pdf.js/src/core.js

696 lines
23 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* 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.
*/
/* globals assertWellFormed, calculateMD5, Catalog, error, info, isArray,
isArrayBuffer, isDict, isName, isStream, isString, Lexer,
Linearization, NullStream, PartialEvaluator, shadow, Stream,
StreamsSequenceStream, stringToPDFString, TODO, Util, warn, XRef */
'use strict';
var globalScope = (typeof window === 'undefined') ? this : window;
var isWorker = (typeof window == 'undefined');
var ERRORS = 0, WARNINGS = 1, INFOS = 5;
var verbosity = WARNINGS;
// The global PDFJS object exposes the API
// In production, it will be declared outside a global wrapper
// In development, it will be declared here
if (!globalScope.PDFJS) {
globalScope.PDFJS = {};
}
// getPdf()
// Convenience function to perform binary Ajax GET
// Usage: getPdf('http://...', callback)
// getPdf({
// url:String ,
// [,progress:Function, error:Function]
// },
// callback)
function getPdf(arg, callback) {
var params = arg;
if (typeof arg === 'string')
params = { url: arg };
//#if !B2G
var xhr = new XMLHttpRequest();
//#else
//var xhr = new XMLHttpRequest({mozSystem: true});
//#endif
xhr.open('GET', params.url);
var headers = params.headers;
if (headers) {
for (var property in headers) {
if (typeof headers[property] === 'undefined')
continue;
xhr.setRequestHeader(property, params.headers[property]);
}
}
xhr.mozResponseType = xhr.responseType = 'arraybuffer';
var protocol = params.url.substring(0, params.url.indexOf(':') + 1);
xhr.expected = (protocol === 'http:' || protocol === 'https:') ? 200 : 0;
if ('progress' in params)
xhr.onprogress = params.progress || undefined;
var calledErrorBack = false;
if ('error' in params) {
xhr.onerror = function errorBack() {
if (!calledErrorBack) {
calledErrorBack = true;
params.error();
}
};
}
xhr.onreadystatechange = function getPdfOnreadystatechange(e) {
if (xhr.readyState === 4) {
if (xhr.status === xhr.expected) {
var data = (xhr.mozResponseArrayBuffer || xhr.mozResponse ||
xhr.responseArrayBuffer || xhr.response);
callback(data);
} else if (params.error && !calledErrorBack) {
calledErrorBack = true;
params.error(e);
}
}
};
xhr.send(null);
}
globalScope.PDFJS.getPdf = getPdf;
globalScope.PDFJS.pdfBug = false;
var Page = (function PageClosure() {
function getDefaultAnnotationAppearance(annotationDict) {
var appearanceState = annotationDict.get('AP');
if (!isDict(appearanceState)) {
return;
}
var appearance;
var appearances = appearanceState.get('N');
if (isDict(appearances)) {
var as = annotationDict.get('AS');
if (as && appearances.has(as.name)) {
appearance = appearances.get(as.name);
}
} else {
appearance = appearances;
}
return appearance;
}
function Page(xref, pageIndex, pageDict, ref) {
this.pageIndex = pageIndex;
this.pageDict = pageDict;
this.xref = xref;
this.ref = ref;
this.displayReadyPromise = null;
}
Page.prototype = {
getPageProp: function Page_getPageProp(key) {
return this.pageDict.get(key);
},
inheritPageProp: function Page_inheritPageProp(key) {
var dict = this.pageDict;
var obj = dict.get(key);
while (obj === undefined) {
dict = dict.get('Parent');
if (!dict)
break;
obj = dict.get(key);
}
return obj;
},
get content() {
return shadow(this, 'content', this.getPageProp('Contents'));
},
get resources() {
return shadow(this, 'resources', this.inheritPageProp('Resources'));
},
get mediaBox() {
var obj = this.inheritPageProp('MediaBox');
// Reset invalid media box to letter size.
if (!isArray(obj) || obj.length !== 4)
obj = [0, 0, 612, 792];
return shadow(this, 'mediaBox', obj);
},
get view() {
var mediaBox = this.mediaBox;
var cropBox = this.inheritPageProp('CropBox');
if (!isArray(cropBox) || cropBox.length !== 4)
return shadow(this, 'view', mediaBox);
// From the spec, 6th ed., p.963:
// "The crop, bleed, trim, and art boxes should not ordinarily
// extend beyond the boundaries of the media box. If they do, they are
// effectively reduced to their intersection with the media box."
