/*!
 * Ext JS Library 3.0.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/**
 * @class Ext.Element
 */
Ext.Element.addMethods({
    /**
     * Gets the x,y coordinates specified by the anchor position on the element.
     * @param {String} anchor (optional) The specified anchor position (defaults to "c").  See {@link #alignTo}
     * for details on supported anchor positions.
     * @param {Boolean} local (optional) True to get the local (element top/left-relative) anchor position instead
     * of page coordinates
     * @param {Object} size (optional) An object containing the size to use for calculating anchor position
     * {width: (target width), height: (target height)} (defaults to the element's current size)
     * @return {Array} [x, y] An array containing the element's x and y coordinates
     */
    getAnchorXY : function(anchor, local, s){
        //Passing a different size is useful for pre-calculating anchors,
        //especially for anchored animations that change the el size.
		anchor = (anchor || "tl").toLowerCase();
        s = s || {};
        
        var me = this,        
        	vp = me.dom == document.body || me.dom == document,
        	w = s.width || vp ? Ext.lib.Dom.getViewWidth() : me.getWidth(),
        	h = s.height || vp ? Ext.lib.Dom.getViewHeight() : me.getHeight(),         	        	
        	xy,       	
        	r = Math.round,
        	o = me.getXY(),
        	scroll = me.getScroll(),
        	extraX = vp ? scroll.left : !local ? o[0] : 0,
        	extraY = vp ? scroll.top : !local ? o[1] : 0,
        	hash = {
	        	c  : [r(w * 0.5), r(h * 0.5)],
	        	t  : [r(w * 0.5), 0],
	        	l  : [0, r(h * 0.5)],
	        	r  : [w, r(h * 0.5)],
	        	b  : [r(w * 0.5), h],
	        	tl : [0, 0],	
	        	bl : [0, h],
	        	br : [w, h],
	        	tr : [w, 0]
        	};
        
        xy = hash[anchor];	
        return [xy[0] + extraX, xy[1] + extraY]; 
    },

    /**
     * Anchors an element to another element and realigns it when the window is resized.
     * @param {Mixed} element The element to align to.
     * @param {String} position The position to align to.
     * @param {Array} offsets (optional) Offset the positioning by [x, y]
     * @param {Boolean/Object} animate (optional) True for the default animation or a standard Element animation config object
     * @param {Boolean/Number} monitorScroll (optional) True to monitor body scroll and reposition. If this parameter
     * is a number, it is used as the buffer delay (defaults to 50ms).
     * @param {Function} callback The function to call after the animation finishes
     * @return {Ext.Element} this
     */
    anchorTo : function(el, alignment, offsets, animate, monitorScroll, callback){        
	    var me = this,
            dom = me.dom;
	    
	    function action(){
            Ext.fly(dom).alignTo(el, alignment, offsets, animate);
            Ext.callback(callback, Ext.fly(dom));
        }
        
        Ext.EventManager.onWindowResize(action, me);
        
        if(!Ext.isEmpty(monitorScroll)){
            Ext.EventManager.on(window, 'scroll', action, me,
                {buffer: !isNaN(monitorScroll) ? monitorScroll : 50});
        }
        action.call(me); // align immediately
        return me;
    },

    /**
     * Gets the x,y coordinates to align this element with another element. See {@link #alignTo} for more info on the
     * supported position values.
     * @param {Mixed} element The element to align to.
     * @param {String} position The position to align to.
     * @param {Array} offsets (optional) Offset the positioning by [x, y]
     * @return {Array} [x, y]
     */
    getAlignToXY : function(el, p, o){	    
        el = Ext.get(el);
        
        if(!el || !el.dom){
            throw "Element.alignToXY with an element that doesn't exist";
        }
        
        o = o || [0,0];
        p = (p == "?" ? "tl-bl?" : (!/-/.test(p) && p !== "" ? "tl-" + p : p || "tl-bl")).toLowerCase();       
                
