jellyfin-web/src/components/focusManager.js
2020-02-16 04:22:50 +01:00

543 lines
15 KiB
JavaScript

define(['dom', 'scrollManager'], function (dom, scrollManager) {
'use strict';
var scopes = [];
function pushScope(elem) {
scopes.push(elem);
}
function popScope(elem) {
if (scopes.length) {
scopes.length -= 1;
}
}
function autoFocus(view, defaultToFirst, findAutoFocusElement) {
var element;
if (findAutoFocusElement !== false) {
element = view.querySelector('*[autofocus]');
if (element) {
focus(element);
return element;
}
}
if (defaultToFirst !== false) {
element = getFocusableElements(view, 1, 'noautofocus')[0];
if (element) {
focus(element);
return element;
}
}
return null;
}
function focus(element) {
try {
element.focus({
preventScroll: scrollManager.isEnabled()
});
} catch (err) {
console.error('Error in focusManager.autoFocus: ' + err);
}
}
var focusableTagNames = ['INPUT', 'TEXTAREA', 'SELECT', 'BUTTON', 'A'];
var focusableContainerTagNames = ['BODY', 'DIALOG'];
var focusableQuery = focusableTagNames.map(function (t) {
if (t === 'INPUT') {
t += ':not([type="range"]):not([type="file"])';
}
return t + ':not([tabindex="-1"]):not(:disabled)';
}).join(',') + ',.focusable';
function isFocusable(elem) {
if (focusableTagNames.indexOf(elem.tagName) !== -1) {
return true;
}
if (elem.classList && elem.classList.contains('focusable')) {
return true;
}
return false;
}
function normalizeFocusable(elem, originalElement) {
if (elem) {
var tagName = elem.tagName;
if (!tagName || tagName === 'HTML' || tagName === 'BODY') {
elem = originalElement;
}
}
return elem;
}
function focusableParent(elem) {
var originalElement = elem;
while (!isFocusable(elem)) {
var parent = elem.parentNode;
if (!parent) {
return normalizeFocusable(elem, originalElement);
}
elem = parent;
}
return normalizeFocusable(elem, originalElement);
}
// Determines if a focusable element can be focused at a given point in time
function isCurrentlyFocusableInternal(elem) {
// http://stackoverflow.com/questions/19669786/check-if-element-is-visible-in-dom
if (elem.offsetParent === null) {
return false;
}
return true;
}
// Determines if a focusable element can be focused at a given point in time
function isCurrentlyFocusable(elem) {
if (elem.disabled) {
return false;
}
if (elem.getAttribute('tabindex') === "-1") {
return false;
}
if (elem.tagName === 'INPUT') {
var type = elem.type;
if (type === 'range') {
return false;
}
if (type === 'file') {
return false;
}
}
return isCurrentlyFocusableInternal(elem);
}
function getDefaultScope() {
return scopes[0] || document.body;
}
function getFocusableElements(parent, limit, excludeClass) {
var elems = (parent || getDefaultScope()).querySelectorAll(focusableQuery);
var focusableElements = [];
for (var i = 0, length = elems.length; i < length; i++) {
var elem = elems[i];
if (excludeClass && elem.classList.contains(excludeClass)) {
continue;
}
if (isCurrentlyFocusableInternal(elem)) {
focusableElements.push(elem);
if (limit && focusableElements.length >= limit) {
break;
}
}
}
return focusableElements;
}
function isFocusContainer(elem, direction) {
if (focusableContainerTagNames.indexOf(elem.tagName) !== -1) {
return true;
}
var classList = elem.classList;
if (classList.contains('focuscontainer')) {
return true;
}
if (direction === 0) {
if (classList.contains('focuscontainer-x')) {
return true;
}
if (classList.contains('focuscontainer-left')) {
return true;
}
} else if (direction === 1) {
if (classList.contains('focuscontainer-x')) {
return true;
}
if (classList.contains('focuscontainer-right')) {
return true;
}
} else if (direction === 2) {
