230 lines
11 KiB
XML
230 lines
11 KiB
XML
<?xml version="1.0" encoding="UTF-8" ?>
|
|
<class name="Callable" version="4.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
|
|
<brief_description>
|
|
A built-in type representing a method or a standalone function.
|
|
</brief_description>
|
|
<description>
|
|
[Callable] is a built-in [Variant] type that represents a function. It can either be a method within an [Object] instance, or a standalone function not related to any object, like a lambda function. Like all [Variant] types, it can be stored in variables and passed to other functions. It is most commonly used for signal callbacks.
|
|
[b]Example:[/b]
|
|
[codeblocks]
|
|
[gdscript]
|
|
func print_args(arg1, arg2, arg3 = ""):
|
|
prints(arg1, arg2, arg3)
|
|
|
|
func test():
|
|
var callable = Callable(self, "print_args")
|
|
callable.call("hello", "world") # Prints "hello world ".
|
|
callable.call(Vector2.UP, 42, callable) # Prints "(0, -1) 42 Node(node.gd)::print_args".
|
|
callable.call("invalid") # Invalid call, should have at least 2 arguments.
|
|
[/gdscript]
|
|
[csharp]
|
|
// Default parameter values are not supported.
|
|
public void PrintArgs(Variant arg1, Variant arg2, Variant arg3 = default)
|
|
{
|
|
GD.PrintS(arg1, arg2, arg3);
|
|
}
|
|
|
|
public void Test()
|
|
{
|
|
// Invalid calls fail silently.
|
|
Callable callable = new Callable(this, MethodName.PrintArgs);
|
|
callable.Call("hello", "world"); // Default parameter values are not supported, should have 3 arguments.
|
|
callable.Call(Vector2.Up, 42, callable); // Prints "(0, -1) 42 Node(Node.cs)::PrintArgs".
|
|
callable.Call("invalid"); // Invalid call, should have 3 arguments.
|
|
}
|
|
[/csharp]
|
|
[/codeblocks]
|
|
In GDScript, it's possible to create lambda functions within a method. Lambda functions are custom callables that are not associated with an [Object] instance. Optionally, lambda functions can also be named. The name will be displayed in the debugger, or when calling [method get_method].
|
|
[codeblock]
|
|
func _init():
|
|
var my_lambda = func (message):
|
|
print(message)
|
|
|
|
# Prints Hello everyone!
|
|
my_lambda.call("Hello everyone!")
|
|
|
|
# Prints "Attack!", when the button_pressed signal is emitted.
|
|
button_pressed.connect(func(): print("Attack!"))
|
|
[/codeblock]
|
|
[b]Note:[/b] Methods of native types such as [Signal], [Array], or [Dictionary] are not of type [Callable] in order to avoid unnecessary overhead. If you need to pass those methods as [Callable], use a lambda function as a wrapper.
|
|
[codeblock]
|
|
func _init():
|
|
var my_dictionary = { "hello": "world" }
|
|
|
|
# This will not work, `clear` is not a callable.
|
|
create_tween().tween_callback(my_dictionary.clear)
|
|
|
|
# This will work, as lambdas are custom callables.
|
|
create_tween().tween_callback(func(): my_dictionary.clear())
|
|
[/codeblock]
|
|
</description>
|
|
<tutorials>
|
|
</tutorials>
|
|
<constructors>
|
|
<constructor name="Callable">
|
|
<return type="Callable" />
|
|
<description>
|
|
Constructs an empty [Callable], with no object nor method bound.
|
|
</description>
|
|
</constructor>
|
|
<constructor name="Callable">
|
|
<return type="Callable" />
|
|
<param index="0" name="from" type="Callable" />
|
|
<description>
|
|
Constructs a [Callable] as a copy of the given [Callable].
|
|
</description>
|
|
</constructor>
|
|
<constructor name="Callable">
|
|
<return type="Callable" />
|
|
<param index="0" name="object" type="Object" />
|
|
<param index="1" name="method" type="StringName" />
|
|
<description>
|
|
Creates a new [Callable] for the method named [param method] in the specified [param object].
|
|
</description>
|
|
</constructor>
|
|
</constructors>
|
|
<methods>
|
|
<method name="bind" qualifiers="vararg const">
|
|
<return type="Callable" />
|
|
<description>
|
|
Returns a copy of this [Callable] with one or more arguments bound. When called, the bound arguments are passed [i]after[/i] the arguments supplied by [method call]. See also [method unbind].
|
|
[b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left.
|
|
</description>
|
|
</method>
|
|
<method name="bindv">
|
|
<return type="Callable" />
|
|
<param index="0" name="arguments" type="Array" />
|
|
<description>
|
|
Returns a copy of this [Callable] with one or more arguments bound, reading them from an array. When called, the bound arguments are passed [i]after[/i] the arguments supplied by [method call]. See also [method unbind].
|
|
[b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left.
|
|
</description>
|
|
</method>
|
|
<method name="call" qualifiers="vararg const">
|
|
<return type="Variant" />
|
|
<description>
|
|
Calls the method represented by this [Callable]. Arguments can be passed and should match the method's signature.
|
|
</description>
|
|
</method>
|
|
<method name="call_deferred" qualifiers="vararg const">
|
|
<return type="void" />
|
|
<description>
|
|
Calls the method represented by this [Callable] in deferred mode, i.e. at the end of the current frame. Arguments can be passed and should match the method's signature.
|
|
[codeblock]
|
|
func _ready():
|
|
grab_focus.call_deferred()
|
|
[/codeblock]
|
|
See also [method Object.call_deferred].
