pdf.js/web/pdf_viewer.js
Jonas Jenwald 06cda4c2e7 Move additional code/methods into BaseViewer and have the extending classes override/extend methods as necessary
This attempts to provide more "default" methods in the base class, in order to reduce unnecessary duplication and to improve self-documentation of the `BaseViewer` class slightly.
The following changes are made (in no particular order):
 - Have `BaseViewer` implement the `_scrollIntoView` method, and *extend* it as necessary in `PDFViewer`/`PDFSinglePageViewer`.
 - Simply inline the `BaseViewer._resizeBuffer` method, in `BaseViewer.update`, since there's only one call-site at this point.
 - Provide a default implementation of `_isScrollModeHorizontal` in `BaseViewer`, and have `PDFSinglePageViewer` override it.
 - Provide a default implementation of `_getVisiblePages`, and have `PDFViewer` extend it and `PDFSinglePageViewer` override it.
2019-01-24 10:31:06 +01:00

72 lines
2.1 KiB
JavaScript

/* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { BaseViewer } from './base_viewer';
import { shadow } from 'pdfjs-lib';
class PDFViewer extends BaseViewer {
get _setDocumentViewerElement() {
return shadow(this, '_setDocumentViewerElement', this.viewer);
}
_scrollIntoView({ pageDiv, pageSpot = null, pageNumber = null, }) {
if (!pageSpot && !this.isInPresentationMode) {
const left = pageDiv.offsetLeft + pageDiv.clientLeft;
const right = left + pageDiv.clientWidth;
const { scrollLeft, clientWidth, } = this.container;
if (this._isScrollModeHorizontal ||
left < scrollLeft || right > scrollLeft + clientWidth) {
pageSpot = { left: 0, top: 0, };
}
}
super._scrollIntoView({ pageDiv, pageSpot, pageNumber, });
}
_getVisiblePages() {
if (this.isInPresentationMode) {
// The algorithm in `getVisibleElements` doesn't work in all browsers and
// configurations (e.g. Chrome) when Presentation Mode is active.
return this._getCurrentVisiblePage();
}
return super._getVisiblePages();
}
_updateHelper(visiblePages) {
if (this.isInPresentationMode) {
return;
}
let currentId = this._currentPageNumber;
let stillFullyVisible = false;
for (const page of visiblePages) {
if (page.percent < 100) {
break;
}
if (page.id === currentId) {
stillFullyVisible = true;
break;
}
}
if (!stillFullyVisible) {
currentId = visiblePages[0].id;
}
this._setCurrentPageNumber(currentId);
}
}
export {
PDFViewer,
};