Fix bug with Save

Subclassing BrowserWindow in es6 style seems to cause some strange bugs
in electron. I've changed this so that methods are added to the
individual instances, as that keeps the object as type BrowserWindow.

Not sure what the problem is with BrowserWindow subclasses. If anyone
knows the reason, would love to hear if there's a better solution!

app/TingappWindow.js

@@ -27,59 +27,58 @@ function setDefaultZoomFactor(zoomFactor) {
   });
 }
 
-class TingappWindow extends BrowserWindow {
-  constructor(options) {
-    const defaultOptions = {
-      width: 700,
-      height: 600,
-      minWidth: 450,
-      minHeight: 300,
-      darkTheme: true,
-      backgroundColor: '#1c1c1c',
-      title: 'Tide',
+function newTingappWindow(options) {
+  const defaultOptions = {
+    width: 700,
+    height: 600,
+    minWidth: 450,
+    minHeight: 300,
+    darkTheme: true,
+    backgroundColor: '#1c1c1c',
+    title: 'Tide',
       webPreferences: {
         // if zoom factor is available synchronously, use that
         zoomFactor: _defaultZoomFactor || undefined, 
       }
-    };
+  };
+  options = Object.assign({}, defaultOptions, options);
 
-    // supply default options (but prefer options already there)
-    options = Object.assign({}, defaultOptions, options);
+  const win = new BrowserWindow(options);
 
-    super(options);
-
-    // render index.html which will contain our root Vue component
-    this.loadURL('file://' + __dirname + '/index.html');
-
-    // if zoom factor isn't loaded yet, use the async method to load/set
-    if (_defaultZoomFactor === null) {
-      this.webContents.on('did-finish-load', () => {
-        getDefaultZoomFactor((zoomFactor) => {
-          console.log('setting zoomFactor to ', zoomFactor);
-          this.webContents.setZoomFactor(zoomFactor);
-        });
+  // if zoom factor isn't loaded yet, use the async method to load/set
+  if (_defaultZoomFactor === null) {
+    win.webContents.on('did-finish-load', () => {
+      getDefaultZoomFactor((zoomFactor) => {
+        console.log('setting zoomFactor to ', zoomFactor);
+        win.webContents.setZoomFactor(zoomFactor);
       });
-    }
+    });
   }
 
-  resetZoom() {
-    this.webContents.setZoomFactor(1.0);
-    setDefaultZoomFactor(1.0);
-  }
-  zoomIn() {
-    this.webContents.getZoomFactor((zoomFactor) => {
-      zoomFactor *= 1.1;
-      this.webContents.setZoomFactor(zoomFactor);
-      setDefaultZoomFactor(zoomFactor);
-    })
-  }
-  zoomOut() {
-    this.webContents.getZoomFactor((zoomFactor) => {
-      zoomFactor /= 1.1;
-      this.webContents.setZoomFactor(zoomFactor);
-      setDefaultZoomFactor(zoomFactor);
-    })
-  }
+  // add some extra methods to win
+  Object.assign(win, {
+    resetZoom() {
+      this.webContents.setZoomFactor(1.0);
+      setDefaultZoomFactor(1.0);
+    },
+    zoomIn() {
+      this.webContents.getZoomFactor((zoomFactor) => {
+        zoomFactor *= 1.1;
+        this.webContents.setZoomFactor(zoomFactor);
+        setDefaultZoomFactor(zoomFactor);
+      })
+    },
+    zoomOut() {
+      this.webContents.getZoomFactor((zoomFactor) => {
+        zoomFactor /= 1.1;
+        this.webContents.setZoomFactor(zoomFactor);
+        setDefaultZoomFactor(zoomFactor);
+      })
+    },
+  });
+
+  win.loadURL('file://' + __dirname + '/index.html');
+  return win;
 }
 
-module.exports = TingappWindow;
+module.exports = newTingappWindow;

app/app.js

@@ -7,14 +7,14 @@ const fs = require('fs');
 const path = require('path');
 const autoupdate = require('./autoupdate');
 const menu = require('./menu');
-const TingappWindow = require('./TingappWindow');
+const newTingappWindow = require('./TingappWindow');
 
 if (require('electron-squirrel-startup')) return;
 
 require('./src/utils/exceptionhandling.js').setup();
 
 function createWindow(on_load) {
-    const newWindow = new TingappWindow();
+    const newWindow = newTingappWindow();
 
     if (on_load) {
         newWindow.webContents.on('did-finish-load', function() {