/// <summary>
/// Tries to find a selection boundary LogicalDirection.Forward of
/// the current position.
/// </summary>
public bool MoveToNextWordBreak(TextNavigator navigator)
{
int index;
// If the array of break positions hasn't been created and
// populated yet, do that work now.
if (null == breakPositions)
{
if (!BreakText(navigator, false, out breakPositions))
{
return(false);
}
}
index = breakPositions.BinarySearch(navigator);
if (index < 0)
{
index = (~index);
}
else
{
index += 1;
}
if ((index > breakPositions.Count - 1) &&
(0 != navigator.TextContainer.End.CompareTo((TextPosition)breakPositions[breakPositions.Count - 1])))
{
breakPositions = null;
if (!BreakText(navigator, false, out breakPositions))
{
return(false);
}
index = breakPositions.BinarySearch(navigator);
if (index < 0)
{
index = (~index);
}
else
{
index += 1;
}
}
if ((index < 0) || (index > breakPositions.Count - 1))
{
return(false);
}
navigator.MoveToPosition((TextPosition)breakPositions[index]);
return(true);
}
internal static string GenerateText(TextPosition begin, TextPosition end)
{
StringBuilder output = new StringBuilder();
TextNavigator navigator = begin.CreateNavigator();
TextSymbolType type;
char[] buffer = new char[1];
char ch;
if (begin.TextContainer != end.TextContainer)
{
throw new ArgumentException(SR.Get(SRID.BeginEndTextContainerMismatch));
}
navigator.MoveToPosition(begin);
type = navigator.GetSymbolType(LogicalDirection.Forward);
while (navigator < end)
{
switch (type)
{
case TextSymbolType.Character:
navigator.GetText(LogicalDirection.Forward, 1, navigator.TextContainer.End, buffer, 0);
ch = buffer[0];
output.Append(ch);
break;
case TextSymbolType.EmbeddedObject:
ch = '\xF8FF'; // Private use Unicode.
output.Append(ch);
break;
case TextSymbolType.ElementStart:
case TextSymbolType.ElementEnd:
if (IsBreakingSymbol(navigator, LogicalDirection.Forward))
{
output.Append(" ");
}
break;
}
navigator.MoveByDistance(1);
type = navigator.GetSymbolType(LogicalDirection.Forward);
}
return(output.ToString());
}
internal bool BreakText(TextPosition position, bool isSpelling, out ArrayList positionList)
{
TextNavigator start = position.CreateNavigator();
TextNavigator end = position.CreateNavigator();
TextNavigator checkLeft = position.CreateNavigator();
TextNavigator checkRight = position.CreateNavigator();
bool leftEdge = false;
bool rightEdge = false;
int distance = 32;
int index;
bool foundBreaks = false;
positionList = null;
while (!(leftEdge && rightEdge))
{
if (!leftEdge)
{
if (start.TextContainer.Start.GetDistanceTo(start) > distance)
{
start.MoveByDistance(-(distance));
}
else
{
start.MoveToPosition(start.TextContainer.Start);
leftEdge = true;
}
MoveNaviForward(start);
MoveNaviBackward(start);
}
if (!rightEdge)
{
if (end.GetDistanceTo(end.TextContainer.End) > distance)
{
end.MoveByDistance(distance);
}
else
{
end.MoveToPosition(end.TextContainer.End);
rightEdge = true;
}
MoveNaviBackward(end);
MoveNaviForward(end);
}
if (BreakText(start, end, isSpelling, out positionList))
{
foundBreaks = true;
}
else
{
continue;
}
if (!leftEdge)
{
index = positionList.BinarySearch(checkLeft);
if (index < 0)
{
index = (~index);
}
index -= 1;
leftEdge = (index >= 0);
}
if (!rightEdge)
{
index = positionList.BinarySearch(checkRight);
if (index < 0)
{
index = (~index);
}
else
{
index += 1;
}
rightEdge = (index < positionList.Count);
}
}
return(foundBreaks);
}