cropBox = Util.intersect(cropBox, mediaBox);
if (!cropBox)
return shadow(this, 'view', mediaBox);
return shadow(this, 'view', cropBox);
},
get annotations() {
return shadow(this, 'annotations', this.inheritPageProp('Annots'));
},
get rotate() {
var rotate = this.inheritPageProp('Rotate') || 0;
// Normalize rotation so it's a multiple of 90 and between 0 and 270
if (rotate % 90 !== 0) {
rotate = 0;
} else if (rotate >= 360) {
rotate = rotate % 360;
} else if (rotate < 0) {
// The spec doesn't cover negatives, assume its counterclockwise
// rotation. The following is the other implementation of modulo.
rotate = ((rotate % 360) + 360) % 360;
}
return shadow(this, 'rotate', rotate);
},
getContentStream: function Page_getContentStream() {
var content = this.content;
if (isArray(content)) {
// fetching items
var xref = this.xref;
var i, n = content.length;
var streams = [];
for (i = 0; i < n; ++i)
streams.push(xref.fetchIfRef(content[i]));
content = new StreamsSequenceStream(streams);
} else if (isStream(content)) {
content.reset();
} else if (!content) {
// replacing non-existent page content with empty one
content = new NullStream();
}
return content;
},
getOperatorList: function Page_getOperatorList(handler, dependency) {
var xref = this.xref;
var contentStream = this.getContentStream();
var resources = this.resources;
var pe = this.pe = new PartialEvaluator(
xref, handler, this.pageIndex,
'p' + this.pageIndex + '_');
var list = pe.getOperatorList(contentStream, resources, dependency);
var annotations = this.getAnnotationsForDraw();
var annotationEvaluator = new PartialEvaluator(
xref, handler, this.pageIndex,
'p' + this.pageIndex + '_annotation');
var annotationsList = annotationEvaluator.getAnnotationsOperatorList(
annotations, dependency);
Util.concatenateToArray(list.fnArray, annotationsList.fnArray);
Util.concatenateToArray(list.argsArray, annotationsList.argsArray);
pe.optimizeQueue(list);
return list;
},
extractTextContent: function Page_extractTextContent() {
var handler = {
on: function nullHandlerOn() {},
send: function nullHandlerSend() {}
};
var xref = this.xref;
var contentStream = this.getContentStream();
var resources = xref.fetchIfRef(this.resources);
var pe = new PartialEvaluator(
xref, handler, this.pageIndex,
'p' + this.pageIndex + '_');
return pe.getTextContent(contentStream, resources);
},
getLinks: function Page_getLinks() {
var links = [];
var annotations = this.getAnnotations();
var i, n = annotations.length;
for (i = 0; i < n; ++i) {
if (annotations[i].type != 'Link')
continue;
links.push(annotations[i]);
}
return links;
},
getAnnotations: function Page_getAnnotations() {
var annotations = this.getAnnotationsBase();
var items = [];
for (var i = 0, length = annotations.length; i < length; ++i) {
items.push(annotations[i].item);
}
return items;
},
getAnnotationsForDraw: function Page_getAnnotationsForDraw() {
var annotations = this.getAnnotationsBase();
var items = [];
for (var i = 0, length = annotations.length; i < length; ++i) {
var item = annotations[i].item;
var annotationDict = annotations[i].dict;
item.annotationFlags = annotationDict.get('F');
var appearance = getDefaultAnnotationAppearance(annotationDict);
if (appearance &&
// TODO(mack): The proper implementation requires that the
// appearance stream overrides Name, but we're currently
// doing it the other way around for 'Text' annotations since we
// have special rendering for it
item.type !== 'Text') {
item.appearance = appearance;
var appearanceDict = appearance.dict;
item.resources = appearanceDict.get('Resources');
item.bbox = appearanceDict.get('BBox') || [0, 0, 1, 1];
item.matrix = appearanceDict.get('Matrix') || [1, 0, 0, 1, 0 ,0];
}
var border = annotationDict.get('BS');
if (isDict(border) && !item.appearance) {
var borderWidth = border.has('W') ? border.get('W') : 1;
if (borderWidth !== 0) {
item.border = {
width: borderWidth,
type: border.get('S') || 'S',
rgb: annotationDict.get('C') || [0, 0, 1]
};
}
}
items.push(item);
}
return items;
},
getAnnotationsBase: function Page_getAnnotationsBase() {
var xref = this.xref;
function getInheritableProperty(annotation, name) {
var item = annotation;
while (item && !item.has(name)) {
item = item.get('Parent');
}
if (!item)
return null;
return item.get(name);
}
function isValidUrl(url) {
if (!url)
return false;
var colon = url.indexOf(':');
if (colon < 0)
return false;
var protocol = url.substr(0, colon);
switch (protocol) {
case 'http':
case 'https':
case 'ftp':
case 'mailto':
return true;
default:
return false;
}
}
var annotations = this.annotations || [];
var i, n = annotations.length;
var items = [];
for (i = 0; i < n; ++i) {
var annotationRef = annotations[i];
var annotation = xref.fetchIfRef(annotationRef);
if (!isDict(annotation))
continue;
var subtype = annotation.get('Subtype');
if (!isName(subtype))
continue;
var item = {};
item.type = subtype.name;
var rect = annotation.get('Rect');
item.rect = Util.normalizeRect(rect);
var includeAnnotation = true;
switch (subtype.name) {
case 'Link':
var a = annotation.get('A');
if (a) {
switch (a.get('S').name) {
case 'URI':
var url = a.get('URI');
// TODO: pdf spec mentions urls can be relative to a Base
// entry in the dictionary.
