pdf.js.mirror/web/pdf_thumbnail_viewer.js
Calixte Denizet 7f76a111c4
Fix the position of the thumbnails on the last line (bug 2016437)
The original issue can only be reproduce when the thumbnails are on two lines.
The fix is just a matter of computing the number of elements on the last line once we've
finished the first line.
2026-03-04 17:30:10 +01:00

1374 lines
42 KiB
JavaScript

/* Copyright 2012 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.
*/
/** @typedef {import("../src/display/api").PDFDocumentProxy} PDFDocumentProxy */
/** @typedef {import("../src/display/api").PDFPageProxy} PDFPageProxy */
/** @typedef {import("./event_utils").EventBus} EventBus */
// eslint-disable-next-line max-len
/** @typedef {import("./pdf_rendering_queue").PDFRenderingQueue} PDFRenderingQueue */
/** @typedef {import("./pdf_link_service.js").PDFLinkService} PDFLinkService */
import {
binarySearchFirstItem,
getVisibleElements,
isValidRotation,
watchScroll,
} from "./ui_utils.js";
import { MathClamp, noContextMenu, stopEvent } from "pdfjs-lib";
import { Menu } from "./menu.js";
import { PDFThumbnailView } from "./pdf_thumbnail_view.js";
import { RenderingStates } from "./renderable_view.js";
const SCROLL_OPTIONS = {
behavior: "instant",
block: "nearest",
inline: "nearest",
container: "nearest",
};
// This value is based on the one used in Firefox.
// See
// https://searchfox.org/firefox-main/rev/04cf27582307a9c351e991c740828d54cf786b76/dom/events/EventStateManager.cpp#2675-2698
// This threshold is used to distinguish between a click and a drag.
const DRAG_THRESHOLD_IN_PIXELS = 5;
const PIXELS_TO_SCROLL_WHEN_DRAGGING = 20;
const SPACE_FOR_DRAG_MARKER_WHEN_NO_NEXT_ELEMENT = 15;
/**
* @typedef {Object} PDFThumbnailViewerOptions
* @property {HTMLDivElement} container - The container for the thumbnail
* elements.
* @property {EventBus} eventBus - The application event bus.
* @property {PDFLinkService} linkService - The navigation/linking service.
* @property {PDFRenderingQueue} renderingQueue - The rendering queue object.
* @property {number} [maxCanvasPixels] - The maximum supported canvas size in
* total pixels, i.e. width * height. Use `-1` for no limit, or `0` for
* CSS-only zooming. The default value is 4096 * 8192 (32 mega-pixels).
* @property {number} [maxCanvasDim] - The maximum supported canvas dimension,
* in either width or height. Use `-1` for no limit.
* The default value is 32767.
* @property {Object} [pageColors] - Overwrites background and foreground colors
* with user defined ones in order to improve readability in high contrast
* mode.
* @property {AbortSignal} [abortSignal] - The AbortSignal for the window
* events.
* @property {boolean} [enableHWA] - Enables hardware acceleration for
* rendering. The default value is `false`.
* @property {boolean} [enableSplitMerge] - Enables split and merge features.
* The default value is `false`.
* @property {Object} [manageMenu] - The menu elements to manage saving edited
* PDF.
* @property {HTMLButtonElement} addFileButton - The button that opens a dialog
* to add a PDF file to merge with the current one.
/**
* Viewer control to display thumbnails for pages in a PDF document.
*/
class PDFThumbnailViewer {
static #draggingScaleFactor = 0;
#enableSplitMerge = false;
#dragAC = null;
#draggedContainer = null;
#thumbnailsPositions = null;
#lastDraggedOverIndex = NaN;
#selectedPages = null;
#draggedImageX = 0;
#draggedImageY = 0;
#draggedImageWidth = 0;
#draggedImageHeight = 0;
#draggedImageOffsetX = 0;
#draggedImageOffsetY = 0;
#dragMarker = null;
#pageNumberToRemove = NaN;
#currentScrollBottom = 0;
#currentScrollTop = 0;
#pagesMapper = null;
#manageSaveAsButton = null;
#manageDeleteButton = null;
#manageCopyButton = null;
#manageCutButton = null;
#copiedThumbnails = null;
#copiedPageNumbers = null;
#isCut = false;
#isOneColumnView = false;
#scrollableContainerWidth = 0;
#scrollableContainerHeight = 0;
#previousStates = {
hasSelectedPages: false,
};
/**
* @param {PDFThumbnailViewerOptions} options
*/
constructor({
container,
eventBus,
linkService,
renderingQueue,
maxCanvasPixels,
maxCanvasDim,
pageColors,
abortSignal,
enableHWA,
enableSplitMerge,
manageMenu,
addFileButton,
}) {
this.scrollableContainer = container.parentElement;
this.container = container;
this.eventBus = eventBus;
this.linkService = linkService;
this.renderingQueue = renderingQueue;
this.maxCanvasPixels = maxCanvasPixels;
this.maxCanvasDim = maxCanvasDim;
this.pageColors = pageColors || null;
this.enableHWA = enableHWA || false;
this.#enableSplitMerge = enableSplitMerge || false;
// TODO: uncomment when the "add file" feature is implemented.
