InputEventGenerator.cc

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#include "InputEventGenerator.hh"
#include "EventDistributor.hh"
#include "InputEvents.hh"
#include "IntegerSetting.hh"
#include "GlobalSettings.hh"
#include "Keys.hh"
#include "checked_cast.hh"
#include "outer.hh"
#include "unreachable.hh"
#include "utf8_unchecked.hh"
#include "build-info.hh"
#include <cassert>
#include <memory>

using std::string;
using std::vector;
using std::make_shared;

namespace openmsx {

InputEventGenerator::InputEventGenerator(CommandController& commandController,
                                         EventDistributor& eventDistributor_,
                                         GlobalSettings& globalSettings_)
        : eventDistributor(eventDistributor_)
        , globalSettings(globalSettings_)
        , grabInput(
                commandController, "grabinput",
                "This setting controls if openMSX takes over mouse and keyboard input",
                false, Setting::DONT_SAVE)
        , escapeGrabCmd(commandController)
        , escapeGrabState(ESCAPE_GRAB_WAIT_CMD)
        , keyRepeat(false)
{
        setGrabInput(grabInput.getBoolean());
        grabInput.attach(*this);
        eventDistributor.registerEventListener(OPENMSX_FOCUS_EVENT, *this);

        osdControlButtonsState = unsigned(~0); // 0 is pressed, 1 is released

#ifndef SDL_JOYSTICK_DISABLED
        SDL_JoystickEventState(SDL_ENABLE); // joysticks generate events
#endif
}

InputEventGenerator::~InputEventGenerator()
{
        eventDistributor.unregisterEventListener(OPENMSX_FOCUS_EVENT, *this);
        grabInput.detach(*this);
}

void InputEventGenerator::wait()
{
        // SDL bug workaround
        if (!SDL_WasInit(SDL_INIT_VIDEO)) {
                SDL_Delay(100);
        }

        if (SDL_WaitEvent(nullptr)) {
                poll();
        }
}

void InputEventGenerator::poll()
{
        // Heuristic to emulate the old SDL1 behavior:
        //
        // SDL1 had a unicode field on each KEYDOWN event. In SDL2 that
        // information is moved to the (new) SDL_TEXTINPUT events.
        //
        // Though our MSX keyboard emulation code needs to relate KEYDOWN
        // events with the associated unicode. We try to mimic this by the
        // following heuristic:
        //   When two successive events in a single batch (so, the same
        //   invocation of poll()) are KEYDOWN followed by TEXTINPUT, then copy
        //   the unicode (of the first character) of the TEXT event to the
        //   KEYDOWN event.
        // Implementing this requires a lookahead of 1 event. So the code below
        // deals with a 'current' and a 'previous' event, and keeps track of
        // whether the previous event is still pending (not yet processed).
        //
        // In a previous version we also added the constraint that these two
        // consecutive events must have the same timestamp, but that had mixed
        // results:
        // - on Linux it worked fine
        // - on Windows the timestamps sometimes did not match
        // - on Mac the timestamps mostly did not match
        // So we removed this constraint.
        //
        // We also split SDL_TEXTINPUT events into (possibly) multiple KEYDOWN
        // events because a single event type makes it easier to handle higher
        // priority listeners that can block the event for lower priority
        // listener (console > hotkey > msx).

        SDL_Event event1, event2;
        auto* prev = &event1;
        auto* curr = &event2;
        bool pending = false;

        while (SDL_PollEvent(curr)) {
                if (pending) {
                        pending = false;
                        if ((prev->type == SDL_KEYDOWN) && (curr->type == SDL_TEXTINPUT)) {
                                const char* utf8 = curr->text.text;
                                auto unicode = utf8::unchecked::next(utf8);
                                handleKeyDown(prev->key, unicode);
                                if (unicode) { // possibly there are more characters
                                        handleText(utf8);
                                }
                                continue;
                        } else {
                                handle(*prev);
                        }
                }
                if (curr->type == SDL_KEYDOWN) {
                        pending = true;
                        std::swap(curr, prev);
                } else {
                        handle(*curr);
                }
        }
        if (pending) {
                handle(*prev);
        }
}

void InputEventGenerator::setKeyRepeat(bool enable)
{
        keyRepeat = enable;
}

void InputEventGenerator::setNewOsdControlButtonState(
                unsigned newState, const EventPtr& origEvent)
{
        unsigned deltaState = osdControlButtonsState ^ newState;
        for (unsigned i = OsdControlEvent::LEFT_BUTTON;
                        i <= OsdControlEvent::B_BUTTON; ++i) {
                if (deltaState & (1 << i)) {
                        if (newState & (1 << i)) {
                                eventDistributor.distributeEvent(
                                        make_shared<OsdControlReleaseEvent>(
                                                i, origEvent));
                        } else {
                                eventDistributor.distributeEvent(
                                        make_shared<OsdControlPressEvent>(
                                                i, origEvent));
                        }
                }
        }
        osdControlButtonsState = newState;
}

