[QuickAccent]Add setting to sort characters by use frequency (#22847)

* [Quick Accent] add toggle switch to sort characters by usage frequency

* [Quick Accent] if enabled, then sort by frequency for all toolbar triggers

* [Quick Accent] add "start selection from the left" toggle switch

* [Quick Accent] fix error SA1000: The keyword 'new' should not be followed by a space

* Fix C# analyzer build error

src/modules/poweraccent/PowerAccent.Core/PowerAccent.cs

@@ -37,6 +37,8 @@ public class PowerAccent : IDisposable
 
     private readonly KeyboardListener _keyboardListener;
 
+    private readonly CharactersUsageInfo _usageInfo;
+
     public PowerAccent()
     {
         LoadUnicodeInfoCache();
@@ -44,6 +46,7 @@ public class PowerAccent : IDisposable
         _keyboardListener = new KeyboardListener();
         _keyboardListener.InitHook();
         _settingService = new SettingsService(_keyboardListener);
+        _usageInfo = new CharactersUsageInfo();
 
         SetEvents();
     }
@@ -88,9 +91,9 @@ public class PowerAccent : IDisposable
     private void ShowToolbar(LetterKey letterKey)
     {
         _visible = true;
-        _characters = (WindowsFunctions.IsCapsLockState() || WindowsFunctions.IsShiftState()) ? ToUpper(Languages.GetDefaultLetterKey(letterKey, _settingService.SelectedLang)) : Languages.GetDefaultLetterKey(letterKey, _settingService.SelectedLang);
-        _characterDescriptions = GetCharacterDescriptions(_characters);
 
+        _characters = GetCharacters(letterKey);
+        _characterDescriptions = GetCharacterDescriptions(_characters);
         _showUnicodeDescription = _settingService.ShowUnicodeDescription;
 
         Task.Delay(_settingService.InputTime).ContinueWith(
@@ -104,6 +107,28 @@ public class PowerAccent : IDisposable
         TaskScheduler.FromCurrentSynchronizationContext());
     }
 
+    private string[] GetCharacters(LetterKey letterKey)
+    {
+        var characters = Languages.GetDefaultLetterKey(letterKey, _settingService.SelectedLang);
+        if (_settingService.SortByUsageFrequency)
+        {
+            characters = characters.OrderByDescending(character => _usageInfo.GetUsageFrequency(character))
+                .ThenByDescending(character => _usageInfo.GetLastUsageTimestamp(character)).
+                ToArray<string>();
+        }
+        else if (!_usageInfo.Empty())
+        {
+            _usageInfo.Clear();
+        }
+
+        if (WindowsFunctions.IsCapsLockState() || WindowsFunctions.IsShiftState())
+        {
+            return ToUpper(characters);
+        }
+
+        return characters;
+    }
+
     private string GetCharacterDescription(string character)
     {
         List<UnicodeCharInfo> unicodeList = new List<UnicodeCharInfo>();
@@ -180,6 +205,11 @@ public class PowerAccent : IDisposable
                     if (_selectedIndex != -1)
                     {
                         WindowsFunctions.Insert(_characters[_selectedIndex], true);
+
+                        if (_settingService.SortByUsageFrequency)
+                        {
+                            _usageInfo.IncrementUsageFrequency(_characters[_selectedIndex]);
+                        }
                     }
 
                     break;
@@ -205,7 +235,7 @@ public class PowerAccent : IDisposable
                 _selectedIndex = _characters.Length / 2;
             }
 
-            if (triggerKey == TriggerKey.Space)
+            if (triggerKey == TriggerKey.Space || _settingService.StartSelectionFromTheLeft)
             {
                 _selectedIndex = 0;
             }

src/modules/poweraccent/PowerAccent.Core/Services/SettingsService.cs

@@ -92,6 +92,8 @@ public class SettingsService
                         }
 
                         ShowUnicodeDescription = settings.Properties.ShowUnicodeDescription;
+                        SortByUsageFrequency = settings.Properties.SortByUsageFrequency;
+                        StartSelectionFromTheLeft = settings.Properties.StartSelectionFromTheLeft;
                     }
                 }
                 catch (Exception ex)
@@ -191,6 +193,36 @@ public class SettingsService
             _showUnicodeDescription = value;
         }
     }
+
+    private bool _sortByUsageFrequency;
+
+    public bool SortByUsageFrequency
+    {
+        get
+        {
+            return _sortByUsageFrequency;
+        }
+
+        set
+        {
+            _sortByUsageFrequency = value;
+        }
+    }
+
+    private bool _startSelectionFromTheLeft;
+
+    public bool StartSelectionFromTheLeft
+    {
+        get
+        {
+            return _startSelectionFromTheLeft;
+        }
+
+        set
+        {
+            _startSelectionFromTheLeft = value;
+        }
+    }
 }
 
 public enum Position

src/modules/poweraccent/PowerAccent.Core/Tools/CharactersUsageInfo.cs

@@ -0,0 +1,51 @@
+// 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.
+
+namespace PowerAccent.Core.Tools
+{
+    public class CharactersUsageInfo
+    {
+        private Dictionary<string, uint> _characterUsageCounters = new Dictionary<string, uint>();
+        private Dictionary<string, long> _characterUsageTimestamp = new Dictionary<string, long>();
+
+        public bool Empty()
+        {
+            return _characterUsageCounters.Count == 0;
+        }
+
+        public void Clear()
+        {
+            _characterUsageCounters.Clear();
+            _characterUsageTimestamp.Clear();
+        }
+
+        public uint GetUsageFrequency(string character)
+        {
+            _characterUsageCounters.TryGetValue(character, out uint frequency);
+
+            return frequency;
+        }
+
+        public long GetLastUsageTimestamp(string character)
+        {
+            _characterUsageTimestamp.TryGetValue(character, out long timestamp);
+
+            return timestamp;
+        }
+
+        public void IncrementUsageFrequency(string character)
+        {
+            if (_characterUsageCounters.ContainsKey(character))
+            {
+                _characterUsageCounters[character]++;
+            }
+            else
+            {
+                _characterUsageCounters.Add(character, 1);
+            }
+
+            _characterUsageTimestamp[character] = DateTimeOffset.Now.ToUnixTimeSeconds();
+        }
+    }
+}