Godot 4 源码分析 - 获取脚本

获取属性列表

今天搂草打兔，取得了脚本内容

因为已能取得属性值，那就再进一步，取得属性名列表

if (SameText(drGet.propertyName, "propertyNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	List *p_list = new List;
	bool p_reversed = true;
	destObject->get_property_list(p_list, p_reversed);
	cofs << "OK";
	for (List::Iterator it = p_list->begin(); it != p_list->end(); ++it) {
		Variant value = destObject->get(it->name);
		cofs << str_format(U"%s[%s] = %s", it->name.utf8().get_data(),
			VarType2String(it->type).c_str(), value.operator String().utf8().get_data());
	}
	delete p_list;
	cofs << GetObjectHint(destObject);	
}

相应地，可以取得函数名列表、子对象列表

if (SameText(drGet.propertyName, "methodNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	List *p_list = new List;
	destObject->get_method_list(p_list);
	cofs << "OK";
	for (List::Iterator it = p_list->begin(); it != p_list->end(); ++it) {
		String content = it->name + "(";
		for (List::Iterator iter = it->arguments.begin(); iter != it->arguments.end(); ++iter) {
			if (iter != it->arguments.begin())
				content += ", ";
			content += str_format("%s %s", VarType2String(iter->type).c_str(), iter->name.utf8().get_data()).c_str();
		}
		content += ")";
		cofs << content;
	}
	delete p_list;
	cofs << GetObjectHint(destObject);	
}
if (SameText(drGet.propertyName, "childNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	if (Node *node = dynamic_cast(destObject)) {
		int count = node->get_child_count();
		for (int i = 0; i < count; ++i) {
			Node *subNode = node->get_child(i);
			cofs << str_format(U"%s[%s]", subNode->get_name().operator String().utf8().get_data(),
					subNode->get_class_name().operator String().utf8().get_data());
		}
		cofs << GetObjectHint(destObject);
	}
}

其中，获取对象信息(GetObjectHint)是期望能显示对象的一些相应信息

#define CAST(T, ptr) dynamic_cast(static_cast(ptr))
std::string GetObjectHint(void* ptr) {
	String result = U"未处理对象";
	if (Object *object = CAST(Object *, ptr)) {
		result = str_format(U" ---==== [%s]类型对象 0X%08x ====---", object->get_class_name().operator String().utf8().get_data(), int(ptr));
		if (Node *node = CAST(Node *, ptr)) {
			String path = node->get_name();
			Node *parent = node->get_parent();
			while (parent) {
				path = parent->get_name().operator String() + U"." + path;
				parent = parent->get_parent();
			}
			result += U"：\n\t\t\t\t\t\t路径信息：";
			result += path + U"\n\t\t\t\t\t\t子对象信息：";
			int count = node->get_child_count();
			for (int i = 0; i < count; ++i) {
				Node *subNode = node->get_child(i);
				result += str_format(U" %s[%s]", String2std(subNode->get_name().operator String()).c_str(),
						String2std(subNode->get_class_name().operator String()).c_str());
			}
		}
	} else if (Engine *engine = CAST(Engine *, ptr)) {
		result = str_format(U"[Engine]类型对象 0X%08x", int(ptr));
	}
	return String2std(result);
}

