Add Duplicate Lines shortcut to CodeTextEditor

This keyboard shortcut has been made with inspiration from the VS Code keyboard shortcut editor.action.copyLinesDownAction. It duplicates all selected lines and inserts them below no matter where the caret is within the line.

2 files changed, 68 insertions, 0 deletions

diff --git a/scene/gui/code_edit.cpp b/scene/gui/code_edit.cpp
index d35d35d36d..e7a2a26a29 100644
--- a/scene/gui/code_edit.cpp
+++ b/scene/gui/code_edit.cpp
@@ -2399,6 +2399,68 @@ void CodeEdit::set_symbol_lookup_word_as_valid(bool p_valid) {
 	}
 }
 
+/* Text manipulation */
+void CodeEdit::duplicate_lines() {
+	begin_complex_operation();
+
+	Vector<int> caret_edit_order = get_caret_index_edit_order();
+	for (const int &caret_index : caret_edit_order) {
+		// The text that will be inserted. All lines in one string.
+		String insert_text;
+
+		// The new line position of the caret after the operation.
+		int new_caret_line = get_caret_line(caret_index);
+		// The new column position of the caret after the operation.
+		int new_caret_column = get_caret_column(caret_index);
+		// The caret positions of the selection. Stays -1 if there is no selection.
+		int select_from_line = -1;
+		int select_to_line = -1;
+		int select_from_column = -1;
+		int select_to_column = -1;
+		// Number of lines of the selection.
+		int select_num_lines = -1;
+
+		if (has_selection(caret_index)) {
+			select_from_line = get_selection_from_line(caret_index);
+			select_to_line = get_selection_to_line(caret_index);
+			select_from_column = get_selection_from_column(caret_index);
+			select_to_column = get_selection_to_column(caret_index);
+			select_num_lines = select_to_line - select_from_line + 1;
+
+			for (int i = select_from_line; i <= select_to_line; i++) {
+				insert_text += "\n" + get_line(i);
+				unfold_line(i);
+			}
+			new_caret_line = select_to_line + select_num_lines;
+		} else {
+			insert_text = "\n" + get_line(new_caret_line);
+			new_caret_line++;
+
+			unfold_line(get_caret_line(caret_index));
+		}
+
+		// The text will be inserted at the end of the current line.
+		set_caret_column(get_line(get_caret_line(caret_index)).length(), false, caret_index);
+
+		deselect(caret_index);
+
+		insert_text_at_caret(insert_text, caret_index);
+		set_caret_line(new_caret_line, false, true, 0, caret_index);
+		set_caret_column(new_caret_column, true, caret_index);
+
+		if (select_from_line != -1) {
+			// Advance the selection by the number of duplicated lines.
+			select_from_line += select_num_lines;
+			select_to_line += select_num_lines;
+
+			select(select_from_line, select_from_column, select_to_line, select_to_column, caret_index);
+		}
+	}
+
+	end_complex_operation();
+	queue_redraw();
+}
+
 /* Visual */
 Color CodeEdit::_get_brace_mismatch_color() const {
 	return theme_cache.brace_mismatch_color;
@@ -2598,6 +2660,9 @@ void CodeEdit::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_symbol_lookup_word_as_valid", "valid"), &CodeEdit::set_symbol_lookup_word_as_valid);
 
+	/* Text manipulation */
+	ClassDB::bind_method(D_METHOD("duplicate_lines"), &CodeEdit::duplicate_lines);
+
 	/* Inspector */
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "symbol_lookup_on_click"), "set_symbol_lookup_on_click_enabled", "is_symbol_lookup_on_click_enabled");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "line_folding"), "set_line_folding_enabled", "is_line_folding_enabled");
diff --git a/scene/gui/code_edit.h b/scene/gui/code_edit.h
index e688af2bda..97c435b52d 100644
--- a/scene/gui/code_edit.h
+++ b/scene/gui/code_edit.h
@@ -486,6 +486,9 @@ public:
 
 	void set_symbol_lookup_word_as_valid(bool p_valid);
 
+	/* Text manipulation */
+	void duplicate_lines();
+
 	CodeEdit();
 	~CodeEdit();
 };