Split jslib into multiple modules (#363)

* Split jslib into multiple modules

electron/src/services/electronMainMessaging.service.ts

@@ -0,0 +1,56 @@
+import { app, dialog, ipcMain, Menu, MenuItem, nativeTheme } from 'electron';
+import { promises as fs } from 'fs';
+import { MessagingService } from 'jslib-common/abstractions/messaging.service';
+import { RendererMenuItem } from '../utils';
+
+import { WindowMain } from '../window.main';
+
+export class ElectronMainMessagingService implements MessagingService {
+    constructor(private windowMain: WindowMain, private onMessage: (message: any) => void) {
+        ipcMain.handle('appVersion', () => {
+            return app.getVersion();
+        });
+
+        ipcMain.handle('systemTheme', () => {
+            return nativeTheme.shouldUseDarkColors ? 'dark' : 'light';
+        });
+
+        ipcMain.handle('showMessageBox', (event, options) => {
+            return dialog.showMessageBox(options);
+        });
+
+        ipcMain.handle('openContextMenu', (event, options: {menu: RendererMenuItem[]}) => {
+            return new Promise(resolve => {
+                const menu = new Menu();
+                options.menu.forEach((m, index) => {
+                    menu.append(new MenuItem({
+                        label: m.label,
+                        type: m.type,
+                        click: () => {
+                            resolve(index);
+                        },
+                    }));
+                });
+                menu.popup({ window: windowMain.win, callback: () => {
+                    resolve(-1);
+                }});
+            });
+        });
+
+        ipcMain.handle('windowVisible', () => {
+            return windowMain.win?.isVisible();
+        });
+
+        nativeTheme.on('updated', () => {
+            windowMain.win?.webContents.send('systemThemeUpdated', nativeTheme.shouldUseDarkColors ? 'dark' : 'light');
+        });
+    }
+
+    send(subscriber: string, arg: any = {}) {
+        const message = Object.assign({}, { command: subscriber }, arg);
+        this.onMessage(message);
+        if (this.windowMain.win != null) {
+            this.windowMain.win.webContents.send('messagingService', message);
+        }
+    }
+}