void ITextRangeProvider.ExpandToEnclosingUnit(TextUnit unit)
{
Misc.SetFocus(_provider._hwnd);
switch (unit)
{
case TextUnit.Character:
// if it is a degenerate range then expand it to be one character.
// otherwise, leave it as it is.
if (Start == End)
{
int moved;
End = MoveEndpointForward(End, TextUnit.Character, 1, out moved);
}
break;
case TextUnit.Word:
{
// this works same as paragraph except we look for word boundaries instead of paragraph boundaries.
// get the text so we can figure out where the boundaries are
string text = _provider.GetText();
ValidateEndpoints();
#if WCP_NLS_ENABLED
// use the same word breaker that Avalon Text uses.
WordBreaker breaker = new WordBreaker();
TextContainer container = new TextContainer(text);
// if the starting point of the range is not already at a word break
// then move it backwards to the nearest word break.
TextNavigator startNavigator = new TextNavigator(Start, container);
if (!breaker.IsAtWordBreak(startNavigator))
{
breaker.MoveToPreviousWordBreak(startNavigator);
Start = startNavigator.Position;
}
// if the range is degenerate or the ending point of the range is not already at a word break
// then move it forwards to the nearest word break.
TextNavigator endNavigator = new TextNavigator(End, container);
if (Start == End || !breaker.IsAtWordBreak(endNavigator))
{
breaker.MoveToNextWordBreak(endNavigator);
End = endNavigator.Position;
}
#else
// move start left until we reach a word boundary.
for (; !AtWordBoundary(text, Start); Start--)
{
;
}
// move end right until we reach word boundary (different from Start).
End = Math.Min(Math.Max(End, Start + 1), text.Length);
for (; !AtWordBoundary(text, End); End++)
{
;
}
#endif
}
break;
case TextUnit.Line:
{
if (_provider.GetLineCount() != 1)
{
int startLine = _provider.LineFromChar(Start);
int endLine = _provider.LineFromChar(End);
MoveTo(_provider.LineIndex(startLine), _provider.LineIndex(endLine + 1));
}
else
{
MoveTo(0, _provider.GetTextLength());
}
}
break;
case TextUnit.Paragraph:
{
// this works same as paragraph except we look for word boundaries instead of paragraph boundaries.
// get the text so we can figure out where the boundaries are
string text = _provider.GetText();
ValidateEndpoints();
// move start left until we reach a paragraph boundary.
for (; !AtParagraphBoundary(text, Start); Start--)
{
;
}
// move end right until we reach a paragraph boundary (different from Start).
End = Math.Min(Math.Max(End, Start + 1), text.Length);
for (; !AtParagraphBoundary(text, End); End++)
{
;
}
}
break;
case TextUnit.Format:
case TextUnit.Page:
case TextUnit.Document:
MoveTo(0, _provider.GetTextLength());
break;
//break;
default:
throw new System.ComponentModel.InvalidEnumArgumentException("unit", (int)unit, typeof(TextUnit));
}
}
// moves an endpoint forward a certain number of units.
// the endpoint is just an index into the text so it could represent either
// the endpoint.
private int MoveEndpointForward(int index, TextUnit unit, int count, out int moved)
{
switch (unit)
{
case TextUnit.Character:
{
int limit = _provider.GetTextLength();
ValidateEndpoints();
moved = Math.Min(count, limit - index);
index = index + moved;
index = index > limit ? limit : index;
}
break;
case TextUnit.Word:
{
string text = _provider.GetText();
ValidateEndpoints();
#if WCP_NLS_ENABLED
// use the same word breaker as Avalon Text.
WordBreaker breaker = new WordBreaker();
TextContainer container = new TextContainer(text);
TextNavigator navigator = new TextNavigator(index, container);
// move forward one word break for each count
for (moved = 0; moved < count && index < text.Length; moved++)
{
if (!breaker.MoveToNextWordBreak(navigator))
{
break;
}
}
index = navigator.Position;
#else
for (moved = 0; moved < count && index < text.Length; moved++)
{
for (index++; !AtWordBoundary(text, index); index++)
{
;
}
}
#endif
}
break;
case TextUnit.Line:
{
// figure out what line we are on. if we are in the middle of a line and
// are moving left then we'll round up to the next line so that we move
// to the beginning of the current line.
int line = _provider.LineFromChar(index);
// limit the number of lines moved to the number of lines available to move
// Note lineMax is always >= 1.
int lineMax = _provider.GetLineCount();
moved = Math.Min(count, lineMax - line - 1);
if (moved > 0)
{
// move the endpoint to the beginning of the destination line.
index = _provider.LineIndex(line + moved);
}
else if (moved == 0 && lineMax == 1)
{
// There is only one line so get the text length as endpoint
index = _provider.GetTextLength();
moved = 1;
}
}
break;
case TextUnit.Paragraph:
{
// just like moving words but we look for paragraph boundaries instead of
// word boundaries.
string text = _provider.GetText();
ValidateEndpoints();
for (moved = 0; moved < count && index < text.Length; moved++)
{
for (index++; !AtParagraphBoundary(text, index); index++)
{
;
}
}
}
break;
case TextUnit.Format:
case TextUnit.Page:
case TextUnit.Document:
{
// since edit controls are plain text moving one uniform format unit will
// take us all the way to the end of the document, just like
// "pages" and document.
int limit = _provider.GetTextLength();
ValidateEndpoints();
// we'll move 1 format unit if we aren't already at the end of the
// document. Otherwise, we won't move at all.
moved = index < limit ? 1 : 0;
index = limit;
}
break;
default:
throw new System.ComponentModel.InvalidEnumArgumentException("unit", (int)unit, typeof(TextUnit));
}
return(index);
}