/*
 * app scale v1.0 beta build 090301 copyright (c) 2009 ilwave ce. http://ilwave.spaces.live.com
 *
 * this class is part of lib - a javascript library which is still on designing, and is an extend copy of class "object" in lib.
 * before using this class, you might include lib.common.js and lib.physical.js first.
 *
 * 注意：本类需要 lib.common.js 和 lib.physical.js 的支持。
 *
 */
 
var scale = object.extend({
	
	construct: function(oframediv, obuttondiv, nheight)
	{
		this.oframediv = oframediv;
		this.obuttondiv = obuttondiv;
		this.nheight = nheight;
		
		this.currframe = -1;
		this.ntargetframe = -1;
		this.arrbuttons = [];
		this.odelay = null;
		
		var _this = this;
		var nframes = page.navigator < 3 ? oframediv.childnodes.length : (oframediv.childnodes.length - 1) / 2;
		
		for (var i=1; i<=nframes; i++)
		{
			var thebutton = document.createelement("a");
				thebutton.tabindex = i;
				thebutton.classname = "s-normal";
				thebutton.href = "javascript:void(0)";
				thebutton.innerhtml = i;

				thebutton.onmouseover = function()
				{
					var ntabindex = this.tabindex;
					var ntargetframe = ntabindex-1;

					_this.ntargetframe = ntargetframe;
					_this.odelay && window.cleartimeout(_this.odelay);
					_this.odelay = window.settimeout(function(){_this.doscale(ntargetframe);}, 200);
				};

				thebutton.onmouseout = function()
				{
					_this.autoscale();
				};

			obuttondiv.appendchild(thebutton) && this.arrbuttons.push(thebutton);
			
			if (this.currframe == -1)
			{
				this.currframe = 0;
				this.highlight(0);
			}
		}
		
		this.autoscale();
	},
	
	scaleto: function(nframe)
	{
		var ncurrtop = this.currframe * this.nheight;
		var arrsteplist = physical.smooth(ncurrtop, nframe * this.nheight, 20, 0);

		for(var i=0; i<arrsteplist.length; i++)
		{
			page.joblist.push(['_("' + this.oframediv.id + '").style.top = "-' + arrsteplist[i] + 'px";', 10]);
		}
		
		page.dojob();
	},
	
	highlight: function(nframe)
	{
		this.arrbuttons[this.currframe].classname = "s-normal";
		this.arrbuttons[nframe].classname = "s-current";
	},
	
	doscale: function(nframe)
	{
		// 核对是否需要滚动以及滚动过快的情况
		if(nframe == this.currframe || nframe != this.ntargetframe) return false;
		
		this.highlight(nframe);
		this.scaleto(nframe);
		this.currframe = nframe;
	},
	
	autoscale: function()
	{
		var _this = this;
		var nnextframe = this.currframe + 1 <= this.arrbuttons.length - 1 ? this.currframe + 1 : 0;
		
		_this.ntargetframe = nnextframe;
		_this.odelay = window.settimeout(function(){_this.doscale(nnextframe); _this.autoscale();}, 5500);
	}

});