// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import {assert, assertNotReached} from '//resources/js/assert.js';
import {KeyboardShortcutList} from '//resources/js/keyboard_shortcut_list.js';
import {isMac} from '//resources/js/platform.js';
import {dedupingMixin, PolymerElement} from '//resources/polymer/v3_0/polymer/polymer_bundled.min.js';
/**
* @fileoverview Listens for a find keyboard shortcut (i.e. Ctrl/Cmd+f or /)
* and keeps track of an stack of potential listeners. Only the listener at the
* top of the stack will be notified that a find shortcut has been invoked.
*/
export const FindShortcutManager = (() => {
/**
* Stack of listeners. Only the top listener will handle the shortcut.
*/
const listeners: FindShortcutMixinInterface[] = [];
/**
* Tracks if any modal context is open in settings. This assumes only one
* modal can be open at a time. The modals that are being tracked include
* cr-dialog and cr-drawer.
* @type {boolean}
*/
let modalContextOpen = false;
const shortcutCtrlF = new KeyboardShortcutList(isMac ? 'meta|f' : 'ctrl|f');
const shortcutSlash = new KeyboardShortcutList('/');
window.addEventListener('keydown', e => {
if (e.defaultPrevented || listeners.length === 0) {
return;
}
const element = e.composedPath()[0] as Element;
if (!shortcutCtrlF.matchesEvent(e) &&
(element.tagName === 'INPUT' || element.tagName === 'TEXTAREA' ||
!shortcutSlash.matchesEvent(e))) {
return;
}
const focusIndex =
listeners.findIndex(listener => listener.searchInputHasFocus());
// If no listener has focus or the first (outer-most) listener has focus,
// try the last (inner-most) listener.
// If a listener has a search input with focus, the next listener that
// should be called is the right before it in |listeners| such that the
// goes from inner-most to outer-most.
const index = focusIndex <= 0 ? listeners.length - 1 : focusIndex - 1;
if (listeners[index]!.handleFindShortcut(modalContextOpen)) {
e.preventDefault();
}
});
window.addEventListener('cr-dialog-open', () => {
modalContextOpen = true;
});
window.addEventListener('cr-drawer-opened', () => {
modalContextOpen = true;
});
window.addEventListener('close', e => {
if (['CR-DIALOG', 'CR-DRAWER'].includes(
(e.composedPath()[0] as Element).nodeName)) {
modalContextOpen = false;
}
});
return Object.freeze({listeners: listeners});
})();
type Constructor<T> = new (...args: any[]) => T;
/**
* Used to determine how to handle find shortcut invocations.
*/
export const FindShortcutMixin = dedupingMixin(
<T extends Constructor<PolymerElement>>(superClass: T): T&
Constructor<FindShortcutMixinInterface> => {
class FindShortcutMixin extends superClass implements
FindShortcutMixinInterface {
findShortcutListenOnAttach: boolean = true;
override connectedCallback() {
super.connectedCallback();
if (this.findShortcutListenOnAttach) {
this.becomeActiveFindShortcutListener();
}
}
override disconnectedCallback() {
super.disconnectedCallback();
if (this.findShortcutListenOnAttach) {
this.removeSelfAsFindShortcutListener();
}
}
becomeActiveFindShortcutListener() {
const listeners = FindShortcutManager.listeners;
assert(
!listeners.includes(this),
'Already listening for find shortcuts.');
listeners.push(this);
}
private handleFindShortcutInternal_() {
assertNotReached('Must override handleFindShortcut()');
}
handleFindShortcut(_modalContextOpen: boolean) {
this.handleFindShortcutInternal_();
return false;
}
removeSelfAsFindShortcutListener() {
const listeners = FindShortcutManager.listeners;
const index = listeners.indexOf(this);
assert(listeners.includes(this), 'Find shortcut listener not found.');
listeners.splice(index, 1);
}
private searchInputHasFocusInternal_() {
assertNotReached('Must override searchInputHasFocus()');
}
searchInputHasFocus() {
this.searchInputHasFocusInternal_();
return false;
}
}
return FindShortcutMixin;
});
export interface FindShortcutMixinInterface {
findShortcutListenOnAttach: boolean;
becomeActiveFindShortcutListener(): void;
/** If handled, return true. */
handleFindShortcut(modalContextOpen: boolean): boolean;
removeSelfAsFindShortcutListener(): void;
searchInputHasFocus(): boolean;
}