Support showing ctrl, alt, win keys pressed down without any other key

- Removed filtering of modifierkey to allow to handle them in ToInputs.
- Filtered triggering of modifier display for modifierkeys themselves in
ToInputs.
- Exposed IsModifierKeyPress as static to be used in KeyPress and
Messages.
- KeyPress.HasModifierPress returns false if key is a modifierkey itself
(allow the merging in Message).
- Removed merge flag in favor of handling the strategy directly in Message.MergeIfNeeded

src/Carnac.Logic/KeyProvider.cs

@@ -20,7 +20,7 @@ public class KeyProvider : IKeyProvider
         readonly IPasswordModeService passwordModeService;
         readonly IDesktopLockEventService desktopLockEventService;
 
-        private readonly IList<Keys> modifierKeys =
+        private static readonly IList<Keys> modifierKeys =
             new List<Keys>
                 {
                     Keys.LControlKey,
@@ -68,7 +68,7 @@ public IObservable<KeyPress> GetKeyStream()
 
                 var keyStreamSubsription = interceptKeysSource.GetKeyStream()
                     .Select(DetectWindowsKey)
-                    .Where(k => !IsModifierKeyPress(k) && k.KeyDirection == KeyDirection.Down)
+                    .Where(k =>  k.KeyDirection == KeyDirection.Down)
                     .Select(ToCarnacKeyPress)
                     .Where(keypress => keypress != null)
                     .Where(k => !passwordModeService.CheckPasswordMode(k.InterceptKeyEventArgs))
@@ -91,7 +91,7 @@ InterceptKeyEventArgs DetectWindowsKey(InterceptKeyEventArgs interceptKeyEventAr
             return interceptKeyEventArgs;
         }
 
-        bool IsModifierKeyPress(InterceptKeyEventArgs interceptKeyEventArgs)
+        public static bool IsModifierKeyPress(InterceptKeyEventArgs interceptKeyEventArgs)
         {
             return modifierKeys.Contains(interceptKeyEventArgs.Key);
         }
@@ -123,6 +123,15 @@ static IEnumerable<string> ToInputs(bool isLetter, bool isWinKeyPressed, Interce
             var controlPressed = interceptKeyEventArgs.ControlPressed;
             var altPressed = interceptKeyEventArgs.AltPressed;
             var shiftPressed = interceptKeyEventArgs.ShiftPressed;
+
+            if (IsModifierKeyPress(interceptKeyEventArgs))
+            {
+                controlPressed = false;
+                altPressed = false;
+                shiftPressed = false;
+                isWinKeyPressed = false;
+            }
+
             if (controlPressed)
                 yield return "Ctrl";
             if (altPressed)

src/Carnac.Logic/Models/Message.cs

@@ -13,7 +13,6 @@ public sealed class Message
         readonly string processName;
         readonly ImageSource processIcon;
         readonly string shortcutName;
-        readonly bool canBeMerged;
         readonly bool isShortcut;
         readonly bool isDeleting;
         readonly DateTime lastMessage;
@@ -29,7 +28,6 @@ public Message(KeyPress key)
         {
             processName = key.Process.ProcessName;
             processIcon = key.Process.ProcessIcon;
-            canBeMerged = !key.HasModifierPressed;
 
             keys = new ReadOnlyCollection<KeyPress>(new[] { key });
             textCollection = new ReadOnlyCollection<string>(CreateTextSequence(key).ToArray());
@@ -49,7 +47,6 @@ public Message(IEnumerable<KeyPress> keys, KeyShortcut shortcut)
             processIcon = allKeys.First().Process.ProcessIcon;
             shortcutName = shortcut.Name;
             isShortcut = true;
-            canBeMerged = false;
 
             this.keys = new ReadOnlyCollection<KeyPress>(allKeys);
 
@@ -63,7 +60,6 @@ private Message(Message initial, Message appended)
             : this(initial.keys.Concat(appended.keys), new KeyShortcut(initial.ShortcutName))
         {
             previous = initial;
-            canBeMerged = true;
         }
 
         private Message(Message initial, bool isDeleting)
@@ -74,14 +70,18 @@ private Message(Message initial, bool isDeleting)
             lastMessage = initial.lastMessage;
         }
 
+        private Message(Message initial, Message replacer, bool replace)
+            : this(replacer.keys, new KeyShortcut(replacer.ShortcutName))
+        {
+            previous = initial;
+         }
+
         public string ProcessName { get { return processName; } }
 
         public ImageSource ProcessIcon { get { return processIcon; } }
 
         public string ShortcutName { get { return shortcutName; } }
 
-        public bool CanBeMerged { get { return canBeMerged; } }
-
         public bool IsShortcut { get { return isShortcut; } }
 
         public Message Previous { get { return previous; } }
@@ -97,21 +97,35 @@ public Message Merge(Message other)
             return new Message(this, other);
         }
 
-        static readonly TimeSpan OneSecond = TimeSpan.FromSeconds(1);
+        public Message Replace(Message newMessage)
+        {
+            return new Message(this, newMessage, true);
+        }
+
+    static readonly TimeSpan OneSecond = TimeSpan.FromSeconds(1);
 
         public static Message MergeIfNeeded(Message previousMessage, Message newMessage)
         {
-            return ShouldCreateNewMessage(previousMessage, newMessage)
-                ? newMessage
-                : previousMessage.Merge(newMessage);
+            // replace key was after standalone modifier keypress, replace by new Message
+            if (previousMessage.keys != null && KeyProvider.IsModifierKeyPress(previousMessage.keys[0].InterceptKeyEventArgs))
+            {
+                return previousMessage.Replace(newMessage);
+            }
+
+            if (ShouldCreateNewMessage(previousMessage, newMessage))
+            {
+                return newMessage;
+            }
+            return previousMessage.Merge(newMessage);
         }
 
         static bool ShouldCreateNewMessage(Message previous, Message current)
         {
             return previous.ProcessName != current.ProcessName ||
                    current.LastMessage.Subtract(previous.LastMessage) > OneSecond ||
-                   !previous.CanBeMerged ||
-                   !current.CanBeMerged;
+                   KeyProvider.IsModifierKeyPress(current.keys[0].InterceptKeyEventArgs) ||
+                   // accumulate also same modifier shortcuts
+                   (previous.keys[0].HasModifierPressed && !previous.keys[0].Input.SequenceEqual(current.keys[0].Input));
         }
 
         public Message FadeOut()
@@ -204,7 +218,6 @@ bool Equals(Message other)
                 && string.Equals(processName, other.processName)
                 && Equals(processIcon, other.processIcon)
                 && string.Equals(shortcutName, other.shortcutName)
-                && canBeMerged.Equals(other.canBeMerged)
                 && isShortcut.Equals(other.isShortcut)
                 && isDeleting.Equals(other.isDeleting)
                 && lastMessage.Equals(other.lastMessage);
@@ -227,7 +240,6 @@ public override int GetHashCode()
                 hashCode = (hashCode * 397) ^ (processName != null ? processName.GetHashCode() : 0);
                 hashCode = (hashCode * 397) ^ (processIcon != null ? processIcon.GetHashCode() : 0);
                 hashCode = (hashCode * 397) ^ (shortcutName != null ? shortcutName.GetHashCode() : 0);
-                hashCode = (hashCode * 397) ^ canBeMerged.GetHashCode();
                 hashCode = (hashCode * 397) ^ isShortcut.GetHashCode();
                 hashCode = (hashCode * 397) ^ isDeleting.GetHashCode();
                 hashCode = (hashCode * 397) ^ lastMessage.GetHashCode();