(function(Y) {
+var TOP = 'top',
+ RIGHT = 'right',
+ BOTTOM = 'bottom',
+ LEFT = 'left',
+
+ getOffsets = function(r1, r2) {
+ var t = Math.max(r1[TOP], r2[TOP]),
+ r = Math.min(r1[RIGHT], r2[RIGHT]),
+ b = Math.min(r1[BOTTOM], r2[BOTTOM]),
+ l = Math.max(r1[LEFT], r2[LEFT]),
+ ret = {};
+
+ ret[TOP] = t;
+ ret[RIGHT] = r;
+ ret[BOTTOM] = b;
+ ret[LEFT] = l;
+ return ret;
+ },
+
+ DOM = Y.DOM;
+
+Y.mix(DOM, {
+ /**
+ * Returns an Object literal containing the following about this element: (top, right, bottom, left)
+ * @method region
+ * @param {HTMLElement} element The DOM element.
+ @return {Object} Object literal containing the following about this element: (top, right, bottom, left)
+ */
+ region: function(node) {
+ var xy = DOM.getXY(node),
+ ret = false;
+
+ if (node && xy) {
+ ret = DOM._getRegion(
+ xy[1], // top
+ xy[0] + node.offsetWidth, // right
+ xy[1] + node.offsetHeight, // bottom
+ xy[0] // left
+ );
+ }
+
+ return ret;
+ },
+
+ /**
+ * Find the intersect information for the passes nodes.
+ * @method intersect
+ * @param {HTMLElement} element The first element
+ * @param {HTMLElement | Object} element2 The element or region to check the interect with
+ * @param {Object} altRegion An object literal containing the region for the first element if we already have the data (for performance i.e. DragDrop)
+ @return {Object} Object literal containing the following intersection data: (top, right, bottom, left, area, yoff, xoff, inRegion)
+ */
+ intersect: function(node, node2, altRegion) {
+ var r = altRegion || DOM.region(node), region = {},
+ n = node2,
+ off;
+
+ if (n.tagName) {
+ region = DOM.region(n);
+ } else if (Y.Lang.isObject(node2)) {
+ region = node2;
+ } else {
+ return false;
+ }
+
+ off = getOffsets(region, r);
+ return {
+ top: off[TOP],
+ right: off[RIGHT],
+ bottom: off[BOTTOM],
+ left: off[LEFT],
+ area: ((off[BOTTOM] - off[TOP]) * (off[RIGHT] - off[LEFT])),
+ yoff: ((off[BOTTOM] - off[TOP])),
+ xoff: (off[RIGHT] - off[LEFT]),
+ inRegion: DOM.inRegion(node, node2, false, altRegion)
+ };
+
+ },
+ /**
+ * Check if any part of this node is in the passed region
+ * @method inRegion
+ * @param {Object} node2 The node to get the region from or an Object literal of the region
+ * $param {Boolean} all Should all of the node be inside the region
+ * @param {Object} altRegion An object literal containing the region for this node if we already have the data (for performance i.e. DragDrop)
+ * @return {Boolean} True if in region, false if not.
+ */
+ inRegion: function(node, node2, all, altRegion) {
+ var region = {},
+ r = altRegion || DOM.region(node),
+ n = node2,
+ off;
+
+ if (n.tagName) {
+ region = DOM.region(n);
+ } else if (Y.Lang.isObject(node2)) {
+ region = node2;
+ } else {
+ return false;
+ }
+
+ if (all) {
+ return (
+ r[LEFT] >= region[LEFT] &&
+ r[RIGHT] <= region[RIGHT] &&
+ r[TOP] >= region[TOP] &&
+ r[BOTTOM] <= region[BOTTOM] );
+ } else {
+ off = getOffsets(region, r);
+ if (off[BOTTOM] >= off[TOP] && off[RIGHT] >= off[LEFT]) {
+ return true;
+ } else {
+ return false;
+ }
+
+ }
+ },
+
+ /**
+ * Check if any part of this element is in the viewport
+ * @method inViewportRegion
+ * @param {HTMLElement} element The DOM element.
+ * @param {Boolean} all Should all of the node be inside the region
+ * @param {Object} altRegion An object literal containing the region for this node if we already have the data (for performance i.e. DragDrop)
+ * @return {Boolean} True if in region, false if not.
+ */
+ inViewportRegion: function(node, all, altRegion) {
+ return DOM.inRegion(node, DOM.viewportRegion(node), all, altRegion);
+
+ },
+
+ _getRegion: function(t, r, b, l) {
+ var region = {};
+
+ region[TOP] = region[1] = t;
+ region[LEFT] = region[0] = l;
+ region[BOTTOM] = b;
+ region[RIGHT] = r;
+ region.width = region[RIGHT] - region[LEFT];
+ region.height = region[BOTTOM] - region[TOP];
+
+ return region;
+ },
+
+ /**
+ * Returns an Object literal containing the following about the visible region of viewport: (top, right, bottom, left)
+ * @method viewportRegion
+ @return {Object} Object literal containing the following about the visible region of the viewport: (top, right, bottom, left)
+ */
+ viewportRegion: function(node) {
+ node = node || Y.config.doc.documentElement;
+ var ret = false,
+ scrollX,
+ scrollY;
+
+ if (node) {
+ scrollX = DOM.docScrollX(node);
+ scrollY = DOM.docScrollY(node);
+
+ ret = DOM._getRegion(scrollY, // top
+ DOM.winWidth(node) + scrollX, // right
+ scrollY + DOM.winHeight(node), // bottom
+ scrollX); // left
+ }
+
+ return ret;
+ }
+});
+})(Y);
+