ChangeTransform

open class ChangeTransform : Transition
kotlin.Any
   ↳ android.transition.Transition
   ↳ android.transition.ChangeTransform

This Transition captures scale and rotation for Views before and after the scene change and animates those changes during the transition. A change in parent is handled as well by capturing the transforms from the parent before and after the scene change and animating those during the transition.
Requires API level 21 (Android 5.0, Lollipop)

Summary

Inherited constants
Public constructors

<init>(context: Context!, attrs: AttributeSet!)

Public methods
open Unit
setReparent(reparent: Boolean)

Sets whether parent changes will be tracked by the ChangeTransform.

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 Array<String!>!

Returns the set of property names used stored in the TransitionValues object passed into #captureStartValues(TransitionValues) that this transition cares about for the purposes of canceling overlapping animations.

open Unit

Captures the values in the start scene for the properties that this transition monitors.

open Unit
setReparentWithOverlay(reparentWithOverlay: Boolean)

Sets whether changes to parent should use an overlay or not.

open Boolean

Returns whether changes to parent should use an overlay or not.

open Unit
captureEndValues(transitionValues: TransitionValues!)

Captures the values in the end scene for the properties that this transition monitors.

open Boolean

Returns whether parent changes will be tracked by the ChangeTransform.

Inherited functions

Public constructors

<init>

ChangeTransform()

<init>

ChangeTransform(context: Context!, attrs: AttributeSet!)

Public methods

setReparent

added in API level 21
open fun setReparent(reparent: Boolean): Unit

Sets whether parent changes will be tracked by the ChangeTransform. If parent changes are tracked, then the transform will adjust to the transforms of the different parents. If they aren't tracked, only the transforms of the transitioning view will be tracked. Default is true.
Requires API level 21 (Android 5.0, Lollipop)

Parameters
reparent Boolean: Set to true to track parent changes or false to only track changes of the transitioning view without considering the parent change.

createAnimator

added in API level 21
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.


Requires API level 19 (Android 4.4, KitKat) Requires API level 21 (Android 5.0, Lollipop)
Parameters
sceneRoot ViewGroup!: The root of the transition hierarchy.
startValues ViewGroup!: The values for a specific target in the start scene.
endValues ViewGroup!: The values for the target in the end scene.
Return
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.

getTransitionProperties

added in API level 21
open fun getTransitionProperties(): Array<String!>!

Returns the set of property names used stored in the TransitionValues object passed into #captureStartValues(TransitionValues) 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.


Requires API level 19 (Android 4.4, KitKat) Requires API level 21 (Android 5.0, Lollipop)
Return
Array<String!>!: An array of property names as described in the class documentation for TransitionValues. The default implementation returns null.

captureStartValues

added in API level 21
open 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(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 #createAnimator(android.view.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.


Requires API level 19 (Android 4.4, KitKat) Requires API level 21 (Android 5.0, Lollipop)
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.

setReparentWithOverlay

added in API level 21
open fun setReparentWithOverlay(reparentWithOverlay: Boolean): Unit

Sets whether changes to parent should use an overlay or not. When the parent change doesn't use an overlay, it affects the transforms of the child. The default value is true.

Note: when Overlays are not used when a parent changes, a view can be clipped when it moves outside the bounds of its parent. Setting android.view.ViewGroup#setClipChildren(boolean) and android.view.ViewGroup#setClipToPadding(boolean) can help. Also, when Overlays are not used and the parent is animating its location, the position of the child view will be relative to its parent's final position, so it may appear to "jump" at the beginning.


Requires API level 21 (Android 5.0, Lollipop)
Parameters
reparentWithOverlay Boolean: true when a changed parent should execute the transition inside the scene root's overlay or false if a parent change only affects the transform of the transitioning view.

getReparentWithOverlay

added in API level 21
open fun getReparentWithOverlay(): Boolean

Returns whether changes to parent should use an overlay or not. When the parent change doesn't use an overlay, it affects the transforms of the child. The default value is true.

Note: when Overlays are not used when a parent changes, a view can be clipped when it moves outside the bounds of its parent. Setting android.view.ViewGroup#setClipChildren(boolean) and android.view.ViewGroup#setClipToPadding(boolean) can help. Also, when Overlays are not used and the parent is animating its location, the position of the child view will be relative to its parent's final position, so it may appear to "jump" at the beginning.


Requires API level 21 (Android 5.0, Lollipop)
Return
Boolean: true when a changed parent should execute the transition inside the scene root's overlay or false if a parent change only affects the transform of the transitioning view.

captureEndValues

added in API level 21
open 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(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 #createAnimator(android.view.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.


Requires API level 19 (Android 4.4, KitKat) Requires API level 21 (Android 5.0, Lollipop)
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.

getReparent

added in API level 21
open fun getReparent(): Boolean

Returns whether parent changes will be tracked by the ChangeTransform. If parent changes are tracked, then the transform will adjust to the transforms of the different parents. If they aren't tracked, only the transforms of the transitioning view will be tracked. Default is true.
Requires API level 21 (Android 5.0, Lollipop)

Return
Boolean: whether parent changes will be tracked by the ChangeTransform.