Yahoo! UI Library

(function(Y) {
/** 
 * Add style management functionality to DOM.
 * @module dom
 * @submodule dom-style
 * @for DOM
 */

var DOCUMENT_ELEMENT = 'documentElement',
    DEFAULT_VIEW = 'defaultView',
    OWNER_DOCUMENT = 'ownerDocument',
    STYLE = 'style',
    FLOAT = 'float',
    CSS_FLOAT = 'cssFloat',
    STYLE_FLOAT = 'styleFloat',
    TRANSPARENT = 'transparent',
    GET_COMPUTED_STYLE = 'getComputedStyle',

    DOCUMENT = Y.config.doc,
    UNDEFINED = undefined,

    re_color = /color$/i;


Y.mix(Y.DOM, {
    CUSTOM_STYLES: {
    },


    /**
     * Sets a style property for a given element.
     * @method setStyle
     * @param {HTMLElement} An HTMLElement to apply the style to.
     * @param {String} att The style property to set. 
     * @param {String|Number} val The value. 
     */
    setStyle: function(node, att, val, style) {
        style = style || node.style;
        var CUSTOM_STYLES = Y.DOM.CUSTOM_STYLES;

        if (style) {
            if (val === null) {
                val = ''; // normalize for unsetting
            }
            if (att in CUSTOM_STYLES) {
                if (CUSTOM_STYLES[att].set) {
                    CUSTOM_STYLES[att].set(node, val, style);
                    return; // NOTE: return
                } else if (typeof CUSTOM_STYLES[att] === 'string') {
                    att = CUSTOM_STYLES[att];
                }
            }
            style[att] = val; 
        }
    },

    /**
     * Returns the current style value for the given property.
     * @method getStyle
     * @param {HTMLElement} An HTMLElement to get the style from.
     * @param {String} att The style property to get. 
     */
    getStyle: function(node, att) {
        var style = node[STYLE],
            CUSTOM_STYLES = Y.DOM.CUSTOM_STYLES,
            val = '';

        if (style) {
            if (att in CUSTOM_STYLES) {
                if (CUSTOM_STYLES[att].get) {
                    return CUSTOM_STYLES[att].get(node, att, style); // NOTE: return
                } else if (typeof CUSTOM_STYLES[att] === 'string') {
                    att = CUSTOM_STYLES[att];
                }
            }
            val = style[att];
            if (val === '') { // TODO: is empty string sufficient?
                val = Y.DOM[GET_COMPUTED_STYLE](node, att);
            }
        }

        return val;
    },

    /**
     * Sets multiple style properties.
     * @method setStyles
     * @param {HTMLElement} node An HTMLElement to apply the styles to. 
     * @param {Object} hash An object literal of property:value pairs. 
     */
    setStyles: function(node, hash) {
        var style = node.style;
        Y.each(hash, function(v, n) {
            Y.DOM.setStyle(node, n, v, style);
        }, Y.DOM);
    },

    /**
     * Returns the computed style for the given node.
     * @method getComputedStyle
     * @param {HTMLElement} An HTMLElement to get the style from.
     * @param {String} att The style property to get. 
     * @return {String} The computed value of the style property. 
     */
    getComputedStyle: function(node, att) {
        var val = '',
            doc = node[OWNER_DOCUMENT];

        if (node[STYLE]) {
            val = doc[DEFAULT_VIEW][GET_COMPUTED_STYLE](node, null)[att];
        }
        return val;
    }
});

// normalize reserved word float alternatives ("cssFloat" or "styleFloat")
if (DOCUMENT[DOCUMENT_ELEMENT][STYLE][CSS_FLOAT] !== UNDEFINED) {
    Y.DOM.CUSTOM_STYLES[FLOAT] = CSS_FLOAT;
} else if (DOCUMENT[DOCUMENT_ELEMENT][STYLE][STYLE_FLOAT] !== UNDEFINED) {
    Y.DOM.CUSTOM_STYLES[FLOAT] = STYLE_FLOAT;
}

// fix opera computedStyle default color unit (convert to rgb)
if (Y.UA.opera) {
    Y.DOM[GET_COMPUTED_STYLE] = function(node, att) {
        var view = node[OWNER_DOCUMENT][DEFAULT_VIEW],
            val = view[GET_COMPUTED_STYLE](node, '')[att];

        if (re_color.test(att)) {
            val = Y.Color.toRGB(val);
        }

        return val;
    };

}

// safari converts transparent to rgba(), others use "transparent"
if (Y.UA.webkit) {
    Y.DOM[GET_COMPUTED_STYLE] = function(node, att) {
        var view = node[OWNER_DOCUMENT][DEFAULT_VIEW],
            val = view[GET_COMPUTED_STYLE](node, '')[att];

        if (val === 'rgba(0, 0, 0, 0)') {
            val = TRANSPARENT; 
        }

        return val;
    };

}
})(Y);