/// <summary>
/// Collecting glyph runs
/// </summary>
static private void AddRun(
ArrayList runs,
SimpleRun run,
ref int nonHiddenLength
)
{
if(run.Length > 0)
{
// dont add 0-length run
runs.Add(run);
if (!run.Ghost)
{
nonHiddenLength += run.Length;
}
}
}
internal bool IsUnderlineCompatible(SimpleRun nextRun)
{
return Typeface.Equals(nextRun.Typeface)
&& EmSize == nextRun.EmSize
&& Baseline == nextRun.Baseline;
}
/// <summary>
/// Create simple run of text,
/// returning null if the specified text run cannot be correctly formatted as simple run
/// </summary>
static internal SimpleRun CreateSimpleTextRun(
CharacterBufferRange charBufferRange,
TextRun textRun,
TextFormatterImp formatter,
int widthLeft,
bool emergencyWrap,
bool breakOnTabs
)
{
Invariant.Assert(textRun is TextCharacters);
SimpleRun run = new SimpleRun(formatter);
run.CharBufferReference = charBufferRange.CharacterBufferReference;
run.TextRun = textRun;
if (!run.TextRun.Properties.Typeface.CheckFastPathNominalGlyphs(
charBufferRange,
run.EmSize,
1.0,
formatter.IdealToReal(widthLeft),
!emergencyWrap,
false,
CultureMapper.GetSpecificCulture(run.TextRun.Properties.CultureInfo),
formatter.TextFormattingMode,
false, //No support for isSideways
breakOnTabs,
out run.Length
))
{
// Getting nominal glyphs is not supported by the font,
// or it is but it results in low typographic quality text
// e.g. OpenType support is not utilized.
return null;
}
run.TextRun.Properties.Typeface.GetCharacterNominalWidthsAndIdealWidth(
new CharacterBufferRange(run.CharBufferReference, run.Length),
run.EmSize,
TextFormatterImp.ToIdeal,
formatter.TextFormattingMode,
false,
out run.NominalAdvances,
out run.IdealWidth
);
return run;
}
/// <summary>
/// Returns a simple text run that represents a Tab.
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="textRun">text run</param>
/// <param name="idealRunOffsetUnRounded">run's offset from the beginning of the line</param>
static private SimpleRun CreateSimpleRunForTab(
FormatSettings settings,
TextRun textRun,
int idealRunOffsetUnRounded
)
{
if (settings == null || textRun == null || textRun.Properties == null || textRun.Properties.Typeface == null)
{
return null;
}
GlyphTypeface glyphTypeface = textRun.Properties.Typeface.TryGetGlyphTypeface();
// Check whether the font has the space character. If not then we have to go through
// font fallback.
// We are not calling CreateSimpleTextRun() because CheckFastPathNominalGlyphs()
// can fail if a font has TypographicAvailabilities. We are simply rendering a space
// so we don't realy care about TypographicFeatures. This is a perf optimization.
if (glyphTypeface == null || !glyphTypeface.HasCharacter(' '))
{
return null;
}
// The full shaping path converts tabs to spaces.
// Note: In order to get exactly the same metrics as we did in FullTextLine (specifically ink bounding box)
// we need to "Draw" a space in place of a Tab (previously we were just ignoring the Tab and rendering nothing)
// which turned out to give different overhang and extent values than those returned using the full shaping path.
// So in order to avoid vertical jiggling when a line is changed from SimpleTextLine to FullTextLine by adding/removing
// a complex character, we need to do the same thing as the full shaping path and draw a space for each tab.
TextRun modifedTextRun = new TextCharacters(" ", textRun.Properties);
CharacterBufferRange characterBufferRange = new CharacterBufferRange(modifedTextRun);
SimpleRun run = new SimpleRun(1, modifedTextRun, Flags.Tab, settings.Formatter);
run.CharBufferReference = characterBufferRange.CharacterBufferReference;
run.TextRun.Properties.Typeface.GetCharacterNominalWidthsAndIdealWidth(
characterBufferRange,
run.EmSize,
TextFormatterImp.ToIdeal,
settings.Formatter.TextFormattingMode,
false,
out run.NominalAdvances
);
int idealIncrementalTab = TextFormatterImp.RealToIdeal(settings.Pap.DefaultIncrementalTab);
// Here we get the next tab stop without snapping the metrics to pixels.
