Added pollForResize option

Defaults to true.

changelog.txt

@@ -56,6 +56,7 @@ OPENSEADRAGON CHANGELOG
     * Viewer.innerTracker.scrollHandler: preventDefaultAction == true prevents viewer zooming on mousewheel/pinch
 * Fixed: IE8 error with custom buttons - "Object doesn't support this action" (#279)
 * Support IIIF servers that don't report tile dimensions (#286)
+* Added a pollForResize option. Default is true. When set to false, the viewer takes no action when its container element is resized.
 
 0.9.131:
 

src/openseadragon.js

@@ -174,6 +174,9 @@
   *     image though it is less effective visually if the HTML5 Canvas is not
   *     availble on the viewing device.
   *
+  * @param {Boolean} [options.pollForResize=true]
+  *     Set to false to prevent polling for viewer size changes. Useful for providing custom resize behavior.
+  *
   * @param {Number} [options.visibilityRatio=0.5]
   *     The percentage ( as a number from 0 to 1 ) of the source image which
   *     must be kept within the viewport.  If the image is dragged beyond that
@@ -532,6 +535,7 @@ window.OpenSeadragon = window.OpenSeadragon || function( options ){
             minZoomImageRatio:      0.9, //-> closer to 0 allows zoom out to infinity
             maxZoomPixelRatio:      1.1, //-> higher allows 'over zoom' into pixels
             pixelsPerWheelLine:     40,
+            pollForResize:          true,
 
             //DEFAULT CONTROL SETTINGS
             showSequenceControl:    true,  //SEQUENCE

src/viewer.js

@@ -1657,6 +1657,7 @@ function updateOnce( viewer ) {
 
     //viewer.profiler.beginUpdate();
 
+    if ( viewer.pollForResize ) {
         containerSize = _getSafeElemSize( viewer.container );
         if ( !containerSize.equals( THIS[ viewer.hash ].prevContainerSize ) ) {
             // maintain image position
@@ -1666,6 +1667,7 @@ function updateOnce( viewer ) {
             THIS[ viewer.hash ].prevContainerSize = containerSize;
             THIS[ viewer.hash ].forceRedraw = true;
         }
+    }
 
     animated = viewer.viewport.update();
 

src/viewport.js

@@ -611,7 +611,7 @@ $.Viewport.prototype = {
     resize: function( newContainerSize, maintain ) {
         var oldBounds = this.getBounds(),
             newBounds = oldBounds,
-            widthDeltaFactor = newContainerSize.x / this.containerSize.x;
+            widthDeltaFactor;
 
         this.containerSize = new $.Point(
             newContainerSize.x,
@@ -619,6 +619,7 @@ $.Viewport.prototype = {
         );
 
         if ( maintain ) {
+            widthDeltaFactor = newContainerSize.x / this.containerSize.x;
             newBounds.width  = oldBounds.width * widthDeltaFactor;
             newBounds.height = newBounds.width / this.getAspectRatio();
         }