LedStatus.cc

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#include "LedStatus.hh"
#include "MSXCliComm.hh"
#include "ReadOnlySetting.hh"
#include "CommandController.hh"
#include "Timer.hh"
#include <memory>

namespace openmsx {

static std::string getLedName(LedStatus::Led led)
{
        static const char* const names[LedStatus::NUM_LEDS] = {
                "power", "caps", "kana", "pause", "turbo", "FDD"
        };
        return names[led];
}

LedStatus::LedStatus(
                RTScheduler& rtScheduler,
                CommandController& commandController,
                MSXCliComm& msxCliComm_)
        : RTSchedulable(rtScheduler)
        , msxCliComm(msxCliComm_)
        , interp(commandController.getInterpreter())
{
        lastTime = Timer::getTime();
        for (int i = 0; i < NUM_LEDS; ++i) {
                ledValue[i] = false;
                std::string name = getLedName(static_cast<Led>(i));
                ledStatus[i] = std::make_unique<ReadOnlySetting>(
                        commandController, "led_" + name,
                        "Current status for LED: " + name,
                        TclObject("off"));
        }
}

LedStatus::~LedStatus() = default;

void LedStatus::setLed(Led led, bool status)
{
        if (ledValue[led] == status) return;
        ledValue[led] = status;

        // Some MSX programs generate tons of LED events (e.g. New Era uses
        // the LEDs as a VU meter while playing samples). Without throttling
        // all these events overload the host CPU. That's why we limit it to
        // 100 events per second.
        auto now = Timer::getTime();
        auto diff = now - lastTime;
        if (diff > 10000) { // 1/100 s
                // handle now
                lastTime = now;
                handleEvent(led);
        } else {
                // schedule to handle it later, if we didn't plan to do so already
                if (!isPendingRT()) {
                        scheduleRT(10000 - diff);
                }
        }
}

void LedStatus::handleEvent(Led led) noexcept
{
        static const string_view ON  = "on";
        static const string_view OFF = "off";
        const string_view& str = ledValue[led] ? ON : OFF;

        ledStatus[led]->setReadOnlyValue(TclObject(str));
        msxCliComm.update(CliComm::LED, getLedName(led), str);
}

void LedStatus::executeRT()
{
        for (int i = 0; i < NUM_LEDS; ++i) {
                if (ledValue[i] != ledStatus[i]->getValue().getBoolean(interp)) {
                        handleEvent(static_cast<Led>(i));
                }
        }
        lastTime = Timer::getTime();
}

} // namespace openmsx