#167 Partial text enhancements

Use # as a shape symbol.
Align text to top.
Do not rerender shaped text.
Send whole words to client.

All these things remove partial text flickering.

src/Common/SIUI.ViewModel/TableInfoViewModel.cs

@@ -403,7 +403,10 @@ public double Volume
 
     private bool _partialText = false;
 
-    public bool PartialText { get => _partialText; set { _partialText = value; OnPropertyChanged(); } }
+    /// <summary>
+    /// Is text displayed partially.
+    /// </summary>
+    public bool PartialText { get => _partialText; set { if (_partialText != value) { _partialText = value; OnPropertyChanged(); } } }
 
     private LayoutMode _layoutMode = LayoutMode.Simple;
 

src/Common/SIUI/Behaviors/FillManager.cs

@@ -7,24 +7,17 @@
 namespace SIUI.Behaviors;
 
 /// <summary>
-/// Поведение, изменяющее размер шрифта текста до максимальной величины, при которой он целиком умещается на экране
+/// Updates text font size dynamically so the text has maximum available font size and fits inside parent.
 /// </summary>
 public static class FillManager
 {
     private static readonly DependencyPropertyDescriptor TextDescriptor = DependencyPropertyDescriptor.FromProperty(TextBlock.TextProperty, typeof(TextBlock));
     private static readonly DependencyPropertyDescriptor FontFamilyDescriptor = DependencyPropertyDescriptor.FromProperty(TextBlock.FontFamilyProperty, typeof(TextBlock));
 
-    public static bool GetFill(DependencyObject obj)
-    {
-        return (bool)obj.GetValue(FillProperty);
-    }
+    public static bool GetFill(DependencyObject obj) => (bool)obj.GetValue(FillProperty);
 
-    public static void SetFill(DependencyObject obj, bool value)
-    {
-        obj.SetValue(FillProperty, value);
-    }
+    public static void SetFill(DependencyObject obj, bool value) => obj.SetValue(FillProperty, value);
 
-    // Using a DependencyProperty as the backing store for Fill.  This enables animation, styling, binding, etc...
     public static readonly DependencyProperty FillProperty =
         DependencyProperty.RegisterAttached("Fill", typeof(bool), typeof(FillManager), new UIPropertyMetadata(false, OnFillChanged));
 
@@ -61,6 +54,13 @@ public static void OnFillChanged(DependencyObject d, DependencyPropertyChangedEv
     public static readonly DependencyProperty HandlerProperty =
         DependencyProperty.RegisterAttached("Handler", typeof(SizeChangedEventHandler), typeof(FillManager), new UIPropertyMetadata(null));
 
+    public static bool GetHandleTextChange(DependencyObject obj) => (bool)obj.GetValue(HandleTextChangeProperty);
+
+    public static void SetHandleTextChange(DependencyObject obj, bool value) => obj.SetValue(HandleTextChangeProperty, value);
+
+    public static readonly DependencyProperty HandleTextChangeProperty =
+        DependencyProperty.RegisterAttached("HandleTextChange", typeof(bool), typeof(FillManager), new PropertyMetadata(true));
+
     private static void TextBlock_Loaded(object sender, RoutedEventArgs e)
     {
         var textBlock = (TextBlock)sender;
@@ -78,7 +78,7 @@ private static void TextBlock_Loaded(object sender, RoutedEventArgs e)
         parent.SizeChanged += handler;
         MeasureFontSize(sender, EventArgs.Empty);
 
-        TextDescriptor.AddValueChanged(textBlock, MeasureFontSize);
+        TextDescriptor.AddValueChanged(textBlock, MeasureFontSizeOnTextChange);
         FontFamilyDescriptor.AddValueChanged(textBlock, MeasureFontSize);
     }
 
@@ -95,7 +95,7 @@ private static void TextBlock_Unloaded(object sender, RoutedEventArgs e)
 
         textBlock.ClearValue(HandlerProperty);
 
-        TextDescriptor.RemoveValueChanged(textBlock, MeasureFontSize);
+        TextDescriptor.RemoveValueChanged(textBlock, MeasureFontSizeOnTextChange);
         FontFamilyDescriptor.RemoveValueChanged(textBlock, MeasureFontSize);
     }
 
@@ -117,16 +117,32 @@ private static void TextBlock_Unloaded(object sender, RoutedEventArgs e)
 
     public static void OnInterlinyageChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) => MeasureFontSize(d, EventArgs.Empty);
 
+    private static void MeasureFontSizeOnTextChange(object? sender, EventArgs e)
+    {
+        if (sender is not DependencyObject dependencyObject)
+        {
+            return;
+        }
+
+        var handleTextChange = GetHandleTextChange(dependencyObject);
+
+        if (!handleTextChange)
+        {
+            return;
+        }
+
+        MeasureFontSize(sender, e);
+    }
+
     /// <summary>
     /// Задаёт как можно больший размер шрифта текстового блока исходя из доступной для него области
     /// </summary>
     /// <param name="sender"></param>
     /// <param name="e"></param>
     private static void MeasureFontSize(object? sender, EventArgs e)
     {
-        var textBlock = sender as TextBlock;
-
-        if (VisualTreeHelper.GetParent(textBlock) is not FrameworkElement parent)
+        if (sender is not TextBlock textBlock
+            || VisualTreeHelper.GetParent(textBlock) is not FrameworkElement parent)
         {
             return;
         }

src/Common/SIUI/Table.xaml

@@ -466,8 +466,10 @@
                                     Margin="10"
                                     TextWrapping="Wrap"
                                     HorizontalAlignment="Left"
+                                    VerticalAlignment="Top"
                                     TextAlignment="Left"
-                                    lb:QuestionReading.IsAttachedPartial="True">                                    
+                                    lb:QuestionReading.IsAttachedPartial="True"
+                                    lb:FillManager.HandleTextChange="False">
                                     <TextBlock.CacheMode>
                                         <BitmapCache EnableClearType="True" SnapsToDevicePixels="False" RenderAtScale="1.5" />
                                     </TextBlock.CacheMode>

src/SICore/SICore/Clients/Game/GameLogic.cs

@@ -57,6 +57,11 @@ public sealed class GameLogic : Logic<GameData>
     /// </summary>
     private const double PartialPrintFrequencyPerSecond = 0.5;
 
