Added multi level undo redo to line edit

2 files changed, 88 insertions, 31 deletions

diff --git a/scene/gui/line_edit.cpp b/scene/gui/line_edit.cpp
index ed8eff436c..f57f58c18d 100644
--- a/scene/gui/line_edit.cpp
+++ b/scene/gui/line_edit.cpp
@@ -161,13 +161,14 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 
 				} break;
 
-				case (KEY_Z): { // Simple One level undo
-
+				case (KEY_Z): { // undo / redo
 					if (editable) {
-
-						undo();
+						if (k->get_shift()) {
+							redo();
+						} else {
+							undo();
+						}
 					}
-
 				} break;
 
 				case (KEY_U): { // Delete from start to cursor
@@ -175,7 +176,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 					if (editable) {
 
 						selection_clear();
-						undo_text = text;
 						text = text.substr(cursor_pos, text.length() - cursor_pos);
 
 						Ref<Font> font = get_font("font");
@@ -205,7 +205,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 					if (editable) {
 
 						selection_clear();
-						undo_text = text;
 						text = text.substr(0, cursor_pos);
 						_text_changed();
 					}
@@ -245,7 +244,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 						break;
 
 					if (selection.enabled) {
-						undo_text = text;
 						selection_delete();
 						break;
 					}
@@ -276,7 +274,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 						set_cursor_position(cc);
 
 					} else {
-						undo_text = text;
 						delete_char();
 					}
 
@@ -382,7 +379,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 					}
 
 					if (selection.enabled) {
-						undo_text = text;
 						selection_delete();
 						break;
 					}
@@ -417,7 +413,6 @@ void LineEdit::_gui_input(Ref<InputEvent> p_event) {
 						delete_text(cursor_pos, cc);
 
 					} else {
-						undo_text = text;
 						set_cursor_position(cursor_pos + 1);
 						delete_char();
 					}
@@ -778,7 +773,6 @@ void LineEdit::copy_text() {
 void LineEdit::cut_text() {
 
 	if (selection.enabled) {
-		undo_text = text;
 		OS::get_singleton()->set_clipboard(text.substr(selection.begin, selection.end - selection.begin));
 		selection_delete();
 	}
@@ -798,23 +792,33 @@ void LineEdit::paste_text() {
 }
 
 void LineEdit::undo() {
-
-	int old_cursor_pos = cursor_pos;
-	text = undo_text;
-
-	Ref<Font> font = get_font("font");
-
-	cached_width = 0;
-	for (int i = 0; i < text.length(); i++)
-		cached_width += font->get_char_size(text[i]).width;
-
-	if (old_cursor_pos > text.length()) {
-		set_cursor_position(text.length());
-	} else {
-		set_cursor_position(old_cursor_pos);
+	if (undo_stack_pos == NULL) {
+		if (undo_stack.size() <= 1) {
+			return;
+		}
+		undo_stack_pos = undo_stack.back();
+	} else if (undo_stack_pos == undo_stack.front()) {
+		return;
 	}
+	undo_stack_pos = undo_stack_pos->prev();
+	TextOperation op = undo_stack_pos->get();
+	text = op.text;
+	set_cursor_position(op.cursor_pos);
+	_emit_text_change();
+}
 
-	_text_changed();
+void LineEdit::redo() {
+	if (undo_stack_pos == NULL) {
+		return;
+	}
+	if (undo_stack_pos == undo_stack.back()) {
+		return;
+	}
+	undo_stack_pos = undo_stack_pos->next();
+	TextOperation op = undo_stack_pos->get();
+	text = op.text;
+	set_cursor_position(op.cursor_pos);
+	_emit_text_change();
 }
 
 void LineEdit::shift_selection_check_pre(bool p_shift) {
@@ -947,8 +951,6 @@ void LineEdit::delete_char() {
 
 void LineEdit::delete_text(int p_from_column, int p_to_column) {
 
-	undo_text = text;
-
 	if (text.size() > 0) {
 		Ref<Font> font = get_font("font");
 		if (font != NULL) {
@@ -1086,8 +1088,6 @@ void LineEdit::append_at_cursor(String p_text) {
 
 	if ((max_length <= 0) || (text.length() + p_text.length() <= max_length)) {
 
-		undo_text = text;
-
 		Ref<Font> font = get_font("font");
 		if (font != NULL) {
 			for (int i = 0; i < p_text.length(); i++)
@@ -1105,6 +1105,7 @@ void LineEdit::append_at_cursor(String p_text) {
 
 void LineEdit::clear_internal() {
 
+	_clear_undo_stack();
 	cached_width = 0;
 	cursor_pos = 0;
 	window_pos = 0;
@@ -1275,6 +1276,11 @@ void LineEdit::menu_option(int p_option) {
 				undo();
 			}
 		} break;
+		case MENU_REDO: {
+			if (editable) {
+				redo();
+			}
+		}
 	}
 }
 
