@pdftron/webviewer-react-toolkit
Version:
A React component library for integrating with PDFTron WebViewer API.
75 lines (74 loc) • 2.89 kB
JavaScript
var validKeys = [
// Valid keys for thumbnail accessibility.
'Tab',
'ArrowLeft',
'ArrowRight',
'ArrowUp',
'ArrowDown',
];
var ThumbnailFocusObservable = /** @class */ (function () {
function ThumbnailFocusObservable() {
var _this = this;
this._handleFirstTab = function (event) {
if (validKeys.includes(event.key)) {
_this._setIsUserTabbing(true);
_this._tabToMouseListener();
}
};
this._handleFirstMouse = function () {
_this._setIsUserTabbing(false);
_this._mouseToTabListener();
};
this._subscribers = [];
this._isUserTabbing = false;
}
Object.defineProperty(ThumbnailFocusObservable.prototype, "value", {
get: function () {
return this._isUserTabbing;
},
enumerable: false,
configurable: true
});
ThumbnailFocusObservable.prototype.subscribe = function (subscriber) {
// If adding first subscriber, begin listening to document.
if (this._subscribers.length === 0) {
if (this._isUserTabbing) {
this._tabToMouseListener();
}
else {
this._mouseToTabListener();
}
}
var exists = this._subscribers.includes(subscriber);
if (!exists)
this._subscribers.push(subscriber);
return this._unsubscribe(subscriber);
};
ThumbnailFocusObservable.prototype._unsubscribe = function (subscriber) {
var _this = this;
return function () {
_this._subscribers = _this._subscribers.filter(function (s) { return s !== subscriber; });
// If no subscribers, stop listening to document.
if (_this._subscribers.length === 0)
_this._removeAllListeners();
};
};
ThumbnailFocusObservable.prototype._setIsUserTabbing = function (isUserTabbing) {
this._isUserTabbing = isUserTabbing;
this._subscribers.forEach(function (subscriber) { return subscriber(); });
};
ThumbnailFocusObservable.prototype._tabToMouseListener = function () {
window.removeEventListener('keydown', this._handleFirstTab);
window.addEventListener('mousedown', this._handleFirstMouse);
};
ThumbnailFocusObservable.prototype._mouseToTabListener = function () {
window.removeEventListener('mousedown', this._handleFirstMouse);
window.addEventListener('keydown', this._handleFirstTab);
};
ThumbnailFocusObservable.prototype._removeAllListeners = function () {
window.removeEventListener('mousedown', this._handleFirstMouse);
window.removeEventListener('keydown', this._handleFirstTab);
};
return ThumbnailFocusObservable;
}());
export var thumbnailFocusObservable = new ThumbnailFocusObservable();