Use tippy.js for context popup

By appending the tooltips to document.body, we can avoid any stacking context issues caused by surrounding element's CSS.

I wasn't able to get this portalling to work with Fomantic popups, so this uses tippy.js instead of Fomantic popups. We should aim to replace all Fomantic popups with this eventually.

Fixes: #20377

package.json

@@ -29,6 +29,7 @@
     "pretty-ms": "7.0.1",
     "sortablejs": "1.15.0",
     "swagger-ui-dist": "4.11.1",
+    "tippy.js": "6.3.7",
     "tributejs": "5.1.3",
     "uint8-to-base64": "0.2.0",
     "vue": "2.6.14",

web_src/js/features/contextpopup.js

@@ -2,6 +2,7 @@ import $ from 'jquery';
 import Vue from 'vue';
 import ContextPopup from '../components/ContextPopup.vue';
 import {parseIssueHref} from '../utils.js';
+import tippy from 'tippy.js';
 
 export default function initContextPopups() {
   const refIssues = $('.ref-issue');
@@ -16,7 +17,6 @@ export default function initContextPopups() {
     if (!owner) return;
 
     const el = document.createElement('div');
-    el.className = 'ui custom popup hidden';
     el.innerHTML = '<div></div>';
     this.parentNode.insertBefore(el, this.nextSibling);
 
@@ -33,17 +33,17 @@ export default function initContextPopups() {
       el.textContent = 'ContextPopup failed to load';
     }
 
-    $(this).popup({
-      variation: 'wide',
-      delay: {
-        show: 250
-      },
+    tippy(this, {
+      appendTo: () => document.body,
+      placement: 'top-start',
+      delay: 250,
+      content: el,
+      allowHTML: true,
+      interactive: true,
+      arrow: `<svg width="16" height="6"><path d="m0 6 8-6 8 6Z" class="tippy-svg-arrow"/><path d="m0 7 8-6 8 6Z" class="tippy-svg-arrow-content"/></svg>`,
       onShow: () => {
-        view.$emit('load-context-popup', {owner, repo, index}, () => {
-          $(this).popup('reposition');
-        });
-      },
-      popup: $(el),
+        view.$emit('load-context-popup', {owner, repo, index});
+      }
     });
   });
 }

web_src/less/features/tippy.less

@@ -0,0 +1,87 @@
+.tippy-box[data-animation="fade"][data-state="hidden"] {
+  opacity: 0;
+}
+
+[data-tippy-root] {
+  max-width: calc(100vw - 10px);
+}
+
+.tippy-box {
+  position: relative;
+  background-color: var(--color-body);
+  color: var(--color-secondary-dark-6);
+  border: 1px solid var(--color-secondary);
+  border-radius: var(--border-radius);
+  padding: .5em;
+  font-size: 1rem;
+  transition-property: transform, visibility, opacity;
+}
+
+.tippy-box[data-inertia][data-state="visible"] {
+  transition-timing-function: cubic-bezier(0.54, 1.5, 0.38, 1.11);
+}
+
+.tippy-content {
+  position: relative;
+  padding: 5px 9px;
+  z-index: 1;
+}
+
+.tippy-svg-arrow {
+  fill: var(--color-secondary);
+}
+
+.tippy-svg-arrow-content {
+  fill: var(--color-body);
+}
+
+.tippy-box[data-placement^="top"] > .tippy-svg-arrow {
+  bottom: 0;
+}
+
+.tippy-box[data-placement^="top"] > .tippy-svg-arrow:after,
+.tippy-box[data-placement^="top"] > .tippy-svg-arrow > svg {
+  top: 16px;
+  transform: rotate(180deg);
+}
+
+.tippy-box[data-placement^="bottom"] > .tippy-svg-arrow {
+  top: 0;
+}
+
+.tippy-box[data-placement^="bottom"] > .tippy-svg-arrow > svg {
+  bottom: 16px;
+}
+
+.tippy-box[data-placement^="left"] > .tippy-svg-arrow {
+  right: 0;
+}
+
+.tippy-box[data-placement^="left"] > .tippy-svg-arrow:after,
+.tippy-box[data-placement^="left"] > .tippy-svg-arrow > svg {
+  transform: rotate(90deg);
+  top: calc(50% - 3px);
+  left: 11px;
+}
+
+.tippy-box[data-placement^="right"] > .tippy-svg-arrow {
+  left: 0;
+}
+
+.tippy-box[data-placement^="right"] > .tippy-svg-arrow:after,
+.tippy-box[data-placement^="right"] > .tippy-svg-arrow > svg {
+  transform: rotate(-90deg);
+  top: calc(50% - 3px);
+  right: 11px;
+}
+
+.tippy-svg-arrow {
+  width: 16px;
+  height: 16px;
+  text-align: initial;
+}
+
+.tippy-svg-arrow,
+.tippy-svg-arrow > svg {
+  position: absolute;
+}

web_src/less/index.less

@@ -9,6 +9,7 @@
 @import "./features/imagediff.less";
 @import "./features/codeeditor.less";
 @import "./features/projects.less";
+@import "./features/tippy.less";
 @import "./markup/content.less";
 @import "./markup/codecopy.less";
 @import "./code/linebutton.less";