einsatzprotokoll/source/DeleteView.mc

import Toybox.Attention;
import Toybox.Graphics;
import Toybox.Lang;
import Toybox.Timer;
import Toybox.WatchUi;

// Long-press confirmation for deleting the last event. Shows a red
// arc that fills over DELETE_HOLD_MS. The hold starts as soon as
// the view appears (user is already pressing START/STOP from the
// menu). Releasing the key before the arc completes cancels.
class DeleteView extends WatchUi.View {

    private var _holdStartMs as Number = 0;
    private var _animTimer as Timer.Timer;
    private var _deleted as Boolean = false;
    private var _started as Boolean = false;

    function initialize() {
        View.initialize();
        _animTimer = new Timer.Timer();
    }

    function onShow() as Void {
        _animTimer.start(method(:_tick), 50, true);
    }

    function onHide() as Void {
        _animTimer.stop();
    }

    function startHold() as Void {
        if (_deleted || _started) { return; }
        _started = true;
        _holdStartMs = System.getTimer();
    }

    function cancel() as Void {
        if (!_deleted) {
            WatchUi.popView(WatchUi.SLIDE_RIGHT);
        }
    }

    function _tick() as Void {
        if (_deleted) { return; }
        if (_started) {
            var elapsed = System.getTimer() - _holdStartMs;
            if (elapsed >= Config.DELETE_HOLD_MS) {
                _performDelete();
                return;
            }
        }
        WatchUi.requestUpdate();
    }

    private function _performDelete() as Void {
        _deleted = true;
        _animTimer.stop();
        EventStore.deleteLast();
        if (Attention has :vibrate) {
            Attention.vibrate([new Attention.VibeProfile(75, 200)] as Array<Attention.VibeProfile>);
        }
        WatchUi.switchToView(new SuccessView(), null, WatchUi.SLIDE_IMMEDIATE);
    }

    function onUpdate(dc as Dc) as Void {
        dc.setColor(Config.COLOR_FG, Config.COLOR_BG);
        dc.clear();

        var cx = LayoutMetrics.centerX(dc);
        var cy = LayoutMetrics.centerY(dc);
        var radius = LayoutMetrics.edgeArcRadius(dc);

        // Red arc showing hold progress.
        var progress = 0.0;
        if (_started) {
            var elapsed = System.getTimer() - _holdStartMs;
            progress = elapsed.toFloat() / Config.DELETE_HOLD_MS.toFloat();
            if (progress > 1.0) { progress = 1.0; }
        }

        if (progress > 0.0) {
            dc.setPenWidth(LayoutMetrics.edgeArcPenWidth(dc));
            dc.setColor(Config.COLOR_DELETE, Config.COLOR_BG);
            var sweep = progress * 360.0;
            dc.drawArc(cx, cy, radius, Graphics.ARC_CLOCKWISE, 90, 90 - sweep);
        }

        // Prompt text.
        dc.setColor(Config.COLOR_FG, Config.COLOR_BG);
        TextUtils.drawResourceCentered(dc, Rez.Strings.delete_hold, cx, cy, Graphics.FONT_TINY);
    }
}