prototype: Add the document.viewport object for querying dimensions and scroll offsets of the browser viewport.

CHANGELOG

@@ -1,5 +1,12 @@
 *SVN*
 
+* Add the document.viewport object for querying dimensions and scroll offsets of the browser viewport.  [Andrew Dupont, Thomas Fuchs, sam]
+  Example:
+    document.viewport.getDimensions()     // { width: 1149, height: 923 }
+    document.viewport.getWidth()          // 1149
+    document.viewport.getHeight()         // 923
+    document.viewport.getScrollOffsets()  // { left: 0, top: 1592 }
+
 * Add support for brackets in quoted attribute value selectors.  Closes #9157.  [Ken Snyder]
 
 * Add some missing semicolons to the source tree.  Closes #9140.  [jdalton]

src/dom.js

@@ -1168,3 +1168,29 @@ Element.addMethods = function(methods) {
   if (Element.extend.refresh) Element.extend.refresh();
   Element.cache = { };
 };
+
+document.viewport = {
+  getDimensions: function() {
+    var dimensions = {};
+    $w('width height').each( function(d) {
+      var D = d.capitalize();
+      dimensions[d] = self['inner' + D] || 
+       (document.documentElement['client' + D] || document.body['client' + D]);
+    });
+    return dimensions;
+  },
+
+  getWidth: function() {
+    return this.getDimensions().width;
+  },
+
+  getHeight: function() {
+    return this.getDimensions().height;
+  },
+  
+  getScrollOffsets: function() {
+    return Element._returnOffset(
+      window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft,
+      window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
+  }
+};

test/unit/dom.html

@@ -1491,6 +1491,31 @@
         elt.absolutize();
         assertUndefined(elt._originalLeft, 'absolutize() did not detect absolute positioning');
       });
+    }},
+    
+    
+    testViewportDimensions: function() {with(this) {
+      window.resizeTo(800, 600);
+      var before = document.viewport.getDimensions();
+      window.resizeBy(50, 50);
+      var after  = document.viewport.getDimensions();
+      
+      assertEqual(before.width + 50, after.width, "NOTE: YOU MUST ALLOW JAVASCRIPT TO RESIZE YOUR WINDOW FOR THESE TESTS TO PASS");
+      assertEqual(before.height + 50, after.height, "NOTE: YOU MUST ALLOW JAVASCRIPT TO RESIZE YOUR WINDOW FOR THESE TESTS TO PASS");
+    }},
+    
+    testViewportScrollOffsets: function() {with(this) {
+      window.scrollTo(0, 0);
+      assertEqual(0, document.viewport.getScrollOffsets().top);
+      
+      window.scrollTo(0, 35);
+      assertEqual(35, document.viewport.getScrollOffsets().top);
+      
+      window.resizeTo(200, 650);
+      window.scrollTo(25, 35);
+      assertEqual(25, document.viewport.getScrollOffsets().left);
+      
+      window.resizeTo(850, 650);
     }}
   }, 'testlog');