godot/core/variant/callable.h
K. S. Ernest (iFire) Lee 9ddebc0c22 Add a const call mode to Object, Variant and Script.
For this to work safely (user not call queue_free or something in the expression), a const call mode was added to Object and Variant (and optionally Script).

This mode ensures only const functions can be called, making it safe to use from the editor.

Co-Authored-By: reduz <reduzio@gmail.com>
2022-06-27 13:33:06 -07:00

181 lines
6.9 KiB
C++

/*************************************************************************/
/* callable.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef CALLABLE_H
#define CALLABLE_H
#include "core/object/object_id.h"
#include "core/string/string_name.h"
#include "core/templates/list.h"
class Object;
class Variant;
class CallableCustom;
// This is an abstraction of things that can be called.
// It is used for signals and other cases where efficient calling of functions
// is required. It is designed for the standard case (object and method)
// but can be optimized or customized.
// Enforce 16 bytes with `alignas` to avoid arch-specific alignment issues on x86 vs armv7.
class Callable {
alignas(8) StringName method;
union {
uint64_t object = 0;
CallableCustom *custom;
};
public:
struct CallError {
enum Error {
CALL_OK,
CALL_ERROR_INVALID_METHOD,
CALL_ERROR_INVALID_ARGUMENT, // expected is variant type
CALL_ERROR_TOO_MANY_ARGUMENTS, // expected is number of arguments
CALL_ERROR_TOO_FEW_ARGUMENTS, // expected is number of arguments
CALL_ERROR_INSTANCE_IS_NULL,
CALL_ERROR_METHOD_NOT_CONST,
};
Error error = Error::CALL_OK;
int argument = 0;
int expected = 0;
};
void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, CallError &r_call_error) const;
void call_deferred(const Variant **p_arguments, int p_argcount) const;
void rpc(int p_id, const Variant **p_arguments, int p_argcount, CallError &r_call_error) const;
_FORCE_INLINE_ bool is_null() const {
return method == StringName() && object == 0;
}
_FORCE_INLINE_ bool is_custom() const {
return method == StringName() && custom != nullptr;
}
_FORCE_INLINE_ bool is_standard() const {
return method != StringName();
}
bool is_valid() const;
Callable bind(const Variant **p_arguments, int p_argcount) const;
Callable unbind(int p_argcount) const;
Object *get_object() const;
ObjectID get_object_id() const;
StringName get_method() const;
CallableCustom *get_custom() const;
uint32_t hash() const;
const Callable *get_base_comparator() const; //used for bind/unbind to do less precise comparisons (ignoring binds) in signal connect/disconnect
bool operator==(const Callable &p_callable) const;
bool operator!=(const Callable &p_callable) const;
bool operator<(const Callable &p_callable) const;
void operator=(const Callable &p_callable);
operator String() const;
Callable(const Object *p_object, const StringName &p_method);
Callable(ObjectID p_object, const StringName &p_method);
Callable(CallableCustom *p_custom);
Callable(const Callable &p_callable);
Callable() {}
~Callable();
};
class CallableCustom {
friend class Callable;
SafeRefCount ref_count;
bool referenced = false;
public:
typedef bool (*CompareEqualFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
typedef bool (*CompareLessFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
//for every type that inherits, these must always be the same for this type
virtual uint32_t hash() const = 0;
virtual String get_as_text() const = 0;
virtual CompareEqualFunc get_compare_equal_func() const = 0;
virtual CompareLessFunc get_compare_less_func() const = 0;
virtual StringName get_method() const;
virtual ObjectID get_object() const = 0; //must always be able to provide an object
virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const = 0;
virtual void rpc(int p_peer_id, const Variant **p_arguments, int p_argcount, Callable::CallError &r_call_error) const;
virtual const Callable *get_base_comparator() const;
CallableCustom();
virtual ~CallableCustom() {}
};
// This is just a proxy object to object signals, its only
// allocated on demand by/for scripting languages so it can
// be put inside a Variant, but it is not
// used by the engine itself.
// Enforce 16 bytes with `alignas` to avoid arch-specific alignment issues on x86 vs armv7.
class Signal {
alignas(8) StringName name;
ObjectID object;
public:
_FORCE_INLINE_ bool is_null() const {
return object.is_null() && name == StringName();
}
Object *get_object() const;
ObjectID get_object_id() const;
StringName get_name() const;
bool operator==(const Signal &p_signal) const;
bool operator!=(const Signal &p_signal) const;
bool operator<(const Signal &p_signal) const;
operator String() const;
Error emit(const Variant **p_arguments, int p_argcount) const;
Error connect(const Callable &p_callable, uint32_t p_flags = 0);
void disconnect(const Callable &p_callable);
bool is_connected(const Callable &p_callable) const;
Array get_connections() const;
Signal(const Object *p_object, const StringName &p_name);
Signal(ObjectID p_object, const StringName &p_name);
Signal() {}
};
struct CallableComparator {
const Callable &func;
bool operator()(const Variant &p_l, const Variant &p_r) const;
};
#endif // CALLABLE_H