+    /// <summary>
+    /// Represents character used to form content shape.
+    /// </summary>
+    private const string ContentShapeCharacter = "#"; // '%' as an alternative
+
     /// <summary>
     /// Execution continuation.
     /// </summary>
@@ -428,14 +433,13 @@ internal void OnContentScreenText(string text, bool waitForFinish, TimeSpan dura
 
         if (_data.IsPartial)
         {
-            // "и" symbol is used as an arbitrary symbol with medium width to define the question text shape
-            // It does not need to be localized
+            // ContentShapeCharacter symbol is used as an arbitrary symbol with medium width to define the question text shape
             // Real question text is sent later and it sequentially replaces test shape
             // Text shape is required to display partial question on the screen correctly
             // (font size and number of lines must be calculated in the beginning to prevent UI flickers on question text growth)
-            var shape = Regex.Replace(text, "[^\r\n\t\f ]", "и");
+            var shape = Regex.Replace(text, "[^\r\n\t\f ]", ContentShapeCharacter);
             _gameActions.SendMessageWithArgs(Messages.TextShape, shape);
-            _gameActions.SendMessageWithArgs(Messages.ContentShape, ContentPlacements.Screen, 0, ContentTypes.Text, shape);
+            _gameActions.SendMessageWithArgs(Messages.ContentShape, ContentPlacements.Screen, 0, ContentTypes.Text, shape.EscapeNewLines());
 
             _data.Text = text;
             _data.TextLength = 0;
@@ -2783,6 +2787,12 @@ private void PrintPartial()
                 text.Length - _data.TextLength,
                 (int)(_data.Settings.AppSettings.ReadingSpeed * PartialPrintFrequencyPerSecond)));
 
+        // Align to next space position
+        while (_data.TextLength + printingLength + 1 < text.Length && !char.IsWhiteSpace(text[_data.TextLength + printingLength]))
+        {
+            printingLength++;
+        }
+
         var subText = text.Substring(_data.TextLength, printingLength);
 
         _gameActions.SendMessageWithArgs(Messages.ContentAppend, ContentPlacements.Screen, 0, ContentTypes.Text, subText.EscapeNewLines());

src/SICore/SICore/Clients/Viewer/IViewerLogic.cs

@@ -140,7 +140,7 @@ public interface IViewerLogic : ILogic
 
     void PrintGreeting();
 
-    void TextShape(string[] mparams);
+    void OnTextShape(string[] mparams) { }
 
     void OnTimeChanged();
 

src/SICore/SICore/Clients/Viewer/Viewer.cs

@@ -807,7 +807,7 @@ await _client.Node.ConnectionsLock.WithLockAsync(() =>
                     break;
 
                 case Messages.TextShape:
-                    _logic.TextShape(mparams);
+                    _logic.OnTextShape(mparams);
                     break;
 
                 case Messages.Atom: // deprecated

src/SICore/SICore/Clients/Viewer/ViewerComputerLogic.cs

@@ -173,11 +173,6 @@ public void PrintGreeting()
 
     }
 
-    public void TextShape(string[] mparams)
-    {
-
-    }
-
     public void OnTimeChanged()
     {
 

src/SICore/SICore/Clients/Viewer/ViewerHumanLogic.cs

@@ -592,7 +592,7 @@ virtual public async void Choice()
         }
     }
 
-    public void TextShape(string[] mparams)
+    public void OnTextShape(string[] mparams)
     {
         var text = new StringBuilder();
 
@@ -606,7 +606,7 @@ public void TextShape(string[] mparams)
             }
         }
 
-        if (!TInfo.PartialText && TInfo.TStage == TableStage.Question)
+        if (TInfo.TStage == TableStage.Question)
         {
             // Toggle TStage change to reapply QuestionTemplateSelector template
             TInfo.TStage = TableStage.Void;

src/SICore/SIData/AppSettingsCore.cs

@@ -59,14 +59,14 @@ public int MultimediaPort
     private int _readingSpeed = DefaultReadingSpeed;
 
     /// <summary>
-    /// Скорость чтения вопроса (символов в секунду)
+    /// Text reading speed (characters per second).
     /// </summary>
     [XmlAttribute]
     [DefaultValue(DefaultReadingSpeed)]
     public int ReadingSpeed
     {
         get => _readingSpeed;
-        set { _readingSpeed = value; OnPropertyChanged(); }
+        set { if (_readingSpeed != value) { _readingSpeed = value; OnPropertyChanged(); } }
     }
 
     [DebuggerBrowsable(DebuggerBrowsableState.Never)]

src/SICore/SIData/SIData.csproj

@@ -21,7 +21,6 @@
     <None Include="key.snk" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="System.Text.Json" Version="6.0.0" />
     <PackageReference Include="System.Xml.XmlSerializer" Version="4.3.0" />
   </ItemGroup>
 </Project>