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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* Turn a dictionary received from postMessage into a key event.
* @param {Object} dict A dictionary representing the key event.
* @return {Event} A key event.
*/
function DeserializeKeyEvent(dict) {
var e = document.createEvent('Event');
e.initEvent('keydown', true, true);
e.keyCode = dict.keyCode;
e.shiftKey = dict.shiftKey;
e.ctrlKey = dict.ctrlKey;
e.altKey = dict.altKey;
e.metaKey = dict.metaKey;
e.fromScriptingAPI = true;
return e;
}
/**
* Turn a key event into a dictionary which can be sent over postMessage.
* @param {Event} event A key event.
* @return {Object} A dictionary representing the key event.
*/
function SerializeKeyEvent(event) {
return {
keyCode: event.keyCode,
shiftKey: event.shiftKey,
ctrlKey: event.ctrlKey,
altKey: event.altKey,
metaKey: event.metaKey
};
}
/**
* An enum containing a value specifying whether the PDF is currently loading,
* has finished loading or failed to load.
* @enum {string}
*/
var LoadState = {LOADING: 'loading', SUCCESS: 'success', FAILED: 'failed'};
/**
* Create a new PDFScriptingAPI. This provides a scripting interface to
* the PDF viewer so that it can be customized by things like print preview.
* @param {Window} window the window of the page containing the pdf viewer.
* @param {Object} plugin the plugin element containing the pdf viewer.
* @constructor
*/
function PDFScriptingAPI(window, plugin) {
this.loadState_ = LoadState.LOADING;
this.pendingScriptingMessages_ = [];
this.setPlugin(plugin);
window.addEventListener('message', event => {
if (event.origin != 'chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai' &&
event.origin != 'chrome://print') {
console.error(
'Received message that was not from the extension: ' + event);
return;
}
switch (event.data.type) {
case 'viewport':
/**
* @type {{
* pageX: number,
* pageY: number,
* pageWidth: number,
* viewportWidth: number,
* viewportHeight: number
* }}
*/
var viewportData = event.data;
if (this.viewportChangedCallback_)
this.viewportChangedCallback_(
viewportData.pageX, viewportData.pageY, viewportData.pageWidth,
viewportData.viewportWidth, viewportData.viewportHeight);
break;
case 'documentLoaded':
var data = /** @type {{load_state: LoadState}} */ (event.data);
this.loadState_ = data.load_state;
if (this.loadCallback_)
this.loadCallback_(this.loadState_ == LoadState.SUCCESS);
break;
case 'getSelectedTextReply':
var data = /** @type {{selectedText: string}} */ (event.data);
if (this.selectedTextCallback_) {
this.selectedTextCallback_(data.selectedText);
this.selectedTextCallback_ = null;
}
break;
case 'sendKeyEvent':
if (this.keyEventCallback_)
this.keyEventCallback_(DeserializeKeyEvent(event.data.keyEvent));
break;
}
}, false);
}
PDFScriptingAPI.prototype = {
/**
* @private
* Send a message to the extension. If messages try to get sent before there
* is a plugin element set, then we queue them up and send them later (this
* can happen in print preview).
* @param {Object} message The message to send.
*/
sendMessage_: function(message) {
if (this.plugin_)
this.plugin_.postMessage(message, '*');
else
this.pendingScriptingMessages_.push(message);
},
/**
* Sets the plugin element containing the PDF viewer. The element will usually
* be passed into the PDFScriptingAPI constructor but may also be set later.
* @param {Object} plugin the plugin element containing the PDF viewer.
*/
setPlugin: function(plugin) {
this.plugin_ = plugin;
if (this.plugin_) {
// Send a message to ensure the postMessage channel is initialized which
// allows us to receive messages.
this.sendMessage_({type: 'initialize'});
// Flush pending messages.
while (this.pendingScriptingMessages_.length > 0)
this.sendMessage_(this.pendingScriptingMessages_.shift());
}
},
/**
* Sets the callback which will be run when the PDF viewport changes.
* @param {Function} callback the callback to be called.