// this.#addFileButton = addFileButton;
if (this.#enableSplitMerge && manageMenu) {
const { button, menu, copy, cut, delete: del, saveAs } = manageMenu;
this.eventBus.on(
"pagesloaded",
() => {
button.disabled = false;
},
{ once: true }
);
this._manageMenu = new Menu(menu, button, [copy, cut, del, saveAs]);
this.#manageSaveAsButton = saveAs;
saveAs.addEventListener("click", this.#saveExtractedPages.bind(this));
this.#manageDeleteButton = del;
del.addEventListener("click", this.#deletePages.bind(this));
this.#manageCopyButton = copy;
copy.addEventListener("click", this.#copyPages.bind(this));
this.#manageCutButton = cut;
cut.addEventListener("click", this.#cutPages.bind(this));
this.#toggleMenuEntries(false);
button.disabled = true;
this.eventBus.on("editingaction", ({ name }) => {
switch (name) {
case "copyPage":
this.#copyPages();
break;
case "cutPage":
this.#cutPages();
break;
case "deletePage":
this.#deletePages();
break;
case "savePage":
this.#saveExtractedPages();
break;
}
});
} else {
manageMenu.button.hidden = true;
}
this.scroll = watchScroll(
this.scrollableContainer,
this.#scrollUpdated.bind(this),
abortSignal
);
this.#resetView();
this.#addEventListeners();
}
/**
* Update the different possible states of this manager, e.g. is there
* something to copy, paste, ...
* @param {Object} details
*/
#dispatchUpdateStates(details) {
const hasChanged = Object.entries(details).some(
([key, value]) => this.#previousStates[key] !== value
);
if (hasChanged) {
this.eventBus.dispatch("editingstateschanged", {
source: this,
details: Object.assign(this.#previousStates, details),
});
}
}
#scrollUpdated() {
this.renderingQueue.renderHighestPriority();
}
getThumbnail(index) {
return this._thumbnails[index];
}
#getVisibleThumbs() {
return getVisibleElements({
scrollEl: this.scrollableContainer,
views: this._thumbnails,
});
}
scrollThumbnailIntoView(pageNumber) {
if (!this.pdfDocument) {
return;
}
const thumbnailView = this._thumbnails[pageNumber - 1];
if (!thumbnailView) {
console.error('scrollThumbnailIntoView: Invalid "pageNumber" parameter.');
return;
}
if (pageNumber !== this._currentPageNumber) {
const prevThumbnailView = this._thumbnails[this._currentPageNumber - 1];
prevThumbnailView?.toggleCurrent(/* isCurrent = */ false);
thumbnailView.toggleCurrent(/* isCurrent = */ true);
this._currentPageNumber = pageNumber;
}
const { first, last, views } = this.#getVisibleThumbs();
// If the thumbnail isn't currently visible, scroll it into view.
if (views.length > 0) {
let shouldScroll = false;
if (pageNumber <= first.id || pageNumber >= last.id) {
shouldScroll = true;
} else {
for (const { id, percent } of views) {
if (id !== pageNumber) {
continue;
}
shouldScroll = percent < 100;
break;
}
}
if (shouldScroll) {
thumbnailView.div.scrollIntoView(SCROLL_OPTIONS);
}
}
this._currentPageNumber = pageNumber;
}
get pagesRotation() {
return this._pagesRotation;
}
set pagesRotation(rotation) {
if (!isValidRotation(rotation)) {
throw new Error("Invalid thumbnails rotation angle.");
}
if (!this.pdfDocument) {
return;
}
if (this._pagesRotation === rotation) {
return; // The rotation didn't change.
}
this._pagesRotation = rotation;
const updateArgs = { rotation };
for (const thumbnail of this._thumbnails) {
thumbnail.update(updateArgs);
}
}
cleanup() {
for (const thumbnail of this._thumbnails) {
if (thumbnail.renderingState !== RenderingStates.FINISHED) {
thumbnail.reset();
}
}
}
#resetView() {
this._thumbnails = [];
this._currentPageNumber = 1;
this._pageLabels = null;
this._pagesRotation = 0;
// Remove the thumbnails from the DOM.
this.container.textContent = "";
}
/**
* @param {PDFDocumentProxy} pdfDocument
*/
setDocument(pdfDocument) {
if (this.pdfDocument) {
this.#cancelRendering();
this.#resetView();
}
this.pdfDocument = pdfDocument;
if (!pdfDocument) {
return;
}
this.#pagesMapper = pdfDocument.pagesMapper;
const firstPagePromise = pdfDocument.getPage(1);
const optionalContentConfigPromise = pdfDocument.getOptionalContentConfig({
intent: "display",
});
firstPagePromise
.then(firstPdfPage => {
const pagesCount = pdfDocument.numPages;
const viewport = firstPdfPage.getViewport({ scale: 1 });
const fragment = document.createDocumentFragment();
for (let pageNum = 1; pageNum <= pagesCount; ++pageNum) {
const thumbnail = new PDFThumbnailView({
container: fragment,
eventBus: this.eventBus,
id: pageNum,
defaultViewport: viewport.clone(),
optionalContentConfigPromise,
linkService: this.linkService,
renderingQueue: this.renderingQueue,
maxCanvasPixels: this.maxCanvasPixels,
maxCanvasDim: this.maxCanvasDim,
pageColors: this.pageColors,
enableHWA: this.enableHWA,
enableSplitMerge: this.#enableSplitMerge,
});
this._thumbnails.push(thumbnail);
}
// Set the first `pdfPage` immediately, since it's already loaded,
// rather than having to repeat the `PDFDocumentProxy.getPage` call in
// the `this.#ensurePdfPageLoaded` method before rendering can start.
