static IEnumerable<Rect> ProcessTextLines(TextView textView, VisualLine visualLine, int segmentStartVC, int segmentEndVC)
{
TextLine lastTextLine = visualLine.TextLines.Last();
Vector scrollOffset = textView.ScrollOffset;
for (int i = 0; i < visualLine.TextLines.Count; i++) {
TextLine line = visualLine.TextLines[i];
double y = visualLine.GetTextLineVisualYPosition(line, VisualYPosition.LineTop);
int visualStartCol = visualLine.GetTextLineVisualStartColumn(line);
int visualEndCol = visualStartCol + line.Length;
if (line != lastTextLine)
visualEndCol -= line.TrailingWhitespaceLength;
if (segmentEndVC < visualStartCol)
break;
if (lastTextLine != line && segmentStartVC > visualEndCol)
continue;
int segmentStartVCInLine = Math.Max(segmentStartVC, visualStartCol);
int segmentEndVCInLine = Math.Min(segmentEndVC, visualEndCol);
y -= scrollOffset.Y;
if (segmentStartVCInLine == segmentEndVCInLine) {
// GetTextBounds crashes for length=0, so we'll handle this case with GetDistanceFromCharacterHit
// We need to return a rectangle to ensure empty lines are still visible
double pos = visualLine.GetTextLineVisualXPosition(line, segmentStartVCInLine);
pos -= scrollOffset.X;
// The following special cases are necessary to get rid of empty rectangles at the end of a TextLine if "Show Spaces" is active.
// If not excluded once, the same rectangle is calculated (and added) twice (since the offset could be mapped to two visual positions; end/start of line), if there is no trailing whitespace.
// Skip this TextLine segment, if it is at the end of this line and this line is not the last line of the VisualLine and the selection continues and there is no trailing whitespace.
if (segmentEndVCInLine == visualEndCol && i < visualLine.TextLines.Count - 1 && segmentEndVC > segmentEndVCInLine && line.TrailingWhitespaceLength == 0)
continue;
if (segmentStartVCInLine == visualStartCol && i > 0 && segmentStartVC < segmentStartVCInLine && visualLine.TextLines[i - 1].TrailingWhitespaceLength == 0)
continue;
yield return new Rect(pos, y, 1, line.Height);
} else {
Rect lastRect = Rect.Empty;
if (segmentStartVCInLine <= visualEndCol) {
foreach (TextBounds b in line.GetTextBounds(segmentStartVCInLine, segmentEndVCInLine - segmentStartVCInLine)) {
double left = b.Rectangle.Left - scrollOffset.X;
double right = b.Rectangle.Right - scrollOffset.X;
if (!lastRect.IsEmpty)
yield return lastRect;
// left>right is possible in RTL languages
lastRect = new Rect(Math.Min(left, right), y, Math.Abs(right - left), line.Height);
}
}
if (segmentEndVC >= visualLine.VisualLengthWithEndOfLineMarker) {
double left = (segmentStartVC > visualLine.VisualLengthWithEndOfLineMarker ? visualLine.GetTextLineVisualXPosition(lastTextLine, segmentStartVC) : line.Width) - scrollOffset.X;
double right = ((segmentEndVC == int.MaxValue || line != lastTextLine) ? Math.Max(((IScrollInfo)textView).ExtentWidth, ((IScrollInfo)textView).ViewportWidth) : visualLine.GetTextLineVisualXPosition(lastTextLine, segmentEndVC)) - scrollOffset.X;
Rect extendSelection = new Rect(Math.Min(left, right), y, Math.Abs(right - left), line.Height);
if (!lastRect.IsEmpty) {
if (extendSelection.IntersectsWith(lastRect)) {
lastRect.Union(extendSelection);
yield return lastRect;
} else {
yield return lastRect;
yield return extendSelection;
}
} else
yield return extendSelection;
} else
yield return lastRect;
}
}
}
static void SetCaretPosition(TextArea textArea, VisualLine targetVisualLine, TextLine targetLine,
int newVisualColumn, bool allowWrapToNextLine)
{
int targetLineStartCol = targetVisualLine.GetTextLineVisualStartColumn(targetLine);
if (!allowWrapToNextLine && newVisualColumn >= targetLineStartCol + targetLine.Length) {
if (newVisualColumn <= targetVisualLine.VisualLength)
newVisualColumn = targetLineStartCol + targetLine.Length - 1;
}
int newOffset = targetVisualLine.GetRelativeOffset(newVisualColumn) + targetVisualLine.FirstDocumentLine.Offset;
SetCaretPosition(textArea, newVisualColumn, newOffset);
}
