git.gag.com Git - debian/openrocket/blob - core/src/net/sf/openrocket/gui/main/SimulationWorker.java

   1 package net.sf.openrocket.gui.main;
   2
   3 import java.util.Arrays;
   4
   5 import javax.swing.SwingWorker;
   6
   7 import net.sf.openrocket.document.Simulation;
   8 import net.sf.openrocket.simulation.FlightData;
   9 import net.sf.openrocket.simulation.SimulationStatus;
  10 import net.sf.openrocket.simulation.exception.SimulationCancelledException;
  11 import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
  12 import net.sf.openrocket.simulation.listeners.SimulationListener;
  13
  14
  15
  16 /**
  17  * A SwingWorker that runs a simulation in a background thread.  The simulation
  18  * always includes a listener that checks whether this SwingWorked has been cancelled,
  19  * and throws a {@link SimulationCancelledException} if it has.  This allows the
  20  * {@link #cancel(boolean)} method to be used to cancel the simulation.
  21  *
  22  * @author Sampo Niskanen <sampo.niskanen@iki.fi>
  23  */
  24 public abstract class SimulationWorker extends SwingWorker<FlightData, SimulationStatus> {
  25
  26         protected final Simulation simulation;
  27         private Throwable throwable = null;
  28
  29         public SimulationWorker(Simulation sim) {
  30                 this.simulation = sim;
  31         }
  32
  33
  34         /**
  35          * Runs the simulation.
  36          */
  37         @Override
  38         protected FlightData doInBackground() {
  39                 if (isCancelled()) {
  40                         throwable = new SimulationCancelledException("The simulation was interrupted.");
  41                         return null;
  42                 }
  43
  44                 SimulationListener[] listeners = getExtraListeners();
  45
  46                 if (listeners != null) {
  47                         listeners = Arrays.copyOf(listeners, listeners.length + 1);
  48                 } else {
  49                         listeners = new SimulationListener[1];
  50                 }
  51
  52                 listeners[listeners.length - 1] = new CancelListener();
  53
  54                 try {
  55                         simulation.simulate(listeners);
  56                 } catch (Throwable e) {
  57                         throwable = e;
  58                         return null;
  59                 }
  60                 return simulation.getSimulatedData();
  61         }
  62
  63
  64         /**
  65          * Return additional listeners to use during the simulation.  The default
  66          * implementation returns an empty array.
  67          *
  68          * @return      additional listeners to use, or <code>null</code>.
  69          */
  70         protected SimulationListener[] getExtraListeners() {
  71                 return new SimulationListener[0];
  72         }
  73
  74
  75         /**
  76          * Called after a simulation is successfully simulated.  This method is not
  77          * called if the simulation ends in an exception.
  78          */
  79         protected abstract void simulationDone();
  80
  81         /**
  82          * Called if the simulation is interrupted due to an exception.
  83          *
  84          * @param t             the Throwable that caused the interruption
  85          */
  86         protected abstract void simulationInterrupted(Throwable t);
  87
  88
  89
  90         /**
  91          * Marks this simulation as done and calls the progress update.
  92          */
  93         @Override
  94         protected final void done() {
  95                 if (throwable == null)
  96                         simulationDone();
  97                 else
  98                         simulationInterrupted(throwable);
  99         }
 100
 101
 102
 103         /**
 104          * A simulation listener that throws a {@link SimulationCancelledException} if
 105          * this SwingWorker has been cancelled.  The conditions is checked every time a step
 106          * is taken.
 107          *
 108          * @author Sampo Niskanen <sampo.niskanen@iki.fi>
 109          */
 110         private class CancelListener extends AbstractSimulationListener {
 111
 112                 @Override
 113                 public void postStep(SimulationStatus status) throws SimulationCancelledException {
 114
 115                         if (isCancelled()) {
 116                                 throw new SimulationCancelledException("The simulation was interrupted.");
 117                         }
 118
 119                 }
 120         }
 121 }