this._thumbnails[0]?.setPdfPage(firstPdfPage);
// Ensure that the current thumbnail is always highlighted on load.
const thumbnailView = this._thumbnails[this._currentPageNumber - 1];
thumbnailView.toggleCurrent(/* isCurrent = */ true);
this.container.append(fragment);
})
.catch(reason => {
console.error("Unable to initialize thumbnail viewer", reason);
});
}
#cancelRendering() {
for (const thumbnail of this._thumbnails) {
thumbnail.cancelRendering();
}
}
/**
* @param {Array|null} labels
*/
setPageLabels(labels) {
if (!this.pdfDocument) {
return;
}
if (!labels) {
this._pageLabels = null;
} else if (
!(Array.isArray(labels) && this.pdfDocument.numPages === labels.length)
) {
this._pageLabels = null;
console.error("PDFThumbnailViewer_setPageLabels: Invalid page labels.");
} else {
this._pageLabels = labels;
}
// Update all the `PDFThumbnailView` instances.
for (let i = 0, ii = this._thumbnails.length; i < ii; i++) {
this._thumbnails[i].setPageLabel(this._pageLabels?.[i] ?? null);
}
}
/**
* @param {PDFThumbnailView} thumbView
* @returns {Promise<PDFPageProxy | null>}
*/
async #ensurePdfPageLoaded(thumbView) {
if (thumbView.pdfPage) {
return thumbView.pdfPage;
}
try {
const pdfPage = await this.pdfDocument.getPage(thumbView.id);
if (!thumbView.pdfPage) {
thumbView.setPdfPage(pdfPage);
}
return pdfPage;
} catch (reason) {
console.error("Unable to get page for thumb view", reason);
return null; // Page error -- there is nothing that can be done.
}
}
#getScrollAhead(visible) {
if (visible.first?.id === 1) {
return true;
} else if (visible.last?.id === this._thumbnails.length) {
return false;
}
return this.scroll.down;
}
forceRendering() {
const visibleThumbs = this.#getVisibleThumbs();
const scrollAhead = this.#getScrollAhead(visibleThumbs);
const thumbView = this.renderingQueue.getHighestPriority(
visibleThumbs,
this._thumbnails,
scrollAhead,
/* preRenderExtra */ false,
/* ignoreDetailViews */ true
);
if (thumbView) {
this.#ensurePdfPageLoaded(thumbView).then(() => {
this.renderingQueue.renderView(thumbView);
});
return true;
}
return false;
}
hasStructuralChanges() {
return this.#pagesMapper?.hasBeenAltered() || false;
}
getStructuralChanges() {
return this.#pagesMapper?.getPageMappingForSaving() || null;
}
static #getScaleFactor(image) {
return (PDFThumbnailViewer.#draggingScaleFactor ||= parseFloat(
getComputedStyle(image).getPropertyValue("--thumbnail-dragging-scale")
));
}
#updateThumbnails(currentPageNumber) {
let newCurrentPageNumber = 0;
const pagesMapper = this.#pagesMapper;
this.container.replaceChildren();
const prevThumbnails = this._thumbnails;
const newThumbnails = (this._thumbnails = []);
const fragment = document.createDocumentFragment();
const isCut = this.#isCut;
const oldThumbnails = new Set(prevThumbnails);
for (let i = 1, ii = pagesMapper.pagesNumber; i <= ii; i++) {
const prevPageNumber = pagesMapper.getPrevPageNumber(i);
if (prevPageNumber < 0) {
let thumbnail = this.#copiedThumbnails.get(-prevPageNumber);
oldThumbnails.delete(thumbnail);
thumbnail.checkbox.checked = false;
if (isCut) {
thumbnail.updateId(i);
fragment.append(thumbnail.div);
} else {
thumbnail = thumbnail.clone(fragment, i);
}
newThumbnails.push(thumbnail);
continue;
}
if (prevPageNumber === currentPageNumber) {
newCurrentPageNumber = i;
}
const newThumbnail = prevThumbnails[prevPageNumber - 1];
newThumbnails.push(newThumbnail);
newThumbnail.updateId(i);
oldThumbnails.delete(newThumbnail);
newThumbnail.checkbox.checked = false;
fragment.append(newThumbnail.div);
}
this.container.append(fragment);
for (const oldThumbnail of oldThumbnails) {
oldThumbnail.destroy();
}
return newCurrentPageNumber;
}
#onStartDragging(draggedThumbnail) {
this.#currentScrollTop = this.scrollableContainer.scrollTop;
this.#currentScrollBottom =
this.#currentScrollTop + this.scrollableContainer.clientHeight;
this.#dragAC = new AbortController();
this.container.classList.add("isDragging");
const startPageNumber = parseInt(
draggedThumbnail.getAttribute("page-number"),
10
);
this.#lastDraggedOverIndex = startPageNumber - 1;
if (!this.#selectedPages?.has(startPageNumber)) {
this.#pageNumberToRemove = startPageNumber;
this.#selectPage(startPageNumber, true);
}
for (const selected of this.#selectedPages) {
const thumbnail = this._thumbnails[selected - 1];
const placeholder = (thumbnail.placeholder =
document.createElement("div"));
placeholder.classList.add("thumbnailImageContainer", "placeholder");
const { div, imageContainer } = thumbnail;
div.classList.add("isDragging");
placeholder.style.height = getComputedStyle(imageContainer).height;
imageContainer.after(placeholder);
if (selected !== startPageNumber) {
imageContainer.classList.add("hidden");
continue;
}
if (this.#selectedPages.size === 1) {
imageContainer.classList.add("draggingThumbnail");
this.#draggedContainer = imageContainer;
continue;
}
// For multiple selected thumbnails, only the one being dragged is shown
// (with the dragging style), while the others are hidden.
