Write some info in README.md, design titlebar, make downloader and very basic instance checker

README.md

@@ -1,3 +1,12 @@
 # OpenModLauncher-Base
 
 A small Minecraft launcher codebase
+
+This is currently a work in progress for another project of mine but it can be used in other projects too as I try to be the least project-specific as I can be.
+
+Please note I reused and rearranged a lot of code from a launcher I've programmed earlier this year. 
+
+## Features
+
+At the time of writing this README, this launcher can only download a Minecraft version specified in meta.json into a given directory.
+Launching Minecraft, installing a mod loader on top of many versions and downloading custom files are the main planned features.

lib/checker.js

@@ -0,0 +1,10 @@
+const path = require("node:path");
+const fs = require("node:fs");
+
+module.exports = {
+	"check_install": function (directory) {
+		return new Promise(function (resolve, reject) {
+			resolve(fs.existsSync(path.join(directory, "versions")));
+		});
+	}
+};

lib/downloader.js

@@ -0,0 +1,146 @@
+const path = require("node:path");
+const fs = require("node:fs");
+const fsPromises = require("node:fs/promises");
+
+const httpsWrapper = require("./util/https.js");
+const utilities = require("./util/functions.js");
+
+let maxConcurrentDownloads = 16;
+let downloadQueue = [];
+let totalDownloads = 0;
+let isDownloading = false;
+let ongoingDownloads = 0;
+
+function waitUntilDownloadsFinish() {
+	return new Promise(async function (resolve, reject) {
+		var downloadCountChecker = setInterval(function () {
+			if (ongoingDownloads < 1 && downloadQueue.length < 1 && !isDownloading) {
+				resolve(clearInterval(downloadCountChecker));
+			}
+		}, 256);
+	});
+}
+
+module.exports = {
+	"download_file": function (url, filePath) {
+		return new Promise(async function (resolve, reject) {
+			var directory = path.dirname(filePath);
+			if (!(await fs.existsSync(directory))) await fsPromises.mkdir(directory, {"recursive": true});
+
+			var writeStream = fs.createWriteStream(filePath);
+			writeStream.on("finish", resolve);
+
+			httpsWrapper.getStream(url).then(function (response) {
+				response.pipe(writeStream);
+			}).catch(reject);
+		});
+	},
+	"process_queue": function (progressCB) {
+		return new Promise(async function (resolve, reject) {
+			totalDownloads = downloadQueue.length;
+			if (downloadQueue.length > 0) isDownloading = true;
+
+			if (progressCB) {
+				progressCB(0.0, 0, downloadQueue.length, totalDownloads);
+			}
+
+			while (downloadQueue.length > 0) {
+				if (ongoingDownloads < maxConcurrentDownloads) {
+					setImmediate(function (downloadData) {
+						module.exports.download_file(downloadData.url, downloadData.path).then(function () {
+							ongoingDownloads--;
+							if (downloadQueue.length < 1) {
+								isDownloading = false;
+							}
+						}).catch(function (error) {
+							ongoingDownloads--;
+							downloadQueue.push(downloadData);
+						});
+					}, downloadQueue.shift());
+					ongoingDownloads++;
+					let progress = (totalDownloads - (downloadQueue.length + ongoingDownloads)) / totalDownloads;
+					if (progressCB) {
+						progressCB(progress, ongoingDownloads, downloadQueue.length, totalDownloads);
+					}
+				} else {
+					await utilities.sleep(256);
+				}
+			}
+
+			waitUntilDownloadsFinish().then(function () {
+				if (progressCB) {
+					progressCB(1.0, 0, 0, totalDownloads);
+				}
+				resolve();
+			}).catch(reject);
+		});
+	},
+	"download_minecraft": function (directory, meta, manifestSource, progressCB) {
+		return new Promise(async function (resolve, reject) {
+			let gameManifest = JSON.parse(await httpsWrapper.get(manifestSource["versions_manifest"]));
+
+			let versionInManifest = gameManifest.versions.find(ver => ver.id == meta["version"]);
+
+			if (!versionInManifest) {
+				return reject(new Error("Minecraft version \"" + meta["version"] + "\" could not be found in given source. "));
+			}
+
+			if (!fs.existsSync(directory)) await fsPromises.mkdir(directory, {"recursive": true});
+
+			let versionDirectory = path.join(directory, "versions", meta["version"]);
+
+			if (!fs.existsSync(versionDirectory)) await fsPromises.mkdir(versionDirectory, {"recursive": true});
+			let versionManifest = JSON.parse(await httpsWrapper.get(versionInManifest.url));
+			fs.writeFileSync(path.join(versionDirectory, meta["version"] + ".json"), JSON.stringify(versionManifest, null, "\t"));
+
+			let librariesDirectory = path.join(directory, "libraries");
+
+			for (let l = 0; l < versionManifest.libraries.length; l++) {
+				let library = versionManifest.libraries[l];
+
+				if ("classifiers" in library.downloads) continue; // Attempt at skipping platform-specific code, hoping the game still starts.
+
+				let libraryFilePath = path.join(librariesDirectory, ...(library.downloads.artifact.path.split("/")));
+
+				downloadQueue.push({
+					"url": library.downloads.artifact.url,
+					"path": libraryFilePath
+				});
+			}
+
+			let assetsDirectory = path.join(directory, "assets");
+
+			let assetIndexesDirectory = path.join(assetsDirectory, "indexes");
+			if (!fs.existsSync(assetIndexesDirectory)) await fsPromises.mkdir(assetIndexesDirectory, {"recursive": true});
+
+			let assetIndexPath = path.join(assetIndexesDirectory, versionManifest.assetIndex.id + ".json");
+			let assetIndex = JSON.parse(await httpsWrapper.get(versionManifest.assetIndex.url));
+			fs.writeFileSync(assetIndexPath, JSON.stringify(assetIndex, null, "\t"));
+
+			let assetObjectsDirectory = path.join(assetsDirectory, "objects");
+			for (const assetLocation in assetIndex.objects) {
+				if (assetIndex.objects.hasOwnProperty(assetLocation)) {
+					let asset = assetIndex.objects[assetLocation];
+
+					let assetPath = [
+						asset.hash.substring(0, 2), asset.hash
+					];
+
+					downloadQueue.push({
+						"url": manifestSource["asset_base"] + assetPath.join("/"),
+						"path": path.join(assetObjectsDirectory, ...assetPath)
+					});
+				}
+			}
+
+			downloadQueue.push({
+				"url": versionManifest.downloads.client.url,
+				"path": path.join(versionDirectory, meta["version"] + ".jar")
+			});
+
+			if (!isDownloading) await module.exports.process_queue(progressCB);
+
+			resolve(true);
+		});
+	}
+};

