Tile load event

CHANGES.md

@@ -5,6 +5,7 @@ Change Log
 
 * Added ability to show tile urls in the 3D Tiles Inspector. [#5592](https://github.com/AnalyticalGraphicsInc/cesium/pull/5592)
 * Added behavior to `Cesium3DTilesInspector` that selects the first tileset hovered over if no tilest is specified. [#5139](https://github.com/AnalyticalGraphicsInc/cesium/issues/5139)
+* Added `tileLoad` event to `Cesium3DTileset`. [#5628](https://github.com/AnalyticalGraphicsInc/cesium/pull/5628)
 * Added ability to provide a `width` and `height` to `scene.pick`. [#5602](https://github.com/AnalyticalGraphicsInc/cesium/pull/5602)
 
 ### 1.35.2 - 2017-07-11

Source/Scene/Cesium3DTileset.js

@@ -366,6 +366,27 @@ define([
          */
         this.allTilesLoaded = new Event();
 
+        /**
+         * The event fired to indicate that a tile's content was loaded.
+         * <p>
+         * The loaded {@link Cesium3DTile} is passed to the event listener.
+         * </p>
+         * <p>
+         * This event is fired during the tileset traversal while the frame is being rendered
+         * so that updates to the tile take effect in the same frame.  Do not create or modify
+         * Cesium entities or primitives during the event listener.
+         * </p>
+         *
+         * @type {Event}
+         * @default new Event()
+         *
+         * @example
+         * tileset.tileLoad.addEventListener(function(tile) {
+         *     console.log('A tile was loaded.');
+         * });
+         */
+        this.tileLoad = new Event();
+
         /**
          * The event fired to indicate that a tile's content was unloaded.
          * <p>
@@ -1223,7 +1244,10 @@ define([
 
         var removeFunction = removeFromProcessingQueue(tileset, tile);
         tile.contentReadyToProcessPromise.then(addToProcessingQueue(tileset, tile));
-        tile.contentReadyPromise.then(removeFunction).otherwise(removeFunction);
+        tile.contentReadyPromise.then(function() {
+            removeFunction();
+            tileset.tileLoad.raiseEvent(tile);
+        }).otherwise(removeFunction);
     }
 
     function requestTiles(tileset, outOfCore) {

Specs/Scene/Cesium3DTilesetSpec.js

@@ -1607,6 +1607,34 @@ defineSuite([
         });
     });
 
+    it('tile load event is raised', function() {
+        viewNothing();
+        return Cesium3DTilesTester.loadTileset(scene, tilesetUrl).then(function(tileset) {
+            var spyUpdate = jasmine.createSpy('listener');
+            tileset.tileLoad.addEventListener(spyUpdate);
+            tileset.maximumMemoryUsage = 0;
+            viewRootOnly();
+            return Cesium3DTilesTester.waitForTilesLoaded(scene, tileset).then(function() {
+                // Root is loaded
+                expect(spyUpdate.calls.count()).toEqual(1);
+                expect(spyUpdate.calls.argsFor(0)[0]).toBe(tileset._root);
+                spyUpdate.calls.reset();
+
+                // Unload from cache
+                viewNothing();
+                scene.renderForSpecs();
+                expect(tileset.statistics.numberOfTilesWithContentReady).toEqual(0);
+
+                // Look at root again
+                viewRootOnly();
+                return Cesium3DTilesTester.waitForTilesLoaded(scene, tileset).then(function() {
+                    expect(spyUpdate.calls.count()).toEqual(1);
+                    expect(spyUpdate.calls.argsFor(0)[0]).toBe(tileset._root);
+                });
+            });
+        });
+    });
+
     it('destroys', function() {
         return Cesium3DTilesTester.loadTileset(scene, tilesetUrl).then(function(tileset) {
             var root = tileset._root;