@@ -1312,10 +1318,43 @@ void LineEdit::_text_changed() {
 	if (expand_to_text_length)
 		minimum_size_changed();
 
+	_emit_text_change();
+	_clear_redo();
+}
+
+void LineEdit::_emit_text_change() {
 	emit_signal("text_changed", text);
 	_change_notify("text");
 }
 
+void LineEdit::_clear_redo() {
+	_create_undo_state();
+	if (undo_stack_pos == NULL) {
+		return;
+	}
+
+	undo_stack_pos = undo_stack_pos->next();
+	while (undo_stack_pos) {
+		List<TextOperation>::Element *elem = undo_stack_pos;
+		undo_stack_pos = undo_stack_pos->next();
+		undo_stack.erase(elem);
+	}
+	_create_undo_state();
+}
+
+void LineEdit::_clear_undo_stack() {
+	undo_stack.clear();
+	undo_stack_pos = NULL;
+	_create_undo_state();
+}
+
+void LineEdit::_create_undo_state() {
+	TextOperation op;
+	op.text = text;
+	op.cursor_pos = cursor_pos;
+	undo_stack.push_back(op);
+}
+
 void LineEdit::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("_toggle_draw_caret"), &LineEdit::_toggle_draw_caret);
@@ -1369,6 +1408,7 @@ void LineEdit::_bind_methods() {
 	BIND_ENUM_CONSTANT(MENU_CLEAR);
 	BIND_ENUM_CONSTANT(MENU_SELECT_ALL);
 	BIND_ENUM_CONSTANT(MENU_UNDO);
+	BIND_ENUM_CONSTANT(MENU_REDO);
 	BIND_ENUM_CONSTANT(MENU_MAX);
 
 	ADD_PROPERTYNZ(PropertyInfo(Variant::STRING, "text"), "set_text", "get_text");
@@ -1388,6 +1428,8 @@ void LineEdit::_bind_methods() {
 
 LineEdit::LineEdit() {
 
+	undo_stack_pos = NULL;
+	_create_undo_state();
 	align = ALIGN_LEFT;
 	cached_width = 0;
 	cursor_pos = 0;
@@ -1421,6 +1463,7 @@ LineEdit::LineEdit() {
 	menu->add_item(TTR("Clear"), MENU_CLEAR);
 	menu->add_separator();
 	menu->add_item(TTR("Undo"), MENU_UNDO, KEY_MASK_CMD | KEY_Z);
+	menu->add_item(TTR("Redo"), MENU_REDO, KEY_MASK_CMD | KEY_MASK_SHIFT | KEY_Z);
 	menu->connect("id_pressed", this, "menu_option");
 	expand_to_text_length = false;
 }
diff --git a/scene/gui/line_edit.h b/scene/gui/line_edit.h
index 661f9b60b9..bece29a37d 100644
--- a/scene/gui/line_edit.h
+++ b/scene/gui/line_edit.h
@@ -56,6 +56,7 @@ public:
 		MENU_CLEAR,
 		MENU_SELECT_ALL,
 		MENU_UNDO,
+		MENU_REDO,
 		MENU_MAX
 
 	};
@@ -92,10 +93,22 @@ private:
 		bool drag_attempt;
 	} selection;
 
+	struct TextOperation {
+		int cursor_pos;
+		String text;
+	};
+	List<TextOperation> undo_stack;
+	List<TextOperation>::Element *undo_stack_pos;
+
+	void _clear_undo_stack();
+	void _clear_redo();
+	void _create_undo_state();
+
 	Timer *caret_blink_timer;
 
 	static void _ime_text_callback(void *p_self, String p_text, Point2 p_selection);
 	void _text_changed();
+	void _emit_text_change();
 	bool expand_to_text_length;
 
 	bool caret_blink_enabled;
@@ -166,6 +179,7 @@ public:
 	void cut_text();
 	void paste_text();
 	void undo();
+	void redo();
 
 	void set_editable(bool p_editable);
 	bool is_editable() const;