const draggedContainer = (this.#draggedContainer =
document.createElement("div"));
draggedContainer.classList.add(
"draggingThumbnail",
"thumbnailImageContainer",
"multiple"
);
draggedContainer.style.height = getComputedStyle(imageContainer).height;
imageContainer.replaceWith(draggedContainer);
imageContainer.classList.remove("thumbnailImageContainer");
draggedContainer.append(imageContainer);
draggedContainer.setAttribute(
"data-multiple-count",
this.#selectedPages.size
);
}
}
#onStopDragging(isDropping = false) {
const draggedContainer = this.#draggedContainer;
this.#draggedContainer = null;
const lastDraggedOverIndex = this.#lastDraggedOverIndex;
this.#lastDraggedOverIndex = NaN;
this.#dragMarker?.remove();
this.#dragMarker = null;
this.#dragAC.abort();
this.#dragAC = null;
this.container.classList.remove("isDragging");
for (const selected of this.#selectedPages) {
const thumbnail = this._thumbnails[selected - 1];
const { div, placeholder, imageContainer } = thumbnail;
placeholder.remove();
imageContainer.classList.remove("draggingThumbnail", "hidden");
div.classList.remove("isDragging");
}
if (draggedContainer.classList.contains("multiple")) {
// Restore the dragged image to its thumbnail.
const originalImageContainer = draggedContainer.firstElementChild;
draggedContainer.replaceWith(originalImageContainer);
originalImageContainer.classList.add("thumbnailImageContainer");
} else {
draggedContainer.style.translate = "";
}
const selectedPages = this.#selectedPages;
if (
!isNaN(lastDraggedOverIndex) &&
isDropping &&
!(
selectedPages.size === 1 &&
(selectedPages.has(lastDraggedOverIndex + 1) ||
selectedPages.has(lastDraggedOverIndex + 2))
)
) {
this._thumbnails[this._currentPageNumber - 1]?.toggleCurrent(
/* isCurrent = */ false
);
this._currentPageNumber = -1;
const newIndex = lastDraggedOverIndex + 1;
const pagesToMove = Array.from(selectedPages).sort((a, b) => a - b);
const pagesMapper = this.#pagesMapper;
let currentPageNumber = isNaN(this.#pageNumberToRemove)
? pagesToMove[0]
: this.#pageNumberToRemove;
pagesMapper.movePages(selectedPages, pagesToMove, newIndex);
currentPageNumber = this.#updateThumbnails(currentPageNumber);
this.#computeThumbnailsPosition();
selectedPages.clear();
this.#pageNumberToRemove = NaN;
this.#updateMenuEntries();
this.eventBus.dispatch("pagesedited", {
source: this,
pagesMapper,
type: "move",
});
setTimeout(() => {
this.forceRendering();
this.linkService.goToPage(currentPageNumber);
}, 0);
}
if (!isNaN(this.#pageNumberToRemove)) {
this.#selectPage(this.#pageNumberToRemove, false);
this.#pageNumberToRemove = NaN;
}
}
#clearSelection() {
for (const pageNumber of this.#selectedPages) {
this._thumbnails[pageNumber - 1].toggleSelected(false);
}
this.#selectedPages.clear();
}
#saveExtractedPages() {
this.eventBus.dispatch("saveextractedpages", {
source: this,
data: this.#pagesMapper.extractPages(this.#selectedPages),
});
this.#clearSelection();
this.#toggleMenuEntries(false);
}
#copyPages(clearSelection = true) {
const pageNumbersToCopy = (this.#copiedPageNumbers = Uint32Array.from(
this.#selectedPages
).sort((a, b) => a - b));
const pagesMapper = this.#pagesMapper;
pagesMapper.copyPages(pageNumbersToCopy);
this.#copiedThumbnails ||= new Map();
for (const pageNumber of pageNumbersToCopy) {
this.#copiedThumbnails.set(pageNumber, this._thumbnails[pageNumber - 1]);
}
this.eventBus.dispatch("pagesedited", {
source: this,
pagesMapper,
pageNumbers: pageNumbersToCopy,
type: "copy",
});
if (clearSelection) {
this.#clearSelection();
}
for (const thumbnail of this._thumbnails) {
thumbnail.addPasteButton(this.#pastePages.bind(this));
}
this.container.classList.add("pasteMode");
this.#toggleMenuEntries(false);
}
#cutPages() {
this.#isCut = true;
this.#copyPages(false);
this.#deletePages(/* type = */ "cut");
}
#pastePages(index) {
this.container.classList.remove("pasteMode");
for (const thumbnail of this._thumbnails) {
thumbnail.removePasteButton();
}
