Package edu.umd.cs.piccolo.activities

Class PActivity

java.lang.Object
edu.umd.cs.piccolo.activities.PActivity
Direct Known Subclasses:
PInterpolatingActivity
public class PActivity extends Object
PActivity controls some time dependent aspect of Piccolo, such as animation. Once created activities must be scheduled with the PActivityScheduler managed by the PRoot to run. They are automatically removed from the scheduler when the animation has finished.

See the PNode.animate*() methods for an example of how to set up and run different activities.

Version:
1.0
Author:
Jesse Grosjean

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    PActivity.PActivityDelegate
    PActivityDelegate is used by classes to learn about and act on the different states that a PActivity goes through, such as when the activity starts and stops stepping.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    TERMINATE_AND_FINISH
    Parameter for terminate that signifies that activity should bail out immediately, but flag activity as finished.
    static final int
    TERMINATE_AND_FINISH_IF_STEPPING
    Parameter for terminate that signifies that activity should bail out immediately, if currently active.
    static final int
    TERMINATE_WITHOUT_FINISHING
    Parameter for terminate that signifies that activity should bail out immediately without flagging activity as finished.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PActivity(long aDuration)
    Constructs a new PActivity.
    PActivity(long aDuration, long aStepRate)
    Constructs a new PActivity.
    PActivity(long aDuration, long aStepRate, long aStartTime)
    Constructs a new PActivity.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    activityFinished()
    This method is called after an activity is has finished running and the activity has been removed from the PActivityScheduler queue.
    protected void
    activityStarted()
    This method is called right before an activity is scheduled to start running.
    protected void
    activityStep(long elapsedTime)
    This is the method that most activities override to perform their behavior.
    PActivityScheduler
    getActivityScheduler()
    Returns the activity scheduler associated with this activity.
    PActivity.PActivityDelegate
    getDelegate()
    Get the delegate for this activity.
    long
    getDuration()
    Return the amount of time that this activity should take to complete, after the startStepping method is called.
    long
    getNextStepTime()
    Gets the next step time desired for this activity.
    long
    getStartTime()
    Return the time that this activity should start running in PRoot global time.
    long
    getStepRate()
    Return the amount of time that this activity should delay between steps.
    long
    getStopTime()
    Return the time when this activity should finish running.
    protected boolean
    isAnimation()
    Return true if this activity is performing an animation.
    boolean
    isStepping()
    Return true if this activity is stepping.
    protected String
    paramString()
    Deprecated.
    see http://code.google.com/p/piccolo2d/issues/detail?id=99
    long
    processStep(long currentTime)
    The activity scheduler calls this method and it is here that the activity decides if it should do a step or not for the given time.
    void
    setActivityScheduler(PActivityScheduler aScheduler)
    Informs the activity of the scheduler that will be responsible for scheduling it.
    void
    setDelegate(PActivity.PActivityDelegate delegate)
    Set the delegate for this activity.
    void
    setDuration(long aDuration)
    Set the amount of time that this activity should take to complete, after the startStepping method is called.
    void
    setStartTime(long aTriggerTime)
    Set the time that this activity should start running in PRoot global time.
    void
    setStepRate(long aStepRate)
    Set the amount of time that this activity should delay between steps.
    void
    startAfter(PActivity first)
    Schedules this activity to start after the first activity has finished.
    void
    terminate()
    Stop this activity immediately, and remove it from the activity scheduler.
    void
    terminate(int terminationBehavior)
    Stop this activity immediately, and remove it from the activity scheduler.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • TERMINATE_WITHOUT_FINISHING

      public static final int TERMINATE_WITHOUT_FINISHING
      Parameter for terminate that signifies that activity should bail out immediately without flagging activity as finished.
      See Also:

    • TERMINATE_AND_FINISH

      public static final int TERMINATE_AND_FINISH
      Parameter for terminate that signifies that activity should bail out immediately, but flag activity as finished.
      See Also:

    • TERMINATE_AND_FINISH_IF_STEPPING

      public static final int TERMINATE_AND_FINISH_IF_STEPPING
      Parameter for terminate that signifies that activity should bail out immediately, if currently active.
      See Also:

  • Constructor Details

    • PActivity

      public PActivity(long aDuration)
      Constructs a new PActivity.
      Parameters:
      aDuration - the amount of time that this activity should take to complete, -1 for infinite.

    • PActivity

      public PActivity(long aDuration, long aStepRate)
      Constructs a new PActivity.
      Parameters:
      aDuration - the amount of time that this activity should take to complete, -1 for infinite.
      aStepRate - the maximum rate that this activity should receive step events.

    • PActivity

      public PActivity(long aDuration, long aStepRate, long aStartTime)
      Constructs a new PActivity.
      Parameters:
      aDuration - the amount of time that this activity should take to complete, -1 for infinite.
      aStepRate - the maximum rate that this activity should receive step events.
      aStartTime - the time (relative to System.currentTimeMillis()) that this activity should start.