测试一下，取得根节点(Book)的所有属性名： Book.propertyNames

261. 15:58:53:368 > 【主线程】 > [Pipe.发送] > 发送数据中内容[DrGraph.78: Request - wait 1000 ms]: 
	[int]类型 > 值 = 2
	[UnicodeString]类型 > 值 = Book
	[UnicodeString]类型 > 值 = propertyNames
262. 15:58:53:614 > 【主线程】 > [Pipe.Read] > 发送数据[DrGraph.78: Request - wait 1000 ms]成功返回 2396 字节... > PIPE响应中内容[godot -> DrGraph.78: Response - no return]: 
	[int]类型 > 值 = 3
	[UnicodeString]类型 > 值 = OK
	[UnicodeString]类型 > 值 = book.gd[NIL] = 
	[UnicodeString]类型 > 值 = singlePage[BOOL] = false
	[UnicodeString]类型 > 值 = middleBarWidth[INT] = 0
	[UnicodeString]类型 > 值 = shader_rect[OBJECT] = ShaderRect:
	[UnicodeString]类型 > 值 = currentPageMode[BOOL] = false
	[UnicodeString]类型 > 值 = currentAreaType[INT] = 5
	[UnicodeString]类型 > 值 = triggleAreaMoment[INT] = 745493
	[UnicodeString]类型 > 值 = currentPageIndex[INT] = 30
	[UnicodeString]类型 > 值 = pageCount[INT] = 100
	[UnicodeString]类型 > 值 = pageImgPath[STRING] = res://Pages/
	[UnicodeString]类型 > 值 = leftMouseDownMoment[INT] = 0
	[UnicodeString]类型 > 值 = underAutoTurnPage[BOOL] = false
	[UnicodeString]类型 > 值 = leftMouseDownPos[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = dllStream[OBJECT] = 
	[UnicodeString]类型 > 值 = AutoTurnObject[OBJECT] = 
	[UnicodeString]类型 > 值 = Node2D[NIL] = 
	[UnicodeString]类型 > 值 = Transform[NIL] = 
	[UnicodeString]类型 > 值 = position[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = rotation[FLOAT] = 0
	[UnicodeString]类型 > 值 = rotation_degrees[FLOAT] = 0
	[UnicodeString]类型 > 值 = scale[VECTOR2] = (1, 1)
	[UnicodeString]类型 > 值 = skew[FLOAT] = 0
	[UnicodeString]类型 > 值 = transform[TRANSFORM2D] = [X: (1, 0), Y: (0, 1), O: (0, 0)]
	[UnicodeString]类型 > 值 = global_position[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = global_rotation[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_rotation_degrees[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_scale[VECTOR2] = (1, 1)
	[UnicodeString]类型 > 值 = global_skew[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_transform[TRANSFORM2D] = [X: (1, 0), Y: (0, 1), O: (0, 0)]
	[UnicodeString]类型 > 值 = CanvasItem[NIL] = 
	[UnicodeString]类型 > 值 = Visibility[NIL] = 
	[UnicodeString]类型 > 值 = visible[BOOL] = true
	[UnicodeString]类型 > 值 = modulate[COLOR] = (1, 1, 1, 1)
	[UnicodeString]类型 > 值 = self_modulate[COLOR] = (1, 1, 1, 1)
	[UnicodeString]类型 > 值 = show_behind_parent[BOOL] = false
	[UnicodeString]类型 > 值 = top_level[BOOL] = false
	[UnicodeString]类型 > 值 = clip_children[INT] = 0
	[UnicodeString]类型 > 值 = light_mask[INT] = 1
	[UnicodeString]类型 > 值 = visibility_layer[INT] = 1
	[UnicodeString]类型 > 值 = Ordering[NIL] = 
	[UnicodeString]类型 > 值 = z_index[INT] = 0
	[UnicodeString]类型 > 值 = z_as_relative[BOOL] = true
	[UnicodeString]类型 > 值 = y_sort_enabled[BOOL] = false
	[UnicodeString]类型 > 值 = Texture[NIL] = 
	[UnicodeString]类型 > 值 = texture_filter[INT] = 0
	[UnicodeString]类型 > 值 = texture_repeat[INT] = 0
	[UnicodeString]类型 > 值 = Material[NIL] = 
	[UnicodeString]类型 > 值 = material[OBJECT] = 
	[UnicodeString]类型 > 值 = use_parent_material[BOOL] = false
	[UnicodeString]类型 > 值 = Node[NIL] = 
	[UnicodeString]类型 > 值 = _import_path[NODE_PATH] = 
	[UnicodeString]类型 > 值 = name[STRING_NAME] = Book
	[UnicodeString]类型 > 值 = unique_name_in_owner[BOOL] = false
	[UnicodeString]类型 > 值 = scene_file_path[STRING] = res://book.tscn
	[UnicodeString]类型 > 值 = owner[OBJECT] = 
	[UnicodeString]类型 > 值 = multiplayer[OBJECT] = 
	[UnicodeString]类型 > 值 = Process[NIL] = 
	[UnicodeString]类型 > 值 = process_mode[INT] = 0
	[UnicodeString]类型 > 值 = process_priority[INT] = 0
	[UnicodeString]类型 > 值 = Editor Description[NIL] = 
	[UnicodeString]类型 > 值 = editor_description[STRING] = 
	[UnicodeString]类型 > 值 = script[OBJECT] = 
	[UnicodeString]类型 > 值 =  ---==== [Node2D]类型对象 0X4d7c5600 ====---：
						路径信息：root.Book
						子对象信息： LeftPage[Sprite2D] RightPage[Sprite2D] ShaderRect[ColorRect] LeftButton[Button] RightButton[Button] AutoTurnTimer[Timer] DrGraph[Node]

看到script属性：[UnicodeString]类型 > 值 = script[OBJECT] =

那就再取得Book.script.propertyNames来看下，结果发现返回了脚本内容

仔细一看，是属性 script/source 的值。那就单独看一下该属性： Book.script.script/source，果然得到相应脚本内容

倒是有点意思，属性名称为 script/source

源码分析

在源码中查找 script/source，在gdscript.cpp中有两处，应该是这个

void GDScript::_get_property_list(List *p_properties) const {
	p_properties->push_back(PropertyInfo(Variant::STRING, "script/source", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL));
}

原来GDScript对象返回属性名称列表时，就添加了这么一个玩意

这样取属性名称列表时，就有一个名为 script/source 的属性

下来看看get该属性时具体有哪些动作，调试跟进

Variant Object::get(const StringName &p_name, bool *r_valid) const {
	Variant ret;

	if (script_instance) {
		if (script_instance->get(p_name, ret)) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}
	}
	if (_extension && _extension->get) {
// C style pointer casts should never trigger a compiler warning because the risk is assumed by the user, so GCC should keep quiet about it.
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wignored-qualifiers"
#endif

		if (_extension->get(_extension_instance, (const GDExtensionStringNamePtr)&p_name, (GDExtensionVariantPtr)&ret)) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic pop
#endif
	}

	// Try built-in getter.
	{
		if (ClassDB::get_property(const_cast