internal TextParagraphCache(
FormatSettings settings,
int firstCharIndex,
int paragraphWidth
)
{
Invariant.Assert(settings != null);
// create full text
_finiteFormatWidth = settings.GetFiniteFormatWidth(paragraphWidth);
_fullText = FullTextState.Create(settings, firstCharIndex, _finiteFormatWidth);
// acquiring LS context
TextFormatterContext context = settings.Formatter.AcquireContext(_fullText, IntPtr.Zero);
_fullText.SetTabs(context);
IntPtr ploparabreakValue = IntPtr.Zero;
LsErr lserr = context.CreateParaBreakingSession(
firstCharIndex,
_finiteFormatWidth,
// breakrec is not needed before the first cp of para cache
// since we handle Bidi break ourselves.
IntPtr.Zero,
ref ploparabreakValue,
ref _penalizedAsJustified
);
// get the exception in context before it is released
Exception callbackException = context.CallbackException;
// release the context
context.Release();
if(lserr != LsErr.None)
{
GC.SuppressFinalize(this);
if(callbackException != null)
{
// rethrow exception thrown in callbacks
throw new InvalidOperationException(SR.Get(SRID.CreateParaBreakingSessionFailure, lserr), callbackException);
}
else
{
// throw with LS error codes
TextFormatterContext.ThrowExceptionFromLsError(SR.Get(SRID.CreateParaBreakingSessionFailure, lserr), lserr);
}
}
_ploparabreak.Value = ploparabreakValue;
// keep context alive till here
GC.KeepAlive(context);
}
/// <summary>
/// Set tab stops
/// </summary>
internal void SetTabs(TextFormatterContext context)
{
unsafe
{
ParaProp pap = _store.Pap;
FormatSettings settings = _store.Settings;
// set up appropriate tab stops
int incrementalTab = TextFormatterImp.RealToIdeal(pap.DefaultIncrementalTab);
int lsTbdCount = pap.Tabs != null ? pap.Tabs.Count : 0;
LsTbd[] lsTbds;
if (_markerStore != null)
{
if (pap.Tabs != null && pap.Tabs.Count > 0)
{
lsTbdCount = pap.Tabs.Count + 1;
lsTbds = new LsTbd[lsTbdCount];
lsTbds[0].ur = settings.TextIndent; // marker requires a tab stop at text start position
fixed(LsTbd *plsTbds = &lsTbds[1])
{
CreateLsTbds(pap, plsTbds, lsTbdCount - 1);
context.SetTabs(incrementalTab, plsTbds - 1, lsTbdCount);
}
}
else
{
LsTbd markerRequiredLsTbd = new LsTbd();
markerRequiredLsTbd.ur = settings.TextIndent; // marker requires a tab stop at text start position
context.SetTabs(incrementalTab, &markerRequiredLsTbd, 1);
}
}
else
{
if (pap.Tabs != null && pap.Tabs.Count > 0)
{
lsTbds = new LsTbd[lsTbdCount];
fixed(LsTbd *plsTbds = &lsTbds[0])
{
CreateLsTbds(pap, plsTbds, lsTbdCount);
context.SetTabs(incrementalTab, plsTbds, lsTbdCount);
}
}
else
{
// work with only incremental tab
context.SetTabs(incrementalTab, null, 0);
}
}
}
}
/// <summary>
/// Create a fulltext state object from formatting info for subsequent fulltext formatting
/// e.g. fulltext line, mix/max computation, potential breakpoints for optimal paragraph formatting.
/// </summary>
internal static FullTextState Create(
FormatSettings settings,
int cpFirst,
int finiteFormatWidth
)
{
// prepare text stores
TextStore store = new TextStore(
settings,
cpFirst,
0,
settings.GetFormatWidth(finiteFormatWidth)
);
ParaProp pap = settings.Pap;
TextStore markerStore = null;
if (pap.FirstLineInParagraph &&
pap.TextMarkerProperties != null &&
pap.TextMarkerProperties.TextSource != null)
{
// create text store specifically for marker
markerStore = new TextStore(
// create specialized settings for marker store e.g. with marker text source
new FormatSettings(
settings.Formatter,
pap.TextMarkerProperties.TextSource,
new TextRunCacheImp(), // no cross-call run cache available for marker store
pap, // marker by default use the same paragraph properties
null, // not consider previousLineBreak
true, // isSingleLineFormatting
settings.TextFormattingMode,
settings.IsSideways
),
0, // marker store always started with cp == 0
TextStore.LscpFirstMarker, // first lscp value for marker text
Constants.IdealInfiniteWidth // formatWidth
);
}
// construct a new fulltext state object
return(new FullTextState(store, markerStore, settings.IsSideways));
}
/// <summary>
/// Create a fulltext state object from formatting info for subsequent fulltext formatting
/// e.g. fulltext line, mix/max computation, potential breakpoints for optimal paragraph formatting.
