0
0
mirror of https://github.com/go-gitea/gitea.git synced 2024-12-05 02:59:13 +01:00
gitea/web_src/js/webcomponents/overflow-menu.js
silverwind 99d7ef5091
Prevent layout shift in <overflow-menu> items (#29831)
There is a small layout shift in when active tab changes. Notice how the
actions SVG is unstable:


![](https://github.com/go-gitea/gitea/assets/115237/a6928e89-5d47-4a91-8f36-1fa22fddbce7)

This is because the active item with bold text is wider then the
inactive one. I have applied [this
trick](https://stackoverflow.com/a/32570813/808699) to prevent this
layout shift. It's only active inside `<overflow-menu>` because I wanted
to avoid changing HTML and doing it in regular JS would cause a flicker.
I don't expect us to introduce other similar menus without
`<overflow-menu>`, so that place is likely fine.


![after](https://github.com/go-gitea/gitea/assets/115237/d6089924-8de6-4ee0-8db4-15f16069a131)

I also changed the weight from 500 to 600, slightly reduced horizontal
padding, merged some tab-bar related CSS rules and a added a small
margin below repo-header so it does not look so crammed against the
buttons on top.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
2024-03-20 17:00:35 +00:00

199 lines
7.3 KiB
JavaScript

import {throttle} from 'throttle-debounce';
import {createTippy} from '../modules/tippy.js';
import {isDocumentFragmentOrElementNode} from '../utils/dom.js';
import octiconKebabHorizontal from '../../../public/assets/img/svg/octicon-kebab-horizontal.svg';
window.customElements.define('overflow-menu', class extends HTMLElement {
updateItems = throttle(100, () => {
if (!this.tippyContent) {
const div = document.createElement('div');
div.classList.add('tippy-target');
div.tabIndex = '-1'; // for initial focus, programmatic focus only
div.addEventListener('keydown', (e) => {
if (e.key === 'Tab') {
const items = this.tippyContent.querySelectorAll('[role="menuitem"]');
if (e.shiftKey) {
if (document.activeElement === items[0]) {
e.preventDefault();
items[items.length - 1].focus();
}
} else {
if (document.activeElement === items[items.length - 1]) {
e.preventDefault();
items[0].focus();
}
}
} else if (e.key === 'Escape') {
e.preventDefault();
e.stopPropagation();
this.button._tippy.hide();
this.button.focus();
} else if (e.key === ' ' || e.code === 'Enter') {
if (document.activeElement?.matches('[role="menuitem"]')) {
e.preventDefault();
e.stopPropagation();
document.activeElement.click();
}
} else if (e.key === 'ArrowDown') {
if (document.activeElement?.matches('.tippy-target')) {
e.preventDefault();
e.stopPropagation();
document.activeElement.querySelector('[role="menuitem"]:first-of-type').focus();
} else if (document.activeElement?.matches('[role="menuitem"]')) {
e.preventDefault();
e.stopPropagation();
document.activeElement.nextElementSibling?.focus();
}
} else if (e.key === 'ArrowUp') {
if (document.activeElement?.matches('.tippy-target')) {
e.preventDefault();
e.stopPropagation();
document.activeElement.querySelector('[role="menuitem"]:last-of-type').focus();
} else if (document.activeElement?.matches('[role="menuitem"]')) {
e.preventDefault();
e.stopPropagation();
document.activeElement.previousElementSibling?.focus();
}
}
});
this.append(div);
this.tippyContent = div;
}
// move items in tippy back into the menu items for subsequent measurement
for (const item of this.tippyItems || []) {
this.menuItemsEl.append(item);
}
// measure which items are partially outside the element and move them into the button menu
this.tippyItems = [];
const menuRight = this.offsetLeft + this.offsetWidth;
const menuItems = this.menuItemsEl.querySelectorAll('.item');
for (const item of menuItems) {
const itemRight = item.offsetLeft + item.offsetWidth;
if (menuRight - itemRight < 38) { // roughly the width of .overflow-menu-button
this.tippyItems.push(item);
}
}
// if there are no overflown items, remove any previously created button
if (!this.tippyItems?.length) {
const btn = this.querySelector('.overflow-menu-button');
btn?._tippy?.destroy();
btn?.remove();
return;
}
// remove aria role from items that moved from tippy to menu
for (const item of menuItems) {
if (!this.tippyItems.includes(item)) {
item.removeAttribute('role');
}
}
// move all items that overflow into tippy
for (const item of this.tippyItems) {
item.setAttribute('role', 'menuitem');
this.tippyContent.append(item);
}
// update existing tippy
if (this.button?._tippy) {
this.button._tippy.setContent(this.tippyContent);
return;
}
// create button initially
const btn = document.createElement('button');
btn.classList.add('overflow-menu-button', 'btn', 'tw-px-2', 'hover:tw-text-text-dark');
btn.setAttribute('aria-label', window.config.i18n.more_items);
btn.innerHTML = octiconKebabHorizontal;
this.append(btn);
this.button = btn;
createTippy(btn, {
trigger: 'click',
hideOnClick: true,
interactive: true,
placement: 'bottom-end',
role: 'menu',
content: this.tippyContent,
onShow: () => { // FIXME: onShown doesn't work (never be called)
setTimeout(() => {
this.tippyContent.focus();
}, 0);
},
});
});
init() {
// for horizontal menus where fomantic boldens active items, prevent this bold text from
// enlarging the menu's active item replacing the text node with a div that renders a
// invisible pseudo-element that enlarges the box.
if (this.matches('.ui.secondary.pointing.menu, .ui.tabular.menu')) {
for (const item of this.querySelectorAll('.item')) {
for (const child of item.childNodes) {
if (child.nodeType === Node.TEXT_NODE) {
const text = child.textContent.trim(); // whitespace is insignificant inside flexbox
if (!text) continue;
const span = document.createElement('span');
span.classList.add('resize-for-semibold');
span.setAttribute('data-text', text);
span.textContent = text;
child.replaceWith(span);
}
}
}
}
// ResizeObserver triggers on initial render, so we don't manually call `updateItems` here which
// also avoids a full-page FOUC in Firefox that happens when `updateItems` is called too soon.
this.resizeObserver = new ResizeObserver((entries) => {
for (const entry of entries) {
const newWidth = entry.contentBoxSize[0].inlineSize;
if (newWidth !== this.lastWidth) {
requestAnimationFrame(() => {
this.updateItems();
});
this.lastWidth = newWidth;
}
}
});
this.resizeObserver.observe(this);
}
connectedCallback() {
this.setAttribute('role', 'navigation');
// check whether the mandatory `.overflow-menu-items` element is present initially which happens
// with Vue which renders differently than browsers. If it's not there, like in the case of browser
// template rendering, wait for its addition.
// The eslint rule is not sophisticated enough or aware of this problem, see
// https://github.com/43081j/eslint-plugin-wc/pull/130
const menuItemsEl = this.querySelector('.overflow-menu-items'); // eslint-disable-line wc/no-child-traversal-in-connectedcallback
if (menuItemsEl) {
this.menuItemsEl = menuItemsEl;
this.init();
} else {
this.mutationObserver = new MutationObserver((mutations) => {
for (const mutation of mutations) {
for (const node of mutation.addedNodes) {
if (!isDocumentFragmentOrElementNode(node)) continue;
if (node.classList.contains('overflow-menu-items')) {
this.menuItemsEl = node;
this.mutationObserver?.disconnect();
this.init();
}
}
}
});
this.mutationObserver.observe(this, {childList: true});
}
}
disconnectedCallback() {
this.mutationObserver?.disconnect();
this.resizeObserver?.disconnect();
}
});