Transition

public abstract class Transition
extends Object implements Cloneable

Known Direct Subclasses ChangeBounds,ChangeClipBounds,ChangeImageTransform,ChangeScroll,ChangeTransform,TransitionSet,Visibility ChangeBounds This transition captures the layout bounds of target views before and after the scene change and animates those changes during the transition.  ChangeClipBounds ChangeClipBounds captures the getClipBounds() before and after the scene change and animates those changes during the transition.  ChangeImageTransform This Transition captures an ImageView's matrix before and after the scene change and animates it during the transition.  ChangeScroll This transition captures the scroll properties of targets before and after the scene change and animates any changes.  ChangeTransform This Transition captures scale and rotation for Views before and after the scene change and animates those changes during the transition.  TransitionSet A TransitionSet is a parent of child transitions (including other TransitionSets).  Visibility This transition tracks changes to the visibility of target views in the start and end scenes.

Known Indirect Subclasses AutoTransition,Explode,Fade,Slide AutoTransition Utility class for creating a default transition that automatically fades, moves, and resizes views during a scene change.  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.

A Transition holds information about animations that will be run on its targets during a scene change. Subclasses of this abstract class may choreograph several child transitions (TransitionSet or they may perform custom animations themselves. Any Transition has two main jobs: (1) capture property values, and (2) play animations based on changes to captured property values. A custom transition knows what property values on View objects are of interest to it, and also knows how to animate changes to those values. For example, the Fade transition tracks changes to visibility-related properties and is able to construct and run animations that fade items in or out based on changes to those properties.

Note: Transitions may not work correctly with either SurfaceView or TextureView, due to the way that these views are displayed on the screen. For SurfaceView, the problem is that the view is updated from a non-UI thread, so changes to the view due to transitions (such as moving and resizing the view) may be out of sync with the display inside those bounds. TextureView is more compatible with transitions in general, but some specific transitions (such as Fade) may not be compatible with TextureView because they rely on ViewOverlay functionality, which does not currently work with TextureView.

Transitions can be declared in XML resource files inside the res/transition directory. Transition resources consist of a tag name for one of the Transition subclasses along with attributes to define some of the attributes of that transition. For example, here is a minimal resource file that declares a ChangeBounds transition:

     <changeBounds/>
 

Note that attributes for the transition are not required, just as they are optional when declared in code; Transitions created from XML resources will use the same defaults as their code-created equivalents. Here is a slightly more elaborate example which declares a TransitionSet transition with ChangeBounds and Fade child transitions:

     <transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
          android:transitionOrdering="sequential">
         <changeBounds/>
         <fade android:fadingMode="fade_out">
             <targets>
                 <target android:targetId="@id/grayscaleContainer"/>
             </targets>
         </fade>
     </transitionSet>
 

In this example, the transitionOrdering attribute is used on the TransitionSet object to change from the default ORDERING_TOGETHER behavior to be ORDERING_SEQUENTIAL instead. Also, the Fade transition uses a fadingMode of OUT instead of the default out-in behavior. Finally, note the use of the targets sub-tag, which takes a set of {code target} tags, each of which lists a specific targetId which this transition acts upon. Use of targets is optional, but can be used to either limit the time spent checking attributes on unchanging views, or limiting the types of animations run on specific views. In this case, we know that only the grayscaleContainer will be disappearing, so we choose to limit the Fade transition to only that view.

Summary