Btukfyl

I use this example ( https://siderite.blogspot.com/2016/03/how-to-draw-outlined-text-in-wpf-and.html#at2665784896 ) for add outline to a text in a TextBlock. However this example don't support Inlines.

I try to add this ability modifying the OnRender and I iterate the Inlines collection to build a Geometry for each Inline block. The problem is that I need to get the position and size of the inline block in the TextBlock instead of those of the whole text in the TextBlock.

This is the source code that I have modified.

protected override void OnRender(DrawingContext drawingContext)

{

    ensureTextBlock();

    base.OnRender(drawingContext);



    foreach (Inline inline in _textBlock.Inlines)

    {

        var textRange = new TextRange(inline.ContentStart, inline.ContentEnd);

        var formattedText = new FormattedText(

            textRange.Text,

            CultureInfo.CurrentUICulture,

            inline.FlowDirection,

            new Typeface(inline.FontFamily, inline.FontStyle, inline.FontWeight, inline.FontStretch),

            inline.FontSize, System.Windows.Media.Brushes.Black // This brush does not matter since we use the geometry of the text.

        );

        formattedText.SetTextDecorations(inline.TextDecorations);





        //*****************************************************************

        //This part get the size and position of the TextBlock

        // Instead I need to find a way to get the size and position of the Inline block



        //formattedText.TextAlignment = _textBlock.TextAlignment;

        //formattedText.Trimming = _textBlock.TextTrimming;



        formattedText.LineHeight = _textBlock.LineHeight;

        formattedText.MaxTextWidth = _textBlock.ActualWidth - _textBlock.Padding.Left - _textBlock.Padding.Right;

        formattedText.MaxTextHeight = _textBlock.ActualHeight - _textBlock.Padding.Top;// - _textBlock.Padding.Bottom;

        while (formattedText.Extent == double.NegativeInfinity)

        {

            formattedText.MaxTextHeight++;

        }



        // Build the geometry object that represents the text.

        var _textGeometry = formattedText.BuildGeometry(new System.Windows.Point(_textBlock.Padding.Left, _textBlock.Padding.Top));



        //*****************************************************************





        var textPen = new System.Windows.Media.Pen(Stroke, StrokeThickness * 2)

        {

            DashCap = PenLineCap.Round,

            EndLineCap = PenLineCap.Round,

            LineJoin = PenLineJoin.Round,

            StartLineCap = PenLineCap.Round

        };



        var boundsGeo = new RectangleGeometry(new Rect(0, 0, ActualWidth, ActualHeight));



        _clipGeometry = Geometry.Combine(boundsGeo, _textGeometry, GeometryCombineMode.Exclude, null);

        drawingContext.PushClip(_clipGeometry);

        drawingContext.DrawGeometry(System.Windows.Media.Brushes.Transparent, textPen, _textGeometry);

        drawingContext.Pop();

    }

}

I need to change the part that get the size and position from the TextBlock in order to get the size and position of the Inline block, but I don't see any property of Inline that can get that information. Any idea?

I have found a way to get the position with:

inline.ElementStart.GetCharacterRect(LogicalDirection.Forward).Left

inline.ElementStart.GetCharacterRect(LogicalDirection.Forward).Top

Then I changed the line that build the geometry in this way:

double posLeft = inline.ElementStart.GetCharacterRect(LogicalDirection.Forward).Left;

double posTop = inline.ElementStart.GetCharacterRect(LogicalDirection.Forward).Top;



var _textGeometry = formattedText.BuildGeometry(new System.Windows.Point(posLeft, posTop));

I still have some problem with wrap because when the text is wrapped the Geometry is built only in the first line.

Use the LineHeight property of the TextBlock:

formattedText.LineHeight = _textBlock.LineHeight;

So you can modify the LineHeight value programmatically.