/// <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;
}
/// <summary>
/// Client to collapse the line to fit for display
/// </summary>
/// <param name="collapsingPropertiesList">a list of collapsing properties</param>
public override TextLine Collapse(
params TextCollapsingProperties[] collapsingPropertiesList
)
{
if (!HasOverflowed)
return this;
Invariant.Assert(_settings != null);
// instantiate a collapsible full text line, collapse it and return the collapsed line
TextMetrics.FullTextLine textLine = new TextMetrics.FullTextLine(
_settings,
_cpFirst,
0, // lineLength
TextFormatterImp.RealToIdeal(_paragraphWidth),
LineFlags.None
);
// When in TextFormattingMode.Display the math processing performed by SimpleTextLine
// involves some rounding operations because of which the decision to collapse the text may
// not be unanimous amongst SimpleTextLine and FullTextLine. There are several watson
// crash reports that are testament to this theory. See Win8 PS bug# 643676. Hence we
// now allow the case where FullTextLine concludes that it doesnt need to collapse the
// text even though SimpleTextLine thought it should.
if (textLine.HasOverflowed)
{
TextLine collapsedTextLine = textLine.Collapse(collapsingPropertiesList);
if (collapsedTextLine != textLine)
{
// if collapsed line is genuinely new,
// Dispose its maker as we no longer need it around, dispose it explicitly
// to reduce unnecessary finalization of this intermediate line.
textLine.Dispose();
}
return collapsedTextLine;
}
return textLine;
}
/// <summary>
/// Client to collapse the line to fit for display
/// </summary>
/// <param name="collapsingPropertiesList">a list of collapsing properties</param>
public override TextLine Collapse(
params TextCollapsingProperties[] collapsingPropertiesList
)
{
if (!HasOverflowed)
return this;
Invariant.Assert(_settings != null);
// instantiate a collapsible full text line, collapse it and return the collapsed line
TextMetrics.FullTextLine textLine = new TextMetrics.FullTextLine(
_settings,
_cpFirst,
0, // lineLength
TextFormatterImp.RealToIdeal(_paragraphWidth),
LineFlags.None
);
Invariant.Assert(textLine.HasOverflowed);
TextLine collapsedTextLine = textLine.Collapse(collapsingPropertiesList);
if (collapsedTextLine != textLine)
{
// if collapsed line is genuinely new,
// Dispose its maker as we no longer need it around, dispose it explicitly
// to reduce unnecessary finalization of this intermediate line.
textLine.Dispose();
}
return collapsedTextLine;
}
