/*** slide obj ***/

dw_scrollObjs = {};
dw_scrollObj.speed = 100; 

function dw_scrollObj(wnId, lyrId, cntId) {
	this.id = wnId; dw_scrollObjs[this.id] = this;
	this.animString = "dw_scrollObjs." + this.id;
	this.load(lyrId, cntId);
}

dw_scrollObj.loadLayer = function(wnId, id, cntId) {
	if ( dw_scrollObjs[wnId] ) dw_scrollObjs[wnId].load(id, cntId);
}

dw_scrollObj.prototype.load = function(lyrId, cntId) {
	if (!document.getElementById) return;
	var wndo, lyr;
	if (this.lyrId) {
        	lyr = document.getElementById(this.lyrId);
	        lyr.style.visibility = "hidden";
	    }
	lyr = document.getElementById(lyrId);
	wndo = document.getElementById(this.id);
	lyr.style.top = this.y = 0; lyr.style.left = this.x = 0;
	this.maxY = (lyr.offsetHeight - wndo.offsetHeight > 0)? lyr.offsetHeight - wndo.offsetHeight: 0;
	this.wd = cntId? document.getElementById(cntId).offsetWidth: lyr.offsetWidth;
	this.maxX = (this.wd - wndo.offsetWidth > 0)? this.wd - wndo.offsetWidth: 0;
	this.lyrId = lyrId; // hold id of currently visible layer
	lyr.style.visibility = "visible";
	this.on_load(); this.ready = true;
}

dw_scrollObj.prototype.on_load = function() {}  

dw_scrollObj.prototype.shiftTo = function(lyr, x, y) {
	lyr.style.left = (this.x = x) + "px"; 
	lyr.style.top = (this.y = y) + "px";
}

dw_scrollObj.GeckoTableBugFix = function() {
	var ua = navigator.userAgent;
	if ( ua.indexOf("Gecko") > -1 && ua.indexOf("Firefox") == -1 
		&& ua.indexOf("Safari") == -1 && ua.indexOf("Konqueror") == -1 ) {
	        dw_scrollObj.hold = []; // holds id's of wndo and its container
	        for (var i=0; arguments[i]; i++) {
        		if ( dw_scrollObjs[ arguments[i] ] ) {
	        	        var wndo = document.getElementById( arguments[i] );
        		        var holderId = wndo.parentNode.id;
	                	var holder = document.getElementById(holderId);
	                	document.body.appendChild( holder.removeChild(wndo) );
        		        wndo.style.zIndex = 1000;
        	        	var pos = getPageOffsets(holder);
		                wndo.style.left = pos.x + "px"; wndo.style.top = pos.y + "px";
        	        	dw_scrollObj.hold[i] = [ arguments[i], holderId ];
	        	}
        	}
	        window.addEventListener("resize", dw_scrollObj.rePositionGecko, true);
	}
}

dw_scrollObj.rePositionGecko = function() {
	if (dw_scrollObj.hold) {
        	for (var i=0; dw_scrollObj.hold[i]; i++) {
	        var wndo = document.getElementById( dw_scrollObj.hold[i][0] );
        	var holder = document.getElementById( dw_scrollObj.hold[i][1] );
	        var pos = getPageOffsets(holder);
        	wndo.style.left = pos.x + "px"; wndo.style.top = pos.y + "px";
	        }
	}
}

function getPageOffsets(el) {
	var left = el.offsetLeft;
	var top = el.offsetTop;
	if ( el.offsetParent && el.offsetParent.clientLeft || el.offsetParent.clientTop ) {
	        left += el.offsetParent.clientLeft;
        	top += el.offsetParent.clientTop;
	}
	while ( el = el.offsetParent ) {
        	left += el.offsetLeft;
	        top += el.offsetTop;
	}
	return { x:left, y:top };
}

/*** Slide ***/

dw_scrollObj.slideDur = 500; // duration of glide

dw_scrollObj.scrollBy = function(wnId, x, y, dur) {
	if ( dw_scrollObjs[wnId] ) dw_scrollObjs[wnId].glideBy(x, y, dur);
}

dw_scrollObj.scrollTo = function(wnId, x, y, dur) {
	if ( dw_scrollObjs[wnId] ) dw_scrollObjs[wnId].glideTo(x, y, dur);
}

dw_scrollObj.prototype.glideBy = function(dx, dy, dur) {
	if ( !document.getElementById || this.sliding ) return;
	this.slideDur = dur || dw_scrollObj.slideDur;
	this.destX = this.destY = this.distX = this.distY = 0;
	this.lyr = document.getElementById(this.lyrId);
	this.startX = this.x; this.startY = this.y;
	if (dy < 0) this.distY = (this.startY + dy >= -this.maxY)? dy: -(this.startY  + this.maxY);
	else if (dy > 0) this.distY = (this.startY + dy <= 0)? dy: -this.startY;
	if (dx < 0) this.distX = (this.startX + dx >= -this.maxX)? dx: -(this.startX + this.maxX);
	else if (dx > 0) this.distX = (this.startX + dx <= 0)? dx: -this.startX;
	this.destX = this.startX + this.distX; this.destY = this.startY + this.distY;
	this.slideTo(this.destX, this.destY);
}

dw_scrollObj.prototype.glideTo = function(destX, destY, dur) {
	if ( !document.getElementById || this.sliding) return;
	this.slideDur = dur || dw_scrollObj.slideDur;
	this.lyr = document.getElementById(this.lyrId); 
	this.startX = this.x; this.startY = this.y;
	this.destX = -Math.max( Math.min(destX, this.maxX), 0);
	this.destY = -Math.max( Math.min(destY, this.maxY), 0);
	this.distY = this.destY - this.startY;
	this.distX =  this.destX - this.startX;
	this.slideTo(this.destX, this.destY);
}

dw_scrollObj.prototype.slideTo = function(destX, destY) {
	this.per = Math.PI/(2 * this.slideDur); this.sliding = true;
	this.slideStart = (new Date()).getTime();
	this.aniTimer = setInterval(this.animString + ".doSlide()",10);
	this.on_slide_start(this.destX);
}

dw_scrollObj.prototype.doSlide = function() {
	var elapsed = (new Date()).getTime() - this.slideStart;
	if (elapsed < this.slideDur) {
		var x = this.startX + this.distX * Math.sin(this.per*elapsed);
		var y = this.startY + this.distY * Math.sin(this.per*elapsed);
		this.shiftTo(this.lyr, x, y); this.on_slide(x, y);
	} else {	// if time's up
		clearInterval(this.aniTimer); this.sliding = false;
		this.shiftTo(this.lyr, this.destX, this.destY);
		this.lyr = null; this.on_slide_end(this.destX, this.destY);
	}
}


dw_scrollObj.prototype.on_slide_start = function(destX) {
	startScroll(destX);
}
dw_scrollObj.prototype.on_slide = function() {}

dw_scrollObj.prototype.on_slide_end = function() {
	endScroll();
}