this.#toggleMenuEntries(true);
const pagesMapper = this.#pagesMapper;
let currentPageNumber = this.#copiedPageNumbers.includes(
this._currentPageNumber
)
? 0
: this._currentPageNumber;
pagesMapper.pastePages(index);
currentPageNumber = this.#updateThumbnails(currentPageNumber);
this.eventBus.dispatch("pagesedited", {
source: this,
pagesMapper,
hasBeenCut: this.#isCut,
type: "paste",
});
this.#copiedThumbnails = null;
this.#isCut = false;
this.#updateMenuEntries();
setTimeout(() => {
this.forceRendering();
this.linkService.goToPage(currentPageNumber || 1);
}, 0);
}
#deletePages(type = "delete") {
const selectedPages = this.#selectedPages;
if (selectedPages.size === 0) {
return;
}
const pagesMapper = this.#pagesMapper;
let currentPageNumber = selectedPages.has(this._currentPageNumber)
? 0
: this._currentPageNumber;
const pagesToDelete = Uint32Array.from(selectedPages).sort((a, b) => a - b);
pagesMapper.deletePages(pagesToDelete);
currentPageNumber = this.#updateThumbnails(currentPageNumber);
selectedPages.clear();
this.#updateMenuEntries();
this.eventBus.dispatch("pagesedited", {
source: this,
pagesMapper,
pageNumbers: pagesToDelete,
type,
});
setTimeout(() => {
this.forceRendering();
this.linkService.goToPage(currentPageNumber || 1);
}, 0);
}
#updateMenuEntries() {
this.#manageSaveAsButton.disabled =
this.#manageDeleteButton.disabled =
this.#manageCopyButton.disabled =
this.#manageCutButton.disabled =
!this.#selectedPages?.size;
this.#dispatchUpdateStates({
hasSelectedPages: !!this.#selectedPages?.size,
});
}
#toggleMenuEntries(enable) {
this.#manageSaveAsButton.disabled =
this.#manageDeleteButton.disabled =
this.#manageCopyButton.disabled =
this.#manageCutButton.disabled =
!enable;
}
#moveDraggedContainer(dx, dy) {
if (this.#isOneColumnView) {
dx = 0;
}
if (
this.#draggedImageX + dx < 0 ||
this.#draggedImageX + this.#draggedImageWidth + dx >
this.#scrollableContainerWidth
) {
dx = 0;
}
if (
this.#draggedImageY + dy < 0 ||
this.#draggedImageY + this.#draggedImageHeight + dy >
this.#scrollableContainerHeight
) {
dy = 0;
}
this.#draggedImageX += dx;
this.#draggedImageY += dy;
this.#draggedImageOffsetX += dx;
this.#draggedImageOffsetY += dy;
this.#draggedContainer.style.translate = `${this.#draggedImageOffsetX}px ${this.#draggedImageOffsetY}px`;
if (
this.#draggedImageY + this.#draggedImageHeight >
this.#currentScrollBottom
) {
this.scrollableContainer.scrollTop = Math.min(
this.scrollableContainer.scrollTop + PIXELS_TO_SCROLL_WHEN_DRAGGING,
this.#scrollableContainerHeight
);
} else if (this.#draggedImageY < this.#currentScrollTop) {
this.scrollableContainer.scrollTop = Math.max(
this.scrollableContainer.scrollTop - PIXELS_TO_SCROLL_WHEN_DRAGGING,
0
);
}
const positionData = this.#findClosestThumbnail(
this.#draggedImageX + this.#draggedImageWidth / 2,
this.#draggedImageY + this.#draggedImageHeight / 2
);
if (!positionData) {
return;
}
let dragMarker = this.#dragMarker;
if (!dragMarker) {
dragMarker = this.#dragMarker = document.createElement("div");
dragMarker.className = "dragMarker";
this.container.firstChild.before(dragMarker);
}
const [index, space] = positionData;
const dragMarkerStyle = dragMarker.style;
const { bbox, x: xPos } = this.#thumbnailsPositions;
let x, y, width, height;
if (index < 0) {
if (xPos.length === 1) {
y = bbox[1] - SPACE_FOR_DRAG_MARKER_WHEN_NO_NEXT_ELEMENT;
x = bbox[4];
width = bbox[2];
} else {
y = bbox[1];
x = bbox[0] - SPACE_FOR_DRAG_MARKER_WHEN_NO_NEXT_ELEMENT;
height = bbox[3];
}
} else if (xPos.length === 1) {
y = bbox[index * 4 + 1] + bbox[index * 4 + 3] + space;
x = bbox[index * 4];
width = bbox[index * 4 + 2];
} else {
y = bbox[index * 4 + 1];
x = bbox[index * 4] + bbox[index * 4 + 2] + space;
height = bbox[index * 4 + 3];
}
dragMarkerStyle.translate = `${x}px ${y}px`;
dragMarkerStyle.width = width ? `${width}px` : "";
dragMarkerStyle.height = height ? `${height}px` : "";
}
#computeThumbnailsPosition() {
// Collect the center of each thumbnail.