|
|
</description>
|
|
</method>
|
|
<method name="callv" qualifiers="const">
|
|
<return type="Variant" />
|
|
<param index="0" name="arguments" type="Array" />
|
|
<description>
|
|
Calls the method represented by this [Callable]. Unlike [method call], this method expects all arguments to be contained inside the [param arguments] [Array].
|
|
</description>
|
|
</method>
|
|
<method name="get_bound_arguments" qualifiers="const">
|
|
<return type="Array" />
|
|
<description>
|
|
Return the bound arguments (as long as [method get_bound_arguments_count] is greater than zero), or empty (if [method get_bound_arguments_count] is less than or equal to zero).
|
|
</description>
|
|
</method>
|
|
<method name="get_bound_arguments_count" qualifiers="const">
|
|
<return type="int" />
|
|
<description>
|
|
Returns the total amount of arguments bound (or unbound) via successive [method bind] or [method unbind] calls. If the amount of arguments unbound is greater than the ones bound, this function returns a value less than zero.
|
|
</description>
|
|
</method>
|
|
<method name="get_method" qualifiers="const">
|
|
<return type="StringName" />
|
|
<description>
|
|
Returns the name of the method represented by this [Callable]. If the callable is a lambda function, returns the function's name.
|
|
</description>
|
|
</method>
|
|
<method name="get_object" qualifiers="const">
|
|
<return type="Object" />
|
|
<description>
|
|
Returns the object on which this [Callable] is called.
|
|
</description>
|
|
</method>
|
|
<method name="get_object_id" qualifiers="const">
|
|
<return type="int" />
|
|
<description>
|
|
Returns the ID of this [Callable]'s object (see [method Object.get_instance_id]).
|
|
</description>
|
|
</method>
|
|
<method name="hash" qualifiers="const">
|
|
<return type="int" />
|
|
<description>
|
|
Returns the 32-bit hash value of this [Callable]'s object.
|
|
[b]Note:[/b] [Callable]s with equal content will always produce identical hash values. However, the reverse is not true. Returning identical hash values does [i]not[/i] imply the callables are equal, because different callables can have identical hash values due to hash collisions. The engine uses a 32-bit hash algorithm for [method hash].
|
|
</description>
|
|
</method>
|
|
<method name="is_custom" qualifiers="const">
|
|
<return type="bool" />
|
|
<description>
|
|
Returns [code]true[/code] if this [Callable] is a custom callable. Custom callables are created from [method bind] or [method unbind]. In GDScript, lambda functions are also custom callables.
|
|
</description>
|
|
</method>
|
|
<method name="is_null" qualifiers="const">
|
|
<return type="bool" />
|
|
<description>
|
|
Returns [code]true[/code] if this [Callable] has no target to call the method on.
|
|
</description>
|
|
</method>
|
|
<method name="is_standard" qualifiers="const">
|
|
<return type="bool" />
|
|
<description>
|
|
Returns [code]true[/code] if this [Callable] is a standard callable. This method is the opposite of [method is_custom]. Returns [code]false[/code] if this callable is a lambda function.
|
|
</description>
|
|
</method>
|
|
<method name="is_valid" qualifiers="const">
|
|
<return type="bool" />
|
|
<description>
|
|
Returns [code]true[/code] if the callable's object exists and has a valid method name assigned, or is a custom callable.
|
|
</description>
|
|
</method>
|
|
<method name="rpc" qualifiers="vararg const">
|
|
<return type="void" />
|
|
<description>
|
|
Perform an RPC (Remote Procedure Call). This is used for multiplayer and is normally not available, unless the function being called has been marked as [i]RPC[/i]. Calling this method on unsupported functions will result in an error. See [method Node.rpc].
|
|
</description>
|
|
</method>
|
|
<method name="rpc_id" qualifiers="vararg const">
|
|
<return type="void" />
|
|
<param index="0" name="peer_id" type="int" />
|
|
<description>
|
|
Perform an RPC (Remote Procedure Call) on a specific peer ID (see multiplayer documentation for reference). This is used for multiplayer and is normally not available unless the function being called has been marked as [i]RPC[/i]. Calling this method on unsupported functions will result in an error. See [method Node.rpc_id].
|
|
</description>
|
|
</method>
|
|
<method name="unbind" qualifiers="const">
|
|
<return type="Callable" />
|
|
<param index="0" name="argcount" type="int" />
|
|
<description>
|
|
Returns a copy of this [Callable] with a number of arguments unbound. In other words, when the new callable is called the last few arguments supplied by the user are ignored, according to [param argcount]. The remaining arguments are passed to the callable. This allows to use the original callable in a context that attempts to pass more arguments than this callable can handle, e.g. a signal with a fixed number of arguments. See also [method bind].
|
|
[b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left.
|
|
[codeblock]
|
|
func _ready():
|
|
foo.unbind(1).call(1, 2) # Calls foo(1).
|
|
foo.bind(3, 4).unbind(1).call(1, 2) # Calls foo(1, 3, 4), note that it does not change the arguments from bind.
|
|
[/codeblock]
|
|
</description>
|
|
</method>
|
|
</methods>
|
|
<operators>
|
|
<operator name="operator !=">
|
|
<return type="bool" />
|
|
<param index="0" name="right" type="Callable" />
|
|
<description>
|
|
Returns [code]true[/code] if both [Callable]s invoke different targets.
|
|
</description>
|
|
</operator>
|
|
<operator name="operator ==">
|
|
<return type="bool" />
|
|
<param index="0" name="right" type="Callable" />
|
|
<description>
|
|
Returns [code]true[/code] if both [Callable]s invoke the same custom target.
|
|
</description>
|
|
</operator>
|
|
</operators>
|
|
</class>
|