/* Description:
*
* This file contains functions that create custom visual effects that are used by many web pages.
*
* New functions should only be added to this file if:
*  * They are used by many different web pages;
*  * They pertain to visual effects.
*
*/

/* function toggle_lightbox_for(div_id) {{{
*
* Description:
*  Shows or hides the requested lightbox. If the lightbox is visible, it'll be hidden.
*  If it's hidden, it'll be shown.
*
* Arguments:
*  div_id      The ID of the div that contains the lightbox content.
*
* Returns:
*  Nothing
*
*/
function toggle_lightbox_for(div_id) {
	var overlay_id = 'lightbox-overlay';

	if ($(div_id).visible()) {
		$(div_id).hide();
		$(overlay_id).hide();
	}
	else {
		$(div_id).show();
		$(overlay_id).show();
	}

	return false;
} // }}}


/* function set_scriptaculous_blind_duration(duration) {{{
*
* Description:
*  Sets the global variable "blind_duration", which controls how long
*  Scriptaculous BlindUp and BlindDown effects last for.
*
* Arguments:
*  duration      The number of seconds that BlindUp and BlindDown effects should last for.
*                This argument is optional. It defaults to 0.5 .
*
* Returns:
*  Nothing
*
*/
function set_scriptaculous_blind_duration(duration) {
	blind_duration = typeof (duration) == 'undefined' ? 0.5 : duration;
}
set_scriptaculous_blind_duration();
// }}}

/* function toggle_blinding_for(element) {{{
*
* Description:
*  Toggles a DOM element to be blinded up or down, depending on
*  whether it's currently visible or hidden.
*
* Arguments:
*  element     The DOM element, or the ID of the DOM element, to toggle.
*
* Returns:
*  Nothing
*
*/
function toggle_blinding_for(element) {
	if ($(element))
	{ Effect.toggle(element, 'blind', { duration: blind_duration }); }
} // }}}

/* function add_blinding_to_form_field(form_field, tooltip) {{{
*
* Description:
*  Causes the "tooltip" element to be shown when the "form_field" element obtains focus,
*  and the "tooltip" element to be hidden when the "form_field" element loses focus.
*
* *** NOTE:
*  Do _NOT_ use this function to set blinding on a password field that was created by an ASP.Net "TextBox" control.
*  I don't know why, but if this function sets the "onblur" event for an ASP.Net password textbox control, the
*  function called by the "onblur" loses all of the variables that would be expected inside the closure.
*
* Arguments:
*  form_field    The DOM element, or the ID of the DOM element, that represents the form field.
*  tooltip       The DOM element, or the ID of the DOM element, that represents the tooltip.
*
* Returns:
*  Nothing
*
*/
function add_blinding_to_form_field(form_field, tooltip) {
	var form_field_element = $(form_field);
	var tooltip_element = $(tooltip);

	if (form_field_element && tooltip_element) {
		form_field_element.onfocus = function() { toggle_blinding_for(tooltip_element); }
		form_field_element.onblur = function() { toggle_blinding_for(tooltip_element); }
	}
} // }}}

/* function hide_and_show_with_blind() {{{
*
* Description:
*  If "element_to_hide" is visible, it will be hidden. "element_to_show" will then be shown.
*
* Arguments:
*  element_to_hide    The element to hide *before* showing "element_to_show". This can be a DOM element object, or a string containing the ID.
*  element_to_show    The element to show. This can be a DOM element object, or a string containing the ID.
*
* Returns:
*  Nothing
*
*/
function hide_and_show_with_blind(element_to_hide, element_to_show) {
	// If "element_to_hide" is hidden, don't call Effect.BlindUp() on it. 
	// This is because the user won't see anything, and it will delay showing "element_to_show".
	if ($(element_to_hide).visible()) {
		Effect.BlindUp(element_to_hide, {
			duration: blind_duration,
			afterFinish: function() { Effect.BlindDown(element_to_show, { duration: blind_duration }); }
		});
	}
	else
	{ Effect.BlindDown(element_to_show, { duration: blind_duration }); }
} // }}}

/* show_if_hidden(element)() {{{
*
* Description:
*  If "element" is hidden, it will be shown.
*
* Arguments:
*  element     The element to show.
*
* Returns:
*  Nothing
*
*/
function show_if_hidden(element) {
	if ($(element) && !$(element).visible())
	{ Effect.BlindDown(element, { duration: blind_duration }); }
} // }}}

/* hide_if_visible(element)() {{{
*
* Description:
*  If "element" is visible, it will be hidden.
*
* Arguments:
*  element     The element to hide.
*
* Returns:
*  Nothing
*
*/
function hide_if_visible(element) {
	if ($(element) && $(element).visible())
	{ Effect.BlindUp(element, { duration: blind_duration }); }
} // }}}