// This is used to determine the closest thumbnail when dragging.
// TODO: handle the RTL case.
const positionsX = [];
const positionsY = [];
const positionsLastX = [];
const bbox = new Float32Array(this._thumbnails.length * 4);
let prevX = -Infinity;
let prevY = -Infinity;
let reminder = -1;
let firstRightX;
let lastRightX;
let firstBottomY;
for (let i = 0, ii = this._thumbnails.length; i < ii; i++) {
const { div } = this._thumbnails[i];
const {
offsetTop: y,
offsetLeft: x,
offsetWidth: w,
offsetHeight: h,
} = div;
if (w === 0) {
// The thumbnail view isn't visible.
return;
}
bbox[i * 4] = x;
bbox[i * 4 + 1] = y;
bbox[i * 4 + 2] = w;
bbox[i * 4 + 3] = h;
if (x > prevX) {
prevX = x + w / 2;
firstRightX ??= prevX + w;
positionsX.push(prevX);
}
if (y > prevY) {
if (reminder === -1 && positionsX.length > 1) {
reminder = ii % positionsX.length;
}
prevY = y + h / 2;
firstBottomY ??= prevY + h;
positionsY.push(prevY);
}
if (reminder > 0 && i >= ii - reminder) {
const cx = x + w / 2;
positionsLastX.push(cx);
lastRightX ??= cx + w;
}
}
const space =
positionsX.length > 1
? (positionsX[1] - firstRightX) / 2
: (positionsY[1] - firstBottomY) / 2;
this.#thumbnailsPositions = {
x: positionsX,
y: positionsY,
lastX: positionsLastX,
space,
lastSpace: (positionsLastX.at(-1) - lastRightX) / 2,
bbox,
};
this.#isOneColumnView = positionsX.length === 1;
({
clientWidth: this.#scrollableContainerWidth,
scrollHeight: this.#scrollableContainerHeight,
} = this.scrollableContainer);
}
#addEventListeners() {
this.eventBus.on("resize", ({ source }) => {
if (source.thumbnailsView === this.container) {
this.#computeThumbnailsPosition();
}
});
this.container.addEventListener("focusout", () => {
this.#dispatchUpdateStates({
hasSelectedPages: false,
});
});
this.container.addEventListener("focusin", () => {
this.#dispatchUpdateStates({
hasSelectedPages: !!this.#selectedPages?.size,
});
});
this.container.addEventListener("keydown", e => {
const { target } = e;
const isCheckbox =
target instanceof HTMLInputElement && target.type === "checkbox";
switch (e.key) {
case "ArrowLeft":
this.#goToNextItem(target, false, true, isCheckbox);
stopEvent(e);
break;
case "ArrowRight":
this.#goToNextItem(target, true, true, isCheckbox);
stopEvent(e);
break;
case "ArrowDown":
this.#goToNextItem(target, true, false, isCheckbox);
stopEvent(e);
break;
case "ArrowUp":
this.#goToNextItem(target, false, false, isCheckbox);
stopEvent(e);
break;
case "Home":
this.#focusThumbnailElement(this._thumbnails[0], isCheckbox);
stopEvent(e);
break;
case "End":
this.#focusThumbnailElement(this._thumbnails.at(-1), isCheckbox);
stopEvent(e);
break;
case "Enter":
case " ":
if (!isCheckbox) {
this.#goToPage(e);
}
// For checkboxes, let the default behavior handle toggling
break;
case "c":
if (
this.#enableSplitMerge &&
(e.ctrlKey || e.metaKey) &&
this.#selectedPages?.size
) {
this.#copyPages();
stopEvent(e);
}
break;
case "x":
if (
this.#enableSplitMerge &&
(e.ctrlKey || e.metaKey) &&
this.#selectedPages?.size
) {
this.#cutPages();
stopEvent(e);
}
break;
case "Delete":
case "Backspace":
if (this.#enableSplitMerge && this.#selectedPages?.size) {
this.#deletePages();
stopEvent(e);
}
break;
}
});
this.container.addEventListener("click", e => {
const { target } = e;
if (target instanceof HTMLInputElement) {
const pageNumber = parseInt(
target.parentElement.getAttribute("page-number"),
10
);
this.#selectPage(pageNumber, target.checked);
return;
}
this.#goToPage(e);
});
this.#addDragListeners();
}
#selectPage(pageNumber, checked) {
const set = (this.#selectedPages ??= new Set());
if (checked) {
set.add(pageNumber);
} else {
set.delete(pageNumber);
}
this.#updateMenuEntries();
}
#addDragListeners() {
if (!this.#enableSplitMerge) {
return;
}
this.container.addEventListener("pointerdown", e => {
const {
target: draggedImage,
clientX: clickX,
clientY: clickY,
pointerId: dragPointerId,
} = e;
if (
e.button !== 0 || // Skip right click.
