Merge pull request #3652 from Gillibald/fixes/TextBlock

TextBlock fixes

src/Avalonia.Controls/TextBlock.cs

@@ -20,6 +20,12 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<IBrush> BackgroundProperty =
             Border.BackgroundProperty.AddOwner<TextBlock>();
 
+        /// <summary>
+        /// Defines the <see cref="Padding"/> property.
+        /// </summary>
+        public static readonly StyledProperty<Thickness> PaddingProperty =
+            Decorator.PaddingProperty.AddOwner<TextBlock>();
+
         // TODO: Define these attached properties elsewhere (e.g. on a Text class) and AddOwner
         // them into TextBlock.
 
@@ -29,7 +35,7 @@ namespace Avalonia.Controls
         public static readonly AttachedProperty<FontFamily> FontFamilyProperty =
             AvaloniaProperty.RegisterAttached<TextBlock, Control, FontFamily>(
                 nameof(FontFamily),
-                defaultValue:  FontFamily.Default,
+                defaultValue: FontFamily.Default,
                 inherits: true);
 
         /// <summary>
@@ -110,20 +116,31 @@ namespace Avalonia.Controls
         static TextBlock()
         {
             ClipToBoundsProperty.OverrideDefaultValue<TextBlock>(true);
+
             AffectsRender<TextBlock>(
-                BackgroundProperty,
+                BackgroundProperty, ForegroundProperty, FontSizeProperty, 
-                ForegroundProperty,
+                FontWeightProperty, FontStyleProperty, TextWrappingProperty, 
-                FontWeightProperty,
+                TextTrimmingProperty, TextAlignmentProperty, FontFamilyProperty, 
-                FontSizeProperty,
+                TextDecorationsProperty, TextProperty, PaddingProperty);
-                FontStyleProperty);
+
+            AffectsMeasure<TextBlock>(
+                FontSizeProperty, FontWeightProperty, FontStyleProperty, 
+                FontFamilyProperty, TextTrimmingProperty, TextProperty,
+                PaddingProperty);
 
             Observable.Merge(
                 TextProperty.Changed,
+                ForegroundProperty.Changed,
                 TextAlignmentProperty.Changed,
+                TextWrappingProperty.Changed,
+                TextTrimmingProperty.Changed,
                 FontSizeProperty.Changed,
                 FontStyleProperty.Changed,
-                FontWeightProperty.Changed
+                FontWeightProperty.Changed,
-            ).AddClassHandler<TextBlock>((x, _) => x.OnTextPropertiesChanged());
+                FontFamilyProperty.Changed,
+                TextDecorationsProperty.Changed,
+                PaddingProperty.Changed
+            ).AddClassHandler<TextBlock>((x, _) => x.InvalidateTextLayout());
         }
 
         /// <summary>
@@ -145,6 +162,15 @@ namespace Avalonia.Controls
             }
         }
 
+        /// <summary>
+        /// Gets or sets the padding to place around the <see cref="Text"/>.
+        /// </summary>
+        public Thickness Padding
+        {
+            get { return GetValue(PaddingProperty); }
+            set { SetValue(PaddingProperty, value); }
+        }
+
         /// <summary>
         /// Gets or sets a brush used to paint the control's background.
         /// </summary>
@@ -363,7 +389,9 @@ namespace Avalonia.Controls
                 context.FillRectangle(background, new Rect(Bounds.Size));
             }
 
-            TextLayout?.Draw(context.PlatformImpl, new Point());
+            var padding = Padding;
+
+            TextLayout?.Draw(context.PlatformImpl, new Point(padding.Left, padding.Top));
         }
 
         /// <summary>
@@ -412,6 +440,10 @@ namespace Avalonia.Controls
                 return new Size();
             }
 
+            var padding = Padding;
+
+            availableSize = availableSize.Deflate(padding);
+
             if (_constraint != availableSize)
             {
                 InvalidateTextLayout();
@@ -419,19 +451,17 @@ namespace Avalonia.Controls
 
             _constraint = availableSize;
 
-            return TextLayout?.Bounds.Size ?? Size.Empty;
+            var measuredSize = TextLayout?.Bounds.Size ?? Size.Empty;
+
+            return measuredSize.Inflate(padding);
         }
 
         protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
         {
             base.OnAttachedToLogicalTree(e);
-            InvalidateTextLayout();
-            InvalidateMeasure();
-        }
 
