javafx.animation.Transition Maven / Gradle / Ivy
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package javafx.animation;
import com.sun.scenario.animation.AbstractMasterTimer;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.scene.Node;
/**
* An abstract class that contains the basic functionalities required by all
* {@code Transition} based animations, such as {@link PathTransition} and
* {@link RotateTransition}.
*
* This class offers a simple framework to define animation. It provides all the
* basic functionality defined in {@link Animation}. {@code Transition} requires
* the implementation of a method {@link #interpolate(double)} which is the
* called in each frame, while the {@code Transition} is running.
*
* In addition an extending class needs to set the duration of a single cycle
* with {@link Animation#setCycleDuration(javafx.util.Duration)}. This duration
* is usually set by the user via a duration property (as in
* {@link FadeTransition#durationProperty() duration}) for example. But it can also be calculated
* by the extending class as is done in {@link ParallelTransition} and
* {@link FadeTransition}.
*
* Below is a simple example. It creates a small animation that updates the
* {@code text} property of a {@link javafx.scene.text.Text} node. It starts
* with an empty {@code String} and adds gradually letter by letter until the
* full {@code String} was set when the animation finishes.
*
*
* {@code
*
* final String content = "Lorem ipsum";
* final Text text = new Text(10, 20, "");
*
* final Animation animation = new Transition() {
* {
* setCycleDuration(Duration.millis(2000));
* }
*
* protected void interpolate(double frac) {
* final int length = content.length();
* final int n = Math.round(length * (float) frac);
* text.setText(content.substring(0, n));
* }
*
* };
*
* animation.play();
* }
*
* @see Animation
*
* @since JavaFX 2.0
*/
public abstract class Transition extends Animation {
/**
* Controls the timing for acceleration and deceleration at each
* {@code Transition} cycle.
*
* This may only be changed prior to starting the transition or after the
* transition has ended. If the value of {@code interpolator} is changed for
* a running {@code Transition}, the animation has to be stopped and started again to
* pick up the new value.
*
* Default interpolator is set to {@link Interpolator#EASE_BOTH}.
*
* @defaultValue EASE_BOTH
*/
private ObjectProperty interpolator;
private static final Interpolator DEFAULT_INTERPOLATOR = Interpolator.EASE_BOTH;
public final void setInterpolator(Interpolator value) {
if ((interpolator != null) || (!DEFAULT_INTERPOLATOR.equals(value))) {
interpolatorProperty().set(value);
}
}
public final Interpolator getInterpolator() {
return (interpolator == null) ? DEFAULT_INTERPOLATOR : interpolator.get();
}
public final ObjectProperty interpolatorProperty() {
if (interpolator == null) {
interpolator = new SimpleObjectProperty(
this, "interpolator", DEFAULT_INTERPOLATOR
);
}
return interpolator;
}
private Interpolator cachedInterpolator;
/**
* Returns the {@link Interpolator}, that was set when the
* {@code Transition} was started.
*
* Changing the {@link #interpolatorProperty() interpolator} of a running {@code Transition} should
* have no immediate effect. Instead the running {@code Transition} should
* continue to use the original {@code Interpolator} until it is stopped and
* started again.
*
* @return the {@code Interpolator} that was set when this
* {@code Transition} was started
*/
protected Interpolator getCachedInterpolator() {
return cachedInterpolator;
}
/**
* The constructor of {@code Transition}.
*
* This constructor allows to define a {@link #getTargetFramerate() target framerate}.
*
* @param targetFramerate
* The custom target frame rate for this {@code Transition}
*/
public Transition(double targetFramerate) {
super(targetFramerate);
}
/**
* The constructor of {@code Transition}.
*/
public Transition() {
}
// For testing purposes
Transition(AbstractMasterTimer timer) {
super(timer);
}
/**
* Returns the first non-{@code null} target {@code Node} in the parent hierarchy of
* this {@code Transition}, or {@code null} if such a node is not found.
*
* A parent animation is one that can have child animations. Examples are
* {@link javafx.animation.SequentialTransition SequentialTransition} and
* {@link javafx.animation.ParallelTransition ParallelTransition}. A parent animation can
* also be a child of another parent animation.
*
* Note that if this {@code Transition} has a target node set and is not a parent animation,
* it will be ignored during the call as this method only queries parent animations.
* @return the target {@code Node}
*/
protected Node getParentTargetNode() {
return (parent != null && parent instanceof Transition) ?
((Transition)parent).getParentTargetNode() : null;
}
/**
* The method {@code interpolate()} has to be provided by implementations of
* {@code Transition}. While a {@code Transition} is running, this method is
* called in every frame.
*
* The parameter defines the current position with the animation. At the
* start, the fraction will be {@code 0.0} and at the end it will be
* {@code 1.0}. How the parameter increases, depends on the
* {@link #interpolatorProperty() interpolator}, e.g. if the
* {@code interpolator} is {@link Interpolator#LINEAR}, the fraction will
* increase linear.
*
* This method must not be called by the user directly.
*
* @param frac
* The relative position
*/
protected abstract void interpolate(double frac);
private double calculateFraction(long currentTicks, long cycleTicks) {
final double frac = cycleTicks <= 0 ? 1.0 : (double) currentTicks / cycleTicks;
return cachedInterpolator.interpolate(0.0, 1.0, frac);
}
@Override
boolean startable(boolean forceSync) {
return super.startable(forceSync)
&& ((getInterpolator() != null) || (!forceSync && (cachedInterpolator != null)));
}
@Override
void sync(boolean forceSync) {
super.sync(forceSync);
if (forceSync || (cachedInterpolator == null)) {
cachedInterpolator = getInterpolator();
}
}
@Override
void doPlayTo(long currentTicks, long cycleTicks) {
setCurrentTicks(currentTicks);
interpolate(calculateFraction(currentTicks, cycleTicks));
}
@Override
void doJumpTo(long currentTicks, long cycleTicks, boolean forceJump) {
setCurrentTicks(currentTicks);
if (getStatus() != Status.STOPPED || forceJump) {
sync(false);
interpolate(calculateFraction(currentTicks, cycleTicks));
}
}
}