diff options
Diffstat (limited to 'ext/mixed/js/document-focus-controller.js')
-rw-r--r-- | ext/mixed/js/document-focus-controller.js | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/ext/mixed/js/document-focus-controller.js b/ext/mixed/js/document-focus-controller.js deleted file mode 100644 index 649b5abe..00000000 --- a/ext/mixed/js/document-focus-controller.js +++ /dev/null @@ -1,110 +0,0 @@ -/* - * Copyright (C) 2020-2021 Yomichan Authors - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <https://www.gnu.org/licenses/>. - */ - -/** - * This class is used to control the document focus when a non-body element contains the main scrollbar. - * Web browsers will not automatically focus a custom element with the scrollbar on load, which results in - * keyboard shortcuts (e.g. arrow keys) not controlling page scroll. Instead, this class will manually - * focus a dummy element inside the main content, which gives keyboard scroll focus to that element. - */ -class DocumentFocusController { - constructor() { - this._contentScrollFocusElement = document.querySelector('#content-scroll-focus'); - } - - prepare() { - window.addEventListener('focus', this._onWindowFocus.bind(this), false); - this._updateFocusedElement(false); - } - - blurElement(element) { - if (document.activeElement !== element) { return; } - element.blur(); - this._updateFocusedElement(false); - } - - // Private - - _onWindowFocus() { - this._updateFocusedElement(false); - } - - _updateFocusedElement(force) { - const target = this._contentScrollFocusElement; - if (target === null) { return; } - - const {activeElement} = document; - if ( - force || - activeElement === null || - activeElement === document.documentElement || - activeElement === document.body - ) { - // Get selection - const selection = window.getSelection(); - const selectionRanges1 = this._getSelectionRanges(selection); - - // Note: This function will cause any selected text to be deselected on Firefox. - target.focus({preventScroll: true}); - - // Restore selection - const selectionRanges2 = this._getSelectionRanges(selection); - if (!this._areRangesSame(selectionRanges1, selectionRanges2)) { - this._setSelectionRanges(selection, selectionRanges1); - } - } - } - - _getSelectionRanges(selection) { - const ranges = []; - for (let i = 0, ii = selection.rangeCount; i < ii; ++i) { - ranges.push(selection.getRangeAt(i)); - } - return ranges; - } - - _setSelectionRanges(selection, ranges) { - selection.removeAllRanges(); - for (const range of ranges) { - selection.addRange(range); - } - } - - _areRangesSame(ranges1, ranges2) { - const ii = ranges1.length; - if (ii !== ranges2.length) { - return false; - } - - for (let i = 0; i < ii; ++i) { - const range1 = ranges1[i]; - const range2 = ranges2[i]; - try { - if ( - range1.compareBoundaryPoints(Range.START_TO_START, range2) !== 0 || - range1.compareBoundaryPoints(Range.END_TO_END, range2) !== 0 - ) { - return false; - } - } catch (e) { - return false; - } - } - - return true; - } -} |