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.traits;
17 import godot.core;
18 import godot.c;
19 import godot.d.bind;
20 import godot.d.reference;
21 import godot.globalenums;
22 import godot.object;
23 import godot.classdb;
24 import godot.reference;
25 /**
26 Reference to a function in an object.
27 
28 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.
29 However, by creating a $(D FuncRef) using the $(D @GDScript.funcref) function, a reference to a function in a given object can be created, passed around and called.
30 */
31 @GodotBaseClass struct FuncRef
32 {
33 	package(godot) enum string _GODOT_internal_name = "FuncRef";
34 public:
35 @nogc nothrow:
36 	union { /** */ godot_object _godot_object; /** */ Reference _GODOT_base; }
37 	alias _GODOT_base this;
38 	alias BaseClasses = AliasSeq!(typeof(_GODOT_base), typeof(_GODOT_base).BaseClasses);
39 	package(godot) __gshared bool _classBindingInitialized = false;
40 	package(godot) static struct GDNativeClassBinding
41 	{
42 		__gshared:
43 		@GodotName("call_func") GodotMethod!(Variant, GodotVarArgs) callFunc;
44 		@GodotName("call_funcv") GodotMethod!(Variant, Array) callFuncv;
45 		@GodotName("get_function") GodotMethod!(String) getFunction;
46 		@GodotName("is_valid") GodotMethod!(bool) isValid;
47 		@GodotName("set_function") GodotMethod!(void, String) setFunction;
48 		@GodotName("set_instance") GodotMethod!(void, GodotObject) setInstance;
49 	}
50 	/// 
51 	pragma(inline, true) bool opEquals(in FuncRef other) const
52 	{ return _godot_object.ptr is other._godot_object.ptr; }
53 	/// 
54 	pragma(inline, true) typeof(null) opAssign(typeof(null) n)
55 	{ _godot_object.ptr = n; return null; }
56 	/// 
57 	pragma(inline, true) bool opEquals(typeof(null) n) const
58 	{ return _godot_object.ptr is n; }
59 	/// 
60 	size_t toHash() const @trusted { return cast(size_t)_godot_object.ptr; }
61 	mixin baseCasts;
62 	/// Construct a new instance of FuncRef.
63 	/// Note: use `memnew!FuncRef` instead.
64 	static FuncRef _new()
65 	{
66 		static godot_class_constructor constructor;
67 		if(constructor is null) constructor = _godot_api.godot_get_class_constructor("FuncRef");
68 		if(constructor is null) return typeof(this).init;
69 		return cast(FuncRef)(constructor());
70 	}
71 	@disable new(size_t s);
72 	/**
73 	Calls the referenced function previously set in $(D _function) or $(D @GDScript.funcref).
74 	*/
75 	Variant callFunc(VarArgs...)(VarArgs varArgs)
76 	{
77 		Array _GODOT_args = Array.make();
78 		foreach(vai, VA; VarArgs)
79 		{
80 			_GODOT_args.append(varArgs[vai]);
81 		}
82 		String _GODOT_method_name = String("call_func");
83 		return this.callv(_GODOT_method_name, _GODOT_args);
84 	}
85 	/**
86 	Calls the referenced function previously set in $(D _function) or $(D @GDScript.funcref). Contrarily to $(D callFunc), this method does not support a variable number of arguments but expects all parameters to be passed via a single $(D Array).
87 	*/
88 	Variant callFuncv(in Array arg_array)
89 	{
90 		checkClassBinding!(typeof(this))();
91 		return ptrcall!(Variant)(GDNativeClassBinding.callFuncv, _godot_object, arg_array);
92 	}
93 	/**
94 	
95 	*/
96 	String getFunction()
97 	{
98 		checkClassBinding!(typeof(this))();
99 		return ptrcall!(String)(GDNativeClassBinding.getFunction, _godot_object);
100 	}
101 	/**
102 	Returns whether the object still exists and has the function assigned.
103 	*/
104 	bool isValid() const
105 	{
106 		checkClassBinding!(typeof(this))();
107 		return ptrcall!(bool)(GDNativeClassBinding.isValid, _godot_object);
108 	}
109 	/**
110 	
111 	*/
112 	void setFunction(in String name)
113 	{
114 		checkClassBinding!(typeof(this))();
115 		ptrcall!(void)(GDNativeClassBinding.setFunction, _godot_object, name);
116 	}
117 	/**
118 	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).
119 	*/
120 	void setInstance(GodotObject instance)
121 	{
122 		checkClassBinding!(typeof(this))();
123 		ptrcall!(void)(GDNativeClassBinding.setInstance, _godot_object, instance);
124 	}
125 	/**
126 	The name of the referenced function.
127 	*/
128 	@property String _function()
129 	{
130 		return getFunction();
131 	}
132 	/// ditto
133 	@property void _function(String v)
134 	{
135 		setFunction(v);
136 	}
137 }