Visibility

Artifact: androidx.transition:transition

Added in 1.0.0

Kotlin |Java

abstract class Visibility : Transition

kotlin.Any
↳	androidx.transition.Transition
	↳	androidx.transition.Visibility

Known direct subclasses

Explode, Fade, Slide

`Explode`	This transition tracks changes to the visibility of target views in the start and end scenes and moves views in or out from the edges of the scene.
`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.
`Slide`	This transition tracks changes to the visibility of target views in the start and end scenes and moves views in or out from one of the edges of the scene.

This transition tracks changes to the visibility of target views in the start and end scenes. Visibility is determined not just by the setVisibility 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, onDisappear or onAppear, onDisappear.

Summary

Constants
`const Int`	`MODE_IN = 1` Mode used in `setMode` to make the transition operate on targets that are appearing.
`const Int`	`MODE_OUT = 2` Mode used in `setMode` to make the transition operate on targets that are disappearing.

Public constructors
`Visibility()`
`Visibility(context: Context, attrs: AttributeSet)`

Public functions
`Unit`	`captureEndValues(transitionValues: TransitionValues)` Captures the values in the end scene for the properties that this transition monitors.
`Unit`	`captureStartValues(transitionValues: TransitionValues)` Captures the values in the start scene for the properties that this transition monitors.
`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.
`Int`	`getMode()` Returns whether appearing and/or disappearing Views are supported.
`Array<String!>?`	`getTransitionProperties()` Returns the set of property names used stored in the `TransitionValues` object passed into `captureStartValues` that this transition cares about for the purposes of canceling overlapping animations.
`Boolean`	`isTransitionRequired( startValues: TransitionValues?, endValues: TransitionValues? )` Returns whether or not the transition should create an Animator, based on the values captured during `captureStartValues` and `captureEndValues`.
`Boolean`	`isVisible(values: TransitionValues?)` Returns whether the view is 'visible' according to the given values object.
`Animator?`	`onAppear( sceneRoot: ViewGroup, view: View, startValues: TransitionValues?, endValues: TransitionValues? )` The default implementation of this method returns a null Animator.
`Animator?`	`onAppear( sceneRoot: ViewGroup, startValues: TransitionValues?, startVisibility: Int, endValues: TransitionValues?, endVisibility: Int )` The default implementation of this method does nothing.
`Animator?`	`onDisappear( sceneRoot: ViewGroup, view: View, startValues: TransitionValues?, endValues: TransitionValues? )` The default implementation of this method returns a null Animator.
`Animator?`	`onDisappear( sceneRoot: ViewGroup, startValues: TransitionValues?, startVisibility: Int, endValues: TransitionValues?, endVisibility: Int )` The default implementation of this method does nothing.
`Unit`	`setMode(mode: Int)` Changes the transition to support appearing and/or disappearing Views, depending on `mode`.

Inherited Constants

From androidx.transition.Transition

`const Int`	`MATCH_ID = 3` With `setMatchOrder`, chooses to match by `getId`.
`const Int`	`MATCH_INSTANCE = 1` With `setMatchOrder`, chooses to match by View instance.
`const Int`	`MATCH_ITEM_ID = 4` With `setMatchOrder`, chooses to match by the `android.widget.Adapter` item id.
`const Int`	`MATCH_NAME = 2` With `setMatchOrder`, chooses to match by `getTransitionName`.

