/*!
* Watermark v1.1.0
*  A jQuery Plugin for adding watermarks to text-based form fields.
*  http://azoffdesign.com/watermark
*
* Intended for use with the latest jQuery
*  http://code.jquery.com/jquery-latest.min.js
*
* Copyright 2010, Jonathan Azoff
* Dual licensed under the MIT or GPL Version 2 licenses.
*  http://jquery.org/license
*
* Date: Wednesday, April 4th 2010
*/

/* 
* Usage:
* 
* $(selector).watermark([options]);
*  "options" is an optional JavaScript object that you may pass if you would like to customize
*  the watermark application. Below is a list of properties that you may set on
*  the options object and their respective effect:
*   - options.color	{String} The color to use for the watermarked text (default "#AAA").
*   - options.text		{String} The text to use for the watermark, overrides the default (default uses title attribute)
*
* Notes:
* 
* The plug-in applies a submit handler to any parent forms so that watermarked text is not submitted when the form is.
* However, this may not prevent all cases of form submission (such as AJAX serialization + submission) so caution should be     
* taken on the server-side to ensure validity of the submitted values.       
*
* Changelog:
*
* 1.1.0 
*   - Updated license
*	 - Refactored to prevent memory leaks, maximize code reuse
*   - Added jslint to the build process
*	 - Namespaced code
*
* 1.0.4
*   - Added fix to clear input before submission if field is empty (thanks alice)
*
* 1.0.3
*   - Fixed css inherit bug for ie7 (thanks ambrauer) *
*
* 1.0.2
*   - Simplified dragging support
*   - Refactored focus initialization behavior 
*
* 1.0.1
*   - Improved listeners so that they handle text dragged into the boxes (thanks to Jury for this one!)
*   
*/

/*jslint onevar: true, strict: true */
/*global jQuery: false */
"use strict";

(function ($, w) {

    // public exposed watermark extension
    w = $.fn.watermark = function (options) {
        return this.each(function () {
            w.init($(this), options);
        });
    };

    // events watermark listens to
    w.events = {
        on: "blur",
        off: "focus drop"
    };

    // reusable constants and strings
    w.constants = {
        color: "#AAA",
        css: "color", // cause I'm anal
        key: "w",
        applied: "watermarked",
        watermarkable: "textarea,input[type='text'],input[type='password']"
    };

    // constructor for each watermarkable element
    w.init = function (obj, options) {

        if (obj.is(w.constants.watermarkable) && !obj.data(w.constants.applied)) {

            options = $.extend({
                text: obj.attr("title"),
                color: w.constants.color
            }, (options || {}));

            obj.closest("form").bind("submit", obj, w.onSubmit);

            // attach handlers
            obj.bind(w.events.on, options, w.on)
			   .bind(w.events.off, options, w.off);

            // apply the watermark
            w.on.call(obj, { data: options });

            obj.data(w.constants.applied, true);

        }

    };

    // applies the watermark
    w.on = function (event, obj, options) {
        obj = $(this);
        options = event.data;
        if (obj.val().length === 0 && !obj.data(w.constants.key)) {

            obj.data(w.constants.key, true)
			   .css(w.constants.css, options.color)
			   .val(options.text);

        }
    };

    // removes the watermark
    w.off = function (event, obj, options) {
        obj = $(this);
        options = event.data;
        if (obj.data(w.constants.key)) {

            obj.data(w.constants.key, false).css(w.constants.css, "");

            // capture drag and drop
            if (event.originalEvent && event.originalEvent.dataTransfer) {
                obj.val(event.originalEvent.dataTransfer.getData("Text"));
            } else {
                obj.val("");
            }

        }
    };

    // clears watermarked elements on parent form submission event
    w.onSubmit = function (event, obj) {
        obj = event.data;
        if (obj.data(w.constants.key)) {
            obj.val("");
        }
        return true;
    };

})(jQuery);