Visibility
abstract class Visibility : Transition
kotlin.Any | ||
↳ | android.transition.Transition | |
↳ | android.transition.Visibility |
This transition tracks changes to the visibility of target views in the start and end scenes. Visibility is determined not just by the View#setVisibility(int)
state of views, but also whether views exist in the current view hierarchy. The class is intended to be a utility for subclasses such as Fade
, which use this visibility information to determine the specific animations to run when visibility changes occur. Subclasses should implement one or both of the methods onAppear(android.view.ViewGroup,android.transition.TransitionValues,int,android.transition.TransitionValues,int)
, onDisappear(android.view.ViewGroup,android.transition.TransitionValues,int,android.transition.TransitionValues,int)
or onAppear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
, onDisappear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
.
Summary
Constants | |
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static Int |
Mode used in |
static Int |
Mode used in |
Inherited constants | |
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Public constructors | |
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Visibility(context: Context!, attrs: AttributeSet!) |
Public methods | |
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open Unit |
captureEndValues(transitionValues: TransitionValues!) |
open Unit |
captureStartValues(transitionValues: TransitionValues!) |
open Animator? |
createAnimator(sceneRoot: ViewGroup, startValues: TransitionValues?, endValues: TransitionValues?) 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. |
open Int |
getMode() Returns whether appearing and/or disappearing Views are supported. |
open Array<String!>! | |
open Boolean |
isTransitionRequired(startValues: TransitionValues?, newValues: TransitionValues?) |
open Boolean |
isVisible(values: TransitionValues!) Returns whether the view is 'visible' according to the given values object. |
open Animator! |
onAppear(sceneRoot: ViewGroup!, startValues: TransitionValues!, startVisibility: Int, endValues: TransitionValues!, endVisibility: Int) The default implementation of this method calls |
open Animator! |
onAppear(sceneRoot: ViewGroup!, view: View!, startValues: TransitionValues!, endValues: TransitionValues!) The default implementation of this method returns a null Animator. |
open Animator! |
onDisappear(sceneRoot: ViewGroup!, startValues: TransitionValues!, startVisibility: Int, endValues: TransitionValues!, endVisibility: Int) Subclasses should override this method or |
open Animator! |
onDisappear(sceneRoot: ViewGroup!, view: View!, startValues: TransitionValues!, endValues: TransitionValues!) The default implementation of this method returns a null Animator. |
open Unit |
Changes the transition to support appearing and/or disappearing Views, depending on |
Inherited functions | |
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Constants
MODE_IN
static val MODE_IN: Int
Mode used in setMode(int)
to make the transition operate on targets that are appearing. Maybe be combined with MODE_OUT
to target Visibility changes both in and out.
Value: 1
MODE_OUT
static val MODE_OUT: Int
Mode used in setMode(int)
to make the transition operate on targets that are disappearing. Maybe be combined with MODE_IN
to target Visibility changes both in and out.
Value: 2
Public constructors
Public methods
captureEndValues
open fun captureEndValues(transitionValues: TransitionValues!): Unit
Parameters | |
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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. |
captureStartValues
open fun captureStartValues(transitionValues: TransitionValues!): Unit
Parameters | |
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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. |
createAnimator
open fun createAnimator(
sceneRoot: ViewGroup,
startValues: TransitionValues?,
endValues: TransitionValues?
): Animator?
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. Subclasses of Transition should override this method. The method should only be called by the transition system; it is not intended to be called from external classes.
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.
Parameters | |
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sceneRoot |
ViewGroup: This value cannot be null . |
startValues |
TransitionValues?: This value may be null . |
endValues |
TransitionValues?: This value may be null . |
Return | |
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Animator? |
This value may be null . |
getMode
open fun getMode(): Int
Returns whether appearing and/or disappearing Views are supported. Returns whether appearing and/or disappearing Views are supported. A combination of MODE_IN
and MODE_OUT
.
Return | |
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Int |
Value is either 0 or a combination of android.transition.Visibility#MODE_IN , android.transition.Visibility#MODE_OUT , android.transition.Fade#IN , and android.transition.Fade#OUT |
getTransitionProperties
open fun getTransitionProperties(): Array<String!>!