this.#pagesMapper.copiedPageNumbers?.length > 0 ||
!isNaN(this.#lastDraggedOverIndex) ||
!draggedImage.classList.contains("thumbnailImageContainer")
) {
// We're already handling a drag, or the target is not draggable.
return;
}
const thumbnail = draggedImage.parentElement;
const pointerDownAC = new AbortController();
const { signal: pointerDownSignal } = pointerDownAC;
let prevDragX = clickX;
let prevDragY = clickY;
let prevScrollTop = this.scrollableContainer.scrollTop;
// When dragging, the thumbnail is scaled down. To keep the cursor at the
// same position on the thumbnail, we need to adjust the offset
// accordingly.
const scaleFactor = PDFThumbnailViewer.#getScaleFactor(draggedImage);
this.#draggedImageOffsetY =
((scaleFactor - 1) * e.layerY + draggedImage.offsetTop) / scaleFactor;
if (this.#isOneColumnView) {
this.#draggedImageOffsetX =
draggedImage.offsetLeft +
((scaleFactor - 1) * 0.5 * draggedImage.offsetWidth) / scaleFactor;
} else {
this.#draggedImageOffsetX =
((scaleFactor - 1) * e.layerX + draggedImage.offsetLeft) /
scaleFactor;
}
this.#draggedImageX = thumbnail.offsetLeft + this.#draggedImageOffsetX;
this.#draggedImageY = thumbnail.offsetTop + this.#draggedImageOffsetY;
this.#draggedImageWidth = draggedImage.offsetWidth / scaleFactor;
this.#draggedImageHeight = draggedImage.offsetHeight / scaleFactor;
this.container.addEventListener(
"pointermove",
ev => {
const { clientX: x, clientY: y, pointerId } = ev;
if (isNaN(this.#lastDraggedOverIndex)) {
if (
pointerId !== dragPointerId ||
(Math.abs(x - clickX) <= DRAG_THRESHOLD_IN_PIXELS &&
Math.abs(y - clickY) <= DRAG_THRESHOLD_IN_PIXELS)
) {
// Not enough movement to be considered a drag.
return;
}
// First movement while dragging.
this.#onStartDragging(thumbnail);
const stopDragging = (_e, isDropping = false) => {
this.#onStopDragging(isDropping);
pointerDownAC.abort();
};
const { signal } = this.#dragAC;
window.addEventListener(
"touchmove",
stopEvent /* Prevent the container from scrolling */,
{ passive: false, signal }
);
window.addEventListener("contextmenu", noContextMenu, { signal });
this.scrollableContainer.addEventListener(
"scrollend",
() => {
const {
scrollableContainer: { clientHeight, scrollTop },
} = this;
this.#currentScrollTop = scrollTop;
this.#currentScrollBottom = scrollTop + clientHeight;
const dy = scrollTop - prevScrollTop;
prevScrollTop = scrollTop;
this.#moveDraggedContainer(0, dy);
},
{ passive: true, signal }
);
window.addEventListener(
"pointerup",
upEv => {
if (upEv.pointerId !== dragPointerId) {
return;
}
// Prevent the subsequent click event after pointerup.
window.addEventListener("click", stopEvent, {
capture: true,
once: true,
signal,
});
stopEvent(upEv);
stopDragging(upEv, /* isDropping = */ true);
},
{ signal }
);
window.addEventListener("blur", stopDragging, { signal });
window.addEventListener("pointercancel", stopDragging, { signal });
window.addEventListener("wheel", stopEvent, {
passive: false,
signal,
});
window.addEventListener(
"keydown",
kEv => {
if (
kEv.key === "Escape" &&
!isNaN(this.#lastDraggedOverIndex)
) {
stopDragging(kEv);
}
},
{ signal }
);
}
const dx = x - prevDragX;
const dy = y - prevDragY;
prevDragX = x;
prevDragY = y;
this.#moveDraggedContainer(dx, dy);
},
{ passive: true, signal: pointerDownSignal }
);
window.addEventListener(
"pointerup",
({ pointerId }) => {
if (pointerId !== dragPointerId) {
return;
}
pointerDownAC.abort();
},
{ signal: pointerDownSignal }
);
window.addEventListener("dragstart", stopEvent, {
capture: true,
signal: pointerDownSignal,
});
});
}
#goToPage(e) {
const { target } = e;
if (target.classList.contains("thumbnailImageContainer")) {
const pageNumber = parseInt(
target.parentElement.getAttribute("page-number"),
10
);
this.linkService.goToPage(pageNumber);
stopEvent(e);
}
}
/**
* Focus either the checkbox or image of a thumbnail.
* @param {PDFThumbnailView} thumbnail
* @param {boolean} focusCheckbox - If true, focus checkbox; otherwise focus
* image
*/
#focusThumbnailElement(thumbnail, focusCheckbox) {
if (focusCheckbox && thumbnail.checkbox) {
thumbnail.checkbox.focus();
} else {
thumbnail.imageContainer.focus();
}
}
/**
* Go to the next/previous menu item.
