Added in API level 11

Summary: Ctors | Methods | Inherited Methods

Keyframe

---

Kotlin |Java

public abstract class Keyframe
extends Object implements Cloneable

java.lang.Object
↳	android.animation.Keyframe

---

This class holds a time/value pair for an animation. The Keyframe class is used by ValueAnimator to define the values that the animation target will have over the course of the animation. As the time proceeds from one keyframe to the other, the value of the target object will animate between the value at the previous keyframe and the value at the next keyframe. Each keyframe also holds an optional TimeInterpolator object, which defines the time interpolation over the intervalue preceding the keyframe.

The Keyframe class itself is abstract. The type-specific factory methods will return a subclass of Keyframe specific to the type of value being stored. This is done to improve performance when dealing with the most common cases (e.g., float and int values). Other types will fall into a more general Keyframe class that treats its values as Objects. Unless your animation requires dealing with a custom type or a data structure that needs to be animated directly (and evaluated using an implementation of TypeEvaluator), you should stick to using float and int as animations using those types have lower runtime overhead than other types.

Summary

Public constructors
Keyframe()

Public methods
abstract Keyframe	clone() Creates and returns a copy of this object.
float	getFraction() Gets the time for this keyframe, as a fraction of the overall animation duration.
TimeInterpolator	getInterpolator() Gets the optional interpolator for this Keyframe.
Class<T>	getType() Gets the type of keyframe.
abstract Object	getValue() Gets the value for this Keyframe.
boolean	hasValue() Indicates whether this keyframe has a valid value.
static Keyframe	ofFloat(float fraction) Constructs a Keyframe object with the given time.
static Keyframe	ofFloat(float fraction, float value) Constructs a Keyframe object with the given time and value.
static Keyframe	ofInt(float fraction, int value) Constructs a Keyframe object with the given time and value.
static Keyframe	ofInt(float fraction) Constructs a Keyframe object with the given time.
static Keyframe	ofObject(float fraction, Object value) Constructs a Keyframe object with the given time and value.
static Keyframe	ofObject(float fraction) Constructs a Keyframe object with the given time.
void	setFraction(float fraction) Sets the time for this keyframe, as a fraction of the overall animation duration.
void	setInterpolator(TimeInterpolator interpolator) Sets the optional interpolator for this Keyframe.
abstract void	setValue(Object value) Sets the value for this Keyframe.

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

Keyframe

public Keyframe ()

Public methods

clone

Added in API level 11

public abstract Keyframe clone ()

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

will be true, and that the expression:

 x.clone().getClass() == x.getClass()

will be true, but these are not absolute requirements. While it is typically the case that:

 x.clone().equals(x)

will be true, this is not an absolute requirement.

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

Returns
Keyframe	a clone of this instance.

getFraction

Added in API level 11

public float getFraction ()

Gets the time for this keyframe, as a fraction of the overall animation duration.

Returns
float	The time associated with this keyframe, as a fraction of the overall animation duration. This should be a value between 0 and 1.

getInterpolator

Added in API level 11

public TimeInterpolator getInterpolator ()

Gets the optional interpolator for this Keyframe. A value of null indicates that there is no interpolation, which is the same as linear interpolation.

Returns
TimeInterpolator	The optional interpolator for this Keyframe.

getType

Added in API level 11

public Class<T> getType ()

Gets the type of keyframe. This information is used by ValueAnimator to determine the type of TypeEvaluator to use when calculating values between keyframes. The type is based on the type of Keyframe created.

Returns
Class<T>	The type of the value stored in the Keyframe.

getValue

Added in API level 11

public abstract Object getValue ()

Gets the value for this Keyframe.

Returns
Object	The value for this Keyframe.

hasValue

Added in API level 11

public boolean hasValue ()

Indicates whether this keyframe has a valid value. This method is called internally when an ObjectAnimator first starts; keyframes without values are assigned values at that time by deriving the value for the property from the target object.

Returns
boolean	boolean Whether this object has a value assigned.

ofFloat

Added in API level 11

public static Keyframe ofFloat (float fraction)

Constructs a Keyframe object with the given time. The value at this time will be derived from the target object when the animation first starts (note that this implies that keyframes with no initial value must be used as part of an ObjectAnimator). The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.

Returns
Keyframe

ofFloat

Added in API level 11

public static Keyframe ofFloat (float fraction, 
                float value)

Constructs a Keyframe object with the given time and value. The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.
value	float: The value that the object will animate to as the animation time approaches the time in this keyframe, and the value animated from as the time passes the time in this keyframe.

Returns
Keyframe

ofInt

Added in API level 11

public static Keyframe ofInt (float fraction, 
                int value)

Constructs a Keyframe object with the given time and value. The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.
value	int: The value that the object will animate to as the animation time approaches the time in this keyframe, and the value animated from as the time passes the time in this keyframe.

Returns
Keyframe

ofInt

Added in API level 11

public static Keyframe ofInt (float fraction)

Constructs a Keyframe object with the given time. The value at this time will be derived from the target object when the animation first starts (note that this implies that keyframes with no initial value must be used as part of an ObjectAnimator). The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.

Returns
Keyframe

ofObject

Added in API level 11

public static Keyframe ofObject (float fraction, 
                Object value)

Constructs a Keyframe object with the given time and value. The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.
value	Object: The value that the object will animate to as the animation time approaches the time in this keyframe, and the value animated from as the time passes the time in this keyframe.

Returns
Keyframe

ofObject

Added in API level 11

public static Keyframe ofObject (float fraction)

Constructs a Keyframe object with the given time. The value at this time will be derived from the target object when the animation first starts (note that this implies that keyframes with no initial value must be used as part of an ObjectAnimator). The time defines the time, as a proportion of an overall animation's duration, at which the value will hold true for the animation. The value for the animation between keyframes will be calculated as an interpolation between the values at those keyframes.

Parameters
fraction	float: The time, expressed as a value between 0 and 1, representing the fraction of time elapsed of the overall animation duration.

Returns
Keyframe

setFraction

Added in API level 11

public void setFraction (float fraction)

Sets the time for this keyframe, as a fraction of the overall animation duration.

Parameters
fraction	float: time associated with this keyframe, as a fraction of the overall animation duration. This should be a value between 0 and 1.

setInterpolator

Added in API level 11

public void setInterpolator (TimeInterpolator interpolator)

Sets the optional interpolator for this Keyframe. A value of null indicates that there is no interpolation, which is the same as linear interpolation.

Parameters
interpolator	TimeInterpolator

Returns
void	The optional interpolator for this Keyframe.

setValue

Added in API level 11

public abstract void setValue (Object value)

Sets the value for this Keyframe.

Parameters
value	Object: value for this Keyframe.