feat: Add "☕️ Caffeine" plugin

README.md

@@ -4,8 +4,9 @@ This repository contains a collection of custom plugins for [Reveal.js](https://
 
 ## Plugins
 
-| Plugin | Description |
-| ------ | ----------- |
+| Plugin                           | Description                                                               |
+| -------------------------------- | ------------------------------------------------------------------------- |
+| [☕️ Caffeine](plugins/caffeine) | Custom plugin to avoid screen going to sleep during active presentations. |
 
 ---
 

plugins/caffeine/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 ForWarD Software (https://forwardsoftware.solutions/)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

plugins/caffeine/README.md

@@ -0,0 +1,40 @@
+# ☕️ Caffeine
+
+> Custom plugin for [Reveal.js](https://revealjs.com/) to avoid screen going to sleep during active presentations
+
+## How To
+
+Simply include `RevealCaffeine` plugin and it will automatically activate on presentation start if [`Screen Wake Lock API`](https://developer.mozilla.org/en-US/docs/Web/API/Screen_Wake_Lock_API) is supported by the browser.
+
+```js
+Reveal.initialize({
+  // ...
+  plugins: [
+    // ...,
+    RevealCaffeine,
+  ],
+});
+```
+
+> [!IMPORTANT]  
+> The Wake Lock will be released when the presentation is paused or the tab is hidden.
+
+## Configuration
+
+You can configure the plugin with the following options:
+
+```js
+// ...
+plugins: [ /* ... */ ],
+caffeine: {
+
+}
+```
+
+## License
+
+MIT
+
+---
+
+Made with ✨ & ❤️ by [ForWarD Software](https://github.com/forwardsoftware) and [contributors](https://github.com/forwardsoftware/revealjs-plugins/graphs/contributors)

plugins/caffeine/gulpfile.mjs

@@ -0,0 +1,77 @@
+import babel from "@rollup/plugin-babel";
+import commonjs from "@rollup/plugin-commonjs";
+import resolve from "@rollup/plugin-node-resolve";
+import strip from "@rollup/plugin-strip";
+import terser from "@rollup/plugin-terser";
+import gulp from "gulp";
+import { rimraf } from "rimraf";
+import { rollup } from "rollup";
+
+const babelConfig = {
+  babelHelpers: "bundled",
+  ignore: ["node_modules"],
+  compact: false,
+  extensions: [".js"],
+  presets: [
+    [
+      "@babel/preset-env",
+      {
+        corejs: 3,
+        useBuiltIns: "usage",
+        modules: false,
+        targets: {
+          browsers: [
+            "last 2 Chrome versions",
+            "last 2 Safari versions",
+            "last 2 iOS versions",
+            "last 2 Firefox versions",
+            "last 2 Edge versions",
+          ],
+        },
+      },
+    ],
+  ],
+  ignore: [/node_modules\/(?!(highlight\.js|marked)\/).*/],
+};
+
+const debugRollupPlugins = [resolve(), commonjs(), babel(babelConfig), terser()];
+
+const prodRollupPlugins = [resolve(), commonjs(), strip(), babel(babelConfig), terser()];
+
+async function compile(variant) {
+  const rollupPlugins = variant === "debug" ? debugRollupPlugins : prodRollupPlugins;
+  const rollupOutputName = variant !== "prod" ? `plugin.${variant}.js` : `plugin.js`;
+  const rollupOutputFormat = variant === "esm" ? "es" : "umd";
+
+  const builder = await rollup({
+    input: `./src/plugin.js`,
+    plugins: rollupPlugins,
+  });
+
+  await builder.write({
+    file: `./dist/${rollupOutputName}`,
+    name: "RevealCaffeine",
+    format: rollupOutputFormat,
+  });
+}
+
+// Creates a UMD and ES module bundle for each plugin
+export async function plugins() {
+  await Promise.all(["debug", "esm", "prod"].map(compile));
+}
+
+// npm run clean / npx gulp clean: clean 'dist' folder
+export const clean = () => rimraf("./dist/");
+
+// npm run build / npx gulp build: build plugins
+export const build = gulp.series(clean, plugins);
+
+// watch files for changes and trigger rebuild tasks
+async function watchFiles() {
+  gulp.watch("src/**/*.js", plugins);
+}
+
+// npm run watch / npx gulp watch: continuously update index.html from deps
+export const watch = gulp.series(build, watchFiles);
+
+export default build;