* @param {HTMLElement} element
* @param {boolean} forward
* @param {boolean} horizontal
* @param {boolean} navigateCheckboxes - If true, focus checkboxes;
* otherwise focus images
*/
#goToNextItem(element, forward, horizontal, navigateCheckboxes = false) {
let currentPageNumber = parseInt(
element.parentElement.getAttribute("page-number"),
10
);
if (isNaN(currentPageNumber)) {
currentPageNumber = this._currentPageNumber;
}
const increment = forward ? 1 : -1;
let nextThumbnail;
if (horizontal) {
const nextPageNumber = MathClamp(
currentPageNumber + increment,
1,
this._thumbnails.length + 1
);
nextThumbnail = this._thumbnails[nextPageNumber - 1];
} else {
const currentThumbnail = this._thumbnails[currentPageNumber - 1];
const { x: currentX, y: currentY } =
currentThumbnail.div.getBoundingClientRect();
let firstWithDifferentY;
for (
let i = currentPageNumber - 1 + increment;
i >= 0 && i < this._thumbnails.length;
i += increment
) {
const thumbnail = this._thumbnails[i];
const { x, y } = thumbnail.div.getBoundingClientRect();
if (!firstWithDifferentY && y !== currentY) {
firstWithDifferentY = thumbnail;
}
if (x === currentX) {
nextThumbnail = thumbnail;
break;
}
}
if (!nextThumbnail) {
nextThumbnail = firstWithDifferentY;
}
}
if (nextThumbnail) {
this.#focusThumbnailElement(nextThumbnail, navigateCheckboxes);
}
}
// Given the drag center (x, y), find the drop slot index: the drag marker
// will be placed after thumbnail[index], or before all thumbnails if index
// is -1. Returns null when the drop slot hasn't changed (no marker update
// needed), or [index, space] where space is the gap (in px) between
// thumbnails at that slot, used to position the marker.
//
// positionsX holds the x-center of each column, positionsY the y-center of
// each row. positionsLastX holds the x-centers for an incomplete last row
// (when the total number of thumbnails is not a multiple of the column
// count).
#findClosestThumbnail(x, y) {
if (!this.#thumbnailsPositions) {
this.#computeThumbnailsPosition();
}
const {
x: positionsX,
y: positionsY,
lastX: positionsLastX,
space: spaceBetweenThumbnails,
lastSpace: lastSpaceBetweenThumbnails,
} = this.#thumbnailsPositions;
const lastDraggedOverIndex = this.#lastDraggedOverIndex;
// Fast-path: reconstruct the row/col of the previous drop slot and check
// whether (x, y) still falls inside the same cell's bounds.
let xPos = lastDraggedOverIndex % positionsX.length;
let yPos = Math.floor(lastDraggedOverIndex / positionsX.length);
let xArray = yPos === positionsY.length - 1 ? positionsLastX : positionsX;
if (
positionsY[yPos] <= y &&
y < (positionsY[yPos + 1] ?? Infinity) &&
xArray[xPos] <= x &&
x < (xArray[xPos + 1] ?? Infinity)
) {
// Fast-path: we're still in the same thumbnail.
return null;
}
let index;
// binarySearchFirstItem returns the first row index whose center is below
// y, i.e. the first i such that positionsY[i] > y.
yPos = binarySearchFirstItem(positionsY, cy => y < cy);
if (this.#isOneColumnView) {
// In a single column the drop slot is simply the row boundary: the marker
// goes after row (yPos - 1), meaning before row yPos. index = -1 when y
// is above the first thumbnail's center (drop before thumbnail 0).
index = yPos - 1;
} else {
// Grid layout: first pick the nearest row, then the nearest column.
if (yPos === positionsY.length) {
// y is below the last row's center — clamp to the last row.
yPos = positionsY.length - 1;
} else {
// Choose between the row just above (yPos - 1) and the row at yPos by
// comparing distances, so the marker snaps to whichever row center is
// closer to y.
const dist1 = Math.abs(positionsY[yPos - 1] - y);
const dist2 = Math.abs(positionsY[yPos] - y);
yPos = dist1 < dist2 ? yPos - 1 : yPos;
}
// The last row may be incomplete, so use its own x-center array.
xArray =
yPos === positionsY.length - 1 && positionsLastX.length > 0
? positionsLastX
: positionsX;
// Find the column: the first column whose center is to the right of x,
// minus 1, gives the column the cursor is in (or -1 if before column 0).
xPos = binarySearchFirstItem(xArray, cx => x < cx) - 1;
if (yPos < 0) {
// y is above the first row: force drop before the very first thumbnail.
if (xPos <= 0) {
xPos = -1;
}
yPos = 0;
}
// Convert (row, col) to a flat thumbnail index, clamped to
// [-1, length-1].
index = MathClamp(
yPos * positionsX.length + xPos,
-1,
this._thumbnails.length - 1
);
}
if (index === lastDraggedOverIndex) {
// No change.
return null;
}
this.#lastDraggedOverIndex = index;
// Use the last-row gap when the drop slot is in the incomplete last row.
const space =
yPos === positionsY.length - 1 && positionsLastX.length > 0 && xPos >= 0
? lastSpaceBetweenThumbnails
: spaceBetweenThumbnails;
return [index, space];
}
}
export { PDFThumbnailViewer };