Allow to define and load script templates per project

Previously it was only possible to create custom script templates per
editor instance which could lead to certain name collisions, but now one
can create such templates per project tailored for specific use cases.

The default path to search for custom script templates is defined in
project settings via `editor/script_templates_search_path` setting as
`res://script_templates` path, yet this can be configured per project.

Templates have at most two origins now:

1. Project-specific, defined in `ProjectSettings`, for instance:
    - res://script_templates/
2. Editor script templates, for instance:
    - %APPDATA%/Godot/script_templates/

As script templates can have the same name over different paths,
the override mechanism was also added, enabling project-specific
templates over the editor ones.

core/project_settings.cpp

@@ -1019,6 +1019,9 @@ ProjectSettings::ProjectSettings() {
 	GLOBAL_DEF("editor/search_in_file_extensions", extensions);
 	custom_prop_info["editor/search_in_file_extensions"] = PropertyInfo(Variant::POOL_STRING_ARRAY, "editor/search_in_file_extensions");
 
+	GLOBAL_DEF("editor/script_templates_search_path", "res://script_templates");
+	custom_prop_info["editor/script_templates_search_path"] = PropertyInfo(Variant::STRING, "editor/script_templates_search_path", PROPERTY_HINT_DIR);
+
 	action = Dictionary();
 	action["deadzone"] = Variant(0.5f);
 	events = Array();

editor/editor_settings.cpp

@@ -1209,6 +1209,11 @@ String EditorSettings::get_script_templates_dir() const {
 	return get_settings_dir().plus_file("script_templates");
 }
 
+String EditorSettings::get_project_script_templates_dir() const {
+
+	return ProjectSettings::get_singleton()->get("editor/script_templates_search_path");
+}
+
 // Cache directory
 
 String EditorSettings::get_cache_dir() const {
@@ -1429,10 +1434,14 @@ bool EditorSettings::is_default_text_editor_theme() {
 	return _is_default_text_editor_theme(p_file.get_file().to_lower());
 }
 
-Vector<String> EditorSettings::get_script_templates(const String &p_extension) {
+Vector<String> EditorSettings::get_script_templates(const String &p_extension, const String &p_custom_path) {
 
 	Vector<String> templates;
-	DirAccess *d = DirAccess::open(get_script_templates_dir());
+	String template_dir = get_script_templates_dir();
+	if (!p_custom_path.empty()) {
+		template_dir = p_custom_path;
+	}
+	DirAccess *d = DirAccess::open(template_dir);
 	if (d) {
 		d->list_dir_begin();
 		String file = d->get_next();

editor/editor_settings.h

@@ -166,6 +166,7 @@ public:
 	String get_project_settings_dir() const;
 	String get_text_editor_themes_dir() const;
 	String get_script_templates_dir() const;
+	String get_project_script_templates_dir() const;
 	String get_cache_dir() const;
 	String get_feature_profiles_dir() const;
 
@@ -187,7 +188,7 @@ public:
 	bool save_text_editor_theme_as(String p_file);
 	bool is_default_text_editor_theme();
 
-	Vector<String> get_script_templates(const String &p_extension);
+	Vector<String> get_script_templates(const String &p_extension, const String &p_custom_path = String());
 	String get_editor_layouts_config() const;
 
 	void add_shortcut(const String &p_name, Ref<ShortCut> &p_shortcut);

editor/script_create_dialog.cpp

@@ -34,6 +34,7 @@
 #include "core/os/file_access.h"
 #include "core/project_settings.h"
 #include "core/script_language.h"
+#include "core/string_builder.h"
 #include "editor/create_dialog.h"
 #include "editor/editor_node.h"
 #include "editor/editor_scale.h"
@@ -238,16 +239,22 @@ void ScriptCreateDialog::_parent_name_changed(const String &p_parent) {
 
 void ScriptCreateDialog::_template_changed(int p_template) {
 
-	String selected_template = p_template == 0 ? "" : template_menu->get_item_text(template_menu->get_selected());
+	String selected_template = p_template == 0 ? "" : template_menu->get_item_text(p_template);
 	EditorSettings::get_singleton()->set_project_metadata("script_setup", "last_selected_template", selected_template);
 	if (p_template == 0) {
 		//default
 		script_template = "";
 		return;
 	}
-	String ext = ScriptServer::get_language(language_menu->get_selected())->get_extension();
-	String name = template_list[p_template - 1] + "." + ext;
-	script_template = EditorSettings::get_singleton()->get_script_templates_dir().plus_file(name);
+	int selected_id = template_menu->get_selected_id();
+
+	for (int i = 0; i < template_list.size(); i++) {
+		const ScriptTemplateInfo &sinfo = template_list[i];
+		if (sinfo.id == selected_id) {
+			script_template = sinfo.dir.plus_file(sinfo.name + "." + sinfo.extension);
+			break;
+		}
+	}
 }
 
 void ScriptCreateDialog::ok_pressed() {
@@ -368,23 +375,77 @@ void ScriptCreateDialog::_lang_changed(int l) {
 	bool use_templates = language->is_using_templates();
 	template_menu->set_disabled(!use_templates);
 	template_menu->clear();
-	if (use_templates) {
 
-		template_list = EditorSettings::get_singleton()->get_script_templates(language->get_extension());
+	if (use_templates) {
+		_update_script_templates(language->get_extension());
 
