pdf.js/web/app_options.js
Jonas Jenwald 8521f70157 Add a new pdfjs.enablePermissions preference, off by default, to allow the PDF documents to disable copying in the viewer (bug 792816)
*Please note:* Most of the necessary API work was done in PR 10033, and the only remaining thing to do here was to implement it in the viewer.

The new preference should thus allow e.g. enterprise users to disable copying in the viewer, for PDF documents whose permissions specify that.

In order to simplify things the "copy"-permission was implemented using CSS, as suggested in https://bugzilla.mozilla.org/show_bug.cgi?id=792816#c55, which should hopefully suffice.[1]
The advantage of this approach, as opposed to e.g. disabling the `textLayer` completely, is first of all that it ensures that searching still works correctly even in copy-protected documents. Secondly this also greatly simplifies the overall implementation, since it doesn't require a lot of code for something that's disabled by default.

---
[1] As the discussion in the bug shows, this kind of copy-protection is not very strong and is also generally easy to remove/circumvent in various ways. Hence a simple solution, targeting "regular"-users rather than "power"-users is hopefully deemed acceptable here.
2020-04-08 18:20:47 +02:00

323 lines
7.7 KiB
JavaScript

/* Copyright 2018 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 { apiCompatibilityParams } from "pdfjs-lib";
import { viewerCompatibilityParams } from "./viewer_compatibility.js";
const OptionKind = {
VIEWER: 0x02,
API: 0x04,
WORKER: 0x08,
PREFERENCE: 0x80,
};
/**
* PLEASE NOTE: To avoid introducing unnecessary dependencies, we specify the
* values below *explicitly* rather than relying on imported types.
*/
const defaultOptions = {
cursorToolOnLoad: {
/** @type {number} */
value: 0,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
defaultUrl: {
/** @type {string} */
value: "compressed.tracemonkey-pldi-09.pdf",
kind: OptionKind.VIEWER,
},
defaultZoomValue: {
/** @type {string} */
value: "",
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
disableHistory: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER,
},
disablePageLabels: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
enablePermissions: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
/**
* The `disablePreferences` is, conditionally, defined below.
*/
enablePrintAutoRotate: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
enableWebGL: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
externalLinkRel: {
/** @type {string} */
value: "noopener noreferrer nofollow",
kind: OptionKind.VIEWER,
},
externalLinkTarget: {
/** @type {number} */
value: 0,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
historyUpdateUrl: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
ignoreDestinationZoom: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
imageResourcesPath: {
/** @type {string} */
value: "./images/",
kind: OptionKind.VIEWER,
},
/**
* The `locale` is, conditionally, defined below.
*/
maxCanvasPixels: {
/** @type {number} */
value: 16777216,
compatibility: viewerCompatibilityParams.maxCanvasPixels,
kind: OptionKind.VIEWER,
},
pdfBugEnabled: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
/**
* The `printResolution` is, conditionally, defined below.
*/
renderer: {
/** @type {string} */
value: "canvas",
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
renderInteractiveForms: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
sidebarViewOnLoad: {
/** @type {number} */
value: -1,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
scrollModeOnLoad: {
/** @type {number} */
value: -1,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
spreadModeOnLoad: {
/** @type {number} */
value: -1,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
textLayerMode: {
/** @type {number} */
value: 1,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
useOnlyCssZoom: {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
viewOnLoad: {
/** @type {boolean} */
value: 0,
kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
},
cMapPacked: {
/** @type {boolean} */
value: true,
kind: OptionKind.API,
},
cMapUrl: {
/** @type {string} */
value:
(typeof PDFJSDev === "undefined" || !PDFJSDev.test("PRODUCTION")
? "../external/bcmaps/"
: "../web/cmaps/"),
kind: OptionKind.API,
},
disableAutoFetch: {
/** @type {boolean} */
value: false,
kind: OptionKind.API + OptionKind.PREFERENCE,
},
disableCreateObjectURL: {
/** @type {boolean} */
value: false,
compatibility: apiCompatibilityParams.disableCreateObjectURL,
kind: OptionKind.API,
},
disableFontFace: {
/** @type {boolean} */
value: false,
kind: OptionKind.API + OptionKind.PREFERENCE,
},
disableRange: {
/** @type {boolean} */
value: false,
kind: OptionKind.API + OptionKind.PREFERENCE,
},
disableStream: {
/** @type {boolean} */
value: false,
kind: OptionKind.API + OptionKind.PREFERENCE,
},
docBaseUrl: {
/** @type {string} */
value: "",
kind: OptionKind.API,
},
fontExtraProperties: {
/** @type {boolean} */
value: false,
kind: OptionKind.API,
},
isEvalSupported: {
/** @type {boolean} */
value: true,
kind: OptionKind.API,
},
maxImageSize: {
/** @type {number} */
value: -1,
kind: OptionKind.API,
},
pdfBug: {
/** @type {boolean} */
value: false,
kind: OptionKind.API,
},
verbosity: {
/** @type {number} */
value: 1,
kind: OptionKind.API,
},
workerPort: {
/** @type {Object} */
value: null,
kind: OptionKind.WORKER,
},
workerSrc: {
/** @type {string} */
value:
(typeof PDFJSDev === "undefined" || !PDFJSDev.test("PRODUCTION")
? "../src/worker_loader.js"
: "../build/pdf.worker.js"),
kind: OptionKind.WORKER,
},
};
if (
typeof PDFJSDev === "undefined" ||
PDFJSDev.test("!PRODUCTION || (GENERIC && !LIB)")
) {
defaultOptions.disablePreferences = {
/** @type {boolean} */
value: false,
kind: OptionKind.VIEWER,
};
defaultOptions.locale = {
/** @type {string} */
value: (typeof navigator !== "undefined" ? navigator.language : "en-US"),
kind: OptionKind.VIEWER,
};
defaultOptions.printResolution = {
/** @type {number} */
value: 150,
kind: OptionKind.VIEWER,
};
}
const userOptions = Object.create(null);
class AppOptions {
constructor() {
throw new Error("Cannot initialize AppOptions.");
}
static get(name) {
const userOption = userOptions[name];
if (userOption !== undefined) {
return userOption;
}
const defaultOption = defaultOptions[name];
if (defaultOption !== undefined) {
return defaultOption.compatibility || defaultOption.value;
}
return undefined;
}
static getAll(kind = null) {
const options = Object.create(null);
for (const name in defaultOptions) {
const defaultOption = defaultOptions[name];
if (kind) {
if ((kind & defaultOption.kind) === 0) {
continue;
}
if (kind === OptionKind.PREFERENCE) {
const value = defaultOption.value,
valueType = typeof value;
if (
valueType === "boolean" ||
valueType === "string" ||
(valueType === "number" && Number.isInteger(value))
) {
options[name] = value;
continue;
}
throw new Error(`Invalid type for preference: ${name}`);
}
}
const userOption = userOptions[name];
options[name] =
userOption !== undefined
? userOption
: defaultOption.compatibility || defaultOption.value;
}
return options;
}
static set(name, value) {
userOptions[name] = value;
}
static remove(name) {
delete userOptions[name];
}
}
export { AppOptions, OptionKind };