Add marks to indicate when a row is too large

A dotted line is shown on the left or on the right to indicate that a part of the row is not visible.

Add a color code for the scroll indicator

src/Color.cpp

@@ -238,6 +238,7 @@ ColorSet::ColorSet()
 	{ Color_urllabel, N_("URL label"), "urllabel", "blue", "urllabel" },
 	{ Color_urltext, N_("URL text"), "urltext", "blue", "urltext" },
 	{ Color_depthbar, N_("depth bar"), "depthbar", "IndianRed", "depthbar" },
+	{ Color_scroll, N_("scroll indicator"), "scroll", "IndianRed", "scroll" },
 	{ Color_language, N_("language"), "language", "Blue", "language" },
 	{ Color_command, N_("command inset"), "command", "black", "command" },
 	{ Color_commandbg, N_("command inset background"), "commandbg", "azure", "commandbg" },

src/ColorCode.h

@@ -91,6 +91,8 @@ enum ColorCode {
 
 	/// Color for the depth bars in the margin
 	Color_depthbar,
+	/// Color that indicates when a row can be scrolled
+	Color_scroll,
 	/// Color for marking foreign language words
 	Color_language,
 

src/RowPainter.cpp

@@ -439,6 +439,23 @@ int RowPainter::paintAppendixStart(int y)
 }
 
 
+void RowPainter::paintTooLargeMarks(bool const left, bool const right)
+{
+	if (left)
+		pi_.pain.line(dotted_line_thickness_, yo_ - row_.ascent(),
+			      dotted_line_thickness_, yo_ + row_.descent(),
+			      Color_scroll,
+			      Painter::line_onoffdash, dotted_line_thickness_);
+	if (right) {
+		int const wwidth = pi_.base.bv->workWidth() - dotted_line_thickness_;
+		pi_.pain.line(wwidth, yo_ - row_.ascent(),
+			      wwidth, yo_ + row_.descent(),
+			      Color_scroll,
+			      Painter::line_onoffdash, dotted_line_thickness_);
+	}
+}
+
+
 void RowPainter::paintFirst()
 {
 	BufferParams const & bparams = pi_.base.bv->buffer().params();

src/RowPainter.h

@@ -66,6 +66,7 @@ public:
 	void paintAppendix();
 	void paintDepthBar();
 	void paintChangeBar();
+	void paintTooLargeMarks(bool const left, bool const right);
 	void paintFirst();
 	void paintLast();
 	void paintText();

src/TextMetrics.cpp

@@ -1942,6 +1942,8 @@ void TextMetrics::drawParagraph(PainterInfo & pi, pit_type const pit, int const
 			rp.paintLast();
 		if (i == 0 && is_rtl)
 			rp.paintFirst();
+		rp.paintTooLargeMarks(row_x < 0,
+				      row_x + row.width() > bv_->workWidth());
 		y += row.descent();
 
 		// Restore full_repaint status.