Fixing issues when color picker freezes (#8376)

* Fixing issue when color picker was frozen because other application was locking clipboard

* Fixed another issue where holding activation keys constantly would trigger show color picker numberous times and it would cause some events to be attached multiple times

src/modules/colorPicker/ColorPickerUI/Helpers/AppStateHandler.cs

@@ -14,6 +14,8 @@ namespace ColorPicker.Helpers
     {
         private readonly IColorEditorViewModel _colorEditorViewModel;
         private ColorEditorWindow _colorEditorWindow;
+        private bool _colorPickerShown;
+        private object _colorPickerVisibilityLock = new object();
 
         [ImportingConstructor]
         public AppStateHandler(IColorEditorViewModel colorEditorViewModel)
@@ -30,16 +32,30 @@ namespace ColorPicker.Helpers
 
         public void ShowColorPicker()
         {
-            AppShown?.Invoke(this, EventArgs.Empty);
-            Application.Current.MainWindow.Opacity = 0;
-            Application.Current.MainWindow.Visibility = Visibility.Visible;
+            lock (_colorPickerVisibilityLock)
+            {
+                if (!_colorPickerShown)
+                {
+                    AppShown?.Invoke(this, EventArgs.Empty);
+                    Application.Current.MainWindow.Opacity = 0;
+                    Application.Current.MainWindow.Visibility = Visibility.Visible;
+                    _colorPickerShown = true;
+                }
+            }
         }
 
         public void HideColorPicker()
         {
-            Application.Current.MainWindow.Opacity = 0;
-            Application.Current.MainWindow.Visibility = Visibility.Collapsed;
-            AppHidden?.Invoke(this, EventArgs.Empty);
+            lock (_colorPickerVisibilityLock)
+            {
+                if (_colorPickerShown)
+                {
+                    Application.Current.MainWindow.Opacity = 0;
+                    Application.Current.MainWindow.Visibility = Visibility.Collapsed;
+                    AppHidden?.Invoke(this, EventArgs.Empty);
+                    _colorPickerShown = false;
+                }
+            }
         }
 
         public void ShowColorPickerEditor()

src/modules/colorPicker/ColorPickerUI/Helpers/ClipboardHelper.cs

@@ -3,7 +3,9 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Runtime.InteropServices;
+using System.Text;
 using System.Windows;
+using static ColorPicker.NativeMethods;
 
 namespace ColorPicker.Helpers
 {
@@ -23,15 +25,24 @@ namespace ColorPicker.Helpers
                 {
                     try
                     {
-                        Clipboard.SetText(colorRepresentationToCopy);
+                        Clipboard.SetDataObject(colorRepresentationToCopy);
                         break;
                     }
                     catch (COMException ex)
                     {
+                        var hwnd = GetOpenClipboardWindow();
+                        var sb = new StringBuilder(501);
+                        _ = GetWindowText(hwnd.ToInt32(), sb, 500);
+                        var applicationUsingClipboard = sb.ToString();
+
                         if ((uint)ex.ErrorCode != ErrorCodeClipboardCantOpen)
                         {
                             Logger.LogError("Failed to set text into clipboard", ex);
                         }
+                        else
+                        {
+                            Logger.LogError("Failed to set text into clipboard, application that is locking clipboard - " + applicationUsingClipboard, ex);
+                        }
                     }
 
                     System.Threading.Thread.Sleep(10);

src/modules/colorPicker/ColorPickerUI/Keyboard/KeyboardMonitor.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
+using System.Diagnostics;
 using System.Windows.Input;
 using ColorPicker.Helpers;
 using ColorPicker.Settings;
@@ -21,10 +22,12 @@ namespace ColorPicker.Keyboard
     {
         private readonly AppStateHandler _appStateHandler;
         private readonly IUserSettings _userSettings;
+        private List<string> _previouslyPressedKeys;
 
         private List<string> _activationKeys = new List<string>();
         private GlobalKeyboardHook _keyboardHook;
         private bool disposedValue;
+        private bool _activationShortcutPressed;
 
         [ImportingConstructor]
         public KeyboardMonitor(AppStateHandler appStateHandler, IUserSettings userSettings)
@@ -80,26 +83,38 @@ namespace ColorPicker.Keyboard
             // If the last key pressed is a modifier key, then currentlyPressedKeys cannot possibly match with _activationKeys
             // because _activationKeys contains exactly 1 non-modifier key. Hence, there's no need to check if `name` is a
             // modifier key or to do any additional processing on it.
-
-            // Check pressed modifier keys.
-            AddModifierKeys(currentlyPressedKeys);
-
             if (e.KeyboardState == GlobalKeyboardHook.KeyboardState.KeyDown || e.KeyboardState == GlobalKeyboardHook.KeyboardState.SysKeyDown)
             {
+                // Check pressed modifier keys.
+                AddModifierKeys(currentlyPressedKeys);
+
                 currentlyPressedKeys.Add(name);
             }
 
             currentlyPressedKeys.Sort();
 
+            if (currentlyPressedKeys.Count == 0 && _previouslyPressedKeys.Count != 0)
+            {
+                // no keys pressed, we can enable activation shortcut again
+                _activationShortcutPressed = false;
+            }
+
+            _previouslyPressedKeys = currentlyPressedKeys;
+
             if (ArraysAreSame(currentlyPressedKeys, _activationKeys))
             {
-                if (_userSettings.ActivationAction.Value == ColorPickerActivationAction.OpenEditor)
+                // avoid triggering this action multiple times as this will be called nonstop while keys are pressed
+                if (!_activationShortcutPressed)
                 {
-                    _appStateHandler.ShowColorPickerEditor();
-                }
-                else
-                {
-                    _appStateHandler.ShowColorPicker();
+                    _activationShortcutPressed = true;
+                    if (_userSettings.ActivationAction.Value == ColorPickerActivationAction.OpenEditor)
+                    {
+                        _appStateHandler.ShowColorPickerEditor();
+                    }
+                    else
+                    {
+                        _appStateHandler.ShowColorPicker();
+                    }
                 }
             }
         }

src/modules/colorPicker/ColorPickerUI/NativeMethods.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
+using System.Text;
 
 namespace ColorPicker
 {
@@ -161,5 +162,11 @@ namespace ColorPicker
             /// </summary>
             public IntPtr AdditionalInformation;
         }
+
+        [DllImport("user32.dll")]
+        internal static extern IntPtr GetOpenClipboardWindow();
+
+        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+        internal static extern int GetWindowText(int hwnd, StringBuilder text, int count);
     }
 }