/// <summary>
/// Client to notify change in part of the cache when text or
/// properties of the run is being added, removed or replaced.
/// </summary>
/// <remarks>
/// The client's expectation of this notification is that TextFormatter
/// retains valid state for run cache in response to this change. It's
/// expected that at least TextFormatter will refetch the runs affected
/// by the change. Subsequent runs may or may not be refected depending
/// on the state of the cache after the change.
/// </remarks>
public void Change(
int textSourceCharacterIndex,
int addition,
int removal
)
{
if (textSourceCharacterIndex < 0)
return;
int cchActive = 0;
for (int i = 0; i < _textRunVector.Count; i++)
cchActive += _textRunVector[i].length;
if (textSourceCharacterIndex >= cchActive)
return;
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition, textSourceCharacterIndex);
_latestPosition = textRunSpanRider.SpanPosition;
// we remove runs from the cache starting from the one containing the change
// to the end of the active range. We do not try to interpret the scope of
// the change and try to minimize the range in which the cache is invalidated,
// because that would require an in-depth understanding of how our client
// implement their formatting change mechanism and how they respond to future
// refetch after the change which could vary among different clients. That
// kind of work is beyond the purpose of this notification.
_latestPosition = _textRunVector.SetValue(
textRunSpanRider.CurrentSpanStart,
cchActive - textRunSpanRider.CurrentSpanStart,
_textRunVector.Default,
_latestPosition
);
}
internal void SetSpanBaseInColumn(IEasyGridCell baseCell, int rowSpan = 1)
{
if (rowSpan <= 1)
{
if (baseCell.Equals(_targetCell))
{
SpanPos = SpanPosition.NoSpan;
_rowSpanSize = 1;
_colSpanSize = 1;
}
return;
}
if (baseCell.Equals(_targetCell))
{
SpanBaseCell = baseCell;
SpanPos = SpanPosition.SpanBase;
_rowSpanSize = rowSpan;
_colSpanSize = 1;
}
else if (_targetCell.RowIndex > baseCell.RowIndex &&
_targetCell.RowIndex <= baseCell.RowIndex + rowSpan)
{
SpanBaseCell = baseCell;
SpanPos = SpanPosition.Spanned;
_rowSpanSize = 0;
}
else
{
//이 영역에 들어가지 않으므로 상태를 유지한다.
}
}
/// <summary>
/// cell에서 부터 시작해서 Row 안에서 몇 개의 column을 span할 것인지 지정한다.
/// 대상 cell이 이 셋팅으로 인하여 어느 위치에 어떻게 들어가는지를 나타낸다.
/// </summary>
/// <param name="cell"></param>
/// <param name="colSpan">1이면 span하지 않는다는 뜻이다.</param>
internal void SetSpanBaseInRow(IEasyGridCell cell, int colSpan = 1)
{
if (colSpan <= 1)
{
if (cell.Equals(_targetCell))
{
SpanPos = SpanPosition.NoSpan;
_colSpanSize = 1;
}
return;
}
if (cell.Equals(_targetCell))
{
SpanBaseCell = cell;
SpanPos = SpanPosition.SpanBase;
_colSpanSize = colSpan;
_rowSpanSize = 1;
}
else if (_targetCell.ColumnIndex > cell.ColumnIndex &&
_targetCell.ColumnIndex < cell.ColumnIndex + colSpan)
{
SpanBaseCell = cell;
SpanPos = SpanPosition.Spanned;
_colSpanSize = 0;
}
else
{
//이 영역에 들어가지 않으므로 상태를 유지한다.
}
}
/// <summary>
/// Client to notify change in part of the cache when text or
/// properties of the run is being added, removed or replaced.
/// </summary>
/// <remarks>
/// The client's expectation of this notification is that TextFormatter
/// retains valid state for run cache in response to this change. It's
/// expected that at least TextFormatter will refetch the runs affected
/// by the change. Subsequent runs may or may not be refected depending
/// on the state of the cache after the change.
/// </remarks>
public void Change(
int textSourceCharacterIndex,
int addition,
int removal
)
{
if (textSourceCharacterIndex < 0)
{
return;
}
int cchActive = 0;
for (int i = 0; i < _textRunVector.Count; i++)
{
cchActive += _textRunVector[i].length;
}
if (textSourceCharacterIndex >= cchActive)
{
return;
}
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition, textSourceCharacterIndex);
_latestPosition = textRunSpanRider.SpanPosition;
// we remove runs from the cache starting from the one containing the change
// to the end of the active range. We do not try to interpret the scope of
// the change and try to minimize the range in which the cache is invalidated,
// because that would require an in-depth understanding of how our client
// implement their formatting change mechanism and how they respond to future
// refetch after the change which could vary among different clients. That
// kind of work is beyond the purpose of this notification.
_latestPosition = _textRunVector.SetValue(
textRunSpanRider.CurrentSpanStart,
cchActive - textRunSpanRider.CurrentSpanStart,
_textRunVector.Default,
_latestPosition
);
}
/// <summary>
/// Default constructor used internally
/// </summary>
/// <remarks>
/// Text layout client never create their own run cache as its implementation
/// should be opaque to them.
/// </remarks>
internal TextRunCacheImp()
{
_textRunVector = new SpanVector(null);
_latestPosition = new SpanPosition();
}
/// <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>
/// Default constructor used internally
/// </summary>
/// <remarks>
/// Text layout client never create their own run cache as its implementation
/// should be opaque to them.
/// </remarks>
internal TextRunCacheImp()
{
_textRunVector = new SpanVector(null);
_latestPosition = new SpanPosition();
}
/// <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);
}