Remove listeners when dropping tiles

src/ol/tile.js

@@ -28,6 +28,13 @@ ol.Tile = function(tileCoord) {
 
   goog.base(this);
 
+  /**
+   * A count incremented each time the tile is inQueue in a tile queue,
+   * and decremented each time the tile is dequeued from a tile queue.
+   * @type {number}
+   */
+  this.inQueue = 0;
+
   /**
    * @type {ol.TileCoord}
    */

src/ol/tilequeue.js

@@ -89,6 +89,8 @@ ol.TileQueue.prototype.dequeue_ = function() {
   }
   var tileKey = tile.getKey();
   delete this.queuedTileKeys_[tileKey];
+  tile.inQueue--;
+  goog.asserts.assert(tile.inQueue >= 0);
   return tile;
 };
 
@@ -110,6 +112,8 @@ ol.TileQueue.prototype.enqueue = function(tile, tileSourceKey, tileCenter) {
       this.heap_.push([priority, tile, tileSourceKey, tileCenter]);
       this.queuedTileKeys_[tileKey] = true;
       this.siftDown_(0, this.heap_.length - 1);
+      tile.inQueue++;
+      goog.asserts.assert(tile.inQueue > 0);
     }
   }
 };
@@ -246,6 +250,11 @@ ol.TileQueue.prototype.reprioritize = function() {
     if (priority == ol.TileQueue.DROP) {
       tileKey = tile.getKey();
       delete this.queuedTileKeys_[tileKey];
+      tile.inQueue--;
+      goog.asserts.assert(tile.inQueue >= 0);
+      if (tile.inQueue === 0) {
+        goog.events.removeAll(tile);
+      }
     } else {
       node[0] = priority;
       heap[n++] = node;

test/spec/ol/tilequeue.test.js

@@ -21,13 +21,20 @@ describe('ol.TileQueue', function() {
   }
 
   function addRandomPriorityTiles(tq, num) {
+    var tiles = [];
     var i, tile, priority;
     for (i = 0; i < num; i++) {
       tile = new ol.Tile();
+      tile.toDrop = (i % 2 === 0) ? true : false;
+      goog.events.listen(tile, goog.events.EventType.CHANGE,
+          goog.nullFunction);
       priority = Math.floor(Math.random() * 100);
       tq.heap_.push([priority, tile, '', new ol.Coordinate(0, 0)]);
       tq.queuedTileKeys_[tile.getKey()] = true;
+      tile.inQueue++;
+      tiles.push(tile);
     }
+    return tiles;
   }
 
   describe('heapify', function() {
@@ -45,16 +52,15 @@ describe('ol.TileQueue', function() {
     it('does reprioritize the array', function() {
 
       var tq = new ol.TileQueue(function() {});
-      addRandomPriorityTiles(tq, 100);
+      var tiles = addRandomPriorityTiles(tq, 100);
 
       tq.heapify_();
 
       // now reprioritize, changing the priority of 50 tiles and removing the
       // rest
 
-      var i = 0;
-      tq.tilePriorityFunction_ = function() {
-        if ((i++) % 2 === 0) {
+      tq.tilePriorityFunction_ = function(tile) {
+        if (tile.toDrop) {
           return ol.TileQueue.DROP;
         }
         return Math.floor(Math.random() * 100);
@@ -64,10 +70,23 @@ describe('ol.TileQueue', function() {
       expect(tq.heap_.length).toEqual(50);
       expect(isHeap(tq)).toBeTruthy();
 
+      var i, tile;
+      for (i = 0; i < tiles.length; ++i) {
+        tile = tiles[i];
+        var hasListener = goog.events.hasListener(tile);
+        if (tile.toDrop) {
+          expect(hasListener).toBeFalsy();
+        } else {
+          expect(hasListener).toBeTruthy();
+        }
+      }
+
     });
   });
 });
 
+goog.require('goog.events');
+goog.require('goog.events.EventType');
 goog.require('ol.Coordinate');
 goog.require('ol.Tile');
 goog.require('ol.TileQueue');