/*
* In-Field Label jQuery Plugin
*
* Branch Author:
*   Copyright (c) 2009 Paul Elliott with Red-Line IT
*   http://github.com/paulelliott/In-Field-Labels-jQuery-Plugin/tree/master
*
* Original Author:
*   Copyright (c) 2009 Doug Neiner
*   http://fuelyourcoding.com/scripts/infield.html
*
* Dual licensed under the MIT and GPL licenses.
* Uses the same license as jQuery, see:
* http://docs.jquery.com/License
*
* @version 0.3
*/
(function ($) {
    $.InFieldLabels = function (label, field, options) {
        // To avoid scope issues, use 'base' instead of 'this'
        // to reference this class from internal events and functions.
        var base = this;

        // Access to jQuery and DOM versions of each element
        base.$label = $(label);
        base.label = label;

        base.$field = $(field);
        base.field = field;

        base.$label.data("InFieldLabels", base);
        base.showing = true;

        base.init = function () {
            // Merge supplied options with default options
            base.options = $.extend({}, $.InFieldLabels.defaultOptions, options);

            // Check if the field is already filled in
            if (base.$field.val() != "") {
                base.$label.hide();
                base.showing = false;
            };

            base.$field.focus(function () {
                base.fadeOnFocus();
            }).blur(function () {
                base.checkForEmpty(true);
            }).bind('keydown.infieldlabel', function (e) {
                // Use of a namespace (.infieldlabel) allows us to
                // unbind just this method later
                base.hideOnChange(e);
            }).change(function (e) {
                base.checkForEmpty();
            }).bind('onPropertyChange', function () {
                base.checkForEmpty();
            });
        };

        // If the label is currently showing
        // then fade it down to the amount
        // specified in the settings
        base.fadeOnFocus = function () {
            base.showing && base.setOpacity(base.options.fadeOpacity);
        };

        base.setOpacity = function (opacity) {
            base.$label.stop().animate({ opacity: opacity }, base.options.fadeDuration);
            base.showing = (opacity > 0.0);
        };

        // Checks for empty as a fail safe
        // set blur to true when passing from
        // the blur event
        base.checkForEmpty = function (blur) {
            if (base.$field.val() == "") {
                base.prepForShow();
                base.setOpacity(blur ? 1.0 : base.options.fadeOpacity);
            } else {
                base.setOpacity(0.0);
            };
        };

        base.prepForShow = function (e) {
            if (!base.showing) {
                // Prepare for a animate in...
                base.$label.css({ opacity: 0.0 }).show();

                // Reattach the keydown event
                base.$field.bind('keydown.infieldlabel', function (e) {
                    base.hideOnChange(e);
                });
            };
        };

        base.hideOnChange = function (e) {
            //Skip shift and tab
            if ((e.keyCode == 16) || (e.keyCode == 9)) return;

            if (base.showing) {
                base.$label.hide();
                base.showing = false;
            };

            // Remove keydown event to save on CPU processing
            base.$field.unbind('keydown.infieldlabel');
        };

        // Run the initialization method
        base.init();
    };

    $.InFieldLabels.defaultOptions = {
        fadeOpacity: 0.5,     // Label opacity with focus.
        fadeDuration: 300,     // Animation duration from 1.0 opacity to the fadeOpacity.
        calculatePadding: false, // Auto-calculate the padding offset for the label.
        labelClass: ''	    // Additional CSS class to apply to the label.
    };

    $.fn.inFieldLabels = function (options) {
        if (options === 'remove') {
            //Removes the label from the selected input fields.
            return this.each(function () {
                var input = $(this);
                input.inFieldLabels('get').remove();
                input.removeData('jquery-infieldlabel-id');
            });
        } else if (options === 'get') {
            //Gets the labels for the selected input fields.
            var labels = [];
            this.each(function () {
                labels = $.merge(labels, $.makeArray($("#" + $(this).data('jquery-infieldlabel-id'))));
            });
            return $(labels);
        } else {
            //Merges the default options into the passed in options.
            if (!options) options = {};
            else if (typeof options === 'string') options = { text: options };
            options = $.extend({}, $.InFieldLabels.defaultOptions, options);

            //Applies the labels to the selected input fields.
            return this.each(function () {
                var $input = $(this);

                if (options.attr)
                    options.text = $input.attr(options.attr);

                //Create the label and store the id in a data field of the form element.
                var id = "infieldlabel" + labelCount++;
                $input.data("jquery-infieldlabel-id", id);
                $("body").append("<label id='" + id + "' for='" + this.id + "' class='infieldlabel " + options.labelClass + "'>" +
          options.text + "</label>");
                var $label = $("#" + id);

                //This will prevent an overlay from closing is in case the label is rendered inside an overlay.
                $label.click(function () {
                    $input.focus();
                    return false;
                });

                //Calculate the offset and padding for the label based on that of the input.
                var offset = $input.offset();
                if (options.calculatePadding === true) {
                    options.padding = (($input.outerHeight() - $input.height()) / 2) + "px " +
            ((($input.outerWidth() - $input.width()) / 2)) + "px";
                }
                $label.css({
                    position: 'absolute',
                    top: offset.top + "px",
                    left: offset.left + "px"
                });
                if (options.padding) $label.css('padding', options.padding);

                // Only create object for input[text], input[password], or textarea
                (new $.InFieldLabels($label[0], this, options));
            });
        }
    };

    var labelCount = 0;
})(jQuery);