consolidate tiled-image-drawn event description and firing code

src/canvasdrawer.js

@@ -479,24 +479,9 @@ class CanvasDrawer extends $.DrawerBase{
         this._drawDebugInfo( tiledImage, lastDrawn );
 
         // Fire tiled-image-drawn event.
-        if( this.viewer ){
+
-            /**
+        this._raiseTiledImageDrawnEvent(tiledImage, lastDrawn);
-            *  Raised when a tiled image is drawn to the canvas. Used internally for testing.
+
-            *  The update-viewport event is preferred if you want to know when a frame has been drawn.
-            *
-            * @event tiled-image-drawn
-            * @memberof OpenSeadragon.Viewer
-            * @type {object}
-            * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
-            * @property {OpenSeadragon.TiledImage} tiledImage - Which TiledImage is being drawn.
-            * @property {Array} tiles - An array of Tile objects that were drawn.
-            * @property {?Object} userData - Arbitrary subscriber-defined object.
-            */
-            this.viewer.raiseEvent( 'tiled-image-drawn', {
-                tiledImage: tiledImage,
-                tiles: lastDrawn,
-            });
-        }
     }
 
     /**

src/drawerbase.js

@@ -252,6 +252,33 @@ $.DrawerBase = class DrawerBase{
         return new OpenSeadragon.Point( Math.round(viewportSize.x * pixelDensityRatio), Math.round(viewportSize.y * pixelDensityRatio));
     }
 
+    /**
+     * Called by implementations to fire the tiled-image-drawn event (used by tests)
+     * @private
+     */
+    _raiseTiledImageDrawnEvent(tiledImage, tiles){
+        if(!this.viewer) {
+            return;
+        }
+
+        /**
+        *  Raised when a tiled image is drawn to the canvas. Used internally for testing.
+        *  The update-viewport event is preferred if you want to know when a frame has been drawn.
+        *
+        * @event tiled-image-drawn
+        * @memberof OpenSeadragon.Viewer
+        * @type {object}
+        * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
+        * @property {OpenSeadragon.TiledImage} tiledImage - Which TiledImage is being drawn.
+        * @property {Array} tiles - An array of Tile objects that were drawn.
+        * @property {?Object} userData - Arbitrary subscriber-defined object.
+        */
+        this.viewer.raiseEvent( 'tiled-image-drawn', {
+            tiledImage: tiledImage,
+            tiles: tiles,
+        });
+    }
+
 };
 
 }( OpenSeadragon ));

src/webgldrawer.js

@@ -352,25 +352,7 @@
                     gl.clear(gl.COLOR_BUFFER_BIT); // clear the back buffer
                 }
 
-                // Fire tiled-image-drawn event. This is used for the tests
+                this._raiseTiledImageDrawnEvent(tiledImage, tilesToDraw.map(info=>info.tile));
-                if( this.viewer ){
-                    /**
-                    * Raised when a tiled image is drawn to the canvas. Used internally for testing.
-                    * The update-viewport event is preferred if you want to know when a frame has been drawn.
-                    *
-                    * @event tiled-image-drawn
-                    * @memberof OpenSeadragon.Viewer
-                    * @type {object}
-                    * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
-                    * @property {OpenSeadragon.TiledImage} tiledImage - Which TiledImage is being drawn.
-                    * @property {Array} tiles - An array of Tile objects that were drawn.
-                    * @property {?Object} userData - Arbitrary subscriber-defined object.
-                    */
-                    this.viewer.raiseEvent( 'tiled-image-drawn', {
-                        tiledImage: tiledImage,
-                        tiles: tilesToDraw.map(info => info.tile),
-                    });
-                }
 
             });
 

test/modules/tiledimage.js

@@ -13,7 +13,8 @@
             viewer = OpenSeadragon({
                 id: 'example',
                 prefixUrl: '/build/openseadragon/images/',
-                springStiffness: 100 // Faster animation = faster tests
+                springStiffness: 100, // Faster animation = faster tests
+                drawer: 'canvas', // always use canvas drawer for these tests
             });
         },
         afterEach: function() {
@@ -132,8 +133,7 @@
     QUnit.test('update', function(assert) {
         var done = assert.async();
         var handlerCount = 0;
-        var testTileDrawingEvent = viewer.drawer.getType() === 'canvas';
+        let expectedHandlers = 4;
-        let expectedHandlers = testTileDrawingEvent ? 4 : 3;
 
         viewer.addHandler('open', function(event) {
             var image = viewer.world.getItemAt(0);
@@ -162,17 +162,17 @@
                 assert.ok(event.tile, 'update-tile event includes tile');
             });
 
-            if(testTileDrawingEvent){
+
-                viewer.addHandler('tile-drawing', function tileDrawingHandler(event) {
+            viewer.addHandler('tile-drawing', function tileDrawingHandler(event) {
-                    viewer.removeHandler('tile-drawing', tileDrawingHandler);
+                viewer.removeHandler('tile-drawing', tileDrawingHandler);
-                    handlerCount++;
+                handlerCount++;
-                    assert.equal(event.eventSource, viewer, 'sender of tile-drawing event was viewer');
+                assert.equal(event.eventSource, viewer, 'sender of tile-drawing event was viewer');
-                    assert.equal(event.tiledImage, image, 'tiledImage of update-level event is correct');
+                assert.equal(event.tiledImage, image, 'tiledImage of update-level event is correct');
-                    assert.ok(event.tile, 'tile-drawing event includes a tile');
+                assert.ok(event.tile, 'tile-drawing event includes a tile');
-                    assert.ok(event.context, 'tile-drawing event includes a context');
+                assert.ok(event.context, 'tile-drawing event includes a context');
-                    assert.ok(event.rendered, 'tile-drawing event includes a rendered');
+                assert.ok(event.rendered, 'tile-drawing event includes a rendered');
-                });
+            });
-            }
+
 
 
             viewer.addHandler('tiled-image-drawn', function tileDrawnHandler(event) {