Change render for renderOnce from Player to RenderContext

src/main/java/com/github/johnnyjayjay/spigotmaps/rendering/AbstractMapRenderer.java

@@ -25,18 +25,21 @@
  */
 public abstract class AbstractMapRenderer extends MapRenderer {
 
-    private final Set<Player> alreadyReceived;
+    private final Set<RenderContext> alreadyReceived;
     private final boolean renderForAllPlayers, renderOnce;
     private final Set<Player> receivers;
     private final Predicate<RenderContext> precondition;
 
+    private boolean stop;
+
     protected AbstractMapRenderer(Set<Player> receivers, boolean renderOnce, Predicate<RenderContext> precondition) {
         super(!receivers.isEmpty());
         this.renderForAllPlayers = receivers.isEmpty();
         this.receivers = receivers;
         this.renderOnce = renderOnce;
         this.precondition = precondition;
         this.alreadyReceived = new HashSet<>(); // TODO consider an implementation with less overhead
+        this.stop = false;
     }
 
     @Override
@@ -45,13 +48,14 @@ public final void render(MapView map, MapCanvas canvas, Player player) {
         if (mayRender(context)) {
             render(context);
             if (renderOnce)
-                alreadyReceived.add(player);
+                alreadyReceived.add(context);
         }
     }
 
     private boolean mayRender(RenderContext context) {
-        return (renderForAllPlayers || receivers.contains(context.getPlayer()))
-                && (!renderOnce || !alreadyReceived.contains(context.getPlayer()))
+        return !stop
+                &&(renderForAllPlayers || receivers.contains(context.getPlayer()))
+                && (!renderOnce || !alreadyReceived.contains(context))
                 && precondition.test(context);
     }
 
@@ -97,12 +101,21 @@ public boolean isRenderOnce() {
         return renderOnce;
     }
 
+    /**
+     * Makes this renderer stop rendering anything, forever.
+     */
+    public void stopRendering() {
+        this.stop = true;
+    }
+
     /**
      * Renders the map after the preconditions have passed, i.e.:
      * <ul>
-     * <li>The predicate's test was successful</li>
      * <li>This renderer applies to the player or</li>
      * <li>This renderer renders maps for all players</li>
+     * <li>This renderer does not only render once or</li>
+     * <li>This renderer has not rendered for the given context yet</li>
+     * <li>The predicate's test was successful</li>
      * </ul>
      *
      * @param context the context for this rendering operation.

src/main/java/com/github/johnnyjayjay/spigotmaps/rendering/RenderContext.java

@@ -5,6 +5,8 @@
 import org.bukkit.map.MapCanvas;
 import org.bukkit.map.MapView;
 
+import java.util.Objects;
+
 /**
  * A container class for every map rendering operation. It contains the subject
  * {@link MapView}, a {@link MapCanvas} as well as the {@link Player} the map is rendered for.
@@ -60,4 +62,18 @@ public MapCanvas getCanvas() {
     public Player getPlayer() {
         return player;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        RenderContext that = (RenderContext) o;
+        return mapView.getId() == that.mapView.getId()
+                && Objects.equals(player, that.player);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mapView.getId(), player);
+    }
 }