/// </summary>
internal static FullTextState Create(
FormatSettings settings,
int cpFirst,
int finiteFormatWidth
)
{
// prepare text stores
TextStore store = new TextStore(
settings,
cpFirst,
0,
settings.GetFormatWidth(finiteFormatWidth)
);
ParaProp pap = settings.Pap;
TextStore markerStore = null;
if( pap.FirstLineInParagraph
&& pap.TextMarkerProperties != null
&& pap.TextMarkerProperties.TextSource != null)
{
// create text store specifically for marker
markerStore = new TextStore(
// create specialized settings for marker store e.g. with marker text source
new FormatSettings(
settings.Formatter,
pap.TextMarkerProperties.TextSource,
new TextRunCacheImp(), // no cross-call run cache available for marker store
pap, // marker by default use the same paragraph properties
null, // not consider previousLineBreak
true, // isSingleLineFormatting
settings.TextFormattingMode,
settings.IsSideways
),
0, // marker store always started with cp == 0
TextStore.LscpFirstMarker, // first lscp value for marker text
Constants.IdealInfiniteWidth // formatWidth
);
}
// construct a new fulltext state object
return new FullTextState(store, markerStore, settings.IsSideways);
}
internal override TextParagraphCache CreateParagraphCache(
#endif
TextSource textSource,
int firstCharIndex,
double paragraphWidth,
TextParagraphProperties paragraphProperties,
TextLineBreak previousLineBreak,
TextRunCache textRunCache
)
{
// prepare formatting settings
FormatSettings settings = PrepareFormatSettings(
textSource,
firstCharIndex,
paragraphWidth,
paragraphProperties,
previousLineBreak,
textRunCache,
true, // optimalBreak
false, // !isSingleLineFormatting
_textFormattingMode
);
//
// Optimal paragraph formatting session specific check
//
if (!settings.Pap.Wrap && settings.Pap.OptimalBreak)
{
// Optimal paragraph must wrap.
throw new ArgumentException(SR.Get(SRID.OptimalParagraphMustWrap));
}
// create paragraph content cache object
return(new TextParagraphCache(
settings,
firstCharIndex,
RealToIdeal(paragraphWidth)
));
}
/// <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>
/// Fetch cached textrun
/// </summary>
internal TextRun FetchTextRun(
FormatSettings settings,
int cpFetch,
int cpFirst,
out int offsetToFirstCp,
out int runLength
)
{
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition, cpFetch);
_latestPosition = textRunSpanRider.SpanPosition;
TextRun textRun = (TextRun)textRunSpanRider.CurrentElement;
if(textRun == null)
{
// run not already cached, fetch new run and cache it
textRun = settings.TextSource.GetTextRun(cpFetch);
if (textRun.Length < 1)
{
throw new ArgumentOutOfRangeException("textRun.Length", SR.Get(SRID.ParameterMustBeGreaterThanZero));
}
Plsrun plsrun = TextRunInfo.GetRunType(textRun);
if (plsrun == Plsrun.Text || plsrun == Plsrun.InlineObject)
{
TextRunProperties properties = textRun.Properties;
if (properties == null)
throw new ArgumentException(SR.Get(SRID.TextRunPropertiesCannotBeNull));
if (properties.FontRenderingEmSize <= 0)
throw new ArgumentException(SR.Get(SRID.PropertyOfClassMustBeGreaterThanZero, "FontRenderingEmSize", "TextRunProperties"));
double realMaxFontRenderingEmSize = Constants.RealInfiniteWidth / Constants.GreatestMutiplierOfEm;
if (properties.FontRenderingEmSize > realMaxFontRenderingEmSize)
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeGreaterThan, "FontRenderingEmSize", "TextRunProperties", realMaxFontRenderingEmSize));
CultureInfo culture = CultureMapper.GetSpecificCulture(properties.CultureInfo);
if (culture == null)
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "CultureInfo", "TextRunProperties"));
if (properties.Typeface == null)
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "Typeface", "TextRunProperties"));
}
//
// TextRun is specifial to SpanVector because TextRun also encodes position which needs to be
// consistent with the positions encoded by SpanVector. In run cache, the begining of a span
// should always correspond to the begining of a cached text run. If the end of the currently fetched
// run overlaps with the begining of an already cached run, the begining of the cached run needs to be
// adjusted as well as its span. Because we can't gurantee the correctness of the overlapped range
// so we'll simply remove the overlapped runs here.
