pdf.js/web/base_tree_viewer.js
Jonas Jenwald 6e9da55a39 Extract common methods from PDFOutlineViewer/PDFAttachmentViewer into a new abstract BaseTreeViewer class
These two classes are unsurprisingly quite similar, and with upcoming changes[1] the amount of (essentially) duplicated code will increase even further.

Notable changes:
 - Collect shared functionality in the `BaseTreeViewer` class, reducing both current and future code-duplication.
 - Reduce unnecessary duplication in the CSS rules, which will be particularly useful with upcoming changes.
 - Tweak the attachmentsView to use links, rather than buttons, to simplify (primarily) the CSS rules.

---
[1] Once API support for "Optional Content" lands, I've got more-or-less finished patches to add viewer support as well.
2020-08-05 23:08:06 +02:00

112 lines
3.0 KiB
JavaScript

/* Copyright 2020 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 { removeNullCharacters } from "pdfjs-lib";
class BaseTreeViewer {
constructor(options) {
if (this.constructor === BaseTreeViewer) {
throw new Error("Cannot initialize BaseTreeViewer.");
}
this.container = options.container;
this.eventBus = options.eventBus;
this.reset();
}
reset() {
this._lastToggleIsShow = true;
// Remove the tree from the DOM.
this.container.textContent = "";
// Ensure that the left (right in RTL locales) margin is always reset,
// to prevent incorrect tree alignment if a new document is opened.
this.container.classList.remove("treeWithDeepNesting");
}
/**
* @private
*/
_dispatchEvent(count) {
throw new Error("Not implemented: _dispatchEvent");
}
/**
* @private
*/
_bindLink(element, params) {
throw new Error("Not implemented: _bindLink");
}
/**
* @private
*/
_normalizeTextContent(str) {
return removeNullCharacters(str) || /* en dash = */ "\u2013";
}
/**
* Prepend a button before a tree item which allows the user to collapse or
* expand all tree items at that level; see `_toggleTreeItem`.
* @private
*/
_addToggleButton(div, hidden = false) {
const toggler = document.createElement("div");
toggler.className = "treeItemToggler";
if (hidden) {
toggler.classList.add("treeItemsHidden");
}
toggler.onclick = evt => {
evt.stopPropagation();
toggler.classList.toggle("treeItemsHidden");
if (evt.shiftKey) {
const shouldShowAll = !toggler.classList.contains("treeItemsHidden");
this._toggleTreeItem(div, shouldShowAll);
}
};
div.insertBefore(toggler, div.firstChild);
}
/**
* Collapse or expand the subtree of a tree item.
*
* @param {Element} root - the root of the item (sub)tree.
* @param {boolean} show - whether to show the item (sub)tree. If false,
* the item subtree rooted at `root` will be collapsed.
* @private
*/
_toggleTreeItem(root, show = false) {
this._lastToggleIsShow = show;
for (const toggler of root.querySelectorAll(".treeItemToggler")) {
toggler.classList.toggle("treeItemsHidden", !show);
}
}
/**
* Collapse or expand all subtrees of the `container`.
* @private
*/
_toggleAllTreeItems() {
this._toggleTreeItem(this.container, !this._lastToggleIsShow);
}
render(params) {
throw new Error("Not implemented: render");
}
}
export { BaseTreeViewer };