/*
Script: Fx.CSS.js
Contains the CSS animation logic. Used by Fx.Tween, Fx.Morph, Fx.Elements.

License:
MIT-style license.
*/

Fx.CSS = new Class({

Extends: Fx,

//prepares the base from/to object

prepare: function(element, property, values){
values = $splat(values);
var values1 = values[1];
if (!$chk(values1)){
values[1] = values[0];
values[0] = element.getStyle(property);
}
var parsed = values.map(this.parse);
return {from: parsed[0], to: parsed[1]};
},

//parses a value into an array

parse: function(value){
value = $lambda(value)();
value = (typeof value == 'string') ? value.split(' ') : $splat(value);
return value.map(function(val){
val = String(val);
var found = false;
Fx.CSS.Parsers.each(function(parser, key){
if (found) return;
var parsed = parser.parse(val);
if ($chk(parsed)) found = {value: parsed, parser: parser};
});
found = found || {value: val, parser: Fx.CSS.Parsers.String};
return found;
});
},

//computes by a from and to prepared objects, using their parsers.

compute: function(from, to, delta){
var computed = [];
(Math.min(from.length, to.length)).times(function(i){
computed.push({value: from[i].parser.compute(from[i].value, to[i].value, delta), parser: from[i].parser});
});
computed.$family = {name: 'fx:css:value'};
return computed;
},

//serves the value as settable

serve: function(value, unit){
if ($type(value) != 'fx:css:value') value = this.parse(value);
var returned = [];
value.each(function(bit){
returned = returned.concat(bit.parser.serve(bit.value, unit));
});
return returned;
},

//renders the change to an element

render: function(element, property, value, unit){
element.setStyle(property, this.serve(value, unit));
},

//searches inside the page css to find the values for a selector

search: function(selector){
if (Fx.CSS.Cache[selector]) return Fx.CSS.Cache[selector];
var to = {};
Array.each(document.styleSheets, function(sheet, j){
var href = sheet.href;
if (href && href.contains('://') && !href.contains(document.domain)) return;
var rules = sheet.rules || sheet.cssRules;
Array.each(rules, function(rule, i){
if (!rule.style) return;
var selectorText = (rule.selectorText) ? rule.selectorText.replace(/^\w+/, function(m){
return m.toLowerCase();
}) : null;
if (!selectorText || !selectorText.test('^' + selector + '$')) return;
Element.Styles.each(function(value, style){
if (!rule.style[style] || Element.ShortStyles[style]) return;
value = String(rule.style[style]);
to[style] = (value.test(/^rgb/)) ? value.rgbToHex() : value;
});
});
});
return Fx.CSS.Cache[selector] = to;
}

});

Fx.CSS.Cache = {};

Fx.CSS.Parsers = new Hash({

Color: {
parse: function(value){
if (value.match(/^#[0-9a-f]{3,6}$/i)) return value.hexToRgb(true);
return ((value = value.match(/(\d+),\s*(\d+),\s*(\d+)/))) ? [value[1], value[2], value[3]] : false;
},
compute: function(from, to, delta){
return from.map(function(value, i){
return Math.round(Fx.compute(from[i], to[i], delta));
});
},
serve: function(value){
return value.map(Number);
}
},

Number: {
parse: parseFloat,
compute: Fx.compute,
serve: function(value, unit){
return (unit) ? value + unit : value;
}
},

String: {
parse: $lambda(false),
compute: $arguments(1),
serve: $arguments(0)
}

});