        var me = this,
        	d = me.dom,
        	a1,
        	a2,
        	x,
        	y,
        	//constrain the aligned el to viewport if necessary
        	w,
        	h,
        	r,
        	dw = Ext.lib.Dom.getViewWidth() -10, // 10px of margin for ie
        	dh = Ext.lib.Dom.getViewHeight()-10, // 10px of margin for ie
        	p1y,
        	p1x,        	
        	p2y,
        	p2x,
        	swapY,
        	swapX,
        	doc = document,
        	docElement = doc.documentElement,
        	docBody = doc.body,
        	scrollX = (docElement.scrollLeft || docBody.scrollLeft || 0)+5,
        	scrollY = (docElement.scrollTop || docBody.scrollTop || 0)+5,
        	c = false, //constrain to viewport
        	p1 = "", 
        	p2 = "",
        	m = p.match(/^([a-z]+)-([a-z]+)(\?)?$/);
        
        if(!m){
           throw "Element.alignTo with an invalid alignment " + p;
        }
        
        p1 = m[1]; 
        p2 = m[2]; 
        c = !!m[3];

        //Subtract the aligned el's internal xy from the target's offset xy
        //plus custom offset to get the aligned el's new offset xy
        a1 = me.getAnchorXY(p1, true);
        a2 = el.getAnchorXY(p2, false);

        x = a2[0] - a1[0] + o[0];
        y = a2[1] - a1[1] + o[1];

        if(c){    
	       w = me.getWidth();
           h = me.getHeight();
           r = el.getRegion();       
           //If we are at a viewport boundary and the aligned el is anchored on a target border that is
           //perpendicular to the vp border, allow the aligned el to slide on that border,
           //otherwise swap the aligned el to the opposite border of the target.
           p1y = p1.charAt(0);
           p1x = p1.charAt(p1.length-1);
           p2y = p2.charAt(0);
           p2x = p2.charAt(p2.length-1);
           swapY = ((p1y=="t" && p2y=="b") || (p1y=="b" && p2y=="t"));
           swapX = ((p1x=="r" && p2x=="l") || (p1x=="l" && p2x=="r"));          
           

           if (x + w > dw + scrollX) {
                x = swapX ? r.left-w : dw+scrollX-w;
           }
           if (x < scrollX) {
               x = swapX ? r.right : scrollX;
           }
           if (y + h > dh + scrollY) {
                y = swapY ? r.top-h : dh+scrollY-h;
            }
           if (y < scrollY){
               y = swapY ? r.bottom : scrollY;
           }
        }
        return [x,y];
    },

    /**
     * Aligns this element with another element relative to the specified anchor points. If the other element is the
     * document it aligns it to the viewport.
     * The position parameter is optional, and can be specified in any one of the following formats:
     * <ul>
     *   <li><b>Blank</b>: Defaults to aligning the element's top-left corner to the target's bottom-left corner ("tl-bl").</li>
     *   <li><b>One anchor (deprecated)</b>: The passed anchor position is used as the target element's anchor point.
     *       The element being aligned will position its top-left corner (tl) to that point.  <i>This method has been
     *       deprecated in favor of the newer two anchor syntax below</i>.</li>
     *   <li><b>Two anchors</b>: If two values from the table below are passed separated by a dash, the first value is used as the
     *       element's anchor point, and the second value is used as the target's anchor point.</li>
     * </ul>
     * In addition to the anchor points, the position parameter also supports the "?" character.  If "?" is passed at the end of
     * the position string, the element will attempt to align as specified, but the position will be adjusted to constrain to
     * the viewport if necessary.  Note that the element being aligned might be swapped to align to a different position than
     * that specified in order to enforce the viewport constraints.
     * Following are all of the supported anchor positions:
<pre>
Value  Description
-----  -----------------------------
tl     The top left corner (default)
t      The center of the top edge
tr     The top right corner
l      The center of the left edge
c      In the center of the element
r      The center of the right edge
bl     The bottom left corner
b      The center of the bottom edge
br     The bottom right corner
</pre>
Example Usage:
<pre><code>
// align el to other-el using the default positioning ("tl-bl", non-constrained)
el.alignTo("other-el");

// align the top left corner of el with the top right corner of other-el (constrained to viewport)
el.alignTo("other-el", "tr?");

// align the bottom right corner of el with the center left edge of other-el
el.alignTo("other-el", "br-l?");

// align the center of el with the bottom left corner of other-el and
// adjust the x position by -6 pixels (and the y position by 0)
el.alignTo("other-el", "c-bl", [-6, 0]);
</code></pre>
     * @param {Mixed} element The element to align to.
     * @param {String} position The position to align to.
     * @param {Array} offsets (optional) Offset the positioning by [x, y]
     * @param {Boolean/Object} animate (optional) true for the default animation or a standard Element animation config object
     * @return {Ext.Element} this
     */
    alignTo : function(element, position, offsets, animate){
	    var me = this;
        return me.setXY(me.getAlignToXY(element, position, offsets),
          		        me.preanim && !!animate ? me.preanim(arguments, 3) : false);
    },
    
