pdf.js/src/core/catalog.js

1460 lines
41 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.
*/
import {
clearPrimitiveCaches,
Dict,
isDict,
isName,
isRef,
isRefsEqual,
isStream,
RefSet,
RefSetCache,
} from "./primitives.js";
import {
collectActions,
MissingDataException,
toRomanNumerals,
} from "./core_utils.js";
import {
createPromiseCapability,
createValidAbsoluteUrl,
DocumentActionEventType,
FormatError,
info,
isBool,
isNum,
isString,
objectSize,
PermissionFlag,
shadow,
stringToPDFString,
stringToUTF8String,
warn,
} from "../shared/util.js";
import { NameTree, NumberTree } from "./name_number_tree.js";
import { ColorSpace } from "./colorspace.js";
import { FileSpec } from "./file_spec.js";
import { GlobalImageCache } from "./image_utils.js";
import { MetadataParser } from "./metadata_parser.js";
import { StructTreeRoot } from "./struct_tree.js";
function fetchDestination(dest) {
if (dest instanceof Dict) {
dest = dest.get("D");
}
return Array.isArray(dest) ? dest : null;
}
class Catalog {
constructor(pdfManager, xref) {
this.pdfManager = pdfManager;
this.xref = xref;
this._catDict = xref.getCatalogObj();
if (!isDict(this._catDict)) {
throw new FormatError("Catalog object is not a dictionary.");
}
this.fontCache = new RefSetCache();
this.builtInCMapCache = new Map();
this.standardFontDataCache = new Map();
this.globalImageCache = new GlobalImageCache();
this.pageKidsCountCache = new RefSetCache();
this.pageIndexCache = new RefSetCache();
this.nonBlendModesSet = new RefSet();
}
get version() {
const version = this._catDict.get("Version");
if (!isName(version)) {
return shadow(this, "version", null);
}
return shadow(this, "version", version.name);
}
get collection() {
let collection = null;
try {
const obj = this._catDict.get("Collection");
if (isDict(obj) && obj.size > 0) {
collection = obj;
}
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
info("Cannot fetch Collection entry; assuming no collection is present.");
}
return shadow(this, "collection", collection);
}
get acroForm() {
let acroForm = null;
try {
const obj = this._catDict.get("AcroForm");
if (isDict(obj) && obj.size > 0) {
acroForm = obj;
}
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
info("Cannot fetch AcroForm entry; assuming no forms are present.");
}
return shadow(this, "acroForm", acroForm);
}
get metadata() {
const streamRef = this._catDict.getRaw("Metadata");
if (!isRef(streamRef)) {
return shadow(this, "metadata", null);
}
const suppressEncryption = !(
this.xref.encrypt && this.xref.encrypt.encryptMetadata
);
const stream = this.xref.fetch(streamRef, suppressEncryption);
let metadata = null;
if (isStream(stream) && isDict(stream.dict)) {
const type = stream.dict.get("Type");
const subtype = stream.dict.get("Subtype");
if (isName(type, "Metadata") && isName(subtype, "XML")) {
// XXX: This should examine the charset the XML document defines,
// however since there are currently no real means to decode arbitrary
// charsets, let's just hope that the author of the PDF was reasonable
// enough to stick with the XML default charset, which is UTF-8.
try {
const data = stringToUTF8String(stream.getString());
if (data) {
metadata = new MetadataParser(data).serializable;
}
} catch (e) {
if (e instanceof MissingDataException) {
throw e;
}
info("Skipping invalid metadata.");
}
}
}
return shadow(this, "metadata", metadata);
}
get markInfo() {
let markInfo = null;
try {
markInfo = this._readMarkInfo();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn("Unable to read mark info.");
}
return shadow(this, "markInfo", markInfo);
}
/**
* @private
*/
_readMarkInfo() {
const obj = this._catDict.get("MarkInfo");
if (!isDict(obj)) {
return null;
}
const markInfo = Object.assign(Object.create(null), {
Marked: false,
UserProperties: false,
Suspects: false,
});
for (const key in markInfo) {
if (!obj.has(key)) {
continue;
}
const value = obj.get(key);
if (!isBool(value)) {
continue;
}
markInfo[key] = value;
}
return markInfo;
}
get structTreeRoot() {
let structTree = null;
try {
structTree = this._readStructTreeRoot();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn("Unable read to structTreeRoot info.");
}
return shadow(this, "structTreeRoot", structTree);
}
/**
* @private
*/
_readStructTreeRoot() {
const obj = this._catDict.get("StructTreeRoot");
if (!isDict(obj)) {
return null;
}
const root = new StructTreeRoot(obj);
root.init();
return root;
}
get toplevelPagesDict() {
const pagesObj = this._catDict.get("Pages");
if (!isDict(pagesObj)) {
throw new FormatError("Invalid top-level pages dictionary.");
}
return shadow(this, "toplevelPagesDict", pagesObj);
}
get documentOutline() {
let obj = null;
try {
obj = this._readDocumentOutline();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn("Unable to read document outline.");
}
return shadow(this, "documentOutline", obj);
}
/**
* @private
*/
_readDocumentOutline() {
let obj = this._catDict.get("Outlines");
if (!isDict(obj)) {
return null;
}
obj = obj.getRaw("First");
if (!isRef(obj)) {
return null;
}
const root = { items: [] };
const queue = [{ obj, parent: root }];
// To avoid recursion, keep track of the already processed items.
