ChangeScroll
  public
  
  
  
  class
  ChangeScroll
  
  
  
  
    extends Transition
  
  
  
  
  
  
| java.lang.Object | ||
| ↳ | android.transition.Transition | |
| ↳ | android.transition.ChangeScroll | |
This transition captures the scroll properties of targets before and after the scene change and animates any changes.
Summary
| Inherited XML attributes | |
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| Inherited constants | 
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| Public constructors | |
|---|---|
| 
      ChangeScroll()
       | |
| 
      ChangeScroll(Context context, AttributeSet attrs)
       | |
| Public methods | |
|---|---|
| 
        
        
        
        
        
        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. | 
| 
        
        
        
        
        
        String[] | 
      getTransitionProperties()
      Returns the set of property names used stored in the  | 
| Inherited methods | |
|---|---|
Public constructors
ChangeScroll
public ChangeScroll (Context context, AttributeSet attrs)
| Parameters | |
|---|---|
| context | Context | 
| attrs | AttributeSet | 
Public methods
captureEndValues
public void captureEndValues (TransitionValues transitionValues)
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(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 thevaluesfield
 of this TransitionValues object and are keyed from
 a String value. For example, to store a view's rotation value,
 a transition might calltransitionValues.values.put("appname:transitionname:rotation",
 view.getRotation()). The target view will already be stored in
 the transitionValues structure when this method is called. | 
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 thevaluesfield
 of this TransitionValues object and are keyed from
 a String value. For example, to store a view's rotation value,
 a transition might calltransitionValues.values.put("appname:transitionname:rotation",
 view.getRotation()). The target view will already be stored in
 the transitionValues structure when this method is called. | 
createAnimator
public 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. 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 | |
|---|---|
| sceneRoot | ViewGroup: This value cannot benull. | 
| startValues | TransitionValues: This value may benull. | 
| endValues | TransitionValues: This value may benull. | 
| Returns | |
|---|---|
| Animator | This value may be null. | 
getTransitionProperties
public String[] getTransitionProperties ()
Returns the set of property names used stored in the TransitionValues
 object passed into captureStartValues(android.transition.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.
| Returns | |
|---|---|
| String[] | An array of property names as described in the class documentation for TransitionValues. The default implementation returnsnull. | 
