void PaintFoldMarker(Graphics g, int lineNumber, Rectangle drawingRectangle) { HighlightColor foldLineColor = textArea.Document.HighlightingStrategy.GetColorFor("FoldLine"); HighlightColor selectedFoldLine = textArea.Document.HighlightingStrategy.GetColorFor("SelectedFoldLine"); List <FoldMarker> foldingsWithStart = textArea.Document.FoldingManager.GetFoldingsWithStart(lineNumber); List <FoldMarker> foldingsBetween = textArea.Document.FoldingManager.GetFoldingsContainsLineNumber(lineNumber); List <FoldMarker> foldingsWithEnd = textArea.Document.FoldingManager.GetFoldingsWithEnd(lineNumber); bool isFoldStart = foldingsWithStart.Count > 0; bool isBetween = foldingsBetween.Count > 0; bool isFoldEnd = foldingsWithEnd.Count > 0; bool isStartSelected = SelectedFoldingFrom(foldingsWithStart); bool isBetweenSelected = SelectedFoldingFrom(foldingsBetween); bool isEndSelected = SelectedFoldingFrom(foldingsWithEnd); int foldMarkerSize = (int)Math.Round(textArea.TextView.FontHeight * 0.5f); foldMarkerSize -= (foldMarkerSize) % 2; int foldMarkerYPos = drawingRectangle.Y + (int)((drawingRectangle.Height - foldMarkerSize) / 2); int xPos = drawingRectangle.X + (drawingRectangle.Width - foldMarkerSize) / 2 + foldMarkerSize / 2; if (isFoldStart) { bool isVisible = true; bool moreLinedOpenFold = false; foreach (FoldMarker foldMarker in foldingsWithStart) { if (foldMarker.IsFolded) { isVisible = false; } else { moreLinedOpenFold = foldMarker.EndLine > foldMarker.StartLine; } } bool isFoldEndFromUpperFold = false; foreach (FoldMarker foldMarker in foldingsWithEnd) { if (foldMarker.EndLine > foldMarker.StartLine && !foldMarker.IsFolded) { isFoldEndFromUpperFold = true; } } DrawFoldMarker(g, new RectangleF(drawingRectangle.X + (drawingRectangle.Width - foldMarkerSize) / 2, foldMarkerYPos, foldMarkerSize, foldMarkerSize), isVisible, isStartSelected ); // draw line above fold marker if (isBetween || isFoldEndFromUpperFold) { g.DrawLine(BrushRegistry.GetPen(isBetweenSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, drawingRectangle.Top, xPos, foldMarkerYPos - 1); } // draw line below fold marker if (isBetween || moreLinedOpenFold) { g.DrawLine(BrushRegistry.GetPen(isEndSelected || (isStartSelected && isVisible) || isBetweenSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, foldMarkerYPos + foldMarkerSize + 1, xPos, drawingRectangle.Bottom); } } else { if (isFoldEnd) { int midy = drawingRectangle.Top + drawingRectangle.Height / 2; // draw fold end marker g.DrawLine(BrushRegistry.GetPen(isEndSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, midy, xPos + foldMarkerSize / 2, midy); // draw line above fold end marker // must be drawn after fold marker because it might have a different color than the fold marker g.DrawLine(BrushRegistry.GetPen(isBetweenSelected || isEndSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, drawingRectangle.Top, xPos, midy); // draw line below fold end marker if (isBetween) { g.DrawLine(BrushRegistry.GetPen(isBetweenSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, midy + 1, xPos, drawingRectangle.Bottom); } } else if (isBetween) { // just draw the line :) g.DrawLine(BrushRegistry.GetPen(isBetweenSelected ? selectedFoldLine.Color : foldLineColor.Color), xPos, drawingRectangle.Top, xPos, drawingRectangle.Bottom); } } }