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diff --git a/gitweb/static/js/adjust-timezone.js b/gitweb/static/js/adjust-timezone.js
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+// Copyright (C) 2011, John 'Warthog9' Hawley <warthog9@eaglescrag.net>
+//               2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview Manipulate dates in gitweb output, adjusting timezone
+ * @license GPLv2 or later
+ */
+
+/**
+ * Get common timezone, add UI for changing timezones, and adjust
+ * dates to use requested common timezone.
+ *
+ * This function is called during onload event (added to window.onload).
+ *
+ * @param {String} tzDefault: default timezone, if there is no cookie
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzCookieInfo.name: name of cookie to store timezone
+ * @param {String} tzClassName: denotes elements with date to be adjusted
+ */
+function onloadTZSetup(tzDefault, tzCookieInfo, tzClassName) {
+	var tzCookieTZ = getCookie(tzCookieInfo.name, tzCookieInfo);
+	var tz = tzDefault;
+
+	if (tzCookieTZ) {
+		// set timezone to value saved in a cookie
+		tz = tzCookieTZ;
+		// refresh cookie, so its expiration counts from last use of gitweb
+		setCookie(tzCookieInfo.name, tzCookieTZ, tzCookieInfo);
+	}
+
+	// add UI for changing timezone
+	addChangeTZ(tz, tzCookieInfo, tzClassName);
+
+	// server-side of gitweb produces datetime in UTC,
+	// so if tz is 'utc' there is no need for changes
+	var nochange = tz === 'utc';
+
+	// adjust dates to use specified common timezone
+	fixDatetimeTZ(tz, tzClassName, nochange);
+}
+
+
+/* ...................................................................... */
+/* Changing dates to use requested timezone */
+
+/**
+ * Replace RFC-2822 dates contained in SPAN elements with tzClassName
+ * CSS class with equivalent dates in given timezone.
+ *
+ * @param {String} tz: numeric timezone in '(-|+)HHMM' format, or 'utc', or 'local'
+ * @param {String} tzClassName: specifies elements to be changed
+ * @param {Boolean} nochange: markup for timezone change, but don't change it
+ */
+function fixDatetimeTZ(tz, tzClassName, nochange) {
+	// sanity check, method should be ensured by common-lib.js
+	if (!document.getElementsByClassName) {
+		return;
+	}
+
+	// translate to timezone in '(-|+)HHMM' format
+	tz = normalizeTimezoneInfo(tz);
+
+	// NOTE: result of getElementsByClassName should probably be cached
+	var classesFound = document.getElementsByClassName(tzClassName, "span");
+	for (var i = 0, len = classesFound.length; i < len; i++) {
+		var curElement = classesFound[i];
+
+		curElement.title = 'Click to change timezone';
+		if (!nochange) {
+			// we use *.firstChild.data (W3C DOM) instead of *.innerHTML
+			// as the latter doesn't always work everywhere in every browser
+			var epoch = parseRFC2822Date(curElement.firstChild.data);
+			var adjusted = formatDateRFC2882(epoch, tz);
+
+			curElement.firstChild.data = adjusted;
+		}
+	}
+}
+
+
+/* ...................................................................... */
+/* Adding triggers, generating timezone menu, displaying and hiding */
+
+/**
+ * Adds triggers for UI to change common timezone used for dates in
+ * gitweb output: it marks up and/or creates item to click to invoke
+ * timezone change UI, creates timezone UI fragment to be attached,
+ * and installs appropriate onclick trigger (via event delegation).