//
// Move the rider to the end of the current run
textRunSpanRider.At(cpFetch + textRun.Length - 1);
_latestPosition = textRunSpanRider.SpanPosition;
if (textRunSpanRider.CurrentElement != _textRunVector.Default)
{
// The end overlaps with one or more cached runs, clear the range from the
// begining of the current fetched run to the end of the last overlapped cached run.
_latestPosition = _textRunVector.SetReference(
cpFetch,
textRunSpanRider.CurrentPosition + textRunSpanRider.Length - cpFetch,
_textRunVector.Default,
_latestPosition
);
}
_latestPosition = _textRunVector.SetReference(cpFetch, textRun.Length, textRun, _latestPosition);
// Refresh the rider's SpanPosition following previous SpanVector.SetReference calls
textRunSpanRider.At(_latestPosition, cpFetch);
}
offsetToFirstCp = textRunSpanRider.CurrentPosition - textRunSpanRider.CurrentSpanStart;
runLength = textRunSpanRider.Length;
Debug.Assert(textRun != null && runLength > 0, "Invalid run!");
bool isText = textRun is ITextSymbols;
if (isText)
{
// Chop text run to optimal length so we dont spend forever analysing
// them all at once.
int looseCharLength = TextStore.TypicalCharactersPerLine - cpFetch + cpFirst;
if(looseCharLength <= 0)
{
// this line already exceeds typical line length, incremental fetch goes
// about a quarter of the typical length.
looseCharLength = (int)Math.Round(TextStore.TypicalCharactersPerLine * 0.25);
}
if(runLength > looseCharLength)
{
if (TextRunInfo.GetRunType(textRun) == Plsrun.Text)
{
//
// When chopping the run at the typical line length,
// - don't chop in between of higher & lower surrogate
// - don't chop combining mark away from its base character
// - don't chop joiner from surrounding characters
//
// Starting from the initial chopping point, we look ahead to find a safe position. We stop at
// a limit in case the run consists of many combining mark & joiner. That is rare and doesn't make
// much sense in shaping already.
//
CharacterBufferReference charBufferRef = textRun.CharacterBufferReference;
// We look ahead by one more line at most. It is not normal to have
// so many combining mark or joiner characters in a row. It doesn't make sense to
// look further if so.
int lookAheadLimit = Math.Min(runLength, looseCharLength + TextStore.TypicalCharactersPerLine);
int sizeOfChar = 0;
int endOffset = 0;
bool canBreakAfterPrecedingChar = false;
for (endOffset = looseCharLength - 1; endOffset < lookAheadLimit; endOffset += sizeOfChar)
{
CharacterBufferRange charString = new CharacterBufferRange(
charBufferRef.CharacterBuffer,
charBufferRef.OffsetToFirstChar + offsetToFirstCp + endOffset,
runLength - endOffset
);
int ch = Classification.UnicodeScalar(charString, out sizeOfChar);
// We can only safely break if the preceding char is not a joiner character (i.e. can-break-after),
// and the current char is not combining or joiner (i.e. can-break-before).
if (canBreakAfterPrecedingChar && !Classification.IsCombining(ch) && !Classification.IsJoiner(ch) )
{
break;
}
canBreakAfterPrecedingChar = !Classification.IsJoiner(ch);
}
looseCharLength = Math.Min(runLength, endOffset);
}
runLength = looseCharLength;
}
}
Debug.Assert(
// valid run found
runLength > 0
// non-text run always fetched at run start
&& ( isText
|| textRunSpanRider.CurrentSpanStart - textRunSpanRider.CurrentPosition == 0)
// span rider of both text and format point to valid position
&& (textRunSpanRider.Length > 0 && textRunSpanRider.CurrentElement != null),
"Text run fetching error!"
