[MouseJump] - add FileSystemWatcher for config (microsoft#26703)

src/modules/MouseUtils/MouseJumpUI/Helpers/SettingsHelper.cs

@@ -0,0 +1,95 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.IO;
+using System.IO.Abstractions;
+using System.Threading;
+using ManagedCommon;
+using Microsoft.PowerToys.Settings.UI.Library;
+using Microsoft.PowerToys.Settings.UI.Library.Utilities;
+
+namespace MouseJumpUI.Helpers;
+
+internal class SettingsHelper
+{
+    public SettingsHelper()
+    {
+        this.LockObject = new();
+        this.CurrentSettings = this.LoadSettings();
+
+        // delay loading settings on change by some time to avoid file in use exception
+        var throttledActionInvoker = new ThrottledActionInvoker();
+        this.FileSystemWatcher = Helper.GetFileWatcher(
+            moduleName: MouseJumpSettings.ModuleName,
+            fileName: "settings.json",
+            onChangedCallback: () => throttledActionInvoker.ScheduleAction(this.ReloadSettings, 250));
+    }
+
+    private IFileSystemWatcher FileSystemWatcher
+    {
+        get;
+    }
+
+    private object LockObject
+    {
+        get;
+    }
+
+    public MouseJumpSettings CurrentSettings
+    {
+        get;
+        private set;
+    }
+
+    private MouseJumpSettings LoadSettings()
+    {
+        lock (this.LockObject)
+        {
+            {
+                var settingsUtils = new SettingsUtils();
+
+                // set this to 1 to disable retries
+                var remainingRetries = 5;
+
+                while (remainingRetries > 0)
+                {
+                    try
+                    {
+                        if (!settingsUtils.SettingsExists(MouseJumpSettings.ModuleName))
+                        {
+                            Logger.LogInfo("MouseJump settings.json was missing, creating a new one");
+                            var defaultSettings = new MouseJumpSettings();
+                            defaultSettings.Save(settingsUtils);
+                        }
+
+                        var settings = settingsUtils.GetSettingsOrDefault<MouseJumpSettings>(MouseJumpSettings.ModuleName);
+                        return settings;
+                    }
+                    catch (IOException ex)
+                    {
+                        Logger.LogError("Failed to read changed settings", ex);
+                        Thread.Sleep(250);
+                    }
+                    catch (Exception ex)
+                    {
+                        Logger.LogError("Failed to read changed settings", ex);
+                        Thread.Sleep(250);
+                    }
+
+                    remainingRetries--;
+                }
+            }
+        }
+
+        const string message = "Failed to read changed settings - ran out of retries";
+        Logger.LogError(message);
+        throw new InvalidOperationException(message);
+    }
+
+    public void ReloadSettings()
+    {
+        this.CurrentSettings = this.LoadSettings();
+    }
+}

src/modules/MouseUtils/MouseJumpUI/Helpers/ThrottledActionInvoker.cs

@@ -0,0 +1,47 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Windows.Threading;
+
+namespace MouseJumpUI.Helpers;
+
+internal sealed class ThrottledActionInvoker
+{
+    private readonly object _invokerLock = new();
+    private readonly DispatcherTimer _timer;
+
+    private Action? _actionToRun;
+
+    public ThrottledActionInvoker()
+    {
+        _timer = new DispatcherTimer();
+        _timer.Tick += Timer_Tick;
+    }
+
+    public void ScheduleAction(Action action, int milliseconds)
+    {
+        lock (_invokerLock)
+        {
+            if (_timer.IsEnabled)
+            {
+                _timer.Stop();
+            }
+
+            _actionToRun = action;
+            _timer.Interval = new TimeSpan(0, 0, 0, 0, milliseconds);
+
+            _timer.Start();
+        }
+    }
+
+    private void Timer_Tick(object? sender, EventArgs? e)
+    {
+        lock (_invokerLock)
+        {
+            _timer.Stop();
+            _actionToRun?.Invoke();
+        }
+    }
+}

src/modules/MouseUtils/MouseJumpUI/MainForm.cs

@@ -19,13 +19,13 @@ namespace MouseJumpUI;
 
 internal partial class MainForm : Form
 {
-    public MainForm(MouseJumpSettings settings)
+    public MainForm(SettingsHelper settingsHelper)
     {
         this.InitializeComponent();
-        this.Settings = settings ?? throw new ArgumentNullException(nameof(settings));
+        this.SettingsHelper = settingsHelper ?? throw new ArgumentNullException(nameof(settingsHelper));
     }
 
-    public MouseJumpSettings Settings
+    public SettingsHelper SettingsHelper
     {
         get;
     }
@@ -171,15 +171,18 @@ private static LayoutInfo GetLayoutInfo(MainForm form)
             .Single(item => item.Screen.Handle == activatedScreenHandle.Value)
             .Index;
 
+        // avoid a race condition - cache the current settings in case they change
+        var currentSettings = form.SettingsHelper.CurrentSettings;
+
         var layoutConfig = new LayoutConfig(
             virtualScreenBounds: ScreenHelper.GetVirtualScreen(),
             screens: screens.Select(item => item.Screen).ToList(),
             activatedLocation: activatedLocation,
             activatedScreenIndex: activatedScreenIndex,
             activatedScreenNumber: activatedScreenIndex + 1,
             maximumFormSize: new(
-                form.Settings.Properties.ThumbnailSize.Width,
-                form.Settings.Properties.ThumbnailSize.Height),
+                currentSettings.Properties.ThumbnailSize.Width,
+                currentSettings.Properties.ThumbnailSize.Height),
             /*
               don't read the panel padding values because they are affected by dpi scaling
               and can give wrong values when moving between monitors with different dpi scaling

src/modules/MouseUtils/MouseJumpUI/Program.cs

@@ -13,6 +13,7 @@
 using interop;
 using ManagedCommon;
 using Microsoft.PowerToys.Settings.UI.Library;
+using MouseJumpUI.Helpers;
 
 namespace MouseJumpUI;
 
@@ -69,8 +70,8 @@ private static void Main(string[] args)
             Application.Exit();
         });
 
-        var settings = Program.ReadSettings();
-        var mainForm = new MainForm(settings);
+        var settingsHelper = new SettingsHelper();
+        var mainForm = new MainForm(settingsHelper);
 
         NativeEventWaiter.WaitForEventLoop(
             Constants.MouseJumpShowPreviewEvent(),

src/settings-ui/Settings.UI.Library/MouseJumpSettings.cs

@@ -2,6 +2,8 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 using Microsoft.PowerToys.Settings.UI.Library.Interfaces;
 
@@ -21,6 +23,22 @@ public MouseJumpSettings()
             Version = "1.0";
         }
 
+        public void Save(ISettingsUtils settingsUtils)
+        {
+            // Save settings to file
+            var options = new JsonSerializerOptions
+            {
+                WriteIndented = true,
+            };
+
+            if (settingsUtils == null)
+            {
+                throw new ArgumentNullException(nameof(settingsUtils));
+            }
+
+            settingsUtils.SaveSettings(JsonSerializer.Serialize(this, options), ModuleName);
+        }
+
         public string GetModuleName()
         {
             return Name;