// ------------------------------------------------------------------
//
// TextSource Implementation
//
// -----------------------------------------------------------------
#region TextSource Implementation
// ------------------------------------------------------------------
// Get a text run at specified text source position.
// ------------------------------------------------------------------
public override TextRun GetTextRun(int dcp)
{
TextRun run = null;
StaticTextPointer position = _owner.TextContainer.CreateStaticPointerAtOffset(dcp);
switch (position.GetPointerContext(LogicalDirection.Forward))
{
case TextPointerContext.Text:
run = HandleText(position);
break;
case TextPointerContext.ElementStart:
run = HandleElementStartEdge(position);
break;
case TextPointerContext.ElementEnd:
run = HandleElementEndEdge(position);
break;
case TextPointerContext.EmbeddedElement:
run = HandleInlineObject(position, dcp);
break;
case TextPointerContext.None:
run = new TextEndOfParagraph(_syntheticCharacterLength);
break;
}
Debug.Assert(run != null, "TextRun has not been created.");
Debug.Assert(run.Length > 0, "TextRun has to have positive length.");
return run;
}
// ------------------------------------------------------------------
//
// 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;
}
public override TextRun GetTextRun(int textSourceCharacterIndex)
{
if (this._itemsCount <= 0)
{
this.UniscribeScriptItemizeOpenType();
}
TextRun result;
if (textSourceCharacterIndex < 0)
{
result = new TextEndOfParagraph(1);
}
else
{
if (textSourceCharacterIndex < this.Text.Length)
{
for (int index = 0; index < this._itemsCount - 1; index++)
{
if (this._items[index].iCharPos <= textSourceCharacterIndex && this._items[index + 1].iCharPos > textSourceCharacterIndex)
{
result = this.MakeTextCharactors(index, textSourceCharacterIndex, this._items[index + 1].iCharPos - textSourceCharacterIndex);
return result;
}
}
result = this.MakeTextCharactors(this._itemsCount - 1, textSourceCharacterIndex, this.Text.Length - textSourceCharacterIndex);
}
else
{
result = new TextEndOfParagraph(1);
}
}
return result;
}
/// <summary>
/// Get a text run at specified text source position.
/// </summary>
public override TextRun GetTextRun(int dcp)
{
TextRun run = null;
StaticTextPointer position = _owner.Host.TextContainer.CreateStaticPointerAtOffset(dcp);
switch (position.GetPointerContext(LogicalDirection.Forward))
{
case TextPointerContext.Text:
run = HandleText(position);
break;
case TextPointerContext.None:
run = new TextEndOfParagraph(_syntheticCharacterLength);
break;
case TextPointerContext.ElementStart:
case TextPointerContext.ElementEnd:
case TextPointerContext.EmbeddedElement:
default:
Invariant.Assert(false, "Unsupported position type.");
break;
}
Invariant.Assert(run != null, "TextRun has not been created.");
Invariant.Assert(run.Length > 0, "TextRun has to have positive length.");
return run;
}
