private void TextView_VisualLineConstructionStarting(object sender, VisualLineConstructionStartEventArgs e)
{
if (_highlighter != null)
{
// Force update of highlighting state up to the position where we start generating visual lines.
// This is necessary in case the document gets modified above the FirstLineInView so that the highlighting state changes.
// We need to detect this case and issue a redraw (through OnHighlightStateChanged)
// before the visual line construction reuses existing lines that were built using the invalid highlighting state.
_lineNumberBeingColorized = e.FirstLineInView.LineNumber - 1;
if (!_isInHighlightingGroup)
{
// avoid opening group twice if there was an exception during the previous visual line construction
// (not ideal, but better than throwing InvalidOperationException "group already open"
// without any way of recovering)
_highlighter.BeginHighlighting();
_isInHighlightingGroup = true;
}
_highlighter.UpdateHighlightingState(_lineNumberBeingColorized);
_lineNumberBeingColorized = 0;
}
}
public void UpdateHighlightingState(int lineNumber)
{
baseHighlighter.UpdateHighlightingState(lineNumber);
}