  • Method Details

    • getStartTime

      public long getStartTime()
      Return the time that this activity should start running in PRoot global time. When this time is reached (or soon after) this activity will have its startStepping() method called.
      Returns:
      time at which this activity should start in PRoot global time.

    • setStartTime

      public void setStartTime(long aTriggerTime)
      Set the time that this activity should start running in PRoot global time. When this time is reached (or soon after) this activity will have its startStepping() method called.
      Parameters:
      aTriggerTime - time at which you want this activity to begin in PRoot global time

    • getStepRate

      public long getStepRate()
      Return the amount of time that this activity should delay between steps.
      Returns:
      the desired milliseconds between steps

    • setStepRate

      public void setStepRate(long aStepRate)
      Set the amount of time that this activity should delay between steps.
      Parameters:
      aStepRate - desired step rate in milliseconds between steps

    • getNextStepTime

      public long getNextStepTime()
      Gets the next step time desired for this activity. Exists since some steps might eat into the step rate otherwise.
      Returns:
      next calculated step time

    • getDuration

      public long getDuration()
      Return the amount of time that this activity should take to complete, after the startStepping method is called.
      Returns:
      time that this activity should take to complete

    • setDuration

      public void setDuration(long aDuration)
      Set the amount of time that this activity should take to complete, after the startStepping method is called.
      Parameters:
      aDuration - desired duration this activity should take (-1 for infinite) once it begins stepping

    • getActivityScheduler

      public PActivityScheduler getActivityScheduler()
      Returns the activity scheduler associated with this activity.
      Returns:
      associated scheduler

    • setActivityScheduler

      public void setActivityScheduler(PActivityScheduler aScheduler)
      Informs the activity of the scheduler that will be responsible for scheduling it.
      Parameters:
      aScheduler - scheduler to associate with this activity

    • isStepping

      public boolean isStepping()
      Return true if this activity is stepping.
      Returns:
      whether this activity is stepping

    • isAnimation

      protected boolean isAnimation()
      Return true if this activity is performing an animation. This is used by the PCanvas to determine if it should set the render quality to PCanvas.animatingRenderQuality or not for each frame it renders.
      Returns:
      whether this activity is an animation, subclasses can override this.

    • activityStarted

      protected void activityStarted()
      This method is called right before an activity is scheduled to start running. After this method is called step() will be called until the activity finishes.

    • activityStep

      protected void activityStep(long elapsedTime)
      This is the method that most activities override to perform their behavior. It will be called repeatedly when the activity is running.
      Parameters:
      elapsedTime - the amount of time that has passed relative to the activities startTime.

    • activityFinished

      protected void activityFinished()
      This method is called after an activity is has finished running and the activity has been removed from the PActivityScheduler queue.

    • getDelegate

      public PActivity.PActivityDelegate getDelegate()
      Get the delegate for this activity. The delegate is notified when the activity starts and stops stepping.
      Returns:
      delegate of this activity, may be null

    • setDelegate

      public void setDelegate(PActivity.PActivityDelegate delegate)
      Set the delegate for this activity. The delegate is notified when the activity starts and stops stepping.
      Parameters:
      delegate - delegate that should be informed of activity events

    • startAfter

      public void startAfter(PActivity first)
      Schedules this activity to start after the first activity has finished. Note that no link is created between these activities, if the startTime or duration of the first activity is later changed this activities start time will not be updated to reflect that change.
      Parameters:
      first - activity after which this activity should be scheduled

    • terminate

      public void terminate()
      Stop this activity immediately, and remove it from the activity scheduler. The default termination behavior is call activityFinished if the activity is currently stepping. Use terminate(terminationBehavior) use a different termination behavior.

    • terminate

      public void terminate(int terminationBehavior)
      Stop this activity immediately, and remove it from the activity scheduler. The termination behavior determines when and if activityStarted and activityFinished get called. The possible termination behaviors are as follow: TERMINATE_WITHOUT_FINISHING - The method activityFinished will never get called and so the activity will be terminated midway. TERMINATE_AND_FINISH - The method activityFinished will always get called. And so the activity will always end in it's completed state. If the activity has not yet started the method activityStarted will also be called. TERMINATE_AND_FINISH_IF_STEPPING - The method activityFinished will only be called if the activity has previously started.
      Parameters:
      terminationBehavior - behavior to use regarding delegate notification and event firing

    • processStep

      public long processStep(long currentTime)
      The activity scheduler calls this method and it is here that the activity decides if it should do a step or not for the given time.
      Parameters:
      currentTime - in global root time
      Returns:
      number of milliseconds in global root time before processStep should be called again, -1 if never

    • getStopTime

      public long getStopTime()
      Return the time when this activity should finish running. At this time (or soon after) the stoppedStepping method will be called
      Returns:
      time at which this activity should be stopped

    • paramString

      protected String paramString()
      Deprecated.
      see http://code.google.com/p/piccolo2d/issues/detail?id=99
      Returns:
      string representation of this activity