init

.gitignore

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+node_modules

README.md

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+# Riot KaTeX
+
+This extension injects KaTeX into the `Riot` chat client for
+`matrix`. This currently works for just one domain
+(matrix.tu-dresden.de). If you want to use it, you have to adjust the
+`manifest.json`.
+
+## Writing LaTeX
+ - `$$x^2$$` renders math block style
+ - `\(x^2\)` renders math inline
+

manifest.json

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+{
+    "manifest_version": 2,
+    "name": "Riot KaTeX",
+    "version": "1.0",
+
+    "description": "Renders formulars in Riot chats using KaTeX.",
+
+    "icons": {
+        "48": "icons/border-48.png"
+    },
+    "permissions": [
+        "activeTab"
+    ],
+    "content_scripts": [
+        {
+            "matches": ["*://matrix.tu-dresden.de/*"],
+            "js": ["node_modules/katex/dist/katex.js",
+                   "node_modules/katex/dist/contrib/auto-render.js",
+                   "node_modules/observable-slim/observable-slim.js",
+                   "riot-katex.js"],
+            "css": ["node_modules/katex/dist/katex.css"],
+            "all_frames": true,
+            "run_at": "document_idle"
+        }
+    ]
+}

package-lock.json

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+{
+  "requires": true,
+  "lockfileVersion": 1,
+  "dependencies": {
+    "commander": {
+      "version": "2.20.3",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
+      "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ=="
+    },
+    "katex": {
+      "version": "0.11.1",
+      "resolved": "https://registry.npmjs.org/katex/-/katex-0.11.1.tgz",
+      "integrity": "sha512-5oANDICCTX0NqYIyAiFCCwjQ7ERu3DQG2JFHLbYOf+fXaMoH8eg/zOq5WSYJsKMi/QebW+Eh3gSM+oss1H/bww==",
+      "requires": {
+        "commander": "^2.19.0"
+      }
+    },
+    "observable-slim": {
+      "version": "0.1.5",
+      "resolved": "https://registry.npmjs.org/observable-slim/-/observable-slim-0.1.5.tgz",
+      "integrity": "sha512-xhDK4EjwM6ehZ6KhTtDc0z5kqBhqoBQPP9pq2n1c+RXA4IcyLIm68ipDwS3nZVXhrCssoKu4LcHDUT1tl0kP9A=="
+    }
+  }
+}

riot-katex.js

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+(function() {
+    /**
+     * Check and set a global guard variable.
+     * If this content script is injected into the same page again,
+     * it will do nothing next time.
+     */
+    if (window.hasRun) {
+        return;
+    }
+    window.hasRun = true;
+
+    const math_config = [
+        {left: "$$", right: "$$", display: true},
+        {left: "\\(", right: "\\)", display: false},
+        {left: "\\[", right: "\\]", display: true}
+    ]
+
+    function init() {
+        const header = document.querySelector('.mx_RoomList');
+        let chat_observer = listen_on_chat_element();
+        function listen_on_chat_element() {
+            const chat_elem = document.querySelector('.mx_RoomView_MessageList');
+            renderMathInElement(chat_elem, math_config);
+
+            const config = { attributes: true, childList: true, subtree: true };
+            const callback = function(mutationsList, observer) {
+                // Use traditional 'for loops' for IE 11
+                for(let mutation of mutationsList) {
+                    if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
+                        for(let node of mutation.addedNodes) {
+                            renderMathInElement(node, math_config);
+                        }
+                    }
+                }
+            };
+            // Create an observer instance linked to the callback function
+            const observer = new MutationObserver(callback);
+
+            // Start observing the target node for configured mutations
+            observer.observe(chat_elem, config);
+            return observer;
+        }
+
+        function change_chat_element(mutationsList, observer) {
+            if (chat_observer) {
+                chat_observer.disconnect();
+            }
+
+            chat_observer = listen_on_chat_element();
+        }
+
+        const header_obs = new MutationObserver(change_chat_element)
+        const config = { attributes: true, childList: true, subtree: true };
+        header_obs.observe(header, config);
+    }
+
+    let  = window.wrappedJSObject;
+
+    function wait_for_matrix() {
+        if(!('matrixChat' in window.wrappedJSObject
+             && window.wrappedJSObject.matrixChat.firstSyncComplete))
+            return setTimeout(wait_for_matrix, 500);
+
+        init();
+    }
+
+    wait_for_matrix();
+})();