WSJT-X/Transceiver/PollingTransceiver.hpp
2019-07-02 10:19:43 -05:00

75 lines
2.2 KiB
C++

#ifndef POLLING_TRANSCEIVER_HPP__
#define POLLING_TRANSCEIVER_HPP__
#include <QObject>
#include "Transceiver/TransceiverBase.hpp"
class QTimer;
//
// Polling Transceiver
//
// Helper base class that encapsulates the emulation of continuous
// update and caching of a transceiver state.
//
// Collaborations
//
// Implements the TransceiverBase post action interface and provides
// the abstract poll() operation for sub-classes to implement. The
// poll operation is invoked every poll_interval seconds.
//
// Responsibilities
//
// Because some rig interfaces don't immediately update after a state
// change request; this class allows a rig a few polls to stabilise
// to the requested state before signalling the change. This means
// that clients don't see intermediate states that are sometimes
// inaccurate, e.g. changing the split TX frequency on Icom rigs
// requires a VFO switch and polls while switched will return the
// wrong current frequency.
//
class PollingTransceiver
: public TransceiverBase
{
Q_OBJECT; // for translation context
protected:
explicit PollingTransceiver (int poll_interval, // in seconds
QObject * parent);
protected:
// Sub-classes implement this and fetch what they can from the rig
// in a non-intrusive manner.
virtual void do_poll () = 0;
void do_post_start () override final;
void do_post_stop () override final;
void do_post_frequency (Frequency, MODE) override final;
void do_post_tx_frequency (Frequency, MODE) override final;
void do_post_mode (MODE) override final;
void do_post_ptt (bool = true) override final;
bool do_pre_update () override final;
private:
void start_timer ();
void stop_timer ();
Q_SLOT void handle_timeout ();
int interval_; // polling interval in milliseconds
QTimer * poll_timer_;
// keep a record of the last state signalled so we can elide
// duplicate updates
Transceiver::TransceiverState last_signalled_state_;
// keep a record of expected state so we can compare with actual
// updates to determine when state changes have bubbled through
Transceiver::TransceiverState next_state_;
unsigned retries_; // number of incorrect polls left
};
#endif