CLK/Activity/Observer.hpp

60 lines
2.0 KiB
C++

//
// ActivityObserver.h
// Clock Signal
//
// Created by Thomas Harte on 07/05/2018.
// Copyright 2018 Thomas Harte. All rights reserved.
//
#pragma once
#include <cstdint>
#include <string>
namespace Activity {
/*!
Provides a purely virtual base class for anybody that wants to receive notifications of
'activity': any feedback from an emulated system which a user could perceive other than
through the machine's native audio and video outputs.
So: status LEDs, drive activity, etc. A receiver may choose to make appropriate noises
and/or to show or unshow status indicators.
*/
class Observer {
public:
virtual ~Observer() {}
/// Provides hints as to the sort of information presented on an LED.
enum LEDPresentation: uint8_t {
/// This LED informs the user of some sort of persistent state, e.g. scroll lock.
/// If this flag is absent then the LED describes an ephemeral state, such as media access.
Persistent = (1 << 0),
};
/// Announces to the receiver that there is an LED of name @c name.
virtual void register_led([[maybe_unused]] const std::string &name, [[maybe_unused]] uint8_t presentation = 0) {}
/// Announces to the receiver that there is a drive of name @c name.
///
/// If a drive has the same name as an LED, that LED goes with this drive.
virtual void register_drive([[maybe_unused]] const std::string &name) {}
/// Informs the receiver of the new state of the LED with name @c name.
virtual void set_led_status([[maybe_unused]] const std::string &name, [[maybe_unused]] bool lit) {}
enum class DriveEvent {
StepNormal,
StepBelowZero,
StepBeyondMaximum
};
/// Informs the receiver that the named event just occurred for the drive with name @c name.
virtual void announce_drive_event([[maybe_unused]] const std::string &name, [[maybe_unused]] DriveEvent event) {}
/// Informs the receiver of the motor-on status of the drive with name @c name.
virtual void set_drive_motor_status([[maybe_unused]] const std::string &name, [[maybe_unused]] bool is_on) {}
};
}