 		String last_lang = EditorSettings::get_singleton()->get_project_metadata("script_setup", "last_selected_language", "");
 		String last_template = EditorSettings::get_singleton()->get_project_metadata("script_setup", "last_selected_template", "");
 
 		template_menu->add_item(TTR("Default"));
+
+		ScriptTemplateInfo *templates = template_list.ptrw();
+
+		Vector<String> origin_names;
+		origin_names.push_back(TTR("Project"));
+		origin_names.push_back(TTR("Editor"));
+		int cur_origin = -1;
+
+		// Populate script template items previously sorted and now grouped by origin
 		for (int i = 0; i < template_list.size(); i++) {
-			String s = template_list[i].capitalize();
-			template_menu->add_item(s);
-			if (language_menu->get_item_text(language_menu->get_selected()) == last_lang && last_template == s) {
-				template_menu->select(i + 1);
+
+			if (int(templates[i].origin) != cur_origin) {
+				template_menu->add_separator();
+
+				String origin_name = origin_names[templates[i].origin];
+
+				int last_index = template_menu->get_item_count() - 1;
+				template_menu->set_item_text(last_index, origin_name);
+
+				cur_origin = templates[i].origin;
+			}
+			String item_name = templates[i].name.capitalize();
+			template_menu->add_item(item_name);
+
+			int new_id = template_menu->get_item_count() - 1;
+			templates[i].id = new_id;
+		}
+		// Disable overridden
+		for (Map<String, Vector<int> >::Element *E = template_overrides.front(); E; E = E->next()) {
+			const Vector<int> &overrides = E->get();
+
+			if (overrides.size() == 1) {
+				continue; // doesn't override anything
+			}
+			const ScriptTemplateInfo &extended = template_list[overrides[0]];
+
+			StringBuilder override_info;
+			override_info += TTR("Overrides");
+			override_info += ": ";
+
+			for (int i = 1; i < overrides.size(); i++) {
+				const ScriptTemplateInfo &overridden = template_list[overrides[i]];
+
+				int disable_index = template_menu->get_item_index(overridden.id);
+				template_menu->set_item_disabled(disable_index, true);
+
+				override_info += origin_names[overridden.origin];
+				if (i < overrides.size() - 1) {
+					override_info += ", ";
+				}
+			}
+			template_menu->set_item_icon(extended.id, get_icon("Override", "EditorIcons"));
+			template_menu->get_popup()->set_item_tooltip(extended.id, override_info.as_string());
+		}
+		// Reselect last selected template
+		for (int i = 0; i < template_menu->get_item_count(); i++) {
+			const String &ti = template_menu->get_item_text(i);
+			if (language_menu->get_item_text(language_menu->get_selected()) == last_lang && last_template == ti) {
+				template_menu->select(i);
+				break;
 			}
 		}
 	} else {
-
 		template_menu->add_item(TTR("N/A"));
 		script_template = "";
 	}
@@ -396,6 +457,41 @@ void ScriptCreateDialog::_lang_changed(int l) {
 	_update_dialog();
 }
 
+void ScriptCreateDialog::_update_script_templates(const String &p_extension) {
+
+	template_list.clear();
+	template_overrides.clear();
+
+	Vector<String> dirs;
+
+	// Ordered from local to global for correct override mechanism
+	dirs.push_back(EditorSettings::get_singleton()->get_project_script_templates_dir());
+	dirs.push_back(EditorSettings::get_singleton()->get_script_templates_dir());
+
+	for (int i = 0; i < dirs.size(); i++) {
+
+		Vector<String> list = EditorSettings::get_singleton()->get_script_templates(p_extension, dirs[i]);
+
+		for (int j = 0; j < list.size(); j++) {
+			ScriptTemplateInfo sinfo;
+			sinfo.origin = ScriptOrigin(i);
+			sinfo.dir = dirs[i];
+			sinfo.name = list[j];
+			sinfo.extension = p_extension;
+			template_list.push_back(sinfo);
+
+			if (!template_overrides.has(sinfo.name)) {
+				Vector<int> overrides;
+				overrides.push_back(template_list.size() - 1); // first one
+				template_overrides.insert(sinfo.name, overrides);
+			} else {
+				Vector<int> &overrides = template_overrides[sinfo.name];
+				overrides.push_back(template_list.size() - 1);
+			}
+		}
+	}
+}
+
 void ScriptCreateDialog::_built_in_pressed() {
 
 	if (internal->is_pressed()) {

editor/script_create_dialog.h

@@ -78,8 +78,25 @@ class ScriptCreateDialog : public ConfirmationDialog {
 	int current_language;
 	int default_language;
 	bool re_check_path;
+
+	enum ScriptOrigin {
+		SCRIPT_ORIGIN_PROJECT,
+		SCRIPT_ORIGIN_EDITOR,
+	};
+	struct ScriptTemplateInfo {
+		int id;
+		ScriptOrigin origin;
+		String dir;
+		String name;
+		String extension;
+	};
+
 	String script_template;
-	Vector<String> template_list;
+	Vector<ScriptTemplateInfo> template_list;
+	Map<String, Vector<int> > template_overrides; // name : indices
+
+	void _update_script_templates(const String &p_extension);
+
 	String base_type;
 
 	void _path_hbox_sorted();