const processed = new RefSet();
processed.put(obj);
const xref = this.xref,
blackColor = new Uint8ClampedArray(3);
while (queue.length > 0) {
const i = queue.shift();
const outlineDict = xref.fetchIfRef(i.obj);
if (outlineDict === null) {
continue;
}
if (!outlineDict.has("Title")) {
throw new FormatError("Invalid outline item encountered.");
}
const data = { url: null, dest: null };
Catalog.parseDestDictionary({
destDict: outlineDict,
resultObj: data,
docBaseUrl: this.pdfManager.docBaseUrl,
});
const title = outlineDict.get("Title");
const flags = outlineDict.get("F") || 0;
const color = outlineDict.getArray("C");
const count = outlineDict.get("Count");
let rgbColor = blackColor;
// We only need to parse the color when it's valid, and non-default.
if (
Array.isArray(color) &&
color.length === 3 &&
(color[0] !== 0 || color[1] !== 0 || color[2] !== 0)
) {
rgbColor = ColorSpace.singletons.rgb.getRgb(color, 0);
}
const outlineItem = {
dest: data.dest,
url: data.url,
unsafeUrl: data.unsafeUrl,
newWindow: data.newWindow,
title: stringToPDFString(title),
color: rgbColor,
count: Number.isInteger(count) ? count : undefined,
bold: !!(flags & 2),
italic: !!(flags & 1),
items: [],
};
i.parent.items.push(outlineItem);
obj = outlineDict.getRaw("First");
if (isRef(obj) && !processed.has(obj)) {
queue.push({ obj, parent: outlineItem });
processed.put(obj);
}
obj = outlineDict.getRaw("Next");
if (isRef(obj) && !processed.has(obj)) {
queue.push({ obj, parent: i.parent });
processed.put(obj);
}
}
return root.items.length > 0 ? root.items : null;
}
get permissions() {
let permissions = null;
try {
permissions = this._readPermissions();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn("Unable to read permissions.");
}
return shadow(this, "permissions", permissions);
}
/**
* @private
*/
_readPermissions() {
const encrypt = this.xref.trailer.get("Encrypt");
if (!isDict(encrypt)) {
return null;
}
let flags = encrypt.get("P");
if (!isNum(flags)) {
return null;
}
// PDF integer objects are represented internally in signed 2's complement
// form. Therefore, convert the signed decimal integer to a signed 2's
// complement binary integer so we can use regular bitwise operations on it.
flags += 2 ** 32;
const permissions = [];
for (const key in PermissionFlag) {
const value = PermissionFlag[key];
if (flags & value) {
permissions.push(value);
}
}
return permissions;
}
get optionalContentConfig() {
let config = null;
try {
const properties = this._catDict.get("OCProperties");
if (!properties) {
return shadow(this, "optionalContentConfig", null);
}
const defaultConfig = properties.get("D");
if (!defaultConfig) {
return shadow(this, "optionalContentConfig", null);
}
const groupsData = properties.get("OCGs");
if (!Array.isArray(groupsData)) {
return shadow(this, "optionalContentConfig", null);
}
const groups = [];
const groupRefs = [];
// Ensure all the optional content groups are valid.