);
return textRun;
}
/// <summary>
/// Constructing a FullTextLine
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="cpFirst">Line's first cp</param>
/// <param name="lineLength">character length of the line</param>
/// <param name="paragraphWidth">paragraph width</param>
/// <param name="lineFlags">line formatting control flags</param>
internal FullTextLine(
FormatSettings settings,
int cpFirst,
int lineLength,
int paragraphWidth,
LineFlags lineFlags
)
: this(settings.TextFormattingMode, settings.Pap.Justify)
{
if ( (lineFlags & LineFlags.KeepState) != 0
|| settings.Pap.AlwaysCollapsible)
{
_statusFlags |= StatusFlags.KeepState;
}
int finiteFormatWidth = settings.GetFiniteFormatWidth(paragraphWidth);
FullTextState fullText = FullTextState.Create(settings, cpFirst, finiteFormatWidth);
// formatting the line
FormatLine(
fullText,
cpFirst,
lineLength,
fullText.FormatWidth,
finiteFormatWidth,
paragraphWidth,
lineFlags,
null // collapsingSymbol
);
}
internal static IList <TextBreakpoint> CreateMultiple(
TextParagraphCache paragraphCache,
int firstCharIndex,
int maxLineWidth,
TextLineBreak previousLineBreak,
IntPtr penaltyRestriction,
out int bestFitIndex
)
{
Invariant.Assert(paragraphCache != null);
// grab full text state from paragraph cache
FullTextState fullText = paragraphCache.FullText;
Invariant.Assert(fullText != null);
FormatSettings settings = fullText.TextStore.Settings;
Invariant.Assert(settings != null);
// update formatting parameters at line start
settings.UpdateSettingsForCurrentLine(
maxLineWidth,
previousLineBreak,
(firstCharIndex == fullText.TextStore.CpFirst)
);
Invariant.Assert(settings.Formatter != null);
// acquiring LS context
TextFormatterContext context = settings.Formatter.AcquireContext(fullText, IntPtr.Zero);
IntPtr previousBreakRecord = IntPtr.Zero;
if (settings.PreviousLineBreak != null)
{
previousBreakRecord = settings.PreviousLineBreak.BreakRecord.Value;
}
// need not consider marker as tab since marker does not affect line metrics and it wasnt drawn.
fullText.SetTabs(context);
LsBreaks lsbreaks = new LsBreaks();
LsErr lserr = context.CreateBreaks(
fullText.GetBreakpointInternalCp(firstCharIndex),
previousBreakRecord,
paragraphCache.Ploparabreak.Value, // para breaking session
penaltyRestriction,
ref lsbreaks,
out bestFitIndex
);
// get the exception in context before it is released
Exception callbackException = context.CallbackException;
// release the context
context.Release();
if (lserr != LsErr.None)
{
if (callbackException != null)
{
// rethrow exception thrown in callbacks
throw callbackException;
}
else
{
// throw with LS error codes
TextFormatterContext.ThrowExceptionFromLsError(SR.Get(SRID.CreateBreaksFailure, lserr), lserr);
}
}
// keep context alive at least till here
GC.KeepAlive(context);
TextBreakpoint[] breakpoints = new TextBreakpoint[lsbreaks.cBreaks];
for (int i = 0; i < lsbreaks.cBreaks; i++)
{
breakpoints[i] = new FullTextBreakpoint(
fullText,
firstCharIndex,
maxLineWidth,
ref lsbreaks,
i // the current break
);
}
return(breakpoints);
}
/// <summary>
/// Fetch cached textrun
/// </summary>
internal TextRun FetchTextRun(
FormatSettings settings,
int cpFetch,
int cpFirst,
out int offsetToFirstCp,
out int runLength
)
{
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition, cpFetch);
_latestPosition = textRunSpanRider.SpanPosition;
TextRun textRun = (TextRun)textRunSpanRider.CurrentElement;
if (textRun == null)
{
// run not already cached, fetch new run and cache it
textRun = settings.TextSource.GetTextRun(cpFetch);
if (textRun.Length < 1)
{
throw new ArgumentOutOfRangeException("textRun.Length", SR.Get(SRID.ParameterMustBeGreaterThanZero));
}
Plsrun plsrun = TextRunInfo.GetRunType(textRun);
