// ------------------------------------------------------------------
//
// TextSource Implementation
//
// -----------------------------------------------------------------
#region TextSource Implementation
// ------------------------------------------------------------------
// Get a text run at specified text source position.
// ------------------------------------------------------------------
public override TextRun GetTextRun(int dcp)
{
Debug.Assert(dcp >= 0, "Character index must be non-negative.");
TextRun run;
// There is only one run of text.
if (dcp < _content.Length)
{
// LineLayout may ask for dcp != 0. This case may only happen during partial
// validation of TextRunCache.
// Example:
// 1) TextRunCache and LineMetrics array were created during measure process.
// 2) Before OnRender is called somebody invalidates render only property.
// This invalidates TextRunCache.
// 3) Before OnRender is called InputHitTest is invoked. Because LineMetrics
// array is valid, we don't have to recreate all lines. There is only
// need to recreate the N-th line (line that has been hit).
// During line recreation LineLayout will not refetch all runs from the
// beginning of TextBlock control - it will ask for the run at the beginning
// of the current line.
// For this reason set 'offsetToFirstChar' to 'dcp' value.
run = new TextCharacters(_content, dcp, _content.Length - dcp, _textProps);
}
else
{
run = new TextEndOfParagraph(_syntheticCharacterLength);
}
return run;
}
/// <summary>
/// Return next TextRun at element edge start position
/// </summary>
/// <param name="position">
/// Current position in text array
/// </param>
protected TextRun HandleElementStartEdge(StaticTextPointer position)
{
Invariant.Assert(position.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.ElementStart, "TextPointer does not point to element start edge.");
//
TextRun run = null;
TextElement element = (TextElement)position.GetAdjacentElement(LogicalDirection.Forward);
Debug.Assert(element != null, "Cannot use ITextContainer that does not provide TextElement instances.");
Invariant.Assert(!(element is Block), "We do not expect any Blocks inside Paragraphs");
// Treat figure and floaters as special hidden runs.
if (element is Figure || element is Floater)
{
// Get the length of the element
int cch = TextContainerHelper.GetElementLength(_paraClient.Paragraph.StructuralCache.TextContainer, element);
// Create special hidden run.
run = new FloatingRun(cch, element is Figure);
if (element is Figure)
{
_hasFigures = true;
}
else
{
_hasFloaters = true;
}
}
else if (element is LineBreak)
{
int cch = TextContainerHelper.GetElementLength(_paraClient.Paragraph.StructuralCache.TextContainer, element);
run = new LineBreakRun(cch, PTS.FSFLRES.fsflrSoftBreak);
}
else if (element.IsEmpty)
{
// Empty TextElement should affect line metrics.
// TextFormatter does not support this feature right now, so as workaround
// TextRun with ZERO WIDTH SPACE is used.
TextProperties textProps = new TextProperties(element, position, false /* inline objects */, true /* get background */);
char[] textBuffer = new char[_elementEdgeCharacterLength * 2];
// Assert that _elementEdgeCharacterLength is 1 before we use hard-coded indices
Invariant.Assert(_elementEdgeCharacterLength == 1, "Expected value of _elementEdgeCharacterLength is 1");
textBuffer[0] = (char)0x200B;
textBuffer[1] = (char)0x200B;
run = new TextCharacters(textBuffer, 0, textBuffer.Length, textProps);
}
else
{
Inline inline = (Inline) element;
DependencyObject parent = inline.Parent;
FlowDirection inlineFlowDirection = inline.FlowDirection;
FlowDirection parentFlowDirection = inlineFlowDirection;
TextDecorationCollection inlineTextDecorations = DynamicPropertyReader.GetTextDecorations(inline);
if(parent != null)
{
parentFlowDirection = (FlowDirection)parent.GetValue(FrameworkElement.FlowDirectionProperty);
}
if (inlineFlowDirection != parentFlowDirection)
{
// Inline's flow direction is different from its parent. Need to create new TextSpanModifier with flow direction
if (inlineTextDecorations == null || inlineTextDecorations.Count == 0)
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
null,
null,
inlineFlowDirection
);
}
else
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
inlineTextDecorations,
inline.Foreground,
inlineFlowDirection
);
}
}
else
{
if (inlineTextDecorations == null || inlineTextDecorations.Count == 0)
{
run = new TextHidden(_elementEdgeCharacterLength);
}
else
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
inlineTextDecorations,
inline.Foreground
);
}
}
}
return run;
}
private TextRun MakeTextCharactors(int index, int textSourceCharacterIndex, int length)
{
