belongs to Maven artifact com.android.support:support-dynamic-animation:28.0.0-alpha1
SpringAnimation
public
final
class
SpringAnimation
extends DynamicAnimation<SpringAnimation>
| java.lang.Object | ||
| ↳ | android.support.animation.DynamicAnimation<android.support.animation.SpringAnimation> | |
| ↳ | android.support.animation.SpringAnimation | |
SpringAnimation is an animation that is driven by a SpringForce. The spring force defines
the spring's stiffness, damping ratio, as well as the rest position. Once the SpringAnimation is
started, on each frame the spring force will update the animation's value and velocity.
The animation will continue to run until the spring force reaches equilibrium. If the spring used
in the animation is undamped, the animation will never reach equilibrium. Instead, it will
oscillate forever.
Developer Guides
To create a simple SpringAnimation that uses the default SpringForce:
// Create an animation to animate view's X property, set the rest position of the
// default spring to 0, and start the animation with a starting velocity of 5000 (pixel/s).
final SpringAnimation anim = new SpringAnimation(view, DynamicAnimation.X, 0)
.setStartVelocity(5000);
anim.start();
Alternatively, a SpringAnimation can take a pre-configured SpringForce, and
use that to drive the animation.
// Create a low stiffness, low bounce spring at position 0.
SpringForce spring = new SpringForce(0)
.setDampingRatio(SpringForce.DAMPING_RATIO_LOW_BOUNCY)
.setStiffness(SpringForce.STIFFNESS_LOW);
// Create an animation to animate view's scaleY property, and start the animation using
// the spring above and a starting value of 0.5. Additionally, constrain the range of value for
// the animation to be non-negative, effectively preventing any spring overshoot.
final SpringAnimation anim = new SpringAnimation(view, DynamicAnimation.SCALE_Y)
.setMinValue(0).setSpring(spring).setStartValue(1);
anim.start();
Summary
Inherited constants |
|---|
From
class
android.support.animation.DynamicAnimation
|
Inherited fields |
|---|
From
class
android.support.animation.DynamicAnimation
|
Public constructors | |
|---|---|
SpringAnimation(FloatValueHolder floatValueHolder)
This creates a SpringAnimation that animates a |
|
SpringAnimation(K object, FloatPropertyCompat<K> property)
This creates a SpringAnimation that animates the property of the given object. |
|
SpringAnimation(K object, FloatPropertyCompat<K> property, float finalPosition)
This creates a SpringAnimation that animates the property of the given object. |
|
Public methods | |
|---|---|
void
|
animateToFinalPosition(float finalPosition)
Updates the final position of the spring. |
boolean
|
canSkipToEnd()
Queries whether the spring can eventually come to the rest position. |
SpringForce
|
getSpring()
Returns the spring that the animation uses for animations. |
SpringAnimation
|
setSpring(SpringForce force)
Uses the given spring as the force that drives this animation. |
void
|
skipToEnd()
Skips to the end of the animation. |
void
|
start()
Starts an animation. |
Inherited methods | |
|---|---|
From
class
android.support.animation.DynamicAnimation
| |
From
class
java.lang.Object
| |
Public constructors
SpringAnimation
SpringAnimation (FloatValueHolder floatValueHolder)
This creates a SpringAnimation that animates a FloatValueHolder instance. During
the animation, the FloatValueHolder instance will be updated via
setValue(float) each frame. The caller can obtain the up-to-date
animation value via getValue().
Note: changing the value in the FloatValueHolder via
setValue(float) outside of the animation during an
animation run will not have any effect on the on-going animation.
| Parameters | |
|---|---|
floatValueHolder |
FloatValueHolder: the property to be animated
|
SpringAnimation
SpringAnimation (K object,
FloatPropertyCompat<K> property)
This creates a SpringAnimation that animates the property of the given object.
Note, a spring will need to setup through setSpring(SpringForce) before
the animation starts.
| Parameters | |
|---|---|
object |
K: the Object whose property will be animated |
property |
FloatPropertyCompat: the property to be animated |
SpringAnimation
SpringAnimation (K object,
FloatPropertyCompat<K> property,
float finalPosition)
This creates a SpringAnimation that animates the property of the given object. A Spring will
be created with the given final position and default stiffness and damping ratio.
This spring can be accessed and reconfigured through setSpring(SpringForce).
| Parameters | |
|---|---|
object |
K: the Object whose property will be animated |
property |
FloatPropertyCompat: the property to be animated |
finalPosition |
float: the final position of the spring to be created. |
Public methods
animateToFinalPosition
void animateToFinalPosition (float finalPosition)
Updates the final position of the spring.
When the animation is running, calling this method would assume the position change of the spring as a continuous movement since last frame, which yields more accurate results than changing the spring position directly throughsetFinalPosition(float).
If the animation hasn't started, calling this method will change the spring position, and
immediately start the animation.
| Parameters | |
|---|---|
finalPosition |
float: rest position of the spring
|
canSkipToEnd
boolean canSkipToEnd ()
Queries whether the spring can eventually come to the rest position.
| Returns | |
|---|---|
boolean |
true if the spring is damped, otherwise false
|
getSpring
SpringForce getSpring ()
Returns the spring that the animation uses for animations.
| Returns | |
|---|---|
SpringForce |
the spring that the animation uses for animations |
setSpring
SpringAnimation setSpring (SpringForce force)
Uses the given spring as the force that drives this animation. If this spring force has its parameters re-configured during the animation, the new configuration will be reflected in the animation immediately.
| Parameters | |
|---|---|
force |
SpringForce: a pre-defined spring force that drives the animation |
| Returns | |
|---|---|
SpringAnimation |
the animation that the spring force is set on |
skipToEnd
void skipToEnd ()
Skips to the end of the animation. If the spring is undamped, an
IllegalStateException will be thrown, as the animation would never reach to an end.
It is recommended to check canSkipToEnd() before calling this method. This method
should only be called on main thread. If animation is not running, no-op.
| Throws | |
|---|---|
IllegalStateException |
if the spring is undamped (i.e. damping ratio = 0) |
AndroidRuntimeException |
if this method is not called on the main thread |
start
void start ()
Starts an animation. If the animation has already been started, no op. Note that calling
start() will not immediately set the property value to start value of the animation.
The property values will be changed at each animation pulse, which happens before the draw
pass. As a result, the changes will be reflected in the next frame, the same as if the values
were set immediately. This method should only be called on main thread.