for (const groupRef of groupsData) {
if (!isRef(groupRef)) {
continue;
}
groupRefs.push(groupRef);
const group = this.xref.fetchIfRef(groupRef);
groups.push({
id: groupRef.toString(),
name: isString(group.get("Name"))
? stringToPDFString(group.get("Name"))
: null,
intent: isString(group.get("Intent"))
? stringToPDFString(group.get("Intent"))
: null,
});
}
config = this._readOptionalContentConfig(defaultConfig, groupRefs);
config.groups = groups;
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn(`Unable to read optional content config: ${ex}`);
}
return shadow(this, "optionalContentConfig", config);
}
_readOptionalContentConfig(config, contentGroupRefs) {
function parseOnOff(refs) {
const onParsed = [];
if (Array.isArray(refs)) {
for (const value of refs) {
if (!isRef(value)) {
continue;
}
if (contentGroupRefs.includes(value)) {
onParsed.push(value.toString());
}
}
}
return onParsed;
}
function parseOrder(refs, nestedLevels = 0) {
if (!Array.isArray(refs)) {
return null;
}
const order = [];
for (const value of refs) {
if (isRef(value) && contentGroupRefs.includes(value)) {
parsedOrderRefs.put(value); // Handle "hidden" groups, see below.
order.push(value.toString());
continue;
}
// Handle nested /Order arrays (see e.g. issue 9462 and bug 1240641).
const nestedOrder = parseNestedOrder(value, nestedLevels);
if (nestedOrder) {
order.push(nestedOrder);
}
}
if (nestedLevels > 0) {
return order;
}
const hiddenGroups = [];
for (const groupRef of contentGroupRefs) {
if (parsedOrderRefs.has(groupRef)) {
continue;
}
hiddenGroups.push(groupRef.toString());
}
if (hiddenGroups.length) {
order.push({ name: null, order: hiddenGroups });
}
return order;
}
function parseNestedOrder(ref, nestedLevels) {
if (++nestedLevels > MAX_NESTED_LEVELS) {
warn("parseNestedOrder - reached MAX_NESTED_LEVELS.");
return null;
}
const value = xref.fetchIfRef(ref);
if (!Array.isArray(value)) {
return null;
}
const nestedName = xref.fetchIfRef(value[0]);
if (typeof nestedName !== "string") {
return null;
}
const nestedOrder = parseOrder(value.slice(1), nestedLevels);
if (!nestedOrder || !nestedOrder.length) {
return null;
}
return { name: stringToPDFString(nestedName), order: nestedOrder };
}
const xref = this.xref,
parsedOrderRefs = new RefSet(),
MAX_NESTED_LEVELS = 10;
return {
name: isString(config.get("Name"))
? stringToPDFString(config.get("Name"))
: null,
creator: isString(config.get("Creator"))
? stringToPDFString(config.get("Creator"))
: null,
baseState: isName(config.get("BaseState"))
? config.get("BaseState").name
: null,
on: parseOnOff(config.get("ON")),
off: parseOnOff(config.get("OFF")),
order: parseOrder(config.get("Order")),
groups: null,
};
}
get numPages() {
const obj = this.toplevelPagesDict.get("Count");
if (!Number.isInteger(obj)) {
throw new FormatError(
"Page count in top-level pages dictionary is not an integer."
);
}
return shadow(this, "numPages", obj);
}
get destinations() {
const obj = this._readDests(),
dests = Object.create(null);
if (obj instanceof NameTree) {
for (const [key, value] of obj.getAll()) {
const dest = fetchDestination(value);
if (dest) {
dests[key] = dest;
}
}
} else if (obj instanceof Dict) {
obj.forEach(function (key, value) {
const dest = fetchDestination(value);
if (dest) {
dests[key] = dest;
}
});
}
return shadow(this, "destinations", dests);
}
getDestination(id) {
const obj = this._readDests();
if (obj instanceof NameTree) {
const dest = fetchDestination(obj.get(id));
if (dest) {
return dest;
}
// Fallback to checking the *entire* NameTree, in an attempt to handle
// corrupt PDF documents with out-of-order NameTrees (fixes issue 10272).
const allDest = this.destinations[id];
if (allDest) {
warn(`Found "${id}" at an incorrect position in the NameTree.`);
return allDest;
}
} else if (obj instanceof Dict) {
const dest = fetchDestination(obj.get(id));
if (dest) {
return dest;
}
}
return null;
}
/**
* @private
*/
_readDests() {
const obj = this._catDict.get("Names");
if (obj && obj.has("Dests")) {
return new NameTree(obj.getRaw("Dests"), this.xref);
} else if (this._catDict.has("Dests")) {
// Simple destination dictionary.
