Limit draw updates

ICGE-Simulation/src/main/java/de/unistuttgart/informatik/fius/icge/simulation/internal/playfield/StandardPlayfield.java

@@ -54,6 +54,37 @@ public class StandardPlayfield implements Playfield {
 
     private Consumer<List<Drawable>> drawablesChangedListener;
 
+    private long             lastEntityDraw            = 0;
+    private volatile boolean delayedEntityDraw         = false;
+    private long             timeBetweenDraws          = 32; //the time between draw calls in milliseconds
+    private Thread           delayedDrawEntitiesThread = new Thread();
+
+    private Runnable delayedEntitiesDrawRunnable = () -> {
+        long timeSinceLastEntityDraw = System.nanoTime() - this.lastEntityDraw;
+        if (timeSinceLastEntityDraw < this.timeBetweenDraws * 1000000) {
+            try {
+                Thread.sleep(this.timeBetweenDraws - timeSinceLastEntityDraw / 1000000);
+            } catch (InterruptedException e) {
+                // TODO Auto-generated catch block
+                e.printStackTrace();
+            }
+        }
+        this.delayedEntityDraw = false;
+        drawEntitiesInternal();
+        this.lastEntityDraw = System.nanoTime();
+    };
+
+    private Runnable restartDelayedEntitiesDrawThreadRunnable = () -> {
+        try {
+            this.delayedDrawEntitiesThread.join();
+        } catch (InterruptedException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+        this.delayedDrawEntitiesThread = new Thread(this.delayedEntitiesDrawRunnable);
+        this.delayedDrawEntitiesThread.start();
+    };
+
     /**
      * Initialize the playfield for the given simulation
      *
@@ -83,9 +114,20 @@ public Simulation getSimulation() {
     }
 
     /**
-     * Converts all entities to drawables and sends them to the playfield drawer.
+     * Converts all entities to drawables and sends them to the playfield drawer if the last draw has not occurred
+     * recently.
      */
     public void drawEntities() {
+        if (!this.delayedEntityDraw) {
+            this.delayedEntityDraw = true;
+            new Thread(this.restartDelayedEntitiesDrawThreadRunnable).start();
+        }
+    }
+
+    /**
+     * Converts all entities to drawables and sends them to the playfield drawer.
+     */
+    private void drawEntitiesInternal() {
         final List<Drawable> drawables = new ArrayList<>();
         for (final Entity entity : this.getAllEntities()) {
             try {
@@ -408,4 +450,23 @@ public void removeDrawablesChangedListener() {
     public String toString() {
         return this.getClass().getSimpleName() + "@" + Integer.toHexString(this.hashCode());
     }
+
+    /**
+     * Get's {@link #timeBetweenDraws timeBetweenDraws}
+     * 
+     * @return time waiting between draw calls in milliseconds
+     */
+    public long getTimeBetweenDraws() {
+        return this.timeBetweenDraws;
+    }
+
+    /**
+     * Set's {@link #timeBetweenDraws timeBetweenDraws}
+     * 
+     * @param timeBetweenDraws
+     *     time waiting between draw calls in milliseconds
+     */
+    public void setTimeBetweenDraws(long timeBetweenDraws) {
+        this.timeBetweenDraws = timeBetweenDraws;
+    }
 }