Widget with checkbox

widget.php

<?php

add_action( 'widgets_init',  'register_my_scheduled_posts_widget' );

function register_my_scheduled_posts_widget() {
	register_widget( 'My_Scheduled_Posts_Widget' );
}

class My_Scheduled_Posts_Widget extends WP_Widget {

	public function __construct() {
		$widget_ops = array(
			'classname' => 'scheduled_recent_entries',
			'description' => __( 'Your site&#8217;s most recent (scheduled) Posts.' ),
			'customize_selective_refresh' => true,
		);
		parent::__construct( 'scheduled-recent-posts', __( 'Scheduled Posts' ), $widget_ops );
	}

	/**
	 * Widget display.
	 */
	public function widget( $args, $instance ) {
		$status_future = (bool) $instance['status_future'];

		/*  ***** Query for recent posts and display them in the front end here *****  */
	}

	/**
	 * Update widget settings.
	 */
	public function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$instance['status_future'] = isset( $new_instance['status_future'] ) ? (bool) $new_instance['status_future'] : false;
		return $instance;
	}

	/**
	 * Widget settings form.
	 */
	public function form( $instance ) {
		$status_future = isset ( $instance['status_future'] ) ? (bool) $instance['status_future'] : false;
?>
<p>
	<input class="checkbox" type="checkbox" <?php checked( $status_future, true ); ?> id="<?php echo $this->get_field_id( 'status_future' ); ?>" name="<?php echo $this->get_field_name( 'status_future' ); ?>">
	<label for="<?php echo $this->get_field_id( 'status_future' ); ?>"><?php _e( 'Show posts with future dates only?', 'custom-post-type-date-archives' ); ?></label>
</p>
<?php
	}
}