openproject/frontend/app/templates/inplace-edit/edit/fields/boolean.html

<div class="switch">
  <input type="checkbox"
         class="focus-input"
         id="checkbox-switch-{{ field.name }}"
         name="value"
         ng-disabled="fieldController.state.isBusy"
         title="{{ fieldController.editTitle }}"
         ng-model="field.value" />
  <label for="checkbox-switch-{{ field.name }}" title="{{ fieldController.editTitle }}"></label>
</div>