Detailed Description

An InputPort is a System resource that describes the kind of input a System accepts, on a given port.

It does not directly contain any runtime input port data; that is always contained in a Context. The actual value will be either the value of an OutputPort to which this is connected, or a fixed value set in a Context.

InputPortBase is the scalar type-independent part of an InputPort.

#include <drake/systems/framework/input_port_base.h>

Public Member Functions
	~InputPortBase () override

InputPortIndex	get_index () const
	Returns the index of this input port within the owning System. More...

bool	is_random () const
	Returns true if this is a random port. More...

std::optional< RandomDistribution >	get_random_type () const
	Returns the RandomDistribution if this is a random port. More...

std::unique_ptr< AbstractValue >	Allocate () const
	Allocates a concrete object suitable for holding the value to be provided by this input port, and returns that as an AbstractValue. More...

const std::string &	get_name () const
	Get port name. More...

std::string	GetFullDescription () const
	Returns a verbose human-readable description of port. More...

PortDataType	get_data_type () const
	Returns the port data type. More...

int	size () const
	Returns the fixed size expected for a vector-valued port. More...

DependencyTicket	ticket () const
	(Advanced.) Returns the DependencyTicket for this port within the owning System. More...

Does not allow copy, move, or assignment
	InputPortBase (const InputPortBase &)=delete

InputPortBase &	operator= (const InputPortBase &)=delete

	InputPortBase (InputPortBase &&)=delete

InputPortBase &	operator= (InputPortBase &&)=delete

Public Member Functions inherited from PortBase
virtual	~PortBase ()

const std::string &	get_name () const
	Get port name. More...

std::string	GetFullDescription () const
	Returns a verbose human-readable description of port. More...

PortDataType	get_data_type () const
	Returns the port data type. More...

int	size () const
	Returns the fixed size expected for a vector-valued port. More...

const std::optional< std::string > &	get_deprecation () const
	When this port is deprecated, returns non-null with a (possibly empty) deprecation message; when this port is not deprecated, returns null. More...

void	set_deprecation (std::optional< std::string > deprecation)
	Sets whether this port is deprecated (and if so, the message). More...

DependencyTicket	ticket () const
	(Advanced.) Returns the DependencyTicket for this port within the owning System. More...

	PortBase (const PortBase &)=delete

PortBase &	operator= (const PortBase &)=delete

	PortBase (PortBase &&)=delete

PortBase &	operator= (PortBase &&)=delete

Protected Types
using	EvalAbstractCallback = std::function< const AbstractValue *(const ContextBase &)>
	Signature of a function suitable for returning the cached value of a particular input port. More...

Protected Member Functions
	InputPortBase (internal::SystemMessageInterface *owning_system, internal::SystemId owning_system_id, std::string name, InputPortIndex index, DependencyTicket ticket, PortDataType data_type, int size, const std::optional< RandomDistribution > &random_type, EvalAbstractCallback eval, ValueProducer::AllocateCallback alloc)
	(Internal use only) Provides derived classes the ability to set the base class members at construction. More...

const AbstractValue &	DoEvalRequired (const ContextBase &context) const
	Evaluate this port; throws an exception if the port is not connected. More...

const AbstractValue *	DoEvalOptional (const ContextBase &context) const
	Evaluate this port; returns nullptr if the port is not connected. More...

void	ThrowRequiredMissing () const
	Throws an exception that this port is not connected, but was expected to be connected (i.e., an Eval caller expected that it was always connected). More...

Protected Member Functions inherited from PortBase
	PortBase (const char kind_string, internal::SystemMessageInterface owning_system, internal::SystemId owning_system_id, std::string name, int index, DependencyTicket ticket, PortDataType data_type, int size)
	Provides derived classes the ability to set the base class members at construction. More...

int	get_int_index () const
	Returns the index of this port within the owning System (i.e., an InputPortIndex or OutputPortIndex, but as a bare integer). More...

const internal::SystemMessageInterface &	get_system_interface () const
	Returns a reference to the system that owns this port. More...

internal::SystemMessageInterface &	get_mutable_system_interface ()
	Returns get_system_interface(), but without the const. More...

void	ValidateSystemId (internal::SystemId id) const
	(Internal use only) Checks whether the given id (nominally obtained from a Context passed to this port) was created for the system that owns this port. More...

void	ThrowValidateContextMismatch () const
	(Internal use only) Throws std::exception with a message that the sanity check(s) related to ValidateContext have failed. More...

template<typename ValueType >
const ValueType &	PortEvalCast (const AbstractValue &abstract) const
	Pull a value of a given type from an abstract value or issue a nice message if the type is not correct. More...

template<typename ValueType , typename T >
const ValueType &	PortEvalCast (const BasicVector< T > &basic) const
	Downcast a basic vector to a more specific subclass, or else issue a nice message if the type is not correct. More...

template<typename ValueType >
const ValueType &	ThrowBadCast (const AbstractValue &abstract) const
	Reports that the user provided a bad ValueType argument to Eval. More...

template<typename ValueType , typename T >
const ValueType &	ThrowBadCast (const BasicVector< T > &basic) const
	Reports that the user provided a bad ValueType argument to Eval. More...

void	ThrowBadCast (const std::string &value_typename, const std::string &eval_typename) const
	Reports that the user provided a bad ValueType argument to Eval. More...