void InputEventGenerator::triggerOsdControlEventsFromJoystickAxisMotion(
        unsigned axis, int value, const EventPtr& origEvent)
{
        unsigned neg_button, pos_button;
        switch (axis) {
        case 0:
                neg_button = 1 << OsdControlEvent::LEFT_BUTTON;
                pos_button = 1 << OsdControlEvent::RIGHT_BUTTON;
                break; // axis 0
        case 1:
                neg_button = 1 << OsdControlEvent::UP_BUTTON;
                pos_button = 1 << OsdControlEvent::DOWN_BUTTON;
                break;
        default:
                // Ignore all other axis (3D joysticks and flight joysticks may
                // have more than 2 axis)
                return;
        }

        if (value > 0) {
                // release negative button, press positive button
                setNewOsdControlButtonState(
                        (osdControlButtonsState | neg_button) & ~pos_button,
                        origEvent);
        } else if (value < 0) {
                // press negative button, release positive button
                setNewOsdControlButtonState(
                        (osdControlButtonsState | pos_button) & ~neg_button,
                        origEvent);
        } else {
                // release both buttons
                setNewOsdControlButtonState(
                        osdControlButtonsState | neg_button | pos_button,
                        origEvent);
        }
}

void InputEventGenerator::triggerOsdControlEventsFromJoystickHat(
        int value, const EventPtr& origEvent)
{
        unsigned dir = 0;
        if (!(value & SDL_HAT_UP   )) dir |= 1 << OsdControlEvent::UP_BUTTON;
        if (!(value & SDL_HAT_DOWN )) dir |= 1 << OsdControlEvent::DOWN_BUTTON;
        if (!(value & SDL_HAT_LEFT )) dir |= 1 << OsdControlEvent::LEFT_BUTTON;
        if (!(value & SDL_HAT_RIGHT)) dir |= 1 << OsdControlEvent::RIGHT_BUTTON;
        unsigned ab = osdControlButtonsState & ((1 << OsdControlEvent::A_BUTTON) |
                                                (1 << OsdControlEvent::B_BUTTON));
        setNewOsdControlButtonState(ab | dir, origEvent);
}

void InputEventGenerator::osdControlChangeButton(
        bool up, unsigned changedButtonMask, const EventPtr& origEvent)
{
        auto newButtonState = up
                ? osdControlButtonsState | changedButtonMask
                : osdControlButtonsState & ~changedButtonMask;
        setNewOsdControlButtonState(newButtonState, origEvent);
}

void InputEventGenerator::triggerOsdControlEventsFromJoystickButtonEvent(
        unsigned button, bool up, const EventPtr& origEvent)
{
        osdControlChangeButton(
                up,
                ((button & 1) ? (1 << OsdControlEvent::B_BUTTON)
                              : (1 << OsdControlEvent::A_BUTTON)),
                origEvent);
}

void InputEventGenerator::triggerOsdControlEventsFromKeyEvent(
        Keys::KeyCode keyCode, bool up, const EventPtr& origEvent)
{
        keyCode = static_cast<Keys::KeyCode>(keyCode & Keys::K_MASK);
        if (keyCode == Keys::K_LEFT) {
                osdControlChangeButton(up, 1 << OsdControlEvent::LEFT_BUTTON,
                                       origEvent);
        } else if (keyCode == Keys::K_RIGHT) {
                osdControlChangeButton(up, 1 << OsdControlEvent::RIGHT_BUTTON,
                                       origEvent);
        } else if (keyCode == Keys::K_UP) {
                osdControlChangeButton(up, 1 << OsdControlEvent::UP_BUTTON,
                                       origEvent);
        } else if (keyCode == Keys::K_DOWN) {
                osdControlChangeButton(up, 1 << OsdControlEvent::DOWN_BUTTON,
                                       origEvent);
        } else if (keyCode == Keys::K_SPACE || keyCode == Keys::K_RETURN) {
                osdControlChangeButton(up, 1 << OsdControlEvent::A_BUTTON,
                                       origEvent);
        } else if (keyCode == Keys::K_ESCAPE) {
                osdControlChangeButton(up, 1 << OsdControlEvent::B_BUTTON,
                                       origEvent);
        }
}

