var buttonsClass = {

    new : func (device) {

        var m = { parents: [ buttonsClass ] };

        m.device = device;

        return m;

    },

    PAN : func (xdir = 0, ydir = 0) {

    },

    AsSwitchNAV : func {

        var n = radios.getValue('nav-tune');

        var tmp = getprop('/instrumentation/nav[' ~ n ~ ']/frequencies/selected-mhz');

        setprop('/instrumentation/nav[' ~ n ~ ']/frequencies/selected-mhz', getprop('/instrumentation/nav[' ~ n ~ ']/frequencies/standby-mhz'));

        setprop('/instrumentation/nav[' ~ n ~ ']/frequencies/standby-mhz', tmp);

        foreach (var c; keys(flightdeck))

            if (contains(flightdeck[c], 'display'))

                flightdeck[c].display.updateNAV({refresh: n+1});

    },

    AsSwitchCOM : func (x) {

        if (x) {

            me.AsSwitchCOM_pushed = getprop('/sim/time/elapsed-sec');

        }

        else {

            var pressed = getprop('/sim/time/elapsed-sec') - me.AsSwitchCOM_pushed;

            if (pressed > 2) {

                setprop('/instrumentation/comm/frequencies/selected-mhz', 121.500);

                radios.setValue('comm1-selected', 1);

                radios.setValue('comm2-selected', 0);

                foreach (var d; keys(flightdeck))

                    if (contains(flightdeck[d], 'display')) {

                        flightdeck[d].display.updateCOMM({refresh: 1});

                        flightdeck[d].display.updateCOMM({refresh: 2});

                    }

            }

            else {

                var c = radios.getValue('comm-tune');

                var tmp = getprop('/instrumentation/comm[' ~ c ~ ']/frequencies/selected-mhz');

                setprop('/instrumentation/comm[' ~ c ~ ']/frequencies/selected-mhz', getprop('/instrumentation/comm[' ~ c ~ ']/frequencies/standby-mhz'));

                setprop('/instrumentation/comm[' ~ c ~ ']/frequencies/standby-mhz', tmp);

                foreach (var d; keys(flightdeck))

                    if (contains(flightdeck[d], 'display'))

                        flightdeck[d].display.updateCOMM({refresh: c+1});

            }

        }

    },

    ALT : func () {

        var alt = getprop('instrumentation/altimeter/indicated-altitude-ft');

        afcs.setIntValue('selected-alt-ft', math.round(alt, 10));

    },

    ValidateTMRREF : func (a = 0) {

        if (a)

            return;

        var (id, selected) = split('-', me.device.windows.selected);

        var state = me.device.windows.state[id];

        selected += state.scroll.offset;

        if (contains(state.objects[selected], 'callback'))

            call(state.objects[selected].callback, [id, selected], me);

    },

    ClearTMRREF : func (a = 0) {

        if (a)

            return;

        me.device.windows.del();

        me.device.data.TMRtimer = nil;

        me.device.knobs.FmsInner = func;

        me.device.knobs.FmsOuter = func;

        me.device.buttons.ENT = func;

        me.device.buttons.FMS = func;

        me.device.buttons.CLR = func;

    },

    MFD_page_wrapper : func (id, selected) {

        var s = me.device.data[id][me.device.display['page selected']];

        var group = s.name;

        var subpage = s.objects[selected].text;

        foreach (var k; keys(me.device.windows.window))

            if (find(id, k) == 0) {

                me.device.windows.del(id);

                break;

            }

        call(me.device.display.MFD[group][subpage], [], me);

    },

    MapMenu : func (a = 0) {

        if (a == 1)

            return;

        var menu_label = 'MAP MENU';

        if (!contains(me.device.windows.window, menu_label ~ '-bg')) {

            var level_min = 13;

            var level_max = 7;

            var levels = [ sprintf('  % 2u >', level_max) ];

            for (var i = level_max + 1; i <= level_min; i += 1)

                append(levels, sprintf(i < level_min ? '< % 2u >' : '< % 2u  ', i));

            var orientation = [ '  NORTH UP >', '<  TRK UP  >' ];

            if (getprop('/instrumentation/gps/route-distance-nm') != nil)

                append(orientation, '<  DTK UP  >');

            append(orientation, '<  HDG UP   ');

            me.device.windows.draw(

                    menu_label,

                    {x: 720, y: 100, w: 300, l:3, sep: 1},

                    [

                        {text: menu_label, type: 'title'},

                        {type: 'separator'},

                        {text: 'ZOOM LEVEL', type: 'normal'},

                        {text: sprintf('%s % 2u %s',

                                me.device.data.zoom > level_max ? '<' : ' ',

                                me.device.data.zoom,

                                me.device.data.zoom < level_min ? '>' : ' '),

                         type: 'selected|end-of-line',

                         choices: levels,

                         callback: func (id, selected) {

                             var z = me.device.windows.state[id].objects[selected].text;

                             foreach (var c; [' ', '<', '>'])

                                 z = string.replace(z, c, '');

                             me.device.data.zoom = z;

                             me.device.map.changeZoom();

                             me.device.map.update();

                         }

                        },

                        {text: 'ORIENTATION', type: 'normal'},

                        {text: (func foreach (var o; orientation) if (find(me.device.data.orientation.text, o) > -1) return o;)(),

                         type: 'editable|end-of-line',

                         choices: orientation,

                         callback: func (id, selected) {

                             var o = me.device.windows.state[id].objects[selected].text;

                             o = substr(o, 2);

                             o = substr(o, 0, size(o) - 2);

                             o = string.trim(o);

                             me.device.data.orientation.text = o;

                             me.device.map.update();

                         }

                        },

                    ]

                );

            me.device.knobs.FmsOuter = me.device.knobs.NavigateMenu;

            me.device.knobs.FmsInner = me.device.knobs.MenuSettings;

            me.device.buttons.CLR = me.device.buttons.MapMenu;

            me.device.buttons.ENT = me.device.buttons.ValidateTMRREF;

        }

        else {

            me.device.buttons.ENT = func;

            me.device.buttons.CLR = func;

            me.device.knobs.FmsInner = func;

            me.device.knobs.FmsOuter = me.device.knobs.MFD_select_page_group;

            me.device.windows.del(menu_label);

        }

    },

    DirectTo : void,

    MENU : void,

    FPL : void,

    PROC : void,

    CLR : void,

    ENT : void,

    FMS : void,

};