Properly raise surroundingText changed

src/Android/Avalonia.Android/AndroidInputMethod.cs

@@ -17,6 +17,8 @@ namespace Avalonia.Android
         public ITextInputMethodClient Client { get; }
 
         public bool IsActive { get; }
+
+        public InputMethodManager IMM { get; }
     }
 
     enum CustomImeFlags
@@ -55,6 +57,8 @@ namespace Avalonia.Android
 
         public ITextInputMethodClient Client => _client;
 
+        public InputMethodManager IMM => _imm;
+
         public void Reset()
         {
             _imm.RestartInput(_host);
@@ -96,7 +100,7 @@ namespace Avalonia.Android
             {
                 var surroundingText = Client.SurroundingText;
 
-                _imm.UpdateSelection(_host, surroundingText.AnchorOffset, surroundingText.CursorOffset, surroundingText.AnchorOffset, surroundingText.CursorOffset);
+                _imm.UpdateSelection(_host, surroundingText.AnchorOffset, surroundingText.CursorOffset, _inputConnection.ComposingRegion.Start, _inputConnection.ComposingRegion.End);
             }
         }
 

src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs

@@ -262,9 +262,11 @@ namespace Avalonia.Android.Platform.SkiaPlatform
     {
         private readonly IAndroidInputMethod _inputMethod;
 
-        public InputConnectionImpl(View? targetView, IAndroidInputMethod inputMethod) :
+        public InputConnectionImpl(View targetView, IAndroidInputMethod inputMethod) :
             base(targetView, false)
         {
+            View = targetView;
+
             _inputMethod = inputMethod;
         }
 
@@ -272,20 +274,12 @@ namespace Avalonia.Android.Platform.SkiaPlatform
         {
         }
 
+        public View View { get; }
+
         public ComposingRegion ComposingRegion { get; private set; }
 
         public string CompositionText { get; private set; }
 
-        public override bool SetSelection(int start, int end)
-        {
-            if (_inputMethod.IsActive)
-            {
-                _inputMethod.Client.SelectInSurroundingText(start, end);
-            }
-
-            return base.SetSelection(start, end);
-        }
-
         public override bool SetComposingRegion(int start, int end)
         {
             if (_inputMethod.IsActive)
@@ -300,21 +294,6 @@ namespace Avalonia.Android.Platform.SkiaPlatform
             return base.SetComposingRegion(start, end);
         }
 
-        public override bool CommitCorrection(CorrectionInfo correctionInfo)
-        {
-            return base.CommitCorrection(correctionInfo);
-        }
-
-        public override bool DeleteSurroundingText(int beforeLength, int afterLength)
-        {
-            if (_inputMethod.IsActive && _inputMethod.Client.SupportsSurroundingText)
-            {
-                _inputMethod.Client.DeleteSurroundingText(beforeLength, afterLength);
-            }
-          
-            return base.DeleteSurroundingText(beforeLength, afterLength);
-        }
-
         public override ICharSequence GetTextBeforeCursorFormatted(int length, [GeneratedEnum] GetTextFlags flags)
         {
             if (_inputMethod.IsActive)
@@ -329,7 +308,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
                     var text = surroundingText.Text.Substring(start, end - start);
 
-                    //System.Diagnostics.Debug.WriteLine($"Text Before: {text}");
+                    System.Diagnostics.Debug.WriteLine($"Text Before: {text}");
 
                     return new Java.Lang.String(text);
                 }
@@ -352,7 +331,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
                     var text = surroundingText.Text.Substring(start, end - start);
 
-                    //System.Diagnostics.Debug.WriteLine($"Text After: {text}");
+                    System.Diagnostics.Debug.WriteLine($"Text After: {text}");
 
                     return new Java.Lang.String(text);
                 }
@@ -368,16 +347,16 @@ namespace Avalonia.Android.Platform.SkiaPlatform
             if (_inputMethod.IsActive)
             {
                 _inputMethod.Client.SetPreeditText(CompositionText);
-
-                if (!string.IsNullOrEmpty(CompositionText))
-                {
-                    ComposingRegion = default;
-                }
             }
 
             return base.SetComposingText(text, newCursorPosition);
         }
 
+        public override bool SendKeyEvent(KeyEvent e)
+        {
+            return base.SendKeyEvent(e);
+        }
+
         public override bool CommitText(ICharSequence text, int newCursorPosition)
         {          
             CompositionText = null;
@@ -386,32 +365,19 @@ namespace Avalonia.Android.Platform.SkiaPlatform
             {
                 _inputMethod.Client.SetPreeditText(null);
 
-                if (string.IsNullOrEmpty(CompositionText) && ComposingRegion.Start != ComposingRegion.End)
+                var textLength = text.Length();
+
+                if (string.IsNullOrEmpty(CompositionText) && ComposingRegion.End > 0)
                 {
-                    _inputMethod.Client.SelectInSurroundingText(ComposingRegion.Start, ComposingRegion.End);
+                    _inputMethod.Client.SelectInSurroundingText(ComposingRegion.Start, ComposingRegion.Start + textLength);
                 }
 