plugins/caffeine/package.json

@@ -0,0 +1,47 @@
+{
+  "name": "@forward-software/reveal.js-caffeine",
+  "version": "1.0.0",
+  "description": "Custom plugin for Reveal.js to avoid screen going to sleep during active presentations",
+  "author": "ForWarD Software (https://forwardsoftware.solutions/)",
+  "license": "MIT",
+  "keywords": [
+    "revealjs",
+    "reveal-js",
+    "reveal-plugin",
+    "reveal-js-plugin",
+    "caffeine",
+    "wakelock"
+  ],
+  "homepage": "https://github.com/forwardsoftware/revealjs-plugins/tree/main/plugins/caffeine#readme",
+  "bugs": "https://github.com/forwardsoftware/revealjs-plugins/issues",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/forwardsoftware/revealjs-plugins.git",
+    "directory": "plugins/caffeine"
+  },
+  "main": "dist/plugin.js",
+  "module": "dist/plugin.esm.js",
+  "files": [
+    "dist"
+  ],
+  "publishConfig": {
+    "access": "public"
+  },
+  "scripts": {
+    "clean": "gulp clean",
+    "watch": "gulp watch",
+    "build": "gulp build"
+  },
+  "devDependencies": {
+    "@babel/core": "catalog:",
+    "@babel/preset-env": "catalog:",
+    "@rollup/plugin-babel": "catalog:",
+    "@rollup/plugin-commonjs": "catalog:",
+    "@rollup/plugin-node-resolve": "catalog:",
+    "@rollup/plugin-strip": "catalog:",
+    "@rollup/plugin-terser": "catalog:",
+    "gulp": "catalog:",
+    "rimraf": "catalog:",
+    "rollup": "catalog:"
+  }
+}

plugins/caffeine/src/plugin.js

@@ -0,0 +1,85 @@
+const DEFAULT_CONFIGURATION = {};
+
+const Plugin = () => {
+  let wakeLockSentinel = null;
+
+  async function acquireWakeLock(evt) {
+    console.debug("☕️ Screen Wake Lock acquiring on", evt.type, "event");
+
+    try {
+      // release existing lock (if any)
+      if (wakeLockSentinel !== null) {
+        releaseWakeLock(evt);
+      }
+
+      // acquire screen wake lock
+      wakeLockSentinel = await navigator.wakeLock.request("screen");
+      console.info("☕️ Screen Wake Lock acquired");
+    } catch (err) {
+      console.error("☕️ Screen Wake Lock API acquire error:", err.name, err.message);
+    }
+  }
+
+  async function releaseWakeLock(evt) {
+    console.debug("☕️ Screen Wake Lock releasing on", evt.type, "event");
+    if (wakeLockSentinel === null) {
+      console.warn("☕️ Screen Wake Lock not yet acquired");
+      return;
+    }
+
+    try {
+      await wakeLockSentinel.release();
+      wakeLockSentinel = null;
+
+      console.info("☕️ Screen Wake Lock released");
+    } catch (err) {
+      console.error("☕️ Screen Wake Lock API release error:", err.name, err.message);
+    }
+  }
+
+  async function handleVisibilityChanged(evt) {
+    console.info("☕️ Tab visibility changed to", document.visibilityState);
+
+    // release/acquire wakelock on tab visibility change
+    switch (document.visibilityState) {
+      case "hidden":
+        return releaseWakeLock(evt);
+
+      case "visible":
+        return acquireWakeLock(evt);
+    }
+  }
+
+  return {
+    id: "caffeine",
+
+    init: function (deck) {
+      const deckConfig = deck.getConfig();
+      const config = Object.assign({}, DEFAULT_CONFIGURATION, deckConfig.caffeine);
+
+      console.info("☕️ Caffeine plugin by ForWarD Software loaded", config);
+
+      if (!navigator.wakeLock) {
+        console.warn("☕️ Screen Wake Lock API NOT supported!");
+        return;
+      }
+
+      console.info("☕️ Screen Wake Lock API supported... attaching event listeners");
+
+      deck.on("paused", releaseWakeLock);
+      deck.on("resumed", acquireWakeLock);
+
+      deck.on("ready", acquireWakeLock);
+
+      document.addEventListener("visibilitychange", handleVisibilityChanged);
+    },
+
+    destroy: function () {
+      document.removeEventListener("visibilitychange", handleVisibilityChanged);
+
+      releaseWakeLock({ type: "destroy" });
+    },
+  };
+};
+
+export default Plugin;