TextCharacters textCharacters = new TextCharacters(this.Text, textSourceCharacterIndex, length, this.JapaneseTextRunProperties);
this.UniscribeScriptShapeOpenType(this.Text, index, textSourceCharacterIndex, length);
return textCharacters;
}
public override TextRun GetTextRun(int textSourceCharacterIndex)
{
var index = textSourceCharacterIndex;
if (runs.ContainsKey(index)) {
var run = runs[index];
runs.Remove(index);
return run;
}
if (index >= text.Length || text[index] == '\r' || text[index] == '\n') {
if (index < text.Length && text[index] != '\r')
return new TextCharacters(" ", null);
else
return new TextEndOfParagraph(1);
}
int defaultTextLength, tokenLength;
TextTokenKind tokenKind;
if (!tokens.Find(index, out defaultTextLength, out tokenKind, out tokenLength)) {
Debug.Fail("Could not find token info");
return new TextCharacters(" ", null);
}
TextCharacters defaultRun = null, tokenRun = null;
if (defaultTextLength != 0) {
var defaultText = text.Substring(index, defaultTextLength);
defaultRun = new TextCharacters(defaultText, new TextProps {
background = (Brush)parent.GetValue(TextElement.BackgroundProperty),
foreground = TextElement.GetForeground(parent),
typeface = new Typeface(
TextElement.GetFontFamily(parent),
TextElement.GetFontStyle(parent),
TextElement.GetFontWeight(parent),
TextElement.GetFontStretch(parent)
),
fontSize = TextElement.GetFontSize(parent),
});
}
index += defaultTextLength;
if (tokenLength != 0) {
var tc = GetColor(tokenKind);
var tokenText = text.Substring(index, tokenLength);
var textProps = new TextProps();
textProps.fontSize = TextElement.GetFontSize(parent);
textProps.foreground = tc.Foreground ?? TextElement.GetForeground(parent);
textProps.background = tc.Background ?? (Brush)parent.GetValue(TextElement.BackgroundProperty);
textProps.typeface = new Typeface(
TextElement.GetFontFamily(parent),
tc.FontStyle ?? TextElement.GetFontStyle(parent),
tc.FontWeight ?? TextElement.GetFontWeight(parent),
TextElement.GetFontStretch(parent)
);
tokenRun = new TextCharacters(tokenText, textProps);
}
Debug.Assert(defaultRun != null || tokenRun != null);
if ((defaultRun != null) ^ (tokenRun != null))
return defaultRun ?? tokenRun;
else {
runs[index] = tokenRun;
return defaultRun;
}
}
// ------------------------------------------------------------------
// Fetch the next run at element open edge position.
//
// position - current position in the text array
// ------------------------------------------------------------------
private TextRun HandleElementStartEdge(StaticTextPointer position)
{
Debug.Assert(position.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.ElementStart, "TextPointer does not point to element start edge.");
//
TextRun run = null;
TextElement element = (TextElement)position.GetAdjacentElement(LogicalDirection.Forward);
Debug.Assert(element != null, "Cannot use ITextContainer that does not provide TextElement instances.");
if (element is LineBreak)
{
run = new TextEndOfLine(_elementEdgeCharacterLength * 2);
}
else if (element.IsEmpty)
{
// Empty TextElement should affect line metrics.
// TextFormatter does not support this feature right now, so as workaround
// TextRun with ZERO WIDTH SPACE is used.
TextRunProperties textProps = new TextProperties(element, position, false /* inline objects */, true /* get background */);
char[] textBuffer = new char[_elementEdgeCharacterLength * 2];
textBuffer[0] = (char)0x200B;
textBuffer[1] = (char)0x200B;
run = new TextCharacters(textBuffer, 0, textBuffer.Length, textProps);
}
else
{
Inline inline = element as Inline;
if (inline == null)
{
run = new TextHidden(_elementEdgeCharacterLength);
}
else
{
DependencyObject parent = inline.Parent;
FlowDirection inlineFlowDirection = inline.FlowDirection;
FlowDirection parentFlowDirection = inlineFlowDirection;
if(parent != null)
{
parentFlowDirection = (FlowDirection)parent.GetValue(FrameworkElement.FlowDirectionProperty);
}
TextDecorationCollection inlineTextDecorations = DynamicPropertyReader.GetTextDecorations(inline);
if (inlineFlowDirection != parentFlowDirection)
{
// Inline's flow direction is different from its parent. Need to create new TextSpanModifier with flow direction
if (inlineTextDecorations == null || inlineTextDecorations.Count == 0)
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
null,
null,
inlineFlowDirection
);
}
else
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
inlineTextDecorations,
inline.Foreground,
inlineFlowDirection
);
}
}
else
{
if (inlineTextDecorations == null || inlineTextDecorations.Count == 0)
{
run = new TextHidden(_elementEdgeCharacterLength);
}
else
{
run = new TextSpanModifier(
_elementEdgeCharacterLength,
inlineTextDecorations,
inline.Foreground
);
}
}
}
}
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;
}