*/
setViewportChangedCallback: function(callback) {
this.viewportChangedCallback_ = callback;
},
/**
* Sets the callback which will be run when the PDF document has finished
* loading. If the document is already loaded, it will be run immediately.
* @param {Function} callback the callback to be called.
*/
setLoadCallback: function(callback) {
this.loadCallback_ = callback;
if (this.loadState_ != LoadState.LOADING && this.loadCallback_)
this.loadCallback_(this.loadState_ == LoadState.SUCCESS);
},
/**
* Sets a callback that gets run when a key event is fired in the PDF viewer.
* @param {Function} callback the callback to be called with a key event.
*/
setKeyEventCallback: function(callback) {
this.keyEventCallback_ = callback;
},
/**
* Resets the PDF viewer into print preview mode.
* @param {string} url the url of the PDF to load.
* @param {boolean} grayscale whether or not to display the PDF in grayscale.
* @param {Array<number>} pageNumbers an array of the page numbers.
* @param {boolean} modifiable whether or not the document is modifiable.
*/
resetPrintPreviewMode: function(url, grayscale, pageNumbers, modifiable) {
this.loadState_ = LoadState.LOADING;
this.sendMessage_({
type: 'resetPrintPreviewMode',
url: url,
grayscale: grayscale,
pageNumbers: pageNumbers,
modifiable: modifiable
});
},
/**
* Load a page into the document while in print preview mode.
* @param {string} url the url of the pdf page to load.
* @param {number} index the index of the page to load.
*/
loadPreviewPage: function(url, index) {
this.sendMessage_({type: 'loadPreviewPage', url: url, index: index});
},
/**
* Select all the text in the document. May only be called after document
* load.
*/
selectAll: function() {
this.sendMessage_({type: 'selectAll'});
},
/**
* Get the selected text in the document. The callback will be called with the
* text that is selected. May only be called after document load.
* @param {Function} callback a callback to be called with the selected text.
* @return {boolean} true if the function is successful, false if there is an
* outstanding request for selected text that has not been answered.
*/
getSelectedText: function(callback) {
if (this.selectedTextCallback_)
return false;
this.selectedTextCallback_ = callback;
this.sendMessage_({type: 'getSelectedText'});
return true;
},
/**
* Print the document. May only be called after document load.
*/
print: function() {
this.sendMessage_({type: 'print'});
},
/**
* Send a key event to the extension.
* @param {Event} keyEvent the key event to send to the extension.
*/
sendKeyEvent: function(keyEvent) {
this.sendMessage_(
{type: 'sendKeyEvent', keyEvent: SerializeKeyEvent(keyEvent)});
},
};
/**
* Creates a PDF viewer with a scripting interface. This is basically 1) an
* iframe which is navigated to the PDF viewer extension and 2) a scripting
* interface which provides access to various features of the viewer for use
* by print preview and accessibility.
* @param {string} src the source URL of the PDF to load initially.
* @param {string} baseUrl the base URL of the PDF viewer
* @return {HTMLIFrameElement} the iframe element containing the PDF viewer.
*/
function PDFCreateOutOfProcessPlugin(src, baseUrl) {
var client = new PDFScriptingAPI(window, null);
var iframe = assertInstanceof(
window.document.createElement('iframe'), HTMLIFrameElement);
iframe.setAttribute('src', baseUrl + '/index.html?' + src);
// Prevent the frame from being tab-focusable.
iframe.setAttribute('tabindex', '-1');
iframe.onload = function() {
client.setPlugin(iframe.contentWindow);
};
// Add the functions to the iframe so that they can be called directly.
iframe.setViewportChangedCallback =
client.setViewportChangedCallback.bind(client);
iframe.setLoadCallback = client.setLoadCallback.bind(client);
iframe.setKeyEventCallback = client.setKeyEventCallback.bind(client);
iframe.resetPrintPreviewMode = client.resetPrintPreviewMode.bind(client);
iframe.loadPreviewPage = client.loadPreviewPage.bind(client);
iframe.sendKeyEvent = client.sendKeyEvent.bind(client);
return iframe;
}
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