/// <summary>
/// Sets or changes the font style
/// </summary>
/// <param name="style">Font style</param>
/// <param name="startIndex">The start index of initial character to apply the change to.</param>
/// <param name="count">The number of characters the change should be applied to.</param>
public void SetFontStyle(FontStyle style, int startIndex, int count)
{
int limit = ValidateRange(startIndex, count);
for (int i = startIndex; i < limit;)
{
SpanRider formatRider = new SpanRider(_formatRuns, _latestPosition, i);
i = Math.Min(limit, i + formatRider.Length);
#pragma warning disable 6506
// Presharp warns that runProps is not validated, but it can never be null
// because the rider is already checked to be in range
GenericTextRunProperties runProps = formatRider.CurrentElement as GenericTextRunProperties;
Invariant.Assert(runProps != null);
Typeface oldTypeface = runProps.Typeface;
if (oldTypeface.Style == style)
continue;
GenericTextRunProperties newProps = new GenericTextRunProperties(
new Typeface(oldTypeface.FontFamily, style, oldTypeface.Weight, oldTypeface.Stretch),
runProps.FontRenderingEmSize,
runProps.FontHintingEmSize,
runProps.TextDecorations,
runProps.ForegroundBrush,
runProps.BackgroundBrush,
runProps.BaselineAlignment,
runProps.CultureInfo,
runProps.NumberSubstitution
);
#pragma warning restore 6506
_latestPosition = _formatRuns.SetValue(formatRider.CurrentPosition, i - formatRider.CurrentPosition, newProps, formatRider.SpanPosition);
InvalidateMetrics(); // invalidate cached metrics
}
}
/// <summary>
/// Sets or changes the text decorations
/// </summary>
/// <param name="textDecorations">Text decorations</param>
/// <param name="startIndex">The start index of initial character to apply the change to.</param>
/// <param name="count">The number of characters the change should be applied to.</param>
public void SetTextDecorations(TextDecorationCollection textDecorations, int startIndex, int count)
{
int limit = ValidateRange(startIndex, count);
for (int i = startIndex; i < limit;)
{
SpanRider formatRider = new SpanRider(_formatRuns, _latestPosition, i);
i = Math.Min(limit, i + formatRider.Length);
#pragma warning disable 6506
// Presharp warns that runProps is not validated, but it can never be null
// because the rider is already checked to be in range
GenericTextRunProperties runProps = formatRider.CurrentElement as GenericTextRunProperties;
Invariant.Assert(runProps != null);
if (runProps.TextDecorations == textDecorations)
continue;
GenericTextRunProperties newProps = new GenericTextRunProperties(
runProps.Typeface,
runProps.FontRenderingEmSize,
runProps.FontHintingEmSize,
textDecorations,
runProps.ForegroundBrush,
runProps.BackgroundBrush,
runProps.BaselineAlignment,
runProps.CultureInfo,
runProps.NumberSubstitution
);
#pragma warning restore 6506
_latestPosition = _formatRuns.SetValue(formatRider.CurrentPosition, i - formatRider.CurrentPosition, newProps, formatRider.SpanPosition);
}
}
/// <summary>
/// Construct a FormattedText object.
/// </summary>
/// <param name="textToFormat">String of text to be displayed.</param>
/// <param name="culture">Culture of text.</param>
/// <param name="flowDirection">Flow direction of text.</param>
/// <param name="typeface">Type face used to display text.</param>
/// <param name="emSize">Font em size in visual units (1/96 of an inch).</param>
/// <param name="foreground">Foreground brush used to render text.</param>
/// <param name="numberSubstitution">Number substitution behavior to apply to the text; can be null,
/// in which case the default number number method for the text culture is used.</param>
public FormattedText(
string textToFormat,
CultureInfo culture,
FlowDirection flowDirection,
Typeface typeface,
double emSize,
Brush foreground,
NumberSubstitution numberSubstitution,
TextFormattingMode textFormattingMode)
{
if (textToFormat == null)
throw new ArgumentNullException("textToFormat");
if (typeface == null)
throw new ArgumentNullException("typeface");
ValidateCulture(culture);
ValidateFlowDirection(flowDirection, "flowDirection");
ValidateFontSize(emSize);
_textFormattingMode = textFormattingMode;
_text = textToFormat;
GenericTextRunProperties runProps = new GenericTextRunProperties(
typeface,
emSize,
12.0f, // default hinting size
null, // decorations
foreground,
null, // highlight background
BaselineAlignment.Baseline,
culture,
numberSubstitution
);
_latestPosition = _formatRuns.SetValue(0, _text.Length, runProps, _latestPosition);
_defaultParaProps = new GenericTextParagraphProperties(
flowDirection,
TextAlignment.Left,
false,
false,
runProps,
TextWrapping.WrapWithOverflow,
0, // line height not specified
0 // indentation not specified
);
InvalidateMetrics();
}