godot.funcref source code

1 /**
2 Reference to a function in an object.
3 
4 Copyright:
5 Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.  
6 Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)  
7 Copyright (c) 2017-2018 Godot-D contributors  
8 
9 License: $(LINK2 https://opensource.org/licenses/MIT, MIT License)
10 
11 
12 */
13 module godot.funcref;
14 import std.meta : AliasSeq, staticIndexOf;
15 import std.traits : Unqual;
16 import godot.d.meta;
17 import godot.core;
18 import godot.c;
19 import godot.d.bind;
20 import godot.d.reference;
21 import godot.object;
22 import godot.classdb;
23 import godot.reference;
24 /**
25 Reference to a function in an object.
26 
27 In GDScript, functions are not $(I first-class objects). This means it is impossible to store them directly as variables, return them from another function, or pass them as arguments.
28 However, by creating a `FuncRef` using the $(D @GDScript.funcref) function, a reference to a function in a given object can be created, passed around and called.
29 */
30 @GodotBaseClass struct FuncRef
31 {
32 	enum string _GODOT_internal_name = "FuncRef";
33 public:
34 @nogc nothrow:
35 	union { godot_object _godot_object; Reference _GODOT_base; }
36 	alias _GODOT_base this;
37 	alias BaseClasses = AliasSeq!(typeof(_GODOT_base), typeof(_GODOT_base).BaseClasses);
38 	package(godot) __gshared bool _classBindingInitialized = false;
39 	package(godot) static struct _classBinding
40 	{
41 		__gshared:
42 		@GodotName("call_func") GodotMethod!(Variant, GodotVarArgs) callFunc;
43 		@GodotName("set_instance") GodotMethod!(void, GodotObject) setInstance;
44 		@GodotName("set_function") GodotMethod!(void, String) setFunction;
45 	}
46 	bool opEquals(in FuncRef other) const { return _godot_object.ptr is other._godot_object.ptr; }
47 	FuncRef opAssign(T : typeof(null))(T n) { _godot_object.ptr = null; }
48 	bool opEquals(typeof(null) n) const { return _godot_object.ptr is null; }
49 	mixin baseCasts;
50 	static FuncRef _new()
51 	{
52 		static godot_class_constructor constructor;
53 		if(constructor is null) constructor = _godot_api.godot_get_class_constructor("FuncRef");
54 		if(constructor is null) return typeof(this).init;
55 		return cast(FuncRef)(constructor());
56 	}
57 	@disable new(size_t s);
58 	/**
59 	Calls the referenced function previously set by $(D setFunction) or $(D @GDScript.funcref).
60 	*/
61 	Variant callFunc(VarArgs...)(VarArgs varArgs)
62 	{
63 		Array _GODOT_args = Array.empty_array;
64 		foreach(vai, VA; VarArgs)
65 		{
66 			_GODOT_args.append(varArgs[vai]);
67 		}
68 		String _GODOT_method_name = String("call_func");
69 		return this.callv(_GODOT_method_name, _GODOT_args);
70 	}
71 	/**
72 	The object containing the referenced function. This object must be of a type actually inheriting from $(D GodotObject), not a built-in type such as $(D long), $(D Vector2) or $(D Dictionary).
73 	*/
74 	void setInstance(GodotObject instance)
75 	{
76 		checkClassBinding!(typeof(this))();
77 		ptrcall!(void)(_classBinding.setInstance, _godot_object, instance);
78 	}
79 	/**
80 	The name of the referenced function to call on the object, without parentheses or any parameters.
81 	*/
82 	void setFunction(StringArg0)(in StringArg0 name)
83 	{
84 		checkClassBinding!(typeof(this))();
85 		ptrcall!(void)(_classBinding.setFunction, _godot_object, name);
86 	}
87 }