return this._catDict.get("Dests");
}
return undefined;
}
get pageLabels() {
let obj = null;
try {
obj = this._readPageLabels();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn("Unable to read page labels.");
}
return shadow(this, "pageLabels", obj);
}
/**
* @private
*/
_readPageLabels() {
const obj = this._catDict.getRaw("PageLabels");
if (!obj) {
return null;
}
const pageLabels = new Array(this.numPages);
let style = null,
prefix = "";
const numberTree = new NumberTree(obj, this.xref);
const nums = numberTree.getAll();
let currentLabel = "",
currentIndex = 1;
for (let i = 0, ii = this.numPages; i < ii; i++) {
const labelDict = nums.get(i);
if (labelDict !== undefined) {
if (!isDict(labelDict)) {
throw new FormatError("PageLabel is not a dictionary.");
}
if (
labelDict.has("Type") &&
!isName(labelDict.get("Type"), "PageLabel")
) {
throw new FormatError("Invalid type in PageLabel dictionary.");
}
if (labelDict.has("S")) {
const s = labelDict.get("S");
if (!isName(s)) {
throw new FormatError("Invalid style in PageLabel dictionary.");
}
style = s.name;
} else {
style = null;
}
if (labelDict.has("P")) {
const p = labelDict.get("P");
if (!isString(p)) {
throw new FormatError("Invalid prefix in PageLabel dictionary.");
}
prefix = stringToPDFString(p);
} else {
prefix = "";
}
if (labelDict.has("St")) {
const st = labelDict.get("St");
if (!(Number.isInteger(st) && st >= 1)) {
throw new FormatError("Invalid start in PageLabel dictionary.");
}
currentIndex = st;
} else {
currentIndex = 1;
}
}
switch (style) {
case "D":
currentLabel = currentIndex;
break;
case "R":
case "r":
currentLabel = toRomanNumerals(currentIndex, style === "r");
break;
case "A":
case "a":
const LIMIT = 26; // Use only the characters A-Z, or a-z.
const A_UPPER_CASE = 0x41,
A_LOWER_CASE = 0x61;
const baseCharCode = style === "a" ? A_LOWER_CASE : A_UPPER_CASE;
const letterIndex = currentIndex - 1;
const character = String.fromCharCode(
baseCharCode + (letterIndex % LIMIT)
);
const charBuf = [];
for (let j = 0, jj = (letterIndex / LIMIT) | 0; j <= jj; j++) {
charBuf.push(character);
}
currentLabel = charBuf.join("");
break;
default:
if (style) {
throw new FormatError(
`Invalid style "${style}" in PageLabel dictionary.`
);
}
currentLabel = "";
}
pageLabels[i] = prefix + currentLabel;
currentIndex++;
}
return pageLabels;
}
get pageLayout() {
const obj = this._catDict.get("PageLayout");
// Purposely use a non-standard default value, rather than 'SinglePage', to
// allow differentiating between `undefined` and /SinglePage since that does
// affect the Scroll mode (continuous/non-continuous) used in Adobe Reader.
let pageLayout = "";
if (isName(obj)) {
switch (obj.name) {
case "SinglePage":
case "OneColumn":
case "TwoColumnLeft":
case "TwoColumnRight":
case "TwoPageLeft":
case "TwoPageRight":
pageLayout = obj.name;
}
}
return shadow(this, "pageLayout", pageLayout);
}
get pageMode() {
const obj = this._catDict.get("PageMode");
let pageMode = "UseNone"; // Default value.
if (isName(obj)) {
switch (obj.name) {
case "UseNone":
case "UseOutlines":
case "UseThumbs":
case "FullScreen":
case "UseOC":
case "UseAttachments":
pageMode = obj.name;
}
}
return shadow(this, "pageMode", pageMode);
}
get viewerPreferences() {
const ViewerPreferencesValidators = {
HideToolbar: isBool,
HideMenubar: isBool,
HideWindowUI: isBool,
FitWindow: isBool,
CenterWindow: isBool,
DisplayDocTitle: isBool,
NonFullScreenPageMode: isName,
Direction: isName,
ViewArea: isName,
ViewClip: isName,
PrintArea: isName,
PrintClip: isName,
PrintScaling: isName,
Duplex: isName,
PickTrayByPDFSize: isBool,
PrintPageRange: Array.isArray,
NumCopies: Number.isInteger,
};
const obj = this._catDict.get("ViewerPreferences");
let prefs = null;
if (isDict(obj)) {
for (const key in ViewerPreferencesValidators) {
if (!obj.has(key)) {
continue;
}
const value = obj.get(key);
// Make sure the (standard) value conforms to the specification.
