Files
azuredatastudio/src/sql/base/browser/dom.ts
2021-04-14 14:09:41 -07:00

101 lines
4.0 KiB
TypeScript

/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the Source EULA. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import { addDisposableListener, EventType } from 'vs/base/browser/dom';
import * as types from 'vs/base/common/types';
import { IDisposable } from 'vs/base/common/lifecycle';
import { StandardKeyboardEvent } from 'vs/base/browser/keyboardEvent';
import { KeyCode, KeyMod } from 'vs/base/common/keyCodes';
export function isHidden(element: HTMLElement): boolean {
return element.style.display === 'none';
}
/**
* Converts a size value into its string representation. This will add px to the end unless
* it already ends with %. If the size value is undefined it will return the defaultValue as-is.
* @param size The size value to convert
* @param defaultValue The default value to use if the size is undefined
*/
export function convertSize(size: number | string | undefined, defaultValue?: string): string {
defaultValue = defaultValue || '';
if (types.isUndefinedOrNull(size)) {
return defaultValue;
}
let convertedSize: string = size ? size.toString() : defaultValue;
convertedSize = convertedSize.toLowerCase();
if (!convertedSize.endsWith('px') && !convertedSize.endsWith('%')) {
convertedSize = convertedSize + 'px';
}
return convertedSize;
}
/**
* Converts a size value into its number representation. Supports px, em and unspecified units.
* @param size The size value to convert
*/
export function convertSizeToNumber(size: number | string | undefined): number {
if (size && typeof (size) === 'string') {
if (size.toLowerCase().endsWith('px')) {
return +size.replace('px', '');
} else if (size.toLowerCase().endsWith('em')) {
return +size.replace('em', '') * 11;
}
} else if (!size) {
return 0;
}
return +size;
}
const tabbableElementsQuerySelector = 'a[href], area[href], input:not([disabled]), select:not([disabled]), textarea:not([disabled]), button:not([disabled]), [tabindex="0"]';
/**
* Get the focusable elements inside a HTML element
* @param container The container element inside which we should look for the focusable elements
* @returns The focusable elements
*/
export function getFocusableElements(container: HTMLElement): HTMLElement[] {
const elements = [];
container.querySelectorAll(tabbableElementsQuerySelector).forEach((element: HTMLElement) => {
const style = window.getComputedStyle(element);
// We should only return the elements that are visible. There are many ways to hide an element, for example setting the
// visibility attribute to hidden/collapse, setting the display property to none, or if one of its ancestors is invisible.
if (element.offsetWidth > 0 && element.offsetHeight > 0 && style.visibility === 'visible') {
elements.push(element);
}
});
return elements;
}
/**
* Trap the keyboard navigation (Tab/Shift+Tab) inside the specified container
* @param container The container element to trap the keyboard focus in
* @returns The object to be disposed when the trap should be removed.
*/
export function trapKeyboardNavigation(container: HTMLElement): IDisposable {
return addDisposableListener(container, EventType.KEY_DOWN, (e) => {
const focusableElements = getFocusableElements(container);
if (focusableElements.length === 0) {
return;
}
const firstFocusable = focusableElements[0];
const lastFocusable = focusableElements[focusableElements.length - 1];
const event = new StandardKeyboardEvent(e);
let elementToFocus = undefined;
if (event.equals(KeyMod.Shift | KeyCode.Tab) && firstFocusable === document.activeElement) {
// Backward navigation
elementToFocus = lastFocusable;
} else if (event.equals(KeyCode.Tab) && lastFocusable === document.activeElement) {
// Forward navigation
elementToFocus = firstFocusable;
}
if (elementToFocus) {
e.preventDefault();
elementToFocus.focus();
}
});
}