if (classList.contains('focuscontainer-y')) {
return true;
}
} else if (direction === 3) {
if (classList.contains('focuscontainer-y')) {
return true;
}
if (classList.contains('focuscontainer-down')) {
return true;
}
}
return false;
}
function getFocusContainer(elem, direction) {
while (!isFocusContainer(elem, direction)) {
elem = elem.parentNode;
if (!elem) {
return getDefaultScope();
}
}
return elem;
}
function getOffset(elem) {
var box;
// Support: BlackBerry 5, iOS 3 (original iPhone)
// If we don't have gBCR, just use 0,0 rather than error
if (elem.getBoundingClientRect) {
box = elem.getBoundingClientRect();
} else {
box = {
top: 0,
left: 0,
width: 0,
height: 0
};
}
if (box.right === null) {
// Create a new object because some browsers will throw an error when trying to set data onto the Rect object
var newBox = {
top: box.top,
left: box.left,
width: box.width,
height: box.height
};
box = newBox;
box.right = box.left + box.width;
box.bottom = box.top + box.height;
}
return box;
}
function nav(activeElement, direction, container, focusableElements) {
activeElement = activeElement || document.activeElement;
if (activeElement) {
activeElement = focusableParent(activeElement);
}
container = container || (activeElement ? getFocusContainer(activeElement, direction) : getDefaultScope());
if (!activeElement) {
autoFocus(container, true, false);
return;
}
var focusableContainer = dom.parentWithClass(activeElement, 'focusable');
var rect = getOffset(activeElement);
// Get elements and work out x/y points
var cache = [];
var point1x = parseFloat(rect.left) || 0;
var point1y = parseFloat(rect.top) || 0;
var point2x = parseFloat(point1x + rect.width - 1) || point1x;
var point2y = parseFloat(point1y + rect.height - 1) || point1y;
// Shortcuts to help with compression
var min = Math.min;
var max = Math.max;
var sourceMidX = rect.left + (rect.width / 2);
var sourceMidY = rect.top + (rect.height / 2);
var focusable = focusableElements || container.querySelectorAll(focusableQuery);
var maxDistance = Infinity;
var minDistance = maxDistance;
var nearestElement;
for (var i = 0, length = focusable.length; i < length; i++) {
var curr = focusable[i];
if (curr === activeElement) {
continue;
}
// Don't refocus into the same container
if (curr === focusableContainer) {
continue;
}
//if (!isCurrentlyFocusableInternal(curr)) {
// continue;
//}
var elementRect = getOffset(curr);
// not currently visible
if (!elementRect.width && !elementRect.height) {
continue;
}
switch (direction) {
case 0:
// left
if (elementRect.left >= rect.left) {
continue;
}
if (elementRect.right === rect.right) {
continue;
}
break;
case 1:
// right
if (elementRect.right <= rect.right) {
continue;
}
if (elementRect.left === rect.left) {
continue;
}
break;
case 2:
// up
if (elementRect.top >= rect.top) {
continue;
}
if (elementRect.bottom >= rect.bottom) {
continue;
}
break;
case 3:
// down
if (elementRect.bottom <= rect.bottom) {
continue;
}
if (elementRect.top <= rect.top) {
continue;
}
break;
default:
break;
}
var x = elementRect.left;
var y = elementRect.top;
var x2 = x + elementRect.width - 1;
var y2 = y + elementRect.height - 1;
var intersectX = intersects(point1x, point2x, x, x2);
var intersectY = intersects(point1y, point2y, y, y2);
var midX = elementRect.left + (elementRect.width / 2);
var midY = elementRect.top + (elementRect.height / 2);
var distX;
var distY;
switch (direction) {
case 0:
// left
distX = Math.abs(point1x - Math.min(point1x, x2));
distY = intersectY ? 0 : Math.abs(sourceMidY - midY);
break;
case 1:
// right
distX = Math.abs(point2x - Math.max(point2x, x));
distY = intersectY ? 0 : Math.abs(sourceMidY - midY);