+ *
+ * @param {String} tzSelected: pre-selected timezone,
+ *                             'utc' or 'local' or '(-|+)HHMM'
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzClassName: specifies elements to install trigger
+ */
+function addChangeTZ(tzSelected, tzCookieInfo, tzClassName) {
+	// make link to timezone UI discoverable
+	addCssRule('.'+tzClassName + ':hover',
+	           'text-decoration: underline; cursor: help;');
+
+	// create form for selecting timezone (to be saved in a cookie)
+	var tzSelectFragment = document.createDocumentFragment();
+	tzSelectFragment = createChangeTZForm(tzSelectFragment,
+	                                      tzSelected, tzCookieInfo, tzClassName);
+
+	// event delegation handler for timezone selection UI (clicking on entry)
+	// see http://www.nczonline.net/blog/2009/06/30/event-delegation-in-javascript/
+	// assumes that there is no existing document.onclick handler
+	document.onclick = function onclickHandler(event) {
+		//IE doesn't pass in the event object
+		event = event || window.event;
+
+		//IE uses srcElement as the target
+		var target = event.target || event.srcElement;
+
+		switch (target.className) {
+		case tzClassName:
+			// don't display timezone menu if it is already displayed
+			if (tzSelectFragment.childNodes.length > 0) {
+				displayChangeTZForm(target, tzSelectFragment);
+			}
+			break;
+		} // end switch
+	};
+}
+
+/**
+ * Create DocumentFragment with UI for changing common timezone in
+ * which dates are shown in.
+ *
+ * @param {DocumentFragment} documentFragment: where attach UI
+ * @param {String} tzSelected: default (pre-selected) timezone
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @returns {DocumentFragment}
+ */
+function createChangeTZForm(documentFragment, tzSelected, tzCookieInfo, tzClassName) {
+	var div = document.createElement("div");
+	div.className = 'popup';
+
+	/* '<div class="close-button" title="(click on this box to close)">X</div>' */
+	var closeButton = document.createElement('div');
+	closeButton.className = 'close-button';
+	closeButton.title = '(click on this box to close)';
+	closeButton.appendChild(document.createTextNode('X'));
+	closeButton.onclick = closeTZFormHandler(documentFragment, tzClassName);
+	div.appendChild(closeButton);
+
+	/* 'Select timezone: <br clear="all">' */
+	div.appendChild(document.createTextNode('Select timezone: '));
+	var br = document.createElement('br');
+	br.clear = 'all';
+	div.appendChild(br);
+
+	/* '<select name="tzoffset">
+	 *    ...
+	 *    <option value="-0700">UTC-07:00</option>
+	 *    <option value="-0600">UTC-06:00</option>
+	 *    ...
+	 *  </select>' */
+	var select = document.createElement("select");
+	select.name = "tzoffset";
+	//select.style.clear = 'all';
+	select.appendChild(generateTZOptions(tzSelected));
+	select.onchange = selectTZHandler(documentFragment, tzCookieInfo, tzClassName);
+	div.appendChild(select);
+
+	documentFragment.appendChild(div);
+
+	return documentFragment;
+}
+
+
+/**
+ * Hide (remove from DOM) timezone change UI, ensuring that it is not
+ * garbage collected and that it can be re-enabled later.
+ *
+ * @param {DocumentFragment} documentFragment: contains detached UI
+ * @param {HTMLSelectElement} target: select element inside of UI
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {DocumentFragment} documentFragment
+ */
+function removeChangeTZForm(documentFragment, target, tzClassName) {
+	// find containing element, where we appended timezone selection UI
+	// `target' is somewhere inside timezone menu
+	var container = target.parentNode, popup = target;
+	while (container &&
+	       container.className !== tzClassName) {
+		popup = container;
+		container = container.parentNode;
+	}
+	// safety check if we found correct container,
+	// and if it isn't deleted already
+	if (!container || !popup ||
+	    container.className !== tzClassName ||
+	    popup.className     !== 'popup') {
+		return documentFragment;
+	}
+
+	// timezone selection UI was appended as last child
+	// see also displayChangeTZForm function
+	var removed = popup.parentNode.removeChild(popup);
+	if (documentFragment.firstChild !== removed) { // the only child
+		// re-append it so it would be available for next time
+		documentFragment.appendChild(removed);
+	}
+	// all of inline style was added by this script
+	// it is not really needed to remove it, but it is a good practice
+	container.removeAttribute('style');
+
+	return documentFragment;
+}
+
+
+/**
+ * Display UI for changing common timezone for dates in gitweb output.
