com.sun.dtv.lwuit.animations
Class Motion

java.lang.Object
  com.sun.dtv.lwuit.animations.Motion

public class Motion
extends Object

Abstracts the notion of physical motion over time from a numeric location to another. This class can be subclassed to implement any motion equation for appropriate physics effects.

This class relies on the System.currentTimeMillis() method to provide transitions between coordinates. The motion can be subclassed to provide every type of motion feel from parabolic motion to spline and linear motion. The default implementation provides a simple algorithm giving the feel of acceleration and deceleration.

Constructor Summary

protected	Motion(int sourceValue, float initVelocity, float friction) Construct a velocity motion.
protected	Motion(int sourceValue, int destinationValue, int duration) Construct a point/destination motion.

Method Summary

static Motion	createFrictionMotion(int sourceValue, float initVelocity, float friction) Creates a friction motion starting from source with initial speed and the friction.
static Motion	createLinearMotion(int sourceValue, int destinationValue, int duration) Creates a linear motion starting from source value all the way to destination value.
static Motion	createSplineMotion(int sourceValue, int destinationValue, int duration) Creates a spline motion starting from source value all the way to destination value.
int	getSourceValue() The number from which we are starting (usually indicating animation start position).
int	getValue() Returns the value for the motion for the current clock time.
boolean	isFinished() Returns true if the motion has run its course and has finished meaning the current time is greater than startTime + duration.
void	setSourceValue(int sourceValue) The number from which we are starting (usually indicating animation start position).
void	start() Sets the start time to the current time.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Motion

protected Motion(int sourceValue,
                 int destinationValue,
                 int duration)

Construct a point/destination motion.

Parameters:

sourceValue - starting value

destinationValue - destination value

duration - motion duration

Motion

protected Motion(int sourceValue,
                 float initVelocity,
                 float friction)

Construct a velocity motion.

Parameters:

sourceValue - starting value

initVelocity - initial velocity

friction - degree of friction

Method Detail

createLinearMotion

public static Motion createLinearMotion(int sourceValue,
                                        int destinationValue,
                                        int duration)

Creates a linear motion starting from source value all the way to destination value.

Parameters:

sourceValue - the number from which we are starting (usually indicating animation start position)

destinationValue - the number to which we are heading (usually indicating animation destination)

duration - the length in milliseconds of the motion (time it takes to get from sourceValue to destinationValue)

Returns:

a Motion object

createSplineMotion

public static Motion createSplineMotion(int sourceValue,
                                        int destinationValue,
                                        int duration)

Creates a spline motion starting from source value all the way to destination value.

Parameters:

sourceValue - the number from which we are starting (usually indicating animation start position)

destinationValue - the number to which we are heading (usually indicating animation destination)

duration - the length in milliseconds of the motion (time it takes to get from sourceValue to destinationValue)

Returns:

a Motion object

createFrictionMotion

public static Motion createFrictionMotion(int sourceValue,
                                          float initVelocity,
                                          float friction)

Creates a friction motion starting from source with initial speed and the friction.

Parameters:

sourceValue - the number from which we are starting (usually indicating animation start position)

initVelocity - the starting velocity

friction - the motion friction

Returns:

a Motion object

start

public void start()

Sets the start time to the current time.

isFinished

public boolean isFinished()

Returns true if the motion has run its course and has finished meaning the current time is greater than startTime + duration.

Returns:

true if System.currentTimeMillis() > duration + startTime

getValue

public int getValue()

Returns the value for the motion for the current clock time. The value is dependent on the Motion type.

Returns:

a value that is relative to the source value

getSourceValue

public int getSourceValue()

The number from which we are starting (usually indicating animation start position).

Returns:

the start position

See Also:

setSourceValue(int)

setSourceValue

public void setSourceValue(int sourceValue)

The number from which we are starting (usually indicating animation start position).

Parameters:

sourceValue - the start position

See Also:

getSourceValue()