if (plsrun == Plsrun.Text || plsrun == Plsrun.InlineObject)
{
TextRunProperties properties = textRun.Properties;
if (properties == null)
{
throw new ArgumentException(SR.Get(SRID.TextRunPropertiesCannotBeNull));
}
if (properties.FontRenderingEmSize <= 0)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassMustBeGreaterThanZero, "FontRenderingEmSize", "TextRunProperties"));
}
double realMaxFontRenderingEmSize = Constants.RealInfiniteWidth / Constants.GreatestMutiplierOfEm;
if (properties.FontRenderingEmSize > realMaxFontRenderingEmSize)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeGreaterThan, "FontRenderingEmSize", "TextRunProperties", realMaxFontRenderingEmSize));
}
CultureInfo culture = CultureMapper.GetSpecificCulture(properties.CultureInfo);
if (culture == null)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "CultureInfo", "TextRunProperties"));
}
if (properties.Typeface == null)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "Typeface", "TextRunProperties"));
}
}
//
// TextRun is specifial to SpanVector because TextRun also encodes position which needs to be
// consistent with the positions encoded by SpanVector. In run cache, the begining of a span
// should always correspond to the begining of a cached text run. If the end of the currently fetched
// run overlaps with the begining of an already cached run, the begining of the cached run needs to be
// adjusted as well as its span. Because we can't gurantee the correctness of the overlapped range
// so we'll simply remove the overlapped runs here.
//
// Move the rider to the end of the current run
textRunSpanRider.At(cpFetch + textRun.Length - 1);
_latestPosition = textRunSpanRider.SpanPosition;
if (textRunSpanRider.CurrentElement != _textRunVector.Default)
{
// The end overlaps with one or more cached runs, clear the range from the
// begining of the current fetched run to the end of the last overlapped cached run.
_latestPosition = _textRunVector.SetReference(
cpFetch,
textRunSpanRider.CurrentPosition + textRunSpanRider.Length - cpFetch,
_textRunVector.Default,
_latestPosition
);
}
_latestPosition = _textRunVector.SetReference(cpFetch, textRun.Length, textRun, _latestPosition);
// Refresh the rider's SpanPosition following previous SpanVector.SetReference calls
textRunSpanRider.At(_latestPosition, cpFetch);
}
// If the TextRun was obtained from the cache, make sure it has the right PixelsPerDip set on its properties.
if (textRun.Properties != null)
{
textRun.Properties.PixelsPerDip = settings.TextSource.PixelsPerDip;
}
offsetToFirstCp = textRunSpanRider.CurrentPosition - textRunSpanRider.CurrentSpanStart;
runLength = textRunSpanRider.Length;
Debug.Assert(textRun != null && runLength > 0, "Invalid run!");
bool isText = textRun is ITextSymbols;
if (isText)
{
// Chop text run to optimal length so we dont spend forever analysing
// them all at once.
int looseCharLength = TextStore.TypicalCharactersPerLine - cpFetch + cpFirst;
if (looseCharLength <= 0)
{
// this line already exceeds typical line length, incremental fetch goes
// about a quarter of the typical length.
looseCharLength = (int)Math.Round(TextStore.TypicalCharactersPerLine * 0.25);
}
if (runLength > looseCharLength)
{
if (TextRunInfo.GetRunType(textRun) == Plsrun.Text)
{
//
// When chopping the run at the typical line length,
// - don't chop in between of higher & lower surrogate
// - don't chop combining mark away from its base character
// - don't chop joiner from surrounding characters
//
// Starting from the initial chopping point, we look ahead to find a safe position. We stop at
// a limit in case the run consists of many combining mark & joiner. That is rare and doesn't make
// much sense in shaping already.
