// Attach non-breaking elements to the text or object on
// their left.
internal static bool MoveNaviBackward(TextNavigator nav)
{
TextSymbolType type;
bool continueLoop = true;
TextPosition position = nav.CreatePosition();
type = nav.GetSymbolType(LogicalDirection.Backward);
while (continueLoop)
{
if (nav.CompareTo(nav.TextContainer.Start) == 0)
{
return(false);
}
switch (type)
{
case TextSymbolType.Character:
case TextSymbolType.EmbeddedObject:
continueLoop = false;
break;
case TextSymbolType.ElementStart:
case TextSymbolType.ElementEnd:
if (IsBreakingSymbol(nav, LogicalDirection.Backward))
{
continueLoop = false;
}
break;
}
nav.MoveByDistance(-1);
type = nav.GetSymbolType(LogicalDirection.Backward);
}
return(nav.CompareTo(position) < 0);
}
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());
}
private static bool IsBreakingSymbol(TextNavigator navigator, LogicalDirection direction)
{
TextSymbolType type = navigator.GetSymbolType(direction);
// (JCS) - This will need to be reworked after the Avalon team has
// an API that can be called to determine if an Element should be
// "breaking" or not.
return((type == TextSymbolType.None) ||
(type == TextSymbolType.EmbeddedObject) ||
(((type == TextSymbolType.ElementStart) ||
(type == TextSymbolType.ElementEnd)
) &&
(navigator.GetElementType(direction).IsAssignableFrom(typeof(InlineElement)))
)
);
}