Add a soft line length guideline to the script editor

The default value is 80. The hard line length guideline's
default column has been moved to 100 to account for the new
soft line length guideline.

It can be disabled by setting its value to the same column as the
hard line length guideline.

This closes https://github.com/godotengine/godot-proposals/issues/347.

2 files changed, 30 insertions, 14 deletions

diff --git a/scene/gui/text_edit.cpp b/scene/gui/text_edit.cpp
index a5c316848e..92da21af84 100644
--- a/scene/gui/text_edit.cpp
+++ b/scene/gui/text_edit.cpp
@@ -753,10 +753,18 @@ void TextEdit::_notification(int p_what) {
 				}
 			}
 
-			if (line_length_guideline) {
-				int x = xmargin_beg + (int)cache.font->get_char_size('0').width * line_length_guideline_col - cursor.x_ofs;
-				if (x > xmargin_beg && x < xmargin_end) {
-					VisualServer::get_singleton()->canvas_item_add_line(ci, Point2(x, 0), Point2(x, size.height), cache.line_length_guideline_color);
+			if (line_length_guidelines) {
+				const int hard_x = xmargin_beg + (int)cache.font->get_char_size('0').width * line_length_guideline_hard_col - cursor.x_ofs;
+				if (hard_x > xmargin_beg && hard_x < xmargin_end) {
+					VisualServer::get_singleton()->canvas_item_add_line(ci, Point2(hard_x, 0), Point2(hard_x, size.height), cache.line_length_guideline_color);
+				}
+
+				// Draw a "Soft" line length guideline, less visible than the hard line length guideline.
+				// It's usually set to a lower column compared to the hard line length guideline.
+				// Only drawn if its column differs from the hard line length guideline.
+				const int soft_x = xmargin_beg + (int)cache.font->get_char_size('0').width * line_length_guideline_soft_col - cursor.x_ofs;
+				if (hard_x != soft_x && soft_x > xmargin_beg && soft_x < xmargin_end) {
+					VisualServer::get_singleton()->canvas_item_add_line(ci, Point2(soft_x, 0), Point2(soft_x, size.height), cache.line_length_guideline_color * Color(1, 1, 1, 0.5));
 				}
 			}
 
@@ -6798,13 +6806,18 @@ bool TextEdit::is_show_line_numbers_enabled() const {
 	return line_numbers;
 }
 
-void TextEdit::set_show_line_length_guideline(bool p_show) {
-	line_length_guideline = p_show;
+void TextEdit::set_show_line_length_guidelines(bool p_show) {
+	line_length_guidelines = p_show;
+	update();
+}
+
+void TextEdit::set_line_length_guideline_soft_column(int p_column) {
+	line_length_guideline_soft_col = p_column;
 	update();
 }
 
-void TextEdit::set_line_length_guideline_column(int p_column) {
-	line_length_guideline_col = p_column;
+void TextEdit::set_line_length_guideline_hard_column(int p_column) {
+	line_length_guideline_hard_col = p_column;
 	update();
 }
 
@@ -7273,8 +7286,9 @@ TextEdit::TextEdit() {
 	tooltip_obj = NULL;
 	line_numbers = false;
 	line_numbers_zero_padded = false;
-	line_length_guideline = false;
-	line_length_guideline_col = 80;
+	line_length_guidelines = false;
+	line_length_guideline_soft_col = 80;
+	line_length_guideline_hard_col = 100;
 	draw_bookmark_gutter = false;
 	draw_breakpoint_gutter = false;
 	draw_fold_gutter = false;
diff --git a/scene/gui/text_edit.h b/scene/gui/text_edit.h
index a849f62bc5..4a4ac3392e 100644
--- a/scene/gui/text_edit.h
+++ b/scene/gui/text_edit.h
@@ -369,8 +369,9 @@ private:
 	bool undo_enabled;
 	bool line_numbers;
 	bool line_numbers_zero_padded;
-	bool line_length_guideline;
-	int line_length_guideline_col;
+	bool line_length_guidelines;
+	int line_length_guideline_soft_col;
+	int line_length_guideline_hard_col;
 	bool draw_bookmark_gutter;
 	bool draw_breakpoint_gutter;
 	int breakpoint_gutter_width;
@@ -765,8 +766,9 @@ public:
 
 	void set_line_numbers_zero_padded(bool p_zero_padded);
 
-	void set_show_line_length_guideline(bool p_show);
-	void set_line_length_guideline_column(int p_column);
+	void set_show_line_length_guidelines(bool p_show);
+	void set_line_length_guideline_soft_column(int p_column);
+	void set_line_length_guideline_hard_column(int p_column);
 
 	void set_bookmark_gutter_enabled(bool p_draw);
 	bool is_bookmark_gutter_enabled() const;