//
CharacterBufferReference charBufferRef = textRun.CharacterBufferReference;
// We look ahead by one more line at most. It is not normal to have
// so many combining mark or joiner characters in a row. It doesn't make sense to
// look further if so.
int lookAheadLimit = Math.Min(runLength, looseCharLength + TextStore.TypicalCharactersPerLine);
int sizeOfChar = 0;
int endOffset = 0;
bool canBreakAfterPrecedingChar = false;
for (endOffset = looseCharLength - 1; endOffset < lookAheadLimit; endOffset += sizeOfChar)
{
CharacterBufferRange charString = new CharacterBufferRange(
charBufferRef.CharacterBuffer,
charBufferRef.OffsetToFirstChar + offsetToFirstCp + endOffset,
runLength - endOffset
);
int ch = Classification.UnicodeScalar(charString, out sizeOfChar);
// We can only safely break if the preceding char is not a joiner character (i.e. can-break-after),
// and the current char is not combining or joiner (i.e. can-break-before).
if (canBreakAfterPrecedingChar && !Classification.IsCombining(ch) && !Classification.IsJoiner(ch))
{
break;
}
canBreakAfterPrecedingChar = !Classification.IsJoiner(ch);
}
looseCharLength = Math.Min(runLength, endOffset);
}
runLength = looseCharLength;
}
}
Debug.Assert(
// valid run found
runLength > 0
// non-text run always fetched at run start
&& (isText ||
textRunSpanRider.CurrentSpanStart - textRunSpanRider.CurrentPosition == 0)
// span rider of both text and format point to valid position
&& (textRunSpanRider.Length > 0 && textRunSpanRider.CurrentElement != null),
"Text run fetching error!"
);
return(textRun);
}
/// <summary>
/// Creating a lightweight text line
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="cpFirst">First cp of the line</param>
/// <param name="paragraphWidth">paragraph width</param>
/// <returns>TextLine instance</returns>
/// <remarks>
/// This method breaks line using Ideal width such that it will be
/// consistent with FullTextLine
/// </remarks>
static public TextLine Create(
FormatSettings settings,
int cpFirst,
int paragraphWidth
)
{
ParaProp pap = settings.Pap;
if( pap.RightToLeft
|| pap.Justify
|| ( pap.FirstLineInParagraph
&& pap.TextMarkerProperties != null)
|| settings.TextIndent != 0
|| pap.ParagraphIndent != 0
|| pap.LineHeight > 0
|| pap.AlwaysCollapsible
|| (pap.TextDecorations != null && pap.TextDecorations.Count != 0)
)
{
// unsupported paragraph properties
return null;
}
int cp = cpFirst;
int nonHiddenLength = 0; // length of non-hidden runs seen so far
// paragraphWidth == 0 means the format width is unlimited.
int widthLeft = (pap.Wrap && paragraphWidth > 0) ? paragraphWidth : int.MaxValue;
int idealRunOffsetUnRounded = 0;
SimpleRun prev = null;
SimpleRun run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth,
idealRunOffsetUnRounded
);
if(run == null)
{
// fail to create run e.g. complex content encountered
return null;
}
else if(!run.EOT && run.IdealWidth <= widthLeft)
{
// create next run
cp += run.Length;
widthLeft -= run.IdealWidth;
idealRunOffsetUnRounded += run.IdealWidth;
prev = run;
run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth,
idealRunOffsetUnRounded
);
if(run == null)
{
return null;
}
}
int trailing = 0;
ArrayList runs = new ArrayList(2);
if(prev != null)
{
AddRun(runs, prev, ref nonHiddenLength);
}
do
{
if(!run.EOT && run.IdealWidth > widthLeft)
{
// linebreaking required, even simple text requires classification-based linebreaking,
// we'll now let LS handle this line.
return null;
}
AddRun(runs, run, ref nonHiddenLength);
// As a security mitigation, we impose a limit on the length of a single line
// (see comments for TextStore.MaxCharactersPerLine) - only non-hidden
// runs count against this limit. If the line exceeds the limit,
// use FullTextLine instead of SimpleTextLine - this assures consistency
// in cases such as collapsing a line.
