implement PreventDefault function for stop quiting application

Author: GregorBiswanger

ElectronNET.API/App.cs

@@ -59,38 +59,53 @@ public event Action WindowAllClosed
         /// Note: If application quit was initiated by autoUpdater.quitAndInstall() then before-quit is emitted after
         /// emitting close event on all windows and closing them.
         /// </summary>
-        public event Func<Task> BeforeQuit
+        public event Func<QuitEventArgs, Task> BeforeQuit
         {
             add
             {
                 if (_beforeQuit == null)
                 {
                     BridgeConnector.Socket.On("app-before-quit" + GetHashCode(), async () =>
                     {
-                        await _beforeQuit();
+                        await _beforeQuit(new QuitEventArgs());
 
-                        if(_willQuit == null && _quitting == null)
+                        if (_preventQuit)
                         {
-                            Exit();
+                            _preventQuit = false;
                         }
-                        else if (_willQuit != null)
+                        else
                         {
-                            await _willQuit();
-                            
-                            if(_quitting == null)
+                            if (_willQuit == null && _quitting == null)
                             {
                                 Exit();
-                            } else
+                            }
+                            else if (_willQuit != null)
+                            {
+                                await _willQuit(new QuitEventArgs());
+
+                                if (_preventQuit)
+                                {
+                                    _preventQuit = false;
+                                }
+                                else
+                                {
+                                    if (_quitting == null)
+                                    {
+                                        Exit();
+                                    }
+                                    else
+                                    {
+                                        await _quitting();
+                                        Exit();
+                                    }
+                                }
+                            }
+                            else if (_quitting != null)
                             {
                                 await _quitting();
                                 Exit();
                             }
                         }
-                        else if(_quitting != null)
-                        {
-                            await _quitting();
-                            Exit();
-                        }
                     });
 
                     BridgeConnector.Socket.Emit("register-app-before-quit-event", GetHashCode());
@@ -106,32 +121,39 @@ public event Func<Task> BeforeQuit
             }
         }
 
-        private event Func<Task> _beforeQuit;
+        private event Func<QuitEventArgs, Task> _beforeQuit;
 
         /// <summary>
         /// Emitted when all windows have been closed and the application will quit. 
         ///
         /// See the description of the window-all-closed event for the differences between the will-quit and 
         /// window-all-closed events.
         /// </summary>
-        public event Func<Task> WillQuit
+        public event Func<QuitEventArgs, Task> WillQuit
         {
             add
             {
                 if (_willQuit == null)
                 {
                     BridgeConnector.Socket.On("app-will-quit" + GetHashCode(), async () =>
                     {
-                        await _willQuit();
+                        await _willQuit(new QuitEventArgs());
 
-                        if(_quitting == null)
+                        if (_preventQuit)
                         {
-                            Exit();
+                            _preventQuit = false;
                         }
                         else
                         {
-                            await _quitting();
-                            Exit();
+                            if (_quitting == null)
+                            {
+                                Exit();
+                            }
+                            else
+                            {
+                                await _quitting();
+                                Exit();
+                            }
                         }
                     });
 
@@ -148,7 +170,7 @@ public event Func<Task> WillQuit
             }
         }
 
-        private event Func<Task> _willQuit;
+        private event Func<QuitEventArgs, Task> _willQuit;
 
         /// <summary>
         /// Emitted when the application is quitting.
@@ -1378,5 +1400,12 @@ public void DockSetIcon(string image)
         {
             BridgeConnector.Socket.Emit("appDockSetIcon", image);
         }
+
+        internal void PreventQuit()
+        {
+            _preventQuit = true;
+        }
+
+        private bool _preventQuit = false;
     }
 }

ElectronNET.API/QuitEventArgs.cs

@@ -0,0 +1,16 @@
+namespace ElectronNET.API
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public sealed class QuitEventArgs
+    {
+        /// <summary>
+        /// Will prevent the default behaviour, which is terminating the application.
+        /// </summary>
+        public void PreventDefault()
+        {
+            Electron.App.PreventQuit();
+        }
+    }
+}

ElectronNET.WebApp/Controllers/ShortcutsController.cs

@@ -22,7 +22,7 @@ public IActionResult Index()
                     await Electron.Dialog.ShowMessageBoxAsync(options);
                 });
 
-                Electron.App.WillQuit += () => Task.Run(() => Electron.GlobalShortcut.UnregisterAll());
+                Electron.App.WillQuit += (args) => Task.Run(() => Electron.GlobalShortcut.UnregisterAll());
             }
 
             return View();

ElectronNET.WebApp/Startup.cs

@@ -5,6 +5,7 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using System.Threading.Tasks;
 
 namespace ElectronNET.WebApp
 {
@@ -61,7 +62,7 @@ public async void ElectronBootstrap()
             });
 
             browserWindow.OnReadyToShow += () => browserWindow.Show();
-            browserWindow.SetTitle(Configuration["DemoTitleInSettings"] );
+            browserWindow.SetTitle(Configuration["DemoTitleInSettings"]);
         }
     }
 }

ElectronNET.WebApp/Views/Shortcuts/Index.cshtml

@@ -47,7 +47,7 @@
     await Electron.Dialog.ShowMessageBoxAsync(options);
 });
 
-Electron.App.WillQuit += () => Task.Run(() => Electron.GlobalShortcut.UnregisterAll());</code></pre>
+Electron.App.WillQuit += (args) => Task.Run(() => Electron.GlobalShortcut.UnregisterAll());</code></pre>
 
           <div class="demo-protip">
             <h2>ProTip</h2>