    // private ==>  used outside of core
    adjustForConstraints : function(xy, parent, offsets){
        return this.getConstrainToXY(parent || document, false, offsets, xy) ||  xy;
    },

    // private ==>  used outside of core
    getConstrainToXY : function(el, local, offsets, proposedXY){   
	    var os = {top:0, left:0, bottom:0, right: 0};

        return function(el, local, offsets, proposedXY){
            el = Ext.get(el);
            offsets = offsets ? Ext.applyIf(offsets, os) : os;

            var vw, vh, vx = 0, vy = 0;
            if(el.dom == document.body || el.dom == document){
                vw =Ext.lib.Dom.getViewWidth();
                vh = Ext.lib.Dom.getViewHeight();
            }else{
                vw = el.dom.clientWidth;
                vh = el.dom.clientHeight;
                if(!local){
                    var vxy = el.getXY();
                    vx = vxy[0];
                    vy = vxy[1];
                }
            }

            var s = el.getScroll();

            vx += offsets.left + s.left;
            vy += offsets.top + s.top;

            vw -= offsets.right;
            vh -= offsets.bottom;

            var vr = vx+vw;
            var vb = vy+vh;

            var xy = proposedXY || (!local ? this.getXY() : [this.getLeft(true), this.getTop(true)]);
            var x = xy[0], y = xy[1];
            var w = this.dom.offsetWidth, h = this.dom.offsetHeight;

            // only move it if it needs it
            var moved = false;

            // first validate right/bottom
            if((x + w) > vr){
                x = vr - w;
                moved = true;
            }
            if((y + h) > vb){
                y = vb - h;
                moved = true;
            }
            // then make sure top/left isn't negative
            if(x < vx){
                x = vx;
                moved = true;
            }
            if(y < vy){
                y = vy;
                moved = true;
            }
            return moved ? [x, y] : false;
        };
    }(),
	    
	    
	        
//         el = Ext.get(el);
//         offsets = Ext.applyIf(offsets || {}, {top : 0, left : 0, bottom : 0, right : 0});

//         var	me = this,
//         	doc = document,
//         	s = el.getScroll(),
//         	vxy = el.getXY(),
//         	vx = offsets.left + s.left, 
//         	vy = offsets.top + s.top,            	
//         	vw = -offsets.right, 
//         	vh = -offsets.bottom, 
//         	vr,
//         	vb,
//         	xy = proposedXY || (!local ? me.getXY() : [me.getLeft(true), me.getTop(true)]),
//         	x = xy[0],
//         	y = xy[1],
//         	w = me.dom.offsetWidth, h = me.dom.offsetHeight,
//         	moved = false; // only move it if it needs it
//       
//         	
//         if(el.dom == doc.body || el.dom == doc){
//             vw += Ext.lib.Dom.getViewWidth();
//             vh += Ext.lib.Dom.getViewHeight();
//         }else{
//             vw += el.dom.clientWidth;
//             vh += el.dom.clientHeight;
//             if(!local){                    
//                 vx += vxy[0];
//                 vy += vxy[1];
//             }
//         }

//         // first validate right/bottom
//         if(x + w > vx + vw){
//             x = vx + vw - w;
//             moved = true;
//         }
//         if(y + h > vy + vh){
//             y = vy + vh - h;
//             moved = true;
//         }
//         // then make sure top/left isn't negative
//         if(x < vx){
//             x = vx;
//             moved = true;
//         }
//         if(y < vy){
//             y = vy;
//             moved = true;
//         }
//         return moved ? [x, y] : false;
//    },
    
    /**
    * Calculates the x, y to center this element on the screen
    * @return {Array} The x, y values [x, y]
    */
    getCenterXY : function(){
        return this.getAlignToXY(document, 'c-c');
    },

    /**
    * Centers the Element in either the viewport, or another Element.
    * @param {Mixed} centerIn (optional) The element in which to center the element.
    */
    center : function(centerIn){
        return this.alignTo(centerIn || document, 'c-c');        
    }    
});