// We do the pixel snapping on the final position of the tab stop (and not on the IncrementalTab)
// to achieve the same results as those in full shaping.
int idealNextTabStopUnRounded = ((idealRunOffsetUnRounded / idealIncrementalTab) + 1) * idealIncrementalTab;
run.IdealWidth = run.NominalAdvances[0] = idealNextTabStopUnRounded - idealRunOffsetUnRounded;
return run;
}
/// <summary>
/// Creating a simple text run
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="charString">character string associated to textrun</param>
/// <param name="textRun">text run</param>
/// <param name="cp">first cp of the run</param>
/// <param name="cpFirst">first cp of the line</param>
/// <param name="runLength">run length</param>
/// <param name="widthLeft">maximum run width</param>
/// <param name="idealRunOffsetUnRounded">run's offset from the beginning of the line</param>
/// <returns>a SimpleRun object</returns>
static public SimpleRun Create(
FormatSettings settings,
CharacterBufferRange charString,
TextRun textRun,
int cp,
int cpFirst,
int runLength,
int widthLeft,
int idealRunOffsetUnRounded
)
{
SimpleRun run = null;
if (textRun is TextCharacters)
{
if ( textRun.Properties.BaselineAlignment != BaselineAlignment.Baseline
|| (textRun.Properties.TextEffects != null && textRun.Properties.TextEffects.Count != 0)
)
{
// fast path does not handle the following conditions
// o non-default baseline alignment
// o text drawing effect (
return null;
}
TextDecorationCollection textDecorations = textRun.Properties.TextDecorations;
if ( textDecorations != null
&& textDecorations.Count != 0
&& !textDecorations.ValueEquals(TextDecorations.Underline))
{
// we only support a single underline
return null;
}
settings.DigitState.SetTextRunProperties(textRun.Properties);
if (settings.DigitState.RequiresNumberSubstitution)
{
// don't support number substitution in fast path
return null;
}
bool canProcessTabsInSimpleShapingPath = CanProcessTabsInSimpleShapingPath(
settings.Pap,
settings.Formatter.TextFormattingMode
);
if (charString[0] == TextStore.CharCarriageReturn)
{
// CR in the middle of text stream treated as explicit paragraph break
// simple hard line break
runLength = 1;
if (charString.Length > 1 && charString[1] == TextStore.CharLineFeed)
{
runLength = 2;
}
// This path handles the case where the backing store breaks the text run in between
// a Carriage Return and a Line Feed. So we fetch the next run to check whether the next
// character is a line feed.
else if (charString.Length == 1)
{
// Prefetch to check for line feed.
TextRun newRun;
int newRunLength;
CharacterBufferRange newBufferRange = settings.FetchTextRun(
cp + 1,
cpFirst,
out newRun,
out newRunLength
);
if (newBufferRange.Length > 0 && newBufferRange[0] == TextStore.CharLineFeed)
{
// Merge the 2 runs.
int lengthOfRun = 2;
char[] characterArray = new char[lengthOfRun];
characterArray[0] = TextStore.CharCarriageReturn;
characterArray[1] = TextStore.CharLineFeed;
TextRun mergedTextRun = new TextCharacters(characterArray, 0, lengthOfRun, textRun.Properties);
return new SimpleRun(lengthOfRun, mergedTextRun, (Flags.EOT | Flags.Ghost), settings.Formatter);
}
}
return new SimpleRun(runLength, textRun, (Flags.EOT | Flags.Ghost), settings.Formatter);
}
else if (charString[0] == TextStore.CharLineFeed)
{
// LF in the middle of text stream treated as explicit paragraph break
// simple hard line break
runLength = 1;
return new SimpleRun(runLength, textRun, (Flags.EOT | Flags.Ghost), settings.Formatter);
}
else if (canProcessTabsInSimpleShapingPath && charString[0] == TextStore.CharTab)
{
return CreateSimpleRunForTab(settings,
textRun,
idealRunOffsetUnRounded);
}
// attempt to create a simple run for text
run = CreateSimpleTextRun(
charString,
textRun,
settings.Formatter,
widthLeft,
settings.Pap.EmergencyWrap,
canProcessTabsInSimpleShapingPath
);
if (run == null)
{
// fail to create simple text run, the run content is too complex
return null;
}
// Check for underline condition
if (textDecorations != null && textDecorations.Count == 1 )
{
run.Underline = textDecorations[0];
}
}
else if (textRun is TextEndOfLine)
{
run = new SimpleRun(runLength, textRun, (Flags.EOT | Flags.Ghost), settings.Formatter);
}
else if (textRun is TextHidden)
{
// hidden run
run = new SimpleRun(runLength, textRun, Flags.Ghost, settings.Formatter);
}
return run;
}
/// <summary>
/// Collecting glyph runs
/// </summary>
static private void AddRun(
ArrayList runs,
SimpleRun run,
SimpleRun prev
)
{
Invariant.Assert(
prev == null || (runs.Count > 0 && prev == runs[runs.Count - 1]),
"Trailing space run is not after the last existing run!"
);
if(run.Length > 0)
{
// dont add 0-length run
runs.Add(run);
}
}