lib/util/functions.js

@@ -0,0 +1,7 @@
+module.exports = {
+	"sleep": function (delay) {
+		return new Promise(function (resolve, reject) {
+			setTimeout(resolve, delay);
+		});
+	}
+};

lib/util/https.js

@@ -0,0 +1,35 @@
+const https = require("https");
+
+module.exports = {
+	"get": function (url) {
+		return new Promise(function (resolve, reject) {
+			var request = https.get(url, function (response) {
+				if (response.statusCode != 200) return reject(new Error("Response status code wasn't 200. "));
+
+				response.setEncoding("utf-8");
+				let body = "";
+
+				response.on("data", function (chunk) {
+					body += chunk;
+				});
+
+				response.on("end", function () {
+					resolve(body);
+				});
+			});
+
+			request.on("error", reject);
+		});
+	},
+	"getStream": function (url) {
+		return new Promise(function (resolve, reject) {
+			var request = https.get(url, function (response) {
+				if (response.statusCode != 200) return reject(new Error("Response status code wasn't 200"));
+
+				resolve(response);
+			});
+
+			request.on("error", reject);
+		});
+	}
+};

main.js

@@ -1,8 +1,49 @@
 const path = require("node:path");
-const child_process = require("node:child_process");
+const fs = require("node:fs");
+const os = require("node:os");
 
 const electron = require("electron");
 
+const downloader = require("./lib/downloader.js");
+const checker = require("./lib/checker.js");
+
+let meta = JSON.parse(fs.readFileSync(path.join(__dirname, "meta.json"), "utf-8"));
+let sources = JSON.parse(fs.readFileSync(path.join(__dirname, "sources.json"), "utf-8"));
+
+let osPlatform = os.platform();
+let userHome = os.homedir();
+
+let gameDirectory;
+switch (osPlatform) {
+	case "win32":
+		gameDirectory = path.join(userHome, "AppData", "Roaming", ...(meta["install_directory"]).split("/"));
+		break;
+	case "darwin":
+		gameDirectory = path.join(userHome, "Library", "Application Support", ...(meta["install_directory"]).split("/"));
+		break;
+	case "linux":
+		gameDirectory = path.join(userHome, ...(meta["install_directory"]).split("/"));
+		break;
+	default:
+		gameDirectory = path.join(userHome, ...(meta["install_directory"]).split("/"));
+		break;
+}
+
+let window;
+
+function showProgress(progress, ongoing, remaining, total) {
+	window.setProgressBar(progress);
+
+	window.webContents.send("event", {
+		"type": "download-progress",
+		"data": {
+			"ongoing": ongoing,
+			"remaining": remaining,
+			"total": total
+		}
+	});
+}
+
 electron.app.on("ready", function () {
 	window = new electron.BrowserWindow({
 		"width": 960,
@@ -14,7 +55,7 @@ electron.app.on("ready", function () {
 		},
 		"title": "OpenModLauncher",
 		"icon": path.join(__dirname, "res", "img", "logo.png"),
-		"frame": true,
+		"frame": false,
 		"transparent": true,
 		"resizable": false,
 		"show": false
@@ -25,6 +66,21 @@ electron.app.on("ready", function () {
 	window.on("ready-to-show", window.show);
 });
 