if (!ViewerPreferencesValidators[key](value)) {
info(`Bad value in ViewerPreferences for "${key}".`);
continue;
}
let prefValue;
switch (key) {
case "NonFullScreenPageMode":
switch (value.name) {
case "UseNone":
case "UseOutlines":
case "UseThumbs":
case "UseOC":
prefValue = value.name;
break;
default:
prefValue = "UseNone";
}
break;
case "Direction":
switch (value.name) {
case "L2R":
case "R2L":
prefValue = value.name;
break;
default:
prefValue = "L2R";
}
break;
case "ViewArea":
case "ViewClip":
case "PrintArea":
case "PrintClip":
switch (value.name) {
case "MediaBox":
case "CropBox":
case "BleedBox":
case "TrimBox":
case "ArtBox":
prefValue = value.name;
break;
default:
prefValue = "CropBox";
}
break;
case "PrintScaling":
switch (value.name) {
case "None":
case "AppDefault":
prefValue = value.name;
break;
default:
prefValue = "AppDefault";
}
break;
case "Duplex":
switch (value.name) {
case "Simplex":
case "DuplexFlipShortEdge":
case "DuplexFlipLongEdge":
prefValue = value.name;
break;
default:
prefValue = "None";
}
break;
case "PrintPageRange":
const length = value.length;
if (length % 2 !== 0) {
// The number of elements must be even.
break;
}
const isValid = value.every((page, i, arr) => {
return (
Number.isInteger(page) &&
page > 0 &&
(i === 0 || page >= arr[i - 1]) &&
page <= this.numPages
);
});
if (isValid) {
prefValue = value;
}
break;
case "NumCopies":
if (value > 0) {
prefValue = value;
}
break;
default:
if (typeof value !== "boolean") {
throw new FormatError(
`viewerPreferences - expected a boolean value for: ${key}`
);
}
prefValue = value;
}
if (prefValue !== undefined) {
if (!prefs) {
prefs = Object.create(null);
}
prefs[key] = prefValue;
} else {
info(`Bad value in ViewerPreferences for "${key}".`);
}
}
}
return shadow(this, "viewerPreferences", prefs);
}
get openAction() {
const obj = this._catDict.get("OpenAction");
const openAction = Object.create(null);
if (isDict(obj)) {
// Convert the OpenAction dictionary into a format that works with
// `parseDestDictionary`, to avoid having to re-implement those checks.
const destDict = new Dict(this.xref);
destDict.set("A", obj);
const resultObj = { url: null, dest: null, action: null };
Catalog.parseDestDictionary({ destDict, resultObj });
if (Array.isArray(resultObj.dest)) {
openAction.dest = resultObj.dest;
} else if (resultObj.action) {
openAction.action = resultObj.action;
}
} else if (Array.isArray(obj)) {
openAction.dest = obj;
}
return shadow(
this,
"openAction",
objectSize(openAction) > 0 ? openAction : null
);
}
get attachments() {
const obj = this._catDict.get("Names");
let attachments = null;
if (obj instanceof Dict && obj.has("EmbeddedFiles")) {
const nameTree = new NameTree(obj.getRaw("EmbeddedFiles"), this.xref);
for (const [key, value] of nameTree.getAll()) {
const fs = new FileSpec(value, this.xref);
if (!attachments) {
attachments = Object.create(null);
}
attachments[stringToPDFString(key)] = fs.serializable;
}
}
return shadow(this, "attachments", attachments);
}
get xfaImages() {
const obj = this._catDict.get("Names");
let xfaImages = null;
if (obj instanceof Dict && obj.has("XFAImages")) {
const nameTree = new NameTree(obj.getRaw("XFAImages"), this.xref);
for (const [key, value] of nameTree.getAll()) {
if (!xfaImages) {
xfaImages = new Dict(this.xref);
}
xfaImages.set(key, value);
}
}
return shadow(this, "xfaImages", xfaImages);
}
_collectJavaScript() {
const obj = this._catDict.get("Names");
let javaScript = null;
function appendIfJavaScriptDict(name, jsDict) {
if (!(jsDict instanceof Dict)) {
return;
}
if (!isName(jsDict.get("S"), "JavaScript")) {
return;
}
let js = jsDict.get("JS");
if (isStream(js)) {
js = js.getString();
} else if (typeof js !== "string") {
return;
}
if (javaScript === null) {
javaScript = new Map();
}
javaScript.set(name, stringToPDFString(js));
}
if (obj instanceof Dict && obj.has("JavaScript")) {
const nameTree = new NameTree(obj.getRaw("JavaScript"), this.xref);
for (const [key, value] of nameTree.getAll()) {
appendIfJavaScriptDict(key, value);
}
}
// Append OpenAction "JavaScript" actions, if any, to the JavaScript map.
