Merge pull request #112575 from Cykyrios/string-placeholder-highlight

Add string placeholder syntax highlighting

Author: Repiteo

doc/classes/EditorSettings.xml

@@ -1646,6 +1646,10 @@
 		<member name="text_editor/theme/highlighting/string_color" type="Color" setter="" getter="">
 			The script editor's color for strings (single-line and multi-line).
 		</member>
+		<member name="text_editor/theme/highlighting/string_placeholder_color" type="Color" setter="" getter="">
+			The script editor's color for string placeholders, such as [code]%s[/code] and [code]{_}[/code]. Refer to the [url=$DOCS_URL/tutorials/scripting/gdscript/gdscript_format_string.html]GDScript format strings documentation[/url] for more details.
+			[b]Note:[/b] Only the default [code]{_}[/code] placeholder patterns are highlighted for the [method String.format] method. Custom patterns still appear as plain strings.
+		</member>
 		<member name="text_editor/theme/highlighting/symbol_color" type="Color" setter="" getter="">
 			The script editor's color for operators ([code]( ) [ ] { } + - * /[/code], ...).
 		</member>

editor/settings/editor_settings.cpp

@@ -716,6 +716,7 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 		"text_editor/theme/highlighting/comment_color",
 		"text_editor/theme/highlighting/doc_comment_color",
 		"text_editor/theme/highlighting/string_color",
+		"text_editor/theme/highlighting/string_placeholder_color",
 		"text_editor/theme/highlighting/background_color",
 		"text_editor/theme/highlighting/text_color",
 		"text_editor/theme/highlighting/line_number_color",
@@ -1711,6 +1712,7 @@ HashMap<StringName, Color> EditorSettings::get_godot2_text_editor_theme() {
 	colors["text_editor/theme/highlighting/comment_color"] = Color(0.4, 0.4, 0.4);
 	colors["text_editor/theme/highlighting/doc_comment_color"] = Color(0.5, 0.6, 0.7);
 	colors["text_editor/theme/highlighting/string_color"] = Color(0.94, 0.43, 0.75);
+	colors["text_editor/theme/highlighting/string_placeholder_color"] = Color(1, 0.75, 0.4);
 	colors["text_editor/theme/highlighting/background_color"] = Color(0.13, 0.12, 0.15);
 	colors["text_editor/theme/highlighting/completion_background_color"] = Color(0.17, 0.16, 0.2);
 	colors["text_editor/theme/highlighting/completion_selected_color"] = Color(0.26, 0.26, 0.27);

editor/themes/editor_theme_manager.cpp

@@ -506,6 +506,7 @@ void EditorThemeManager::_populate_text_editor_styles(const Ref<EditorTheme> &p_
 			colors["text_editor/theme/highlighting/comment_color"] = p_config.dark_icon_and_font ? dim_color : Color(0.08, 0.08, 0.08, 0.5);
 			colors["text_editor/theme/highlighting/doc_comment_color"] = p_config.dark_icon_and_font ? Color(0.6, 0.7, 0.8, 0.8) : Color(0.15, 0.15, 0.4, 0.7);
 			colors["text_editor/theme/highlighting/string_color"] = p_config.dark_icon_and_font ? Color(1, 0.93, 0.63) : Color(0.6, 0.42, 0);
+			colors["text_editor/theme/highlighting/string_placeholder_color"] = p_config.dark_icon_and_font ? Color(1, 0.75, 0.4) : Color(0.93, 0.6, 0.33);
 
 			// Use the brightest background color on a light theme (which generally uses a negative contrast rate).
 			colors["text_editor/theme/highlighting/background_color"] = p_config.dark_icon_and_font ? p_config.dark_color_2 : p_config.dark_color_3;

modules/gdscript/editor/gdscript_highlighter.cpp

@@ -244,18 +244,66 @@ Dictionary GDScriptSyntaxHighlighter::_get_line_syntax_highlighting_impl(int p_l
 						int region_end_index = -1;
 						int end_key_length = color_regions[in_region].end_key.length();
 						const char32_t *end_key = color_regions[in_region].end_key.get_data();
+						int placeholder_end = from;
 						for (; from < line_length; from++) {
 							if (line_length - from < end_key_length) {
-								// Don't break if '\' to highlight esc chars.
-								if (str.find_char('\\', from) < 0) {
+								// Don't break if '\' to highlight escape sequences,
+								// and '%' and '{' to highlight placeholders.
+								if (str.find_char('\\', from) == -1 && str.find_char('%', from) == -1 && str.find_char('{', from) == -1) {
 									break;
 								}
 							}
 
