State Base Class

[中文]

Public header: #include "brookesia/lib_utils/state_base.hpp"

Overview

state_base defines the base state abstraction for state machines with enter, exit, and update callbacks, plus timeouts and update intervals.

Features

  • Standard lifecycle: on_enter / on_exit / on_update

  • Timeout actions and update intervals

  • Easy to subclass for custom states

API Reference

Header File

Classes

class StateBase

Base class for state machine states.

Provides lifecycle hooks (on_enter, on_exit, on_update) and configuration for timeout and periodic update intervals.

Public Functions

inline explicit StateBase(const std::string &name)

Constructor.

Parameters

name – State name.

virtual ~StateBase() = default

Virtual destructor.

inline virtual bool on_enter(const std::string &from_state = "", const std::string &action = "")

Hook invoked before the state becomes active.

Parameters

  • from_state – Name of the previous state, or an empty string for the initial state.

  • action – Transition action name, or an empty string when not specified.

Returns

true to allow the transition, or false to reject entry.

inline virtual bool on_exit(const std::string &to_state = "", const std::string &action = "")

Hook invoked before the state is left.

Parameters

  • to_state – Name of the next state, or an empty string when unspecified.

  • action – Transition action name, or an empty string when not specified.

Returns

true to allow the transition, or false to reject exit.

inline virtual void on_update()

Hook invoked periodically while the state remains active.

Note

This callback is scheduled only when set_update_interval() configures a non-zero interval.

inline void set_timeout(uint32_t ms, const std::string &action)

Configure an automatic timeout transition for this state.

Parameters

  • ms – Timeout duration in milliseconds. A value of 0 disables the timeout.

  • action – Action name triggered when the timeout expires.

inline void set_update_interval(uint32_t interval_ms)

Configure the periodic update interval for this state.

Parameters

interval_ms – Update period in milliseconds. A value of 0 disables on_update() scheduling.

inline const std::string &get_name() const

Get the state name.

Returns

State name.

inline uint32_t get_timeout_ms() const

Get the configured timeout duration.

Returns

Timeout duration in milliseconds, or 0 when no timeout is configured.

inline const std::string &get_timeout_action() const

Get the action triggered when the timeout expires.

Returns

Configured timeout action name.

inline uint32_t get_update_interval() const

Get the configured periodic update interval.

Returns

Update interval in milliseconds, or 0 when periodic updates are disabled.