if (nonHiddenLength >= TextStore.MaxCharactersPerLine)
{
return null;
}
prev = run;
cp += run.Length;
widthLeft -= run.IdealWidth;
idealRunOffsetUnRounded += run.IdealWidth;
if(run.EOT)
{
// we're done
break;
}
run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth,
idealRunOffsetUnRounded
);
if( run == null
|| ( run.Underline != null
&& prev != null
&& prev.Underline != null
&& !prev.IsUnderlineCompatible(run))
)
{
// fail to create run or
// runs cannot support averaging underline
return null;
}
} while(true);
int trailingSpaceWidth = 0;
CollectTrailingSpaces(
runs,
settings.Formatter,
ref trailing,
ref trailingSpaceWidth
);
// create a simple line
return new SimpleTextLine(
settings,
cpFirst,
paragraphWidth,
runs,
ref trailing,
ref trailingSpaceWidth
) as TextLine;
}
/// <summary>
/// Constructing a lightweight text line
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="cpFirst">line first cp</param>
/// <param name="paragraphWidth">paragraph width</param>
/// <param name="runs">collection of simple runs</param>
/// <param name="trailing">line trailing spaces</param>
/// <param name="trailingSpaceWidth">line trailing spaces width</param>
/// <Remarks>
/// SimpleTextLine is constructed with Ideal width such that the line breaking
/// behavior is consistent with the FullTextLine
/// </Remarks>
public SimpleTextLine(
FormatSettings settings,
int cpFirst,
int paragraphWidth,
ArrayList runs,
ref int trailing,
ref int trailingSpaceWidth
)
{
// Compute line metrics
int count = 0;
_settings = settings;
double realAscent = 0;
double realDescent = 0;
double realHeight = 0;
ParaProp pap = settings.Pap;
TextFormatterImp formatter = settings.Formatter;
int idealWidth = 0;
while(count < runs.Count)
{
SimpleRun run = (SimpleRun)runs[count];
if(run.Length > 0)
{
if(run.EOT)
{
// EOT run has no effect on height, it is part of trailing spaces
trailing += run.Length;
_cpLengthEOT += run.Length;
}
else
{
realHeight = Math.Max(realHeight, run.Height);
realAscent = Math.Max(realAscent, run.Baseline);
realDescent = Math.Max(realDescent, run.Height - run.Baseline);
}
_cpLength += run.Length;
idealWidth += run.IdealWidth;
}
count++;
}
// Roundtrip run baseline and height to take its precision back to the specified formatting resolution.
//
// We have to do this to guarantee sameness of line alignment metrics produced by fast and full path.
// This is critical for TextBlock/TextFlow. They rely on the fact that line created during Measure must
// yield the same metrics as one created during Render, while there is no guarantee that the paragraph
// properties of that same line remains the same in both timings e.g. Measure may not specify
// justification (which results in us formatting the line in fast path), while Render might
// (which results in us formatting that same line in full path).
_baselineOffset = formatter.IdealToReal(TextFormatterImp.RealToIdeal(realAscent));
if (realAscent + realDescent == realHeight)
{
_height = formatter.IdealToReal(TextFormatterImp.RealToIdeal(realHeight));
}
else
{
_height = formatter.IdealToReal(TextFormatterImp.RealToIdeal(realAscent) + TextFormatterImp.RealToIdeal(realDescent));
}
if(_height <= 0)
{
// line is empty (containing only EOP)
// we need to work out the line height
// It needs to be exactly the same as in full path.
_height = formatter.IdealToReal((int)Math.Round(pap.DefaultTypeface.LineSpacing(pap.EmSize, Constants.DefaultIdealToReal, Util.PixelsPerDip, _settings.TextFormattingMode)));
_baselineOffset = formatter.IdealToReal((int)Math.Round(pap.DefaultTypeface.Baseline(pap.EmSize, Constants.DefaultIdealToReal, Util.PixelsPerDip, _settings.TextFormattingMode)));
}
// Initialize the array of runs and set the TrimTrailingUnderline flag
// for runs that contain trailing spaces at the end of the line.
_runs = new SimpleRun[count];
for(int i = count - 1, t = trailing; i >= 0; --i)
{
SimpleRun run = (SimpleRun)runs[i];
if (t > 0)
{
run.TrimTrailingUnderline = true;
t -= run.Length;
}
_runs[i] = run;
}
_cpFirst = cpFirst;
_trailing = trailing;
int idealWidthAtTrailing = idealWidth - trailingSpaceWidth;
if(pap.Align != TextAlignment.Left)
{
switch(pap.Align)
{
case TextAlignment.Right:
_idealOffsetUnRounded = paragraphWidth - idealWidthAtTrailing;
_offset = formatter.IdealToReal(_idealOffsetUnRounded);
break;
case TextAlignment.Center:
// exactly consistent with FullTextLine
_idealOffsetUnRounded = (int)Math.Round((paragraphWidth - idealWidthAtTrailing) * 0.5);
_offset = formatter.IdealToReal(_idealOffsetUnRounded);
break;
}
}
// converting all the ideal values to real values
_width = formatter.IdealToReal(idealWidth);
_widthAtTrailing = formatter.IdealToReal(idealWidthAtTrailing);
_paragraphWidth = formatter.IdealToReal(paragraphWidth);
// paragraphWidth == 0 means format width is unlimited and hence not overflowable.
