/// <summary>
/// Client to ask for the possible smallest and largest paragraph width that can fully contain the passing text content
/// </summary>
/// <param name="textSource">an object representing text layout clients text source for TextFormatter.</param>
/// <param name="firstCharIndex">character index to specify where in the source text the line starts</param>
/// <param name="paragraphProperties">properties that can change from one paragraph to the next, such as text flow direction, text alignment, or indentation.</param>
/// <param name="textRunCache">an object representing content cache of the client.</param>
/// <returns>min max paragraph width</returns>
public override MinMaxParagraphWidth FormatMinMaxParagraphWidth(
TextSource textSource,
int firstCharIndex,
TextParagraphProperties paragraphProperties,
TextRunCache textRunCache
)
{
// prepare formatting settings
FormatSettings settings = PrepareFormatSettings(
textSource,
firstCharIndex,
0, // infinite paragraphWidth
paragraphProperties,
null, // always format the whole paragraph - no previousLineBreak
textRunCache,
false, // optimalBreak
true, // isSingleLineFormatting
_textFormattingMode
);
// create specialized line specifically for min/max calculation
TextMetrics.FullTextLine line = new TextMetrics.FullTextLine(
settings,
firstCharIndex,
0, // lineLength
0, // paragraph width has no significant meaning in min/max calculation
(LineFlags.KeepState | LineFlags.MinMax)
);
// line width in this case is the width of a line when the entire paragraph is laid out
// as a single long line.
MinMaxParagraphWidth minMax = new MinMaxParagraphWidth(line.MinWidth, line.Width);
line.Dispose();
return(minMax);
}
private void UpdateFormattedText03()
{
// Index into the text of the TextSource object.
int textStorePosition = 0;
// The position of the current line.
Point linePosition = new Point(0, 0);
// Create a DrawingGroup object for storing formatted text.
myTextDisplay = new DrawingGroup();
DrawingContext drawingContext = myTextDisplay.Open();
// Update the text store.
customTextSource.Text = textToFormat.Text;
// Create a TextFormatter object.
TextFormatter formatter = TextFormatter.Create();
// Create common paragraph property settings.
CustomTextParagraphProperties customTextParagraphProperties
= new CustomTextParagraphProperties();
// <SnippetTextFormattingSnippet3>
MinMaxParagraphWidth minMaxParaWidth =
formatter.FormatMinMaxParagraphWidth(customTextSource, 0, customTextParagraphProperties);
// Format each line of text from the text store and draw it.
while (textStorePosition < customTextSource.Text.Length)
{
// Create a textline from the text store using the TextFormatter object.
using (TextLine myTextLine = formatter.FormatLine(
customTextSource,
textStorePosition,
minMaxParaWidth.MinWidth,
customTextParagraphProperties,
null))
{
// Draw the formatted text into the drawing context.
myTextLine.Draw(drawingContext, linePosition, InvertAxes.None);
// Update the index position in the text store.
textStorePosition += myTextLine.Length;
// Update the line position coordinate for the displayed line.
linePosition.Y += myTextLine.Height;
}
}
// </SnippetTextFormattingSnippet3>
TextLine myTextLine2 = formatter.FormatLine(
customTextSource,
0,
minMaxParaWidth.MaxWidth,
customTextParagraphProperties,
null);
myTextLine2.Draw(drawingContext, linePosition, InvertAxes.None);
// Persist the drawn text content.
drawingContext.Close();
// Display the formatted text in the DrawingGroup object.
myDrawingBrush.Drawing = myTextDisplay;
}
/// <summary>
/// Client to ask for the possible smallest and largest paragraph width that can fully contain the passing text content
/// </summary>
/// <param name="textSource">an object representing text layout clients text source for TextFormatter.</param>
/// <param name="firstCharIndex">character index to specify where in the source text the line starts</param>
/// <param name="paragraphProperties">properties that can change from one paragraph to the next, such as text flow direction, text alignment, or indentation.</param>
/// <param name="textRunCache">an object representing content cache of the client.</param>
/// <returns>min max paragraph width</returns>
public override MinMaxParagraphWidth FormatMinMaxParagraphWidth(
TextSource textSource,
int firstCharIndex,
TextParagraphProperties paragraphProperties,
TextRunCache textRunCache
)
{
// prepare formatting settings
FormatSettings settings = PrepareFormatSettings(
textSource,
firstCharIndex,
0, // infinite paragraphWidth
paragraphProperties,
null, // always format the whole paragraph - no previousLineBreak
textRunCache,
false, // optimalBreak
true, // isSingleLineFormatting
_textFormattingMode
);
// create specialized line specifically for min/max calculation
TextMetrics.FullTextLine line = new TextMetrics.FullTextLine(
settings,
firstCharIndex,
0, // lineLength
0, // paragraph width has no significant meaning in min/max calculation
(LineFlags.KeepState | LineFlags.MinMax)
);
// line width in this case is the width of a line when the entire paragraph is laid out
// as a single long line.
MinMaxParagraphWidth minMax = new MinMaxParagraphWidth(line.MinWidth, line.Width);
line.Dispose();
return minMax;
}