-                ComposingRegion = new ComposingRegion(ComposingRegion.Start, ComposingRegion.Start + text.Length());
+                ComposingRegion = new ComposingRegion(ComposingRegion.Start, ComposingRegion.Start + textLength);
             }
 
             return base.CommitText(text, newCursorPosition);
         }
 
-        public override bool PerformEditorAction([GeneratedEnum] ImeAction actionCode)
-        {
-            return base.PerformEditorAction(actionCode);
-        }
-
-        public override bool PerformPrivateCommand(string action, Bundle data)
-        {
-            return base.PerformPrivateCommand(action, data);
-        }
-
-        public override bool SendKeyEvent(KeyEvent e)
-        {
-            return base.SendKeyEvent(e);
-        }
-
         public override bool FinishComposingText()
         {
             CompositionText = null;
@@ -427,14 +393,16 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
     public readonly struct ComposingRegion
     {
+        private readonly int _start = -1;
+        private readonly int _end = -1;
+
         public ComposingRegion(int start, int end)
         {
-            Start = start;
+            _start = start;
-            End = end;
+            _end = end;
         }
 
-        public int Start { get; }
+        public int Start => _start;
-
+        public int End => _end;
-        public int End { get; }
     }
 }

src/Avalonia.Controls/TextBoxTextInputMethodClient.cs

@@ -43,7 +43,7 @@ namespace Avalonia.Controls
         {
             get
             {
-                if(_presenter is null)
+                if(_presenter is null || _parent is null)
                 {
                     return default;
                 }
@@ -56,7 +56,7 @@ namespace Avalonia.Controls
 
                 var lineText = _presenter.Text?.Substring(lineStart, textLine.Length);
 
-                var anchorOffset = Math.Max(0, _presenter.SelectionStart - lineStart);
+                var anchorOffset = Math.Max(0, _parent.SelectionStart - lineStart);
 
                 var cursorOffset = Math.Max(0, _presenter.SelectionEnd - lineStart);
 
@@ -87,16 +87,19 @@ namespace Avalonia.Controls
 
         public void SelectInSurroundingText(int start, int end)
         {
-            if(_parent == null)
+            if(_parent is null ||_presenter is null)
             {
                 return;
             }
 
-            //start and end are relative to surroundingText
+            var lineIndex = _presenter.TextLayout.GetLineIndexFromCharacterIndex(_presenter.CaretIndex, false);
-            var surroundingText = SurroundingText;
 
-            var selectionStart = surroundingText.AnchorOffset + start;
+            var textLine = _presenter.TextLayout.TextLines[lineIndex];
-            var selectionEnd = surroundingText.AnchorOffset + end;
+
+            var lineStart = textLine.FirstTextSourceIndex;
+
+            var selectionStart = lineStart + start;
+            var selectionEnd = lineStart + end;
              
             _parent.SelectionStart = selectionStart;
             _parent.SelectionEnd = selectionEnd;
@@ -104,13 +107,23 @@ namespace Avalonia.Controls
         
         public void SetPresenter(TextPresenter? presenter, TextBox? parent)
         {
+            if(_parent != null)
+            {
+                _parent.PropertyChanged -= OnParentPropertyChanged;
+            }
+
             _parent = parent;
 
+            if(_parent != null)
+            {
+                _parent.PropertyChanged += OnParentPropertyChanged;
+            }
+
             if (_presenter != null)
             {
                 _presenter.PreeditText = null;
 
-                _presenter.CaretBoundsChanged -= OnCaretBoundsChanged;
+                _presenter.CaretBoundsChanged -= OnCaretBoundsChanged;             
             }
            
             _presenter = presenter;
@@ -125,6 +138,17 @@ namespace Avalonia.Controls
             OnCaretBoundsChanged(this, EventArgs.Empty);
         }
 
+        private void OnParentPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
+        {
+            if(e.Property == TextBox.SelectionStartProperty || e.Property == TextBox.SelectionEndProperty)
+            {
+                if (SupportsSurroundingText)
+                {
+                    SurroundingTextChanged?.Invoke(this, e);
+                }
+            }
+        }
+
         public void DeleteSurroundingText(int beforeLength, int afterLength)
         {
             if (_parent != null && _presenter != null && string.IsNullOrEmpty(_presenter.PreeditText))
@@ -142,11 +166,6 @@ namespace Avalonia.Controls
         {
             Dispatcher.UIThread.Post(() =>
             {
-                if (SupportsSurroundingText)
-                {
-                    SurroundingTextChanged?.Invoke(this, e);
-                }
-
                 CursorRectangleChanged?.Invoke(this, e);
 
             }, DispatcherPriority.Input);