Updated posioning code to fix fullscreen mode and fix jiggly zooming

Author: altert

openseadragon-fabricjs-overlay.js

@@ -92,31 +92,26 @@
                 this._canvasdiv.setAttribute('height', this._containerHeight);
                 this._canvas.setAttribute('height', this._containerHeight);
             }
-            this._viewportOrigin = new OpenSeadragon.Point(0, 0);
-            var boundsRect = this._viewer.viewport.getBounds(true);
-            this._viewportOrigin.x = boundsRect.x;
-            this._viewportOrigin.y = boundsRect.y * this.imgAspectRatio;
 
-            this._viewportWidth = boundsRect.width;
-            this._viewportHeight = boundsRect.height * this.imgAspectRatio;
-            this.imgWidth = this._viewer.viewport.contentSize.x;
-            this.imgHeight = this._viewer.viewport.contentSize.y;
-            this.imgAspectRatio = this.imgWidth / this.imgHeight;
-
         },
        resizecanvas: function() {
-           
-           
+ 
+           var origin = new OpenSeadragon.Point(0, 0);         
            var viewportZoom = this._viewer.viewport.getZoom(true);
            var image1 = this._viewer.world.getItemAt(0);
            var zoom = image1.viewportToImageZoom(viewportZoom);     
 
-           var x=((this._viewportOrigin.x/this.imgWidth-this._viewportOrigin.x )/this._viewportWidth)*this._containerWidth;
-           var y=((this._viewportOrigin.y/this.imgHeight-this._viewportOrigin.y )/this._viewportHeight)*this._containerHeight;
            this._fabricCanvas.setWidth(this._containerWidth);
-           this._fabricCanvas.setHeight(this._containerHeight);
-           this._fabricCanvas.absolutePan(new fabric.Point(-x,-y));
+           this._fabricCanvas.setHeight(this._containerHeight);        
            this._fabricCanvas.setZoom(zoom);
+                
+           var image1WindowPoint = image1.imageToWindowCoordinates(origin);        
+           var x=Math.round(image1WindowPoint.x);
+           var y=Math.round(image1WindowPoint.y);
+           var canvasOffset=this._canvasdiv.getBoundingClientRect();
+           
+           this._fabricCanvas.absolutePan(new fabric.Point(canvasOffset.left-x,canvasOffset.top-y));
+           
        }
 
     };