const openAction = this._catDict.get("OpenAction");
if (openAction) {
appendIfJavaScriptDict("OpenAction", openAction);
}
return javaScript;
}
get javaScript() {
const javaScript = this._collectJavaScript();
return shadow(
this,
"javaScript",
javaScript ? [...javaScript.values()] : null
);
}
get jsActions() {
const javaScript = this._collectJavaScript();
let actions = collectActions(
this.xref,
this._catDict,
DocumentActionEventType
);
if (javaScript) {
if (!actions) {
actions = Object.create(null);
}
for (const [key, val] of javaScript) {
if (key in actions) {
actions[key].push(val);
} else {
actions[key] = [val];
}
}
}
return shadow(this, "jsActions", actions);
}
fontFallback(id, handler) {
const promises = [];
this.fontCache.forEach(function (promise) {
promises.push(promise);
});
return Promise.all(promises).then(translatedFonts => {
for (const translatedFont of translatedFonts) {
if (translatedFont.loadedName === id) {
translatedFont.fallback(handler);
return;
}
}
});
}
cleanup(manuallyTriggered = false) {
clearPrimitiveCaches();
this.globalImageCache.clear(/* onlyData = */ manuallyTriggered);
this.pageKidsCountCache.clear();
this.pageIndexCache.clear();
this.nonBlendModesSet.clear();
const promises = [];
this.fontCache.forEach(function (promise) {
promises.push(promise);
});
return Promise.all(promises).then(translatedFonts => {
for (const { dict } of translatedFonts) {
delete dict.cacheKey;
}
this.fontCache.clear();
this.builtInCMapCache.clear();
this.standardFontDataCache.clear();
});
}
getPageDict(pageIndex) {
const capability = createPromiseCapability();
const nodesToVisit = [this._catDict.getRaw("Pages")];
const visitedNodes = new RefSet();
const xref = this.xref,
pageKidsCountCache = this.pageKidsCountCache;
let count,
currentPageIndex = 0;
function next() {
while (nodesToVisit.length) {
const currentNode = nodesToVisit.pop();
if (isRef(currentNode)) {
count = pageKidsCountCache.get(currentNode);
// Skip nodes where the page can't be.
if (count > 0 && currentPageIndex + count < pageIndex) {
currentPageIndex += count;
continue;
}
// Prevent circular references in the /Pages tree.
if (visitedNodes.has(currentNode)) {
capability.reject(
new FormatError("Pages tree contains circular reference.")
);
return;
}
visitedNodes.put(currentNode);
xref.fetchAsync(currentNode).then(function (obj) {
if (isDict(obj, "Page") || (isDict(obj) && !obj.has("Kids"))) {
if (pageIndex === currentPageIndex) {
// Cache the Page reference, since it can *greatly* improve
// performance by reducing redundant lookups in long documents
// where all nodes are found at *one* level of the tree.
if (currentNode && !pageKidsCountCache.has(currentNode)) {
pageKidsCountCache.put(currentNode, 1);
}
capability.resolve([obj, currentNode]);
} else {
currentPageIndex++;
next();
}
return;
}
nodesToVisit.push(obj);
next();
}, capability.reject);
return;
}
// Must be a child page dictionary.
if (!isDict(currentNode)) {
capability.reject(
new FormatError(
"Page dictionary kid reference points to wrong type of object."
)
);
return;
}
count = currentNode.get("Count");
if (Number.isInteger(count) && count >= 0) {
// Cache the Kids count, since it can reduce redundant lookups in
// documents where all nodes are found at *one* level of the tree.
const objId = currentNode.objId;
if (objId && !pageKidsCountCache.has(objId)) {
pageKidsCountCache.put(objId, count);
}
// Skip nodes where the page can't be.
if (currentPageIndex + count <= pageIndex) {
currentPageIndex += count;
continue;
}
}
const kids = currentNode.get("Kids");
if (!Array.isArray(kids)) {
// Prevent errors in corrupt PDF documents that violate the
// specification by *inlining* Page dicts directly in the Kids
// array, rather than using indirect objects (fixes issue9540.pdf).
if (
isName(currentNode.get("Type"), "Page") ||
(!currentNode.has("Type") && currentNode.has("Contents"))
) {
if (currentPageIndex === pageIndex) {
capability.resolve([currentNode, null]);
return;
}
currentPageIndex++;
continue;
}
capability.reject(
new FormatError("Page dictionary kids object is not an array.")