-							if (!is_symbol(str[from])) {
+							if (!is_symbol(str[from]) && str[from] != '%') {
 								continue;
 							}
 
+							if (str[from] == '%' || str[from] == '{') {
+								int placeholder_start = from;
+								bool is_percent = str[from] == '%';
+
+								from++;
+
+								if (is_percent) {
+									if (str[from] == '%') {
+										placeholder_end = from + 1;
+									} else {
+										const String allowed_chars = "+.-*0123456789";
+										const String placeholder_types = "cdfosvxX";
+										for (int i = 0; i < line_length - from; i++) {
+											if (allowed_chars.contains_char(str[from + i]) &&
+													!placeholder_types.contains_char(str[from + i]) &&
+													(str[from + i] != end_key[0] || (str[from + i] == end_key[0] && str[from + i - 1] == '\\'))) {
+												continue;
+											}
+											if (placeholder_types.contains_char(str[from + i])) {
+												placeholder_end = from + i + 1;
+											}
+											break;
+										}
+									}
+								} else {
+									for (int i = 0; i < line_length - from; i++) {
+										if (str[from + i] != '}' && (str[from + i] != end_key[0] || (str[from + i] == end_key[0] && str[from + i - 1] == '\\'))) {
+											continue;
+										}
+										if (str[from + i] == '}') {
+											placeholder_end = from + i + 1;
+										}
+										break;
+									}
+								}
+
+								if (placeholder_end > placeholder_start) {
+									Dictionary placeholder_highlighter_info;
+									placeholder_highlighter_info["color"] = placeholder_color;
+									color_map[placeholder_start] = placeholder_highlighter_info;
+									Dictionary region_continue_highlighter_info;
+									region_continue_highlighter_info["color"] = region_color;
+									color_map[placeholder_end] = region_continue_highlighter_info;
+								}
+							}
+
 							if (str[from] == '\\') {
 								if (!color_regions[in_region].r_prefix) {
 									Dictionary escape_char_highlighter_info;
@@ -280,7 +328,7 @@ Dictionary GDScriptSyntaxHighlighter::_get_line_syntax_highlighting_impl(int p_l
 									}
 
 									Dictionary region_continue_highlighter_info;
-									region_continue_highlighter_info["color"] = region_color;
+									region_continue_highlighter_info["color"] = from < placeholder_end ? placeholder_color : region_color;
 									color_map[from + 1] = region_continue_highlighter_info;
 								}
 
@@ -315,6 +363,7 @@ Dictionary GDScriptSyntaxHighlighter::_get_line_syntax_highlighting_impl(int p_l
 					prev_is_binary_op = false;
 					continue;
 				}
+				color_map.sort(); // Prevents e.g. escape sequences from being overridden by string placeholders.
 			}
 		}
 
@@ -813,6 +862,7 @@ void GDScriptSyntaxHighlighter::_update_cache() {
 
 	/* Strings */
 	string_color = EDITOR_GET("text_editor/theme/highlighting/string_color");
+	placeholder_color = EDITOR_GET("text_editor/theme/highlighting/string_placeholder_color");
 	add_color_region(ColorRegion::TYPE_STRING, "\"", "\"", string_color);
 	add_color_region(ColorRegion::TYPE_STRING, "'", "'", string_color);
 	add_color_region(ColorRegion::TYPE_MULTILINE_STRING, "\"\"\"", "\"\"\"", string_color);

modules/gdscript/editor/gdscript_highlighter.h

@@ -89,6 +89,7 @@ class GDScriptSyntaxHighlighter : public EditorSyntaxHighlighter {
 	Color number_color;
 	Color member_variable_color;
 	Color string_color;
+	Color placeholder_color;
 	Color node_path_color;
 	Color node_ref_color;
 	Color annotation_color;