From 2e035f1c71f2cd045f3f2400517430c77af8da06 Mon Sep 17 00:00:00 2001
From: Dustin Moore <dustmoo@gmail.com>
Date: Wed, 29 May 2013 14:07:08 -0700
Subject: [PATCH] Partial Fix for when hiding openseadragon container

Hiding the container div was breaking the viewport. This patch fixes
that by defaulting to the home view when hidden. (Better fix would
maintain last position)
---
 src/viewport.js | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/viewport.js b/src/viewport.js
index 7b100283..83c10df7 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -235,6 +235,13 @@ $.Viewport.prototype = {
      * @function
      */
     getCenter: function( current ) {
+        //Patch: if centerspring is NaN use home bonds center instead. Only used if container div is hidden.
+        //To Do: Make it smarter by storing last good position or refactoring so hidden div doesn't return NaN
+        //results
+        homeCenter = this.homeBounds.getCenter();
+        currentX = isNaN(this.centerSpringX.current.value) ? homeCenter.x : this.centerSpringX.current.value;
+        currentY = isNaN(this.centerSpringY.current.value) ? homeCenter.y : this.centerSpringY.current.value;
+
         var centerCurrent = new $.Point(
                 this.centerSpringX.current.value,
                 this.centerSpringY.current.value
@@ -569,9 +576,12 @@ $.Viewport.prototype = {
      * @return {OpenSeadragon.Viewport} Chainable.
      */
     resize: function( newContainerSize, maintain ) {
+        //Set current size to 1 if 0 (hidden div)
+        var currentsize = this.containerSize.x == 0 ? 1 : this.containerSize.x;
+
         var oldBounds = this.getBounds(),
             newBounds = oldBounds,
-            widthDeltaFactor = newContainerSize.x / this.containerSize.x;
+            widthDeltaFactor = newContainerSize.x / currentsize;
 
         this.containerSize = new $.Point(
             newContainerSize.x, 
@@ -579,8 +589,14 @@ $.Viewport.prototype = {
         );
 
         if (maintain) {
-            newBounds.width  = oldBounds.width * widthDeltaFactor;
-            newBounds.height = newBounds.width / this.getAspectRatio();
+            newBounds.width  = isNaN(oldBounds.width * widthDeltaFactor) ? 0 : oldBounds.width * widthDeltaFactor;
+            newBounds.height = isNaN(newBounds.width / this.getAspectRatio()) ? 0 : newBounds.width / this.getAspectRatio();
+        }
+
+        //Still getting NaN results when restoring from hidden div, this resets to homebounds.
+        //ToDo: figure out how to stop NaN results when div is hidden.
+        if(isNaN(newBounds.width) || isNaN(newBounds.height) || isNaN(newBounds.x) || isNaN(newBounds.y)){
+            newBounds = this.getHomeBounds();
         }
 
         if( this.viewer ){