Member Typedef Documentation

◆ EvalAbstractCallback

using EvalAbstractCallback = std::function<const AbstractValue*(const ContextBase&)>

protected

Signature of a function suitable for returning the cached value of a particular input port.

Will return nullptr if the port is not connected.

Constructor & Destructor Documentation

◆ InputPortBase() [1/3]

InputPortBase ( const InputPortBase & )

delete

◆ InputPortBase() [2/3]

InputPortBase ( InputPortBase && )

delete

◆ ~InputPortBase()

~InputPortBase ( )

override

◆ InputPortBase() [3/3]

InputPortBase	(	internal::SystemMessageInterface *	owning_system,
		internal::SystemId	owning_system_id,
		std::string	name,
		InputPortIndex	index,
		DependencyTicket	ticket,
		PortDataType	data_type,
		int	size,
		const std::optional< RandomDistribution > &	random_type,
		EvalAbstractCallback	eval,
		ValueProducer::AllocateCallback	alloc
	)

protected

(Internal use only) Provides derived classes the ability to set the base class members at construction.

Parameters

owning_system	The System that owns this input port.
owning_system_id	The ID of owning_system.
name	A name for the port. Input port names should be non-empty and unique within a single System.
index	The index to be assigned to this InputPort.
ticket	The DependencyTicket to be assigned to this InputPort.
data_type	Whether the port described is vector- or abstract-valued.
size	If the port described is vector-valued, the number of elements. Ignored for abstract-valued ports.
random_type	Input ports may optionally be labeled as random, if the port is intended to model a random-source "noise" or "disturbance" input.

Member Function Documentation

◆ Allocate()

std::unique_ptr<AbstractValue> Allocate ( ) const

Allocates a concrete object suitable for holding the value to be provided by this input port, and returns that as an AbstractValue.

The returned object will never be null.

◆ DoEvalOptional()

const AbstractValue* DoEvalOptional ( const ContextBase & context ) const

protected

Evaluate this port; returns nullptr if the port is not connected.

◆ DoEvalRequired()

const AbstractValue& DoEvalRequired ( const ContextBase & context ) const

protected

Evaluate this port; throws an exception if the port is not connected.

◆ get_data_type()

PortDataType get_data_type

Returns the port data type.

◆ get_index()

InputPortIndex get_index ( ) const

Returns the index of this input port within the owning System.

For a Diagram, this will be the index within the Diagram, not the index within a LeafSystem whose input port was exported.

◆ get_name()

const std::string& get_name

Get port name.

◆ get_random_type()

std::optional<RandomDistribution> get_random_type ( ) const

Returns the RandomDistribution if this is a random port.

◆ GetFullDescription()

std::string GetFullDescription

Returns a verbose human-readable description of port.

This is useful for error messages or debugging.

◆ is_random()

bool is_random ( ) const

Returns true if this is a random port.

◆ operator=() [1/2]

InputPortBase& operator= ( InputPortBase && )

delete

◆ operator=() [2/2]

InputPortBase& operator= ( const InputPortBase & )

delete

◆ size()

int size

Returns the fixed size expected for a vector-valued port.

Not meaningful for abstract-valued ports.

◆ ThrowRequiredMissing()

void ThrowRequiredMissing ( ) const

protected

Throws an exception that this port is not connected, but was expected to be connected (i.e., an Eval caller expected that it was always connected).

◆ ticket()

DependencyTicket ticket

(Advanced.) Returns the DependencyTicket for this port within the owning System.

The documentation for this class was generated from the following file:

drake/systems/framework/input_port_base.h

Detailed Description

Public Member Functions

Protected Types

Protected Member Functions

Member Typedef Documentation

◆ EvalAbstractCallback

Constructor & Destructor Documentation

◆ InputPortBase() [1/3]

◆ InputPortBase() [2/3]

◆ ~InputPortBase()

◆ InputPortBase() [3/3]

Member Function Documentation

◆ Allocate()

◆ DoEvalOptional()

◆ DoEvalRequired()

◆ get_data_type()

◆ get_index()

◆ get_name()

◆ get_random_type()

◆ GetFullDescription()

◆ is_random()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ size()

◆ ThrowRequiredMissing()

◆ ticket()