void InputEventGenerator::handleKeyDown(const SDL_KeyboardEvent& key, uint32_t unicode)
{
        EventPtr event;
        /*if (PLATFORM_ANDROID && evt.key.keysym.sym == SDLK_WORLD_93) {
                event = make_shared<JoystickButtonDownEvent>(0, 0);
                triggerOsdControlEventsFromJoystickButtonEvent(
                        0, false, event);
                androidButtonA = true;
        } else if (PLATFORM_ANDROID && evt.key.keysym.sym == SDLK_WORLD_94) {
                event = make_shared<JoystickButtonDownEvent>(0, 1);
                triggerOsdControlEventsFromJoystickButtonEvent(
                        1, false, event);
                androidButtonB = true;
        } else*/ {
                auto keyCode = Keys::getCode(
                        key.keysym.sym, key.keysym.mod,
                        key.keysym.scancode, false);
                event = make_shared<KeyDownEvent>(keyCode, unicode);
                triggerOsdControlEventsFromKeyEvent(keyCode, false, event);
        }
        eventDistributor.distributeEvent(event);
}

void InputEventGenerator::handleText(const char* utf8)
{
        while (true) {
                auto unicode = utf8::unchecked::next(utf8);
                if (unicode == 0) return;
                eventDistributor.distributeEvent(
                        make_shared<KeyDownEvent>(Keys::K_NONE, unicode));
        }
}

void InputEventGenerator::handle(const SDL_Event& evt)
{
        EventPtr event;
        switch (evt.type) {
        case SDL_KEYUP:
                // Virtual joystick of SDL Android port does not have joystick
                // buttons. It has however up to 6 virtual buttons that can be
                // mapped to SDL keyboard events. Two of these virtual buttons
                // will be mapped to keys SDLK_WORLD_93 and 94 and are
                // interpeted here as joystick buttons (respectively button 0
                // and 1).
                // TODO Android code should be rewritten for SDL2
                /*if (PLATFORM_ANDROID && evt.key.keysym.sym == SDLK_WORLD_93) {
                        event = make_shared<JoystickButtonUpEvent>(0, 0);
                        triggerOsdControlEventsFromJoystickButtonEvent(
                                0, true, event);
                        androidButtonA = false;
                } else if (PLATFORM_ANDROID && evt.key.keysym.sym == SDLK_WORLD_94) {
                        event = make_shared<JoystickButtonUpEvent>(0, 1);
                        triggerOsdControlEventsFromJoystickButtonEvent(
                                1, true, event);
                        androidButtonB = false;
                } else*/ {
                        auto keyCode = Keys::getCode(
                                evt.key.keysym.sym, evt.key.keysym.mod,
                                evt.key.keysym.scancode, true);
                        event = make_shared<KeyUpEvent>(keyCode);
                        triggerOsdControlEventsFromKeyEvent(keyCode, true, event);
                }
                break;
        case SDL_KEYDOWN:
                handleKeyDown(evt.key, 0);
                break;

        case SDL_MOUSEBUTTONUP:
                event = make_shared<MouseButtonUpEvent>(evt.button.button);
                break;
        case SDL_MOUSEBUTTONDOWN:
                event = make_shared<MouseButtonDownEvent>(evt.button.button);
                break;
        case SDL_MOUSEWHEEL: {
                int x = evt.wheel.x;
                int y = evt.wheel.y;
                if (evt.wheel.direction == SDL_MOUSEWHEEL_FLIPPED)
                {
                        x = -x;
                        y = -y;
                }
                event = make_shared<MouseWheelEvent>(x, y);
                break;
        }
        case SDL_MOUSEMOTION:
                event = make_shared<MouseMotionEvent>(
                        evt.motion.xrel, evt.motion.yrel,
                        evt.motion.x,    evt.motion.y);
                break;

        case SDL_JOYBUTTONUP:
                event = make_shared<JoystickButtonUpEvent>(
                        evt.jbutton.which, evt.jbutton.button);
                triggerOsdControlEventsFromJoystickButtonEvent(
                        evt.jbutton.button, true, event);
                break;
        case SDL_JOYBUTTONDOWN:
                event = make_shared<JoystickButtonDownEvent>(
                        evt.jbutton.which, evt.jbutton.button);
                triggerOsdControlEventsFromJoystickButtonEvent(
                        evt.jbutton.button, false, event);
                break;
        case SDL_JOYAXISMOTION: {
                auto& setting = globalSettings.getJoyDeadzoneSetting(evt.jaxis.which);
                int threshold = (setting.getInt() * 32768) / 100;
                auto value = (evt.jaxis.value < -threshold) ? evt.jaxis.value
                           : (evt.jaxis.value >  threshold) ? evt.jaxis.value
                                                            : 0;
                event = make_shared<JoystickAxisMotionEvent>(
                        evt.jaxis.which, evt.jaxis.axis, value);
                triggerOsdControlEventsFromJoystickAxisMotion(
                        evt.jaxis.axis, value, event);
                break;
        }
        case SDL_JOYHATMOTION:
                event = make_shared<JoystickHatEvent>(
                        evt.jhat.which, evt.jhat.hat, evt.jhat.value);
                triggerOsdControlEventsFromJoystickHat(evt.jhat.value, event);
                break;