if (!isValidUrl(url))
url = '';
item.url = url;
break;
case 'GoTo':
item.dest = a.get('D');
break;
case 'GoToR':
var url = a.get('F');
if (isDict(url)) {
// We assume that the 'url' is a Filspec dictionary
// and fetch the url without checking any further
url = url.get('F') || '';
}
// TODO: pdf reference says that GoToR
// can also have 'NewWindow' attribute
if (!isValidUrl(url))
url = '';
item.url = url;
item.dest = a.get('D');
break;
default:
TODO('unrecognized link type: ' + a.get('S').name);
}
} else if (annotation.has('Dest')) {
// simple destination link
var dest = annotation.get('Dest');
item.dest = isName(dest) ? dest.name : dest;
}
break;
case 'Widget':
var fieldType = getInheritableProperty(annotation, 'FT');
if (!isName(fieldType))
break;
// Do not display digital signatures since we do not currently
// validate them.
if (fieldType.name === 'Sig') {
includeAnnotation = false;
break;
}
item.fieldType = fieldType.name;
// Building the full field name by collecting the field and
// its ancestors 'T' properties and joining them using '.'.
var fieldName = [];
var namedItem = annotation, ref = annotationRef;
while (namedItem) {
var parent = namedItem.get('Parent');
var parentRef = namedItem.getRaw('Parent');
var name = namedItem.get('T');
if (name) {
fieldName.unshift(stringToPDFString(name));
} else {
// The field name is absent, that means more than one field
// with the same name may exist. Replacing the empty name
// with the '`' plus index in the parent's 'Kids' array.
// This is not in the PDF spec but necessary to id the
// the input controls.
var kids = parent.get('Kids');
var j, jj;
for (j = 0, jj = kids.length; j < jj; j++) {
var kidRef = kids[j];
if (kidRef.num == ref.num && kidRef.gen == ref.gen)
break;
}
fieldName.unshift('`' + j);
}
namedItem = parent;
ref = parentRef;
}
item.fullName = fieldName.join('.');
var alternativeText = stringToPDFString(annotation.get('TU') || '');
item.alternativeText = alternativeText;
var da = getInheritableProperty(annotation, 'DA') || '';
var m = /([\d\.]+)\sTf/.exec(da);
if (m)
item.fontSize = parseFloat(m[1]);
item.textAlignment = getInheritableProperty(annotation, 'Q');
item.flags = getInheritableProperty(annotation, 'Ff') || 0;
break;
case 'Text':
var content = annotation.get('Contents');
var title = annotation.get('T');
item.content = stringToPDFString(content || '');
item.title = stringToPDFString(title || '');
item.name = !annotation.has('Name') ? 'Note' :
annotation.get('Name').name;
break;
default:
var appearance = getDefaultAnnotationAppearance(annotation);
if (!appearance) {
TODO('unimplemented annotation type: ' + subtype.name);
}
break;
}
if (includeAnnotation) {
items.push({
item: item,
dict: annotation
});
}
}
return items;
}
};
return Page;
})();
/**
* The `PDFDocument` holds all the data of the PDF file. Compared to the
* `PDFDoc`, this one doesn't have any job management code.
* Right now there exists one PDFDocument on the main thread + one object
* for each worker. If there is no worker support enabled, there are two
* `PDFDocument` objects on the main thread created.
*/
var PDFDocument = (function PDFDocumentClosure() {
function PDFDocument(arg, password) {
if (isStream(arg))
init.call(this, arg, password);
else if (isArrayBuffer(arg))
init.call(this, new Stream(arg), password);
else
error('PDFDocument: Unknown argument type');
}
function init(stream, password) {
assertWellFormed(stream.length > 0, 'stream must have data');
this.stream = stream;
this.setup(password);
this.acroForm = this.catalog.catDict.get('AcroForm');
}
function find(stream, needle, limit, backwards) {
var pos = stream.pos;
var end = stream.end;
var str = '';
if (pos + limit > end)
limit = end - pos;
for (var n = 0; n < limit; ++n)
str += stream.getChar();
stream.pos = pos;
var index = backwards ? str.lastIndexOf(needle) : str.indexOf(needle);
if (index == -1)
return false; /* not found */
stream.pos += index;
return true; /* found */
}
var DocumentInfoValidators = {
get entries() {
// Lazily build this since all the validation functions below are not
// defined until after this file loads.
