generate local .desktop file so it shows among apps in linux desktop environments

src/services/app_icon.js

@@ -0,0 +1,65 @@
+"use strict";
+
+const path = require('path');
+const {APP_PNG_ICON_DIR} = require("./resource_dir");
+const log = require("./log");
+const os = require('os');
+const fs = require('fs');
+
+const template = `[Desktop Entry]
+Type=Application
+Name=Trilium Notes
+Icon=#APP_PNG_ICON_DIR#/128x128.png
+Exec=#EXE_PATH#
+Categories=Office
+Terminal=false
+`;
+
+/**
+ * Installs .desktop icon into standard ~/.local/share/applications directory.
+ * We overwrite this file during every run as it might have been updated.
+ */
+async function installLocalAppIcon() {
+    if (["win32", "darwin"].includes(os.platform())) {
+        return;
+    }
+
+    const desktopDir = path.resolve(os.homedir(), '.local/share/applications');
+
+    fs.stat(desktopDir, function (err, stats) {
+        if (err) {
+            // Directory doesn't exist so we won't attempt to create the .desktop file
+            return;
+        }
+
+        if (stats.isDirectory()) {
+            const desktopFilePath = path.resolve(desktopDir, "trilium-notes.desktop");
+
+            fs.writeFile(desktopFilePath, getDesktopFileContent(), function (err) {
+                if (err) {
+                   log.error("Desktop icon installation to ~/.local/share/applications failed.");
+                }
+            });
+        }
+    });
+}
+
+function getDesktopFileContent() {
+    return template
+        .replace("#APP_PNG_ICON_DIR#", escapePath(APP_PNG_ICON_DIR))
+        .replace("#EXE_PATH#", escapePath(getExePath()));
+}
+
+function escapePath(path) {
+    return path.replace(" ", "\\ ");
+}
+
+function getExePath() {
+    const appPath = require('electron').app.getAppPath();
+
+    return path.resolve(appPath, 'trilium');
+}
+
+module.exports = {
+    installLocalAppIcon
+};