this method to make targets disappear with the desired transition. The
method should only be called from
onDisappear(android.view.ViewGroup, android.transition.TransitionValues, int, android.transition.TransitionValues, int)
.
Parameters | |
---|---|
sceneRoot |
ViewGroup : The root of the transition hierarchy |
view |
View : The View to make disappear. This will be in the target scene's View
hierarchy or in an ViewGroupOverlay and will be
VISIBLE. |
startValues |
TransitionValues : The target values in the start scene |
endValues |
TransitionValues : The target values in the end scene |
Returns | |
---|---|
Animator |
An Animator to be started at the appropriate time in the overall transition for this scene change. A null value means no animation should be run. |