102 lines
3.1 KiB
JavaScript
102 lines
3.1 KiB
JavaScript
class ModalHandler {
|
|
static exists() {
|
|
return document.getElementById("modal-container") !== null;
|
|
}
|
|
|
|
static getModalContainer() {
|
|
let container = document.getElementById("modal-container");
|
|
|
|
if (container === undefined) {
|
|
return;
|
|
}
|
|
|
|
return container;
|
|
}
|
|
|
|
static getFocusableElements() {
|
|
let container = this.getModalContainer();
|
|
|
|
if (container === undefined) {
|
|
return;
|
|
}
|
|
|
|
return container.querySelectorAll('button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])');
|
|
}
|
|
|
|
static setupFocusTrap() {
|
|
let focusableElements = this.getFocusableElements();
|
|
|
|
if (focusableElements === undefined) {
|
|
return;
|
|
}
|
|
|
|
let firstFocusableElement = focusableElements[0];
|
|
let lastFocusableElement = focusableElements[focusableElements.length - 1];
|
|
|
|
this.getModalContainer().onkeydown = (e) => {
|
|
if (e.key !== 'Tab') {
|
|
return;
|
|
}
|
|
|
|
// If there is only one focusable element in the dialog we always want to focus that one with the tab key.
|
|
// This handles the special case of having just one focusable element in a dialog where keyboard focus is placed on an element that is not in the tab order.
|
|
if (focusableElements.length === 1) {
|
|
firstFocusableElement.focus();
|
|
e.preventDefault();
|
|
return;
|
|
}
|
|
|
|
if (e.shiftKey && document.activeElement === firstFocusableElement) {
|
|
lastFocusableElement.focus();
|
|
e.preventDefault();
|
|
} else if (!e.shiftKey && document.activeElement === lastFocusableElement) {
|
|
firstFocusableElement.focus();
|
|
e.preventDefault();
|
|
}
|
|
};
|
|
}
|
|
|
|
static open(fragment, initialFocusElementId) {
|
|
if (ModalHandler.exists()) {
|
|
return;
|
|
}
|
|
|
|
this.activeElement = document.activeElement;
|
|
|
|
let container = document.createElement("div");
|
|
container.id = "modal-container";
|
|
container.setAttribute("role", "dialog");
|
|
container.appendChild(document.importNode(fragment, true));
|
|
document.body.appendChild(container);
|
|
|
|
let closeButton = document.querySelector("button.btn-close-modal");
|
|
if (closeButton !== null) {
|
|
closeButton.onclick = (event) => {
|
|
event.preventDefault();
|
|
ModalHandler.close();
|
|
};
|
|
}
|
|
|
|
let initialFocusElement;
|
|
if (initialFocusElementId !== undefined) {
|
|
initialFocusElement = document.getElementById(initialFocusElementId);
|
|
} else {
|
|
initialFocusElement = this.getFocusableElements()[0];
|
|
}
|
|
|
|
initialFocusElement.focus();
|
|
|
|
this.setupFocusTrap();
|
|
}
|
|
|
|
static close() {
|
|
let container = this.getModalContainer();
|
|
if (container !== null) {
|
|
container.parentNode.removeChild(container);
|
|
}
|
|
|
|
if (this.activeElement !== undefined) {
|
|
this.activeElement.focus();
|
|
}
|
|
}
|
|
}
|