Return | |
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Array<String!>! |
An array of property names as described in the class documentation for TransitionValues . The default implementation returns null . |
isTransitionRequired
open fun isTransitionRequired(
startValues: TransitionValues?,
newValues: TransitionValues?
): Boolean
Parameters | |
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startValues |
TransitionValues?: the values from captureStartValues, This may be null if the View did not exist in the start state. |
endValues |
the values from captureEndValues. This may be null if the View did not exist in the end state. |
isVisible
open fun isVisible(values: TransitionValues!): Boolean
Returns whether the view is 'visible' according to the given values object. This is determined by testing the same properties in the values object that are used to determine whether the object is appearing or disappearing in the android.transition.Transition#createAnimator(android.view.ViewGroup,android.transition.TransitionValues,android.transition.TransitionValues)
method. This method can be called by, for example, subclasses that want to know whether the object is visible in the same way that Visibility determines it for the actual animation.
Parameters | |
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values |
TransitionValues!: The TransitionValues object that holds the information by which visibility is determined. |
Return | |
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Boolean |
True if the view reference by values is visible, false otherwise. |
onAppear
open fun onAppear(
sceneRoot: ViewGroup!,
startValues: TransitionValues!,
startVisibility: Int,
endValues: TransitionValues!,
endVisibility: Int
): Animator!
The default implementation of this method calls onAppear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
. Subclasses should override this method or onAppear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
. if they need to create an Animator when targets appear. The method should only be called by the Visibility class; it is not intended to be called from external classes.
Parameters | |
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sceneRoot |
ViewGroup!: The root of the transition hierarchy |
startValues |
TransitionValues!: The target values in the start scene |
startVisibility |
Int: The target visibility in the start scene |
endValues |
TransitionValues!: The target values in the end scene |
endVisibility |
Int: The target visibility in the end scene |
Return | |
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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. |
onAppear
open fun onAppear(
sceneRoot: ViewGroup!,
view: View!,
startValues: TransitionValues!,
endValues: TransitionValues!
): Animator!
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 | |
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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 |
Return | |
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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
open fun onDisappear(
sceneRoot: ViewGroup!,
startValues: TransitionValues!,
startVisibility: Int,
endValues: TransitionValues!,
endVisibility: Int
): Animator!
Subclasses should override this method or onDisappear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
if they need to create an Animator when targets disappear. The method should only be called by the Visibility class; it is not intended to be called from external classes.
The default implementation of this method attempts to find a View to use to call onDisappear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
, 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 android.view.ViewGroupOverlay
and passed as the view
parameter in onDisappear(android.view.ViewGroup,android.view.View,android.transition.TransitionValues,android.transition.TransitionValues)
. If a visible View is changed to be View#GONE
or View#INVISIBLE
, then it can be used as the view
and 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 make it disappear.
Parameters | |
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sceneRoot |
ViewGroup!: The root of the transition hierarchy |
startValues |
TransitionValues!: The target values in the start scene |
startVisibility |
Int: The target visibility in the start scene |
endValues |
TransitionValues!: The target values in the end scene |
endVisibility |
Int: The target visibility in the end scene |
Return | |
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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
open fun onDisappear(
sceneRoot: ViewGroup!,
view: View!,
startValues: TransitionValues!,
endValues: TransitionValues!
): Animator!
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 | |
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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 android.view.ViewGroupOverlay and will be VISIBLE. |
startValues |
TransitionValues!: The target values in the start scene |
endValues |
TransitionValues!: The target values in the end scene |
Return | |
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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. |
setMode
open fun setMode(mode: Int): Unit
Changes the transition to support appearing and/or disappearing Views, depending on mode
.
Parameters | |
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mode |
Int: The behavior supported by this transition, a combination of MODE_IN and MODE_OUT . Value is either 0 or a combination of android.transition.Visibility#MODE_IN , android.transition.Visibility#MODE_OUT , android.transition.Fade#IN , and android.transition.Fade#OUT |