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Diffstat (limited to 'gitweb/static/js/adjust-timezone.js')
-rw-r--r-- | gitweb/static/js/adjust-timezone.js | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/gitweb/static/js/adjust-timezone.js b/gitweb/static/js/adjust-timezone.js new file mode 100644 index 000000000000..0c677795006a --- /dev/null +++ b/gitweb/static/js/adjust-timezone.js @@ -0,0 +1,330 @@ +// 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±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 */ |