-        private void OnTextPropertiesChanged()
-        {
             InvalidateTextLayout();
+
             InvalidateMeasure();
         }
     }

src/Avalonia.Visuals/Media/TextFormatting/SimpleTextFormatter.cs

@@ -201,18 +201,17 @@ namespace Avalonia.Media.TextFormatting
             var availableWidth = paragraphWidth;
             var currentWidth = 0.0;
             var runIndex = 0;
+            var length = 0;
 
             while (runIndex < textRuns.Count)
             {
                 var currentRun = textRuns[runIndex];
 
-                currentWidth += currentRun.GlyphRun.Bounds.Width;
+                if (currentWidth + currentRun.GlyphRun.Bounds.Width > availableWidth)
-
-                if (currentWidth > availableWidth)
                 {
-                    var measuredLength = MeasureText(currentRun, paragraphWidth);
+                    var measuredLength = MeasureText(currentRun, paragraphWidth - currentWidth);
 
-                    if (measuredLength < text.End)
+                    if (measuredLength < currentRun.Text.Length)
                     {
                         var currentBreakPosition = -1;
 
@@ -241,15 +240,19 @@ namespace Avalonia.Media.TextFormatting
                         }
                     }
 
-                    var splitResult = SplitTextRuns(textRuns, measuredLength);
+                    length += measuredLength;
+
+                    var splitResult = SplitTextRuns(textRuns, length);
 
                     var textLineMetrics =
                         TextLineMetrics.Create(splitResult.First, paragraphWidth, paragraphProperties.TextAlignment);
 
-                    return new SimpleTextLine(text.Take(measuredLength), splitResult.First, textLineMetrics);
+                    return new SimpleTextLine(text.Take(length), splitResult.First, textLineMetrics);
                 }
 
-                availableWidth -= currentRun.GlyphRun.Bounds.Width;
+                currentWidth += currentRun.GlyphRun.Bounds.Width;
+
+                length += currentRun.GlyphRun.Characters.Length;
 
                 runIndex++;
             }
@@ -281,12 +284,18 @@ namespace Avalonia.Media.TextFormatting
 
                 if (measuredWidth + advance > availableWidth)
                 {
+                    index--;
                     break;
                 }
 
                 measuredWidth += advance;
             }
 
+            if(index < 0)
+            {
+                return 0;
+            }
+
             var cluster = textRun.GlyphRun.GlyphClusters[index];
 
             var characterHit = textRun.GlyphRun.FindNearestCharacterHit(cluster, out _);
@@ -355,7 +364,7 @@ namespace Avalonia.Media.TextFormatting
                     continue;
                 }
 
-                var firstCount = currentRun.GlyphRun.Characters.Length > 1 ? i + 1 : i;
+                var firstCount = currentRun.GlyphRun.Characters.Length >= 1 ? i + 1 : i;
 
                 var first = new ShapedTextRun[firstCount];
 

src/Avalonia.Visuals/Media/TextFormatting/TextLayout.cs

@@ -233,6 +233,12 @@ namespace Avalonia.Media.TextFormatting
 
                         var textLine = TextFormatter.Current.FormatLine(textSource, 0, MaxWidth, _paragraphProperties);
 
+                        if (!double.IsPositiveInfinity(MaxHeight) && bottom + textLine.LineMetrics.Size.Height > MaxHeight)
+                        {
+                            currentPosition = _text.Length;
+                            break;
+                        }
+
                         UpdateBounds(textLine, ref left, ref right, ref bottom);
 
                         textLines.Add(textLine);
@@ -253,17 +259,17 @@ namespace Avalonia.Media.TextFormatting
                     {
                         var emptyTextLine = CreateEmptyTextLine(currentPosition);
 
+                        if (!double.IsPositiveInfinity(MaxHeight) && bottom + emptyTextLine.LineMetrics.Size.Height > MaxHeight)
+                        {
+                            break;
+                        }
+
                         UpdateBounds(emptyTextLine, ref left, ref right, ref bottom);
 
                         textLines.Add(emptyTextLine);
 
                         break;
                     }
-
-                    if (!double.IsPositiveInfinity(MaxHeight) && MaxHeight < Bounds.Height)
-                    {
-                        break;
-                    }
                 }
 
                 Bounds = new Rect(left, 0, right, bottom);