+electron.ipcMain.handle("minimize", function (event) {
+	return window.minimize();
+});
+
+electron.ipcMain.handle("close", function (event) {
+	return window.close();
+});
+
+electron.ipcMain.handle("is-installed", function (event) {
+	return checker.check_install(gameDirectory);
+});
+electron.ipcMain.handle("install", function (event) {
+	return downloader.download_minecraft(gameDirectory, meta["minecraft"], sources["minecraft"], showProgress);
+});
+
 electron.app.on("window-all-closed", function () {
 	electron.app.quit();
 });

meta.json

@@ -1,5 +1,6 @@
 {
+	"install_directory": "games/.openmod",
 	"minecraft": {
-		"version": "${MINECRAFT_VERSION}"
+		"version": "1.7.10"
 	}
 }

preload.js

@@ -0,0 +1,18 @@
+const electron = require("electron");
+
+electron.contextBridge.exposeInMainWorld("minimizeWindow", function () {
+	return electron.ipcRenderer.invoke("minimize");
+});
+
+electron.contextBridge.exposeInMainWorld("closeWindow", function () {
+	return electron.ipcRenderer.invoke("close");
+});
+
+electron.contextBridge.exposeInMainWorld("game", {
+	"isInstalled": function () {
+		return electron.ipcRenderer.invoke("is-installed");
+	},
+	"install": function () {
+		return electron.ipcRenderer.invoke("install");
+	}
+});

res/css/main.css

@@ -0,0 +1,47 @@
+:root {
+	color: rgba(248, 248, 248, 1.0);
+}
+
+body {
+	margin: 0px;
+}
+
+#titlebar {
+	display: flex;
+	flex-direction: row;
+	justify-content: space-between;
+	align-items: center;
+	-webkit-app-region: drag;
+	width: 100%;
+	height: 24px;
+	position: absolute;
+	top: 0px;
+	left: 0px;
+	background-color: rgba(16, 16, 16, 1.0);
+}
+
+#window-actions {
+	display: flex;
+	flex-direction: row;
+	height: 100%;
+	-webkit-app-region: no-drag;
+	pointer-events: all;
+}
+
+.window-action {
+	background-color: rgba(24, 24, 32, 1.0);
+	width: 32px;
+	height: 100%;
+}
+
+.window-action:hover {
+	background-color: rgba(48, 48, 64, 1.0);
+}
+
+#window-close {
+	background-color: rgba(128, 0, 0, 1.0);
+}
+
+#window-close:hover {
+	background-color: rgba(248, 0, 0, 1.0);
+}

sources.json

@@ -1,5 +1,9 @@
 {
 	"minecraft": {
-		"versions_manifest": "https://launchermeta.mojang.com/mc/game/version_manifest_v2.json"
+		"versions_manifest": "https://launchermeta.mojang.com/mc/game/version_manifest_v2.json",
+		"asset_base": "https://resources.download.minecraft.net/"
+	},
+	"custom": {
+		"files_manifest": "${CUSTOM_MANIFEST_URL}"
 	}
 }

views/main.html

@@ -3,10 +3,20 @@
 	<head>
 		<meta charset="utf-8">
 		<title>OpenModLauncher</title>
+
+		<link rel="stylesheet" href="../res/css/main.css">
 	</head>
 	<body>
 		<div id="titlebar">
+			<span>OpenModLauncher</span>
+			<div id="window-actions">
+				<div class="window-action" id="window-minimize" onclick="minimizeWindow();">
 
 				</div>
+				<div class="window-action" id="window-close" onclick="closeWindow();">
+
+				</div>
+			</div>
+		</div>
 	</body>
 </html>