);
return;
}
// Always check all `Kids` nodes, to avoid getting stuck in an empty
// node further down in the tree (see issue5644.pdf, issue8088.pdf),
// and to ensure that we actually find the correct `Page` dict.
for (let last = kids.length - 1; last >= 0; last--) {
nodesToVisit.push(kids[last]);
}
}
capability.reject(new Error(`Page index ${pageIndex} not found.`));
}
next();
return capability.promise;
}
getPageIndex(pageRef) {
const cachedPageIndex = this.pageIndexCache.get(pageRef);
if (cachedPageIndex !== undefined) {
return Promise.resolve(cachedPageIndex);
}
// The page tree nodes have the count of all the leaves below them. To get
// how many pages are before we just have to walk up the tree and keep
// adding the count of siblings to the left of the node.
const xref = this.xref;
function pagesBeforeRef(kidRef) {
let total = 0,
parentRef;
return xref
.fetchAsync(kidRef)
.then(function (node) {
if (
isRefsEqual(kidRef, pageRef) &&
!isDict(node, "Page") &&
!(isDict(node) && !node.has("Type") && node.has("Contents"))
) {
throw new FormatError(
"The reference does not point to a /Page dictionary."
);
}
if (!node) {
return null;
}
if (!isDict(node)) {
throw new FormatError("Node must be a dictionary.");
}
parentRef = node.getRaw("Parent");
return node.getAsync("Parent");
})
.then(function (parent) {
if (!parent) {
return null;
}
if (!isDict(parent)) {
throw new FormatError("Parent must be a dictionary.");
}
return parent.getAsync("Kids");
})
.then(function (kids) {
if (!kids) {
return null;
}
const kidPromises = [];
let found = false;
for (let i = 0, ii = kids.length; i < ii; i++) {
const kid = kids[i];
if (!isRef(kid)) {
throw new FormatError("Kid must be a reference.");
}
if (isRefsEqual(kid, kidRef)) {
found = true;
break;
}
kidPromises.push(
xref.fetchAsync(kid).then(function (obj) {
if (!isDict(obj)) {
throw new FormatError("Kid node must be a dictionary.");
}
if (obj.has("Count")) {
total += obj.get("Count");
} else {
// Page leaf node.
total++;
}
})
);
}
if (!found) {
throw new FormatError("Kid reference not found in parent's kids.");
}
return Promise.all(kidPromises).then(function () {
return [total, parentRef];
});
});
}
let total = 0;
const next = ref =>
pagesBeforeRef(ref).then(args => {
if (!args) {
this.pageIndexCache.put(pageRef, total);
return total;
}
const [count, parentRef] = args;
total += count;
return next(parentRef);
});
return next(pageRef);
}
/**
* @typedef ParseDestDictionaryParameters
* @property {Dict} destDict - The dictionary containing the destination.
* @property {Object} resultObj - The object where the parsed destination
* properties will be placed.
* @property {string} [docBaseUrl] - The document base URL that is used when
* attempting to recover valid absolute URLs from relative ones.
*/
/**
* Helper function used to parse the contents of destination dictionaries.
* @param {ParseDestDictionaryParameters} params
*/
static parseDestDictionary(params) {
// Lets URLs beginning with 'www.' default to using the 'http://' protocol.
function addDefaultProtocolToUrl(url) {
return url.startsWith("www.") ? `http://${url}` : url;
}
// According to ISO 32000-1:2008, section 12.6.4.7, URIs should be encoded
// in 7-bit ASCII. Some bad PDFs use UTF-8 encoding; see Bugzilla 1122280.