return shadow(this, 'entries', {
Title: isString,
Author: isString,
Subject: isString,
Keywords: isString,
Creator: isString,
Producer: isString,
CreationDate: isString,
ModDate: isString,
Trapped: isName
});
}
};
PDFDocument.prototype = {
get linearization() {
var length = this.stream.length;
var linearization = false;
if (length) {
try {
linearization = new Linearization(this.stream);
if (linearization.length != length)
linearization = false;
} catch (err) {
warn('The linearization data is not available ' +
'or unreadable pdf data is found');
linearization = false;
}
}
// shadow the prototype getter with a data property
return shadow(this, 'linearization', linearization);
},
get startXRef() {
var stream = this.stream;
var startXRef = 0;
var linearization = this.linearization;
if (linearization) {
// Find end of first obj.
stream.reset();
if (find(stream, 'endobj', 1024))
startXRef = stream.pos + 6;
} else {
// Find startxref by jumping backward from the end of the file.
var step = 1024;
var found = false, pos = stream.end;
while (!found && pos > 0) {
pos -= step - 'startxref'.length;
if (pos < 0)
pos = 0;
stream.pos = pos;
found = find(stream, 'startxref', step, true);
}
if (found) {
stream.skip(9);
var ch;
do {
ch = stream.getChar();
} while (Lexer.isSpace(ch));
var str = '';
while ((ch - '0') <= 9) {
str += ch;
ch = stream.getChar();
}
startXRef = parseInt(str, 10);
if (isNaN(startXRef))
startXRef = 0;
}
}
// shadow the prototype getter with a data property
return shadow(this, 'startXRef', startXRef);
},
get mainXRefEntriesOffset() {
var mainXRefEntriesOffset = 0;
var linearization = this.linearization;
if (linearization)
mainXRefEntriesOffset = linearization.mainXRefEntriesOffset;
// shadow the prototype getter with a data property
return shadow(this, 'mainXRefEntriesOffset', mainXRefEntriesOffset);
},
// Find the header, remove leading garbage and setup the stream
// starting from the header.
checkHeader: function PDFDocument_checkHeader() {
var stream = this.stream;
stream.reset();
if (find(stream, '%PDF-', 1024)) {
// Found the header, trim off any garbage before it.
stream.moveStart();
// Reading file format version
var MAX_VERSION_LENGTH = 12;
var version = '', ch;
while ((ch = stream.getChar()) > ' ') {
if (version.length >= MAX_VERSION_LENGTH) {
break;
}
version += ch;
}
// removing "%PDF-"-prefix
this.pdfFormatVersion = version.substring(5);
return;
}
// May not be a PDF file, continue anyway.
},
setup: function PDFDocument_setup(password) {
this.checkHeader();
var xref = new XRef(this.stream,
this.startXRef,
this.mainXRefEntriesOffset,
password);
this.xref = xref;
this.catalog = new Catalog(xref);
},
get numPages() {
var linearization = this.linearization;
var num = linearization ? linearization.numPages : this.catalog.numPages;
// shadow the prototype getter
return shadow(this, 'numPages', num);
},
getDocumentInfo: function PDFDocument_getDocumentInfo() {
var docInfo = {
PDFFormatVersion: this.pdfFormatVersion,
IsAcroFormPresent: !!this.acroForm
};
if (this.xref.trailer.has('Info')) {
var infoDict = this.xref.trailer.get('Info');
var validEntries = DocumentInfoValidators.entries;
// Only fill the document info with valid entries from the spec.
for (var key in validEntries) {
if (infoDict.has(key)) {
var value = infoDict.get(key);
// Make sure the value conforms to the spec.
if (validEntries[key](value)) {
docInfo[key] = typeof value !== 'string' ? value :
stringToPDFString(value);
} else {
info('Bad value in document info for "' + key + '"');
}
}
}
}
return shadow(this, 'getDocumentInfo', docInfo);
},
getFingerprint: function PDFDocument_getFingerprint() {
var xref = this.xref, fileID;
if (xref.trailer.has('ID')) {
fileID = '';
var id = xref.trailer.get('ID')[0];
id.split('').forEach(function(el) {
fileID += Number(el.charCodeAt(0)).toString(16);
});
} else {
// If we got no fileID, then we generate one,
// from the first 100 bytes of PDF
var data = this.stream.bytes.subarray(0, 100);
var hash = calculateMD5(data, 0, data.length);
fileID = '';
for (var i = 0, length = hash.length; i < length; i++) {
fileID += Number(hash[i]).toString(16);
}
}
return shadow(this, 'getFingerprint', fileID);
},
getPage: function PDFDocument_getPage(n) {
return this.catalog.getPage(n);
}
};
return PDFDocument;
})();