// we keep paragraphWidth for alignment calculation
if (paragraphWidth > 0 && _widthAtTrailing > _paragraphWidth)
{
_statusFlags |= StatusFlags.HasOverflowed;
}
}
/// <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>
/// Creating a simple text run
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="cp">first cp of the run</param>
/// <param name="cpFirst">first cp of the line</param>
/// <param name="widthLeft">maxium run width</param>
/// <param name="widthMax">maximum column 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,
int cp,
int cpFirst,
int widthLeft,
int widthMax,
int idealRunOffsetUnRounded
)
{
TextRun textRun;
int runLength;
CharacterBufferRange charBufferRange = settings.FetchTextRun(
cp,
cpFirst,
out textRun,
out runLength
);
return Create(
settings,
charBufferRange,
textRun,
cp,
cpFirst,
runLength,
widthLeft,
idealRunOffsetUnRounded
);
}
/// <summary>
/// Creating a lightweight text line
/// </summary>
/// <param name="settings">text formatting settings</param>
/// <param name="cpFirst">First cp of the line</param>
/// <param name="paragraphWidth">paragraph width</param>
/// <returns>TextLine instance</returns>
/// <remarks>
/// This method breaks line using Ideal width such that it will be
/// consistent with FullTextLine
/// </remarks>
static public TextLine Create(
FormatSettings settings,
int cpFirst,
int paragraphWidth
)
{
ParaProp pap = settings.Pap;
if( pap.RightToLeft
|| pap.Justify
|| ( pap.FirstLineInParagraph
&& pap.TextMarkerProperties != null)
|| settings.TextIndent != 0
|| pap.ParagraphIndent != 0
|| pap.LineHeight > 0
|| pap.AlwaysCollapsible
|| (pap.TextDecorations != null && pap.TextDecorations.Count != 0)
)
{
// unsupported paragraph properties
return null;
}
int cp = cpFirst;
// paragraphWidth == 0 means the format width is unlimited.
int widthLeft = (pap.Wrap && paragraphWidth > 0) ? paragraphWidth : int.MaxValue;
SimpleRun prev = null;
SimpleRun run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth
);
if(run == null)
{
// fail to create run e.g. complex content encountered
return null;
}
else if(!run.EOT && run.IdealWidth <= widthLeft)
{
// create next run
cp += run.Length;
widthLeft -= run.IdealWidth;
prev = run;
run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth
);
if(run == null)
{
return null;
}
}
int trailing = 0;
ArrayList runs = new ArrayList(2);
if(prev != null)
{
AddRun(runs, prev, null);
}
do
{
if(!run.EOT && run.IdealWidth > widthLeft)
{
// linebreaking required, even simple text requires classification-based linebreaking,
// we'll now let LS handle this line.
return null;
}
AddRun(runs, run, null);
prev = run;
cp += run.Length;
widthLeft -= run.IdealWidth;
if(run.EOT)
{
// we're done
break;
}
run = SimpleRun.Create(
settings,
cp,
cpFirst,
widthLeft,
paragraphWidth
);
if( run == null
|| ( run.Underline != null
&& prev != null
&& prev.Underline != null
&& !prev.IsUnderlineCompatible(run))
)
{
// fail to create run or
// runs cannot support averaging underline
return null;
}
} while(true);
int trailingSpaceWidth = 0;
CollectTrailingSpaces(
runs,
settings.Formatter,
ref trailing,
ref trailingSpaceWidth
);
// create a simple line
return new SimpleTextLine(
settings,
cpFirst,
paragraphWidth,
runs,
ref trailing,
ref trailingSpaceWidth
) as TextLine;
}