        case SDL_TEXTINPUT:
                handleText(evt.text.text);
                break;

        case SDL_WINDOWEVENT:
                switch (evt.window.event) {
                case SDL_WINDOWEVENT_FOCUS_GAINED:
                        event = make_shared<FocusEvent>(true);
                        break;
                case SDL_WINDOWEVENT_FOCUS_LOST:
                        event = make_shared<FocusEvent>(false);
                        break;
                case SDL_WINDOWEVENT_RESIZED:
                        event = make_shared<ResizeEvent>(
                                evt.window.data1, evt.window.data2);
                        break;
                case SDL_WINDOWEVENT_EXPOSED:
                        event = make_shared<SimpleEvent>(OPENMSX_EXPOSE_EVENT);
                        break;
                default:
                        break;
                }
                break;

        case SDL_QUIT:
                event = make_shared<QuitEvent>();
                break;

        default:
                break;
        }

#if 0
        if (event) {
                std::cerr << "SDL event converted to: " << event->toString() << '\n';
        } else {
                std::cerr << "SDL event was of unknown type, not converted to an openMSX event\n";
        }
#endif

        if (event) eventDistributor.distributeEvent(event);
}


void InputEventGenerator::update(const Setting& setting)
{
        assert(&setting == &grabInput); (void)setting;
        escapeGrabState = ESCAPE_GRAB_WAIT_CMD;
        setGrabInput(grabInput.getBoolean());
}

int InputEventGenerator::signalEvent(const std::shared_ptr<const Event>& event)
{
        auto& focusEvent = checked_cast<const FocusEvent&>(*event);
        switch (escapeGrabState) {
                case ESCAPE_GRAB_WAIT_CMD:
                        // nothing
                        break;
                case ESCAPE_GRAB_WAIT_LOST:
                        if (!focusEvent.getGain()) {
                                escapeGrabState = ESCAPE_GRAB_WAIT_GAIN;
                        }
                        break;
                case ESCAPE_GRAB_WAIT_GAIN:
                        if (focusEvent.getGain()) {
                                escapeGrabState = ESCAPE_GRAB_WAIT_CMD;
                        }
                        setGrabInput(true);
                        break;
                default:
                        UNREACHABLE;
        }
        return 0;
}

void InputEventGenerator::setGrabInput(bool grab)
{
        SDL_SetRelativeMouseMode(grab ? SDL_TRUE : SDL_FALSE);

        // TODO is this still the correct place in SDL2
        // TODO get the SDL_window
        //SDL_Window* window = ...;
        //SDL_SetWindowGrab(window, grab ? SDL_TRUE : SDL_FALSE);
}


// Wrap SDL joystick button functions to handle the 'fake' android joystick
// buttons. The method InputEventGenerator::handle() already takes care of fake
// events for the andoid joystick buttons, these two wrappers handle the direct
// joystick button state queries.
int InputEventGenerator::joystickNumButtons(SDL_Joystick* joystick)
{
        if (PLATFORM_ANDROID) {
                return 2;
        } else {
                return SDL_JoystickNumButtons(joystick);
        }
}
bool InputEventGenerator::joystickGetButton(SDL_Joystick* joystick, int button)
{
        if (PLATFORM_ANDROID) {
                switch (button) {
                case 0: return androidButtonA;
                case 1: return androidButtonB;
                default: UNREACHABLE; return false;
                }
        } else {
                return SDL_JoystickGetButton(joystick, button) != 0;
        }
}


// class EscapeGrabCmd

InputEventGenerator::EscapeGrabCmd::EscapeGrabCmd(
                CommandController& commandController_)
        : Command(commandController_, "escape_grab")
{
}

void InputEventGenerator::EscapeGrabCmd::execute(
        span<const TclObject> /*tokens*/, TclObject& /*result*/)
{
        auto& inputEventGenerator = OUTER(InputEventGenerator, escapeGrabCmd);
        if (inputEventGenerator.grabInput.getBoolean()) {
                inputEventGenerator.escapeGrabState =
                        InputEventGenerator::ESCAPE_GRAB_WAIT_LOST;
                inputEventGenerator.setGrabInput(false);
        }
}

string InputEventGenerator::EscapeGrabCmd::help(
        const vector<string>& /*tokens*/) const
{
        return "Temporarily release input grab.";
}

} // namespace openmsx