+ * To be used from 'onclick' event handler.
+ *
+ * @param {HTMLElement} target: where to install/display UI
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ */
+function displayChangeTZForm(target, tzSelectFragment) {
+	// for absolute positioning to be related to target element
+	target.style.position = 'relative';
+	target.style.display = 'inline-block';
+
+	// show/display UI for changing timezone
+	target.appendChild(tzSelectFragment);
+}
+
+
+/* ...................................................................... */
+/* List of timezones for timezone selection menu */
+
+/**
+ * Generate list of timezones for creating timezone select UI
+ *
+ * @returns {Object[]} list of e.g. { value: '+0100', descr: 'GMT+01:00' }
+ */
+function generateTZList() {
+	var timezones = [
+		{ value: "utc",   descr: "UTC/GMT"},
+		{ value: "local", descr: "Local (per browser)"}
+	];
+
+	// generate all full hour timezones (no fractional timezones)
+	for (var x = -12, idx = timezones.length; x <= +14; x++, idx++) {
+		var hours = (x >= 0 ? '+' : '-') + padLeft(x >=0 ? x : -x, 2);
+		timezones[idx] = { value: hours + '00', descr: 'UTC' + hours + ':00'};
+		if (x === 0) {
+			timezones[idx].descr = 'UTC\u00B100:00'; // 'UTC&plusmn;00:00'
+		}
+	}
+
+	return timezones;
+}
+
+/**
+ * Generate <options> elements for timezone select UI
+ *
+ * @param {String} tzSelected: default timezone
+ * @returns {DocumentFragment} list of options elements to appendChild
+ */
+function generateTZOptions(tzSelected) {
+	var elems = document.createDocumentFragment();
+	var timezones = generateTZList();
+
+	for (var i = 0, len = timezones.length; i < len; i++) {
+		var tzone = timezones[i];
+		var option = document.createElement("option");
+		if (tzone.value === tzSelected) {
+			option.defaultSelected = true;
+		}
+		option.value = tzone.value;
+		option.appendChild(document.createTextNode(tzone.descr));
+
+		elems.appendChild(option);
+	}
+
+	return elems;
+}
+
+
+/* ...................................................................... */
+/* Event handlers and/or their generators */
+
+/**
+ * Create event handler that select timezone and closes timezone select UI.
+ * To be used as $('select[name="tzselect"]').onchange handler.
+ *
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ * @param {Object} tzCookieInfo: object literal with info about cookie to store timezone
+ * @param {String} tzCookieInfo.name: name of cookie to save result of selection
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {Function} event handler
+ */
+function selectTZHandler(tzSelectFragment, tzCookieInfo, tzClassName) {
+	//return function selectTZ(event) {
+	return function (event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		var selected = target.options.item(target.selectedIndex);
+		removeChangeTZForm(tzSelectFragment, target, tzClassName);
+
+		if (selected) {
+			selected.defaultSelected = true;
+			setCookie(tzCookieInfo.name, selected.value, tzCookieInfo);
+			fixDatetimeTZ(selected.value, tzClassName);
+		}
+	};
+}
+
+/**
+ * Create event handler that closes timezone select UI.
+ * To be used e.g. as $('.closebutton').onclick handler.
+ *
+ * @param {DocumentFragment} tzSelectFragment: timezone selection UI
+ * @param {String} tzClassName: specifies element where UI was installed
+ * @returns {Function} event handler
+ */
+function closeTZFormHandler(tzSelectFragment, tzClassName) {
+	//return function closeTZForm(event) {
+	return function (event) {
+		event = event || window.event;
+		var target = event.target || event.srcElement;
+
+		removeChangeTZForm(tzSelectFragment, target, tzClassName);
+	};
+}
+
+/* end of adjust-timezone.js */