Inherited functions

From androidx.transition.Transition

`Transition`	`addListener(listener: Transition.TransitionListener)` Adds a listener to the set of listeners that are sent events through the life of an animation, such as start, repeat, and end.
`Transition`	`addTarget(targetId: @IdRes Int)` Adds the id of a target view that this Transition is interested in animating.
`Transition`	`addTarget(targetName: String)` Adds the transitionName of a target view that this Transition is interested in animating.
`Transition`	`addTarget(targetType: Class<Any!>)` Adds the Class of a target view that this Transition is interested in animating.
`Transition`	`addTarget(target: View)` Sets the target view instances that this Transition is interested in animating.
`Transition`	`clone()`
`Transition`	`excludeChildren(targetId: @IdRes Int, exclude: Boolean)` Whether to add the children of the given id to the list of targets to exclude from this transition.
`Transition`	`excludeChildren(target: View, exclude: Boolean)` Whether to add the children of given target to the list of target children to exclude from this transition.
`Transition`	`excludeChildren(type: Class<Any!>, exclude: Boolean)` Whether to add the given type to the list of types whose children should be excluded from this transition.
`Transition`	`excludeTarget(targetId: @IdRes Int, exclude: Boolean)` Whether to add the given id to the list of target ids to exclude from this transition.
`Transition`	`excludeTarget(targetName: String, exclude: Boolean)` Whether to add the given transitionName to the list of target transitionNames to exclude from this transition.
`Transition`	`excludeTarget(target: View, exclude: Boolean)` Whether to add the given target to the list of targets to exclude from this transition.
`Transition`	`excludeTarget(type: Class<Any!>, exclude: Boolean)` Whether to add the given type to the list of types to exclude from this transition.
`Long`	`getDuration()` Returns the duration set on this transition.
`Rect?`	`getEpicenter()` Returns the epicenter as specified by the `android.transition.Transition.EpicenterCallback` or null if no callback exists.
`Transition.EpicenterCallback?`	`getEpicenterCallback()` Returns the callback used to find the epicenter of the Transition.
`TimeInterpolator?`	`getInterpolator()` Returns the interpolator set on this transition.
`String`	`getName()` Returns the name of this Transition.
`PathMotion`	`getPathMotion()` Returns the algorithm object used to interpolate along two dimensions.
`TransitionPropagation?`	`getPropagation()` Returns the `android.transition.TransitionPropagation` used to calculate Animator start delays.
`Transition`	`getRootTransition()` If this Transition is not part of a TransitionSet, this is returned.
`Long`	`getStartDelay()` Returns the startDelay set on this transition.
`(Mutable)List<Int!>`	`getTargetIds()` Returns the array of target IDs that this transition limits itself to tracking and animating.
`(Mutable)List<String!>?`	`getTargetNames()` Returns the list of target transitionNames that this transition limits itself to tracking and animating.
`(Mutable)List<Class<Any!>!>?`	`getTargetTypes()` Returns the list of target transitionNames that this transition limits itself to tracking and animating.
`(Mutable)List<View!>`	`getTargets()` Returns the array of target views that this transition limits itself to tracking and animating.
`TransitionValues?`	`getTransitionValues(view: View, start: Boolean)` This method can be called by transitions to get the TransitionValues for any particular view during the transition-playing process.
`Boolean`	`isSeekingSupported()` Returns `true` if the Transition can be used by `controlDelayedTransition`.
`Transition`	`removeListener(listener: Transition.TransitionListener)` Removes a listener from the set listening to this animation.
`Transition`	`removeTarget(target: Class<Any!>)` Removes the given target from the list of targets that this Transition is interested in animating.
`Transition`	`removeTarget(targetId: @IdRes Int)` Removes the given targetId from the list of ids that this Transition is interested in animating.
`Transition`	`removeTarget(targetName: String)` Removes the given targetName from the list of transitionNames that this Transition is interested in animating.
`Transition`	`removeTarget(target: View)` Removes the given target from the list of targets that this Transition is interested in animating.
`Transition`	`setDuration(duration: Long)` Sets the duration of this transition.
`Unit`	`setEpicenterCallback(epicenterCallback: Transition.EpicenterCallback?)` Sets the callback to use to find the epicenter of a Transition.
`Transition`	`setInterpolator(interpolator: TimeInterpolator?)` Sets the interpolator of this transition.
`Unit`	`setMatchOrder(matches: IntArray?)` Sets the order in which Transition matches View start and end values.
`Unit`	`setPathMotion(pathMotion: PathMotion?)` Sets the algorithm used to calculate two-dimensional interpolation.
`Unit`	`setPropagation(transitionPropagation: TransitionPropagation?)` Sets the method for determining Animator start delays.
`Transition`	`setStartDelay(startDelay: Long)` Sets the startDelay of this transition.
`String`	`toString()`

Constants

MODE_IN

Added in 1.0.0

const val MODE_IN = 1: Int

Mode used in setMode to make the transition operate on targets that are appearing. Maybe be combined with MODE_OUT to target Visibility changes both in and out.

