Bounds: Added extendXY() method

This is a simpler variant of the extend() method, but with less overhead.

lib/OpenLayers/BaseTypes/Bounds.js

@@ -392,6 +392,32 @@ OpenLayers.Bounds = OpenLayers.Class({
         }
     },
 
+    /**
+     * APIMethod: extendXY
+     * Extend the bounds to include the XY coordinate specified.
+     *
+     * Parameters:
+     * x - {number} The X part of the the coordinate.
+     * y - {number} The Y part of the the coordinate.
+     */
+    extendXY:function(x, y) {
+        // clear cached center location
+        this.centerLonLat = null;
+
+        if ((this.left == null) || (x < this.left)) {
+            this.left = x;
+        }
+        if ((this.bottom == null) || (y < this.bottom)) {
+            this.bottom = y;
+        }
+        if ((this.right == null) || (x > this.right)) {
+            this.right = x;
+        }
+        if ((this.top == null) || (y > this.top)) {
+            this.top = y;
+        }
+    },
+
     /**
      * APIMethod: containsLonLat
      * Returns whether the bounds object contains the given <OpenLayers.LonLat>.

tests/BaseTypes/Bounds.html

@@ -539,6 +539,39 @@
     }
 
 
+    function test_Bounds_extendXY(t) {
+        t.plan(3);
+
+        // null bounds to start
+        var originalBounds = new OpenLayers.Bounds();
+
+        var bounds = originalBounds.clone();
+        bounds.extendXY(4, 5);
+
+        t.ok(bounds.equals(new OpenLayers.Bounds(4,5,4,5)), "uninitialized bounds can be safely extended");
+
+        // left, bottom
+        originalBounds = new OpenLayers.Bounds(10,20,50,80);
+
+        bounds = originalBounds.clone();
+        bounds.extendXY(5, 10);
+
+        t.ok( ((bounds.left == 5) &&
+               (bounds.bottom == 10) &&
+               (bounds.right == originalBounds.right) &&
+               (bounds.top == originalBounds.top)), "extendXY correctly modifies left and bottom");
+
+        // right, top
+        bounds = originalBounds.clone();
+        bounds.extendXY(60, 90);
+
+        t.ok( ((bounds.left == originalBounds.left) &&
+               (bounds.bottom == originalBounds.bottom) &&
+               (bounds.right == 60) &&
+               (bounds.top == 90)), "extendXY correctly modifies right and top");
+    }
+
+
     function test_Bounds_wrapDateLine(t) {
         t.plan( 13 );