在屏幕阅读器上工作的空闲超时警告模式

时间:2016-08-13 03:04:26

标签: javascript jquery accessibility screen-readers

我需要帮助处理用户空闲时触发的模态。它运行良好,直到我在运行NVDA的Firefox上进行测试。使用箭头键时以及在移动设备上滑动时会出现焦点问题。当模态出现并且用户使用箭头或滑动时,如果我等待点击它,焦点将在几秒后从“是”按钮反弹到标题。我已将工作示例加载到:https://jsfiddle.net/ncanqaam/

我将空闲时间段更改为一分钟,并删除了调用服务器以扩展用户会话的部分。

var state ="L";
var timeoutPeriod = 540000;
var oneMinute = 60000;
var sevenMinutes = 60000;

var lastActivity = new Date();

function getIdleTime() {
    return new Date().getTime() - lastActivity.getTime();
}

//Add Movement Detection
function addMovementListener() {
    $(document).on('mousemove',  onMovementHandler);
    $(document).on('keypress',  onMovementHandler);
    $(document).on('touchstart touchend',  onMovementHandler);
}
//Remove Movement Detection
function removeMovementListener() {
    $(document).off('mousemove', onMovementHandler);
    $(document).off('keypress',  onMovementHandler);
    $(document).off('touchstart touchend',  onMovementHandler);
}

//Create Movement Handler
function onMovementHandler(ev) {
    lastActivity = new Date();
    console.log("Something moved, idle time = " + lastActivity.getTime());
}

function hide() {
    $('#overlayTY').removeClass('opened'); // remove the overlay in order to  make the main screen available again
    $('#overlayTY, #modal-session-timeout').css('display', 'none'); // hide the modal window
    $('#modal-session-timeout').attr('aria-hidden', 'true'); // mark the modal window as hidden
    $('#modal-session-timeout').removeAttr('aria-hidden'); // mark the main page as visible
}

if (state == "L") {
    $(document).ready(function() {
        //Call Event Listerner to for movement detection
        addMovementListener();
        setInterval(checkIdleTime, 5000);
    });

    function endSession() {
        console.log('Goodbye!');
    }

    var modalActive = false;
    function checkIdleTime() {
        var idleTime = getIdleTime();
        console.log("The total idle time is " + idleTime / oneMinute + " minutes.");

        if (idleTime > sevenMinutes) {
            var prevFocus = $(document.activeElement);
            console.log('previously: ' + prevFocus);
            var modal = new window.AccessibleModal({
                mainPage: $('#oc-container'),
                overlay: $('#overlayTY').css('display', 'block'),
                modal: $('#modal-session-timeout')
            });

            if (modalActive === false) {
                console.log(modalActive);
                $('#modal-session-timeout').insertBefore('#oc-container');
                $('#overlayTY').insertBefore('#modal-session-timeout');
                modal.show();
                $('#modal-overlay').removeClass('opened');
                modalActive = true;
                console.log(modalActive);
                console.log('the modal is active');
                $('.js-timeout-refresh').on('click touchstart touchend', function(){
                    hide();
                    modalActive = false;
                    prevFocus.focus();
                    addMovementListener();
                    lastActivity = new Date();
                });

                $('.js-timeout-session-end').on('click touchstart touchend', function(){
                    hide();
                    $('#overlayTY').css('display', 'none');
                    endSession();
                });
            }   
        }
        if ($('#overlayTY').css('display') === 'block'){
            removeMovementListener();
        }

        if (idleTime > timeoutPeriod) {
            endSession();
        }
    }
}

2 个答案:

答案 0 :(得分:0)

可能的解决方案

  1. 当叠加可见时,禁用正文上的指针事件。这将限制主体元素上的键盘/滑动事件
  2. 使用JS / jQuery触发对按钮
  3. 的关注

答案 1 :(得分:0)

问题出在Voiceover Safari上,当用户在锚点或按钮上滑动时,焦点会设置在这些元素上;但是,如果元素是H2,它将不会获得焦点,因为本身它不应该接收任何焦点。为了补偿我试图在H2上设置手势事件但是,Voiceover Safari需要时间来读取元素文本或标记输出加载,因此它可以防止任何事件被触发,这会在尝试将焦点设置为从加载的模态时产生问题超时功能而不是可点击元素。希望Apple将来能解决这个问题。