MODE_OUT

Added in 1.0.0

const val MODE_OUT = 2: Int

Mode used in setMode to make the transition operate on targets that are disappearing. Maybe be combined with MODE_IN to target Visibility changes both in and out.

Public constructors

Visibility

Added in 1.0.0

Visibility()

Visibility

Added in 1.0.0

Visibility(context: Context, attrs: AttributeSet)

Public functions

captureEndValues

fun captureEndValues(transitionValues: TransitionValues): Unit

Captures the values in the end scene for the properties that this transition monitors. These values are then passed as the endValues structure in a later call to createAnimator. 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 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

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.

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.

See also
`captureStartValues`
`createAnimator`

captureStartValues

fun captureStartValues(transitionValues: TransitionValues): Unit

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. 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 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

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.

transitionValues: TransitionValues

See also
`captureEndValues`
`createAnimator`

createAnimator

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 view field.

Parameters
`sceneRoot: ViewGroup`	The root of the transition hierarchy.
`startValues: TransitionValues?`	The values for a specific target in the start scene.
`endValues: TransitionValues?`	The values for the target in the end scene.

Returns
`Animator?`	A 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.

getMode

Added in 1.0.0

fun getMode(): Int

Returns whether appearing and/or disappearing Views are supported.

Returns
`Int`	whether appearing and/or disappearing Views are supported. A combination of `MODE_IN` and `MODE_OUT`.

getTransitionProperties

fun getTransitionProperties(): Array<String!>?

Returns the set of property names used stored in the TransitionValues object passed into captureStartValues that this transition cares about for the purposes of canceling overlapping animations. When any transition is started on a given scene root, all transitions currently running on that same scene root are checked to see whether the properties on which they based their animations agree with the end values of the same properties in the new transition. If the end values are not equal, then the old animation is canceled since the new transition will start a new animation to these new values. If the values are equal, the old animation is allowed to continue and no new animation is started for that transition.

A transition does not need to override this method. However, not doing so will mean that the cancellation logic outlined in the previous paragraph will be skipped for that transition, possibly leading to artifacts as old transitions and new transitions on the same targets run in parallel, animating views toward potentially different end values.

Returns
`Array<String!>?`	An array of property names as described in the class documentation for `TransitionValues`. The default implementation returns `null`.

isTransitionRequired

fun isTransitionRequired(
    startValues: TransitionValues?,
    endValues: TransitionValues?
): Boolean

Returns whether or not the transition should create an Animator, based on the values captured during captureStartValues and captureEndValues. The default implementation compares the property values returned from getTransitionProperties, or all property values if getTransitionProperties() returns null. Subclasses may override this method to provide logic more specific to the transition implementation.

Parameters
`startValues: TransitionValues?`	the values from captureStartValues, This may be `null` if the View did not exist in the start state.
`endValues: TransitionValues?`	the values from captureEndValues. This may be `null` if the View did not exist in the end state.

isVisible

Added in 1.0.0

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 createAnimator 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
`values: TransitionValues?`	The TransitionValues object that holds the information by which visibility is determined.

Returns
`Boolean`	True if the view reference by `values` is visible, false otherwise.

onAppear

Added in 1.0.0

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.

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.

onAppear

Added in 1.0.0

fun onAppear(
    sceneRoot: ViewGroup,
    startValues: TransitionValues?,
    startVisibility: Int,
    endValues: TransitionValues?,
    endVisibility: Int
): Animator?

The default implementation of this method does nothing. Subclasses should override 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
`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

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

Added in 1.0.0

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.

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 `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

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

Added in 1.0.0

fun onDisappear(
    sceneRoot: ViewGroup,
    startValues: TransitionValues?,
    startVisibility: Int,
    endValues: TransitionValues?,
    endVisibility: Int
): Animator?

The default implementation of this method does nothing. Subclasses should override 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.

Parameters
`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

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.

setMode

Added in 1.0.0

fun setMode(mode: Int): Unit

Changes the transition to support appearing and/or disappearing Views, depending on mode.

Parameters
`mode: Int`	The behavior supported by this transition, a combination of `MODE_IN` and `MODE_OUT`.