function tryConvertUrlEncoding(url) {
try {
return stringToUTF8String(url);
} catch (e) {
return url;
}
}
const destDict = params.destDict;
if (!isDict(destDict)) {
warn("parseDestDictionary: `destDict` must be a dictionary.");
return;
}
const resultObj = params.resultObj;
if (typeof resultObj !== "object") {
warn("parseDestDictionary: `resultObj` must be an object.");
return;
}
const docBaseUrl = params.docBaseUrl || null;
let action = destDict.get("A"),
url,
dest;
if (!isDict(action)) {
if (destDict.has("Dest")) {
// A /Dest entry should *only* contain a Name or an Array, but some bad
// PDF generators ignore that and treat it as an /A entry.
action = destDict.get("Dest");
} else {
action = destDict.get("AA");
if (isDict(action)) {
if (action.has("D")) {
// MouseDown
action = action.get("D");
} else if (action.has("U")) {
// MouseUp
action = action.get("U");
}
}
}
}
if (isDict(action)) {
const actionType = action.get("S");
if (!isName(actionType)) {
warn("parseDestDictionary: Invalid type in Action dictionary.");
return;
}
const actionName = actionType.name;
switch (actionName) {
case "URI":
url = action.get("URI");
if (isName(url)) {
// Some bad PDFs do not put parentheses around relative URLs.
url = "/" + url.name;
} else if (isString(url)) {
url = addDefaultProtocolToUrl(url);
}
// TODO: pdf spec mentions urls can be relative to a Base
// entry in the dictionary.
break;
case "GoTo":
dest = action.get("D");
break;
case "Launch":
// We neither want, nor can, support arbitrary 'Launch' actions.
// However, in practice they are mostly used for linking to other PDF
// files, which we thus attempt to support (utilizing `docBaseUrl`).
/* falls through */
case "GoToR":
const urlDict = action.get("F");
if (isDict(urlDict)) {
// We assume that we found a FileSpec dictionary
// and fetch the URL without checking any further.
url = urlDict.get("F") || null;
} else if (isString(urlDict)) {
url = urlDict;
}
// NOTE: the destination is relative to the *remote* document.
let remoteDest = action.get("D");
if (remoteDest) {
if (isName(remoteDest)) {
remoteDest = remoteDest.name;
}
if (isString(url)) {
const baseUrl = url.split("#")[0];
if (isString(remoteDest)) {
url = baseUrl + "#" + remoteDest;
} else if (Array.isArray(remoteDest)) {
url = baseUrl + "#" + JSON.stringify(remoteDest);
}
}
}
// The 'NewWindow' property, equal to `LinkTarget.BLANK`.
const newWindow = action.get("NewWindow");
if (isBool(newWindow)) {
resultObj.newWindow = newWindow;
}
break;
case "Named":
const namedAction = action.get("N");
if (isName(namedAction)) {
resultObj.action = namedAction.name;
}
break;
case "JavaScript":
const jsAction = action.get("JS");
let js;
if (isStream(jsAction)) {
js = jsAction.getString();
} else if (isString(jsAction)) {
js = jsAction;
}
if (js) {
// Attempt to recover valid URLs from `JS` entries with certain
// white-listed formats:
// - window.open('http://example.com')
// - app.launchURL('http://example.com', true)
const URL_OPEN_METHODS = ["app.launchURL", "window.open"];
const regex = new RegExp(
"^\\s*(" +
URL_OPEN_METHODS.join("|").split(".").join("\\.") +
")\\((?:'|\")([^'\"]*)(?:'|\")(?:,\\s*(\\w+)\\)|\\))",
"i"
);
const jsUrl = regex.exec(stringToPDFString(js));
if (jsUrl && jsUrl[2]) {
url = jsUrl[2];
if (jsUrl[3] === "true" && jsUrl[1] === "app.launchURL") {
resultObj.newWindow = true;
}
break;
}
}
/* falls through */
default:
if (
actionName === "JavaScript" ||
actionName === "ResetForm" ||
actionName === "SubmitForm"
) {
// Don't bother the user with a warning for actions that require
// scripting support, since those will be handled separately.
break;
}
warn(`parseDestDictionary - unsupported action: "${actionName}".`);
break;
}
} else if (destDict.has("Dest")) {
// Simple destination.
dest = destDict.get("Dest");
}
if (isString(url)) {
url = tryConvertUrlEncoding(url);
const absoluteUrl = createValidAbsoluteUrl(url, docBaseUrl);
if (absoluteUrl) {
resultObj.url = absoluteUrl.href;
}
resultObj.unsafeUrl = url;
}
if (dest) {
if (isName(dest)) {
dest = dest.name;
}
if (isString(dest) || Array.isArray(dest)) {
resultObj.dest = dest;
}
}
}
}
export { Catalog };