break;
case 2:
// up
distY = Math.abs(point1y - Math.min(point1y, y2));
distX = intersectX ? 0 : Math.abs(sourceMidX - midX);
break;
case 3:
// down
distY = Math.abs(point2y - Math.max(point2y, y));
distX = intersectX ? 0 : Math.abs(sourceMidX - midX);
break;
default:
break;
}
var dist = Math.sqrt(distX * distX + distY * distY);
if (dist < minDistance) {
nearestElement = curr;
minDistance = dist;
}
}
if (nearestElement) {
// See if there's a focusable container, and if so, send the focus command to that
if (activeElement) {
var nearestElementFocusableParent = dom.parentWithClass(nearestElement, 'focusable');
if (nearestElementFocusableParent && nearestElementFocusableParent !== nearestElement) {
if (focusableContainer !== nearestElementFocusableParent) {
nearestElement = nearestElementFocusableParent;
}
}
}
focus(nearestElement);
}
}
function intersectsInternal(a1, a2, b1, b2) {
return (b1 >= a1 && b1 <= a2) || (b2 >= a1 && b2 <= a2);
}
function intersects(a1, a2, b1, b2) {
return intersectsInternal(a1, a2, b1, b2) || intersectsInternal(b1, b2, a1, a2);
}
function sendText(text) {
var elem = document.activeElement;
elem.value = text;
}
function focusFirst(container, focusableSelector) {
var elems = container.querySelectorAll(focusableSelector);
for (var i = 0, length = elems.length; i < length; i++) {
var elem = elems[i];
if (isCurrentlyFocusableInternal(elem)) {
focus(elem);
break;
}
}
}
function focusLast(container, focusableSelector) {
var elems = [].slice.call(container.querySelectorAll(focusableSelector), 0).reverse();
for (var i = 0, length = elems.length; i < length; i++) {
var elem = elems[i];
if (isCurrentlyFocusableInternal(elem)) {
focus(elem);
break;
}
}
}
function moveFocus(sourceElement, container, focusableSelector, offset) {
var elems = container.querySelectorAll(focusableSelector);
var list = [];
var i;
var length;
var elem;
for (i = 0, length = elems.length; i < length; i++) {
elem = elems[i];
if (isCurrentlyFocusableInternal(elem)) {
list.push(elem);
}
}
var currentIndex = -1;
for (i = 0, length = list.length; i < length; i++) {
elem = list[i];
if (sourceElement === elem || elem.contains(sourceElement)) {
currentIndex = i;
break;
}
}
if (currentIndex === -1) {
return;
}
var newIndex = currentIndex + offset;
newIndex = Math.max(0, newIndex);
newIndex = Math.min(newIndex, list.length - 1);
var newElem = list[newIndex];
if (newElem) {
focus(newElem);
}
}
return {
autoFocus: autoFocus,
focus: focus,
focusableParent: focusableParent,
getFocusableElements: getFocusableElements,
moveLeft: function (sourceElement, options) {
var container = options ? options.container : null;
var focusableElements = options ? options.focusableElements : null;
nav(sourceElement, 0, container, focusableElements);
},
moveRight: function (sourceElement, options) {
var container = options ? options.container : null;
var focusableElements = options ? options.focusableElements : null;
nav(sourceElement, 1, container, focusableElements);
},
moveUp: function (sourceElement, options) {
var container = options ? options.container : null;
var focusableElements = options ? options.focusableElements : null;
nav(sourceElement, 2, container, focusableElements);
},
moveDown: function (sourceElement, options) {
var container = options ? options.container : null;
var focusableElements = options ? options.focusableElements : null;
nav(sourceElement, 3, container, focusableElements);
},
sendText: sendText,
isCurrentlyFocusable: isCurrentlyFocusable,
pushScope: pushScope,
popScope: popScope,
focusFirst: focusFirst,
focusLast: focusLast,
moveFocus: moveFocus
};
});