Files
edx-platform/lms/static/js/dialog_tab_controls.js
2016-09-29 19:21:03 +05:00

74 lines
2.4 KiB
JavaScript

var DialogTabControls = (function() {
'use strict';
var focusableChildren,
numElements,
currentIndex,
focusableElementSelectors = 'a, input[type=text], input[type=submit], select, textarea, button',
setCurrentIndex = function(currentElement) {
var elementIndex = focusableChildren.index(currentElement);
if (elementIndex >= 0) {
currentIndex = elementIndex;
}
},
initializeTabKeyValues = function(elementName, $closeButton) {
focusableChildren = $(elementName).find(focusableElementSelectors);
if ($closeButton) {
focusableChildren = focusableChildren.add($closeButton);
}
numElements = focusableChildren.length;
currentIndex = 0;
focusableChildren[currentIndex].focus();
focusableChildren.on('click', function() {
setCurrentIndex(this);
});
},
focusElement = function() {
var focusableElement = focusableChildren[currentIndex];
if (focusableElement) {
focusableElement.focus();
}
},
focusPrevious = function() {
currentIndex--;
if (currentIndex < 0) {
currentIndex = numElements - 1;
}
focusElement();
},
focusNext = function() {
currentIndex++;
if (currentIndex >= numElements) {
currentIndex = 0;
}
focusElement();
},
setKeydownListener = function($element, $closeButton) {
$element.on('keydown', function(e) {
var keyCode = e.keyCode || e.which,
escapeKeyCode = 27,
tabKeyCode = 9;
if (keyCode === escapeKeyCode) {
e.preventDefault();
if ($closeButton) {
$closeButton.click();
}
}
if (keyCode === tabKeyCode && e.shiftKey) {
e.preventDefault();
focusPrevious();
} else if (keyCode === tabKeyCode) {
e.preventDefault();
focusNext();
}
});
};
return {
initializeTabKeyValues: initializeTabKeyValues,
setKeydownListener: setKeydownListener
};
}());