function injectKeyHold(key): Signal<boolean>;

@Component({
  template: `{{ isShiftHeld() ? 'Shift is pressed!' : 'Press Shift' }}`,
})
export class ShiftIndicatorComponent {
  isShiftHeld = injectKeyHold('Shift')
}

@Component({
  template: `
    <span [style.opacity]="ctrl() ? 1 : 0.3">Ctrl</span>
    <span [style.opacity]="shift() ? 1 : 0.3">Shift</span>
  `,
})
export class ModifierIndicatorsComponent {
  ctrl = injectKeyHold('Control')
  shift = injectKeyHold('Shift')
}