// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import type {PinchEventDetail} from './gesture_detector.js';
import {GestureDetector} from './gesture_detector.js';
import type {SwipeDirection} from './swipe_detector.js';
import {SwipeDetector} from './swipe_detector.js';
interface InProcessPdfPluginElement extends HTMLEmbedElement {
postMessage(message: any): void;
}
const channel = new MessageChannel();
const sizer = document.querySelector<HTMLElement>('#sizer')!;
const plugin = document.querySelector<InProcessPdfPluginElement>('embed')!;
const srcUrl = new URL(plugin.src);
let parentOrigin = srcUrl.origin;
if (parentOrigin === 'chrome-untrusted://print') {
// Within Print Preview, the source origin differs from the parent origin.
parentOrigin = 'chrome://print';
}
// Plugin-to-parent message handlers. All messages are passed through, but some
// messages may affect this frame, too.
let isFormFieldFocused = false;
plugin.addEventListener('message', e => {
const message = (e as MessageEvent).data;
switch (message.type) {
case 'formFocusChange':
// TODO(crbug.com/40810904): Ideally, the plugin would just consume
// interesting keyboard events first.
isFormFieldFocused = (message as {focused: boolean}).focused;
break;
}
channel.port1.postMessage(message);
});
// Parent-to-plugin message handlers. Most messages are passed through, but some
// messages (with handlers that `return` immediately) are meant only for this
// frame, not the plugin.
let isPresentationMode = false;
channel.port1.onmessage = e => {
switch (e.data.type) {
case 'loadArray':
if (plugin.src.startsWith('blob:')) {
URL.revokeObjectURL(plugin.src);
}
plugin.src = URL.createObjectURL(new Blob([e.data.dataToLoad]));
plugin.setAttribute('has-edits', '');
return;
case 'setPresentationMode':
isPresentationMode = e.data.enablePresentationMode;
gestureDetector.setPresentationMode(isPresentationMode);
swipeDetector.setPresentationMode(isPresentationMode);
if (isPresentationMode) {
document.documentElement.className = 'fullscreen';
} else {
document.documentElement.className = '';
// Ensure that directional keys still work after exiting.
plugin.focus();
}
break;
case 'syncScrollToRemote':
// TODO(crbug.com/40218278): Implement smooth scrolling correctly.
window.scrollTo({
left: e.data.x,
top: e.data.y,
});
channel.port1.postMessage({
type: 'ackScrollToRemote',
x: window.scrollX,
y: window.scrollY,
});
return;
case 'updateSize':
sizer.style.width = `${e.data.width}px`;
sizer.style.height = `${e.data.height}px`;
return;
case 'viewport':
// Snoop on "viewport" message to support real RTL scrolling in Print
// Preview.
// TODO(crbug.com/40737077): Support real RTL scrolling in the PDF viewer.
if (parentOrigin === 'chrome://print' && e.data.layoutOptions) {
switch (e.data.layoutOptions.direction) {
case 1:
document.dir = 'rtl';
break;
case 2:
document.dir = 'ltr';
break;
default:
document.dir = '';
break;
}
}
break;
}
plugin.postMessage(e.data);
};
// Entangle parent-child message channel.
window.parent.postMessage(
{type: 'connect', token: srcUrl.href}, parentOrigin, [channel.port2]);
// Forward "scroll" events back to the parent frame's `Viewport`.
window.addEventListener('scroll', () => {
channel.port1.postMessage({
type: 'syncScrollFromRemote',
x: window.scrollX,
y: window.scrollY,
});
});
/**
* Relays gesture events to the parent frame.
* @param e The gesture event.
*/
function relayGesture(e: Event): void {
const gestureEvent = e as CustomEvent<PinchEventDetail>;
channel.port1.postMessage({
type: 'gesture',
gesture: {
type: gestureEvent.type,
detail: gestureEvent.detail,
},
});
}
const gestureDetector = new GestureDetector(plugin);
for (const type of ['pinchstart', 'pinchupdate', 'pinchend', 'wheel']) {
gestureDetector.getEventTarget().addEventListener(type, relayGesture);
}
/**
* Relays swipe events to the parent frame.
* @param e The swipe event.
*/
function relaySwipe(e: Event): void {
const swipeEvent = e as CustomEvent<SwipeDirection>;
channel.port1.postMessage({
type: 'swipe',
direction: swipeEvent.detail,
});
}
const swipeDetector = new SwipeDetector(plugin);
swipeDetector.getEventTarget().addEventListener('swipe', relaySwipe);
document.addEventListener('keydown', e => {
// Only forward potential shortcut keys.
switch (e.key) {
case ' ':
// Preventing Space happens in the "keypress" event handler.
break;
case 'PageDown':
case 'PageUp':
// Prevent PageDown/PageUp when there are no modifier keys.
if (!hasKeyModifiers(e)) {
e.preventDefault();
break;
}
return;
case 'ArrowDown':
case 'ArrowLeft':
case 'ArrowRight':
case 'ArrowUp':
// Don't prevent arrow navigation in form fields, or if modified.
if (!isFormFieldFocused && !hasKeyModifiers(e)) {
e.preventDefault();
break;
}
return;
case 'Escape':
case 'Tab':
// Print Preview is interested in Escape and Tab.
break;
case '=':
case '-':
case '+':
// Ignore zoom shortcuts in Presentation mode.
if (isPresentationMode && hasCtrlModifier(e)) {
e.preventDefault();
}
return;
case 'a':
// Take over Ctrl+A (but not other combinations like Ctrl-Shift-A).
// Note that on macOS, "Ctrl" is Command.
if (hasCtrlModifierOnly(e)) {
e.preventDefault();
break;
}
return;
default:
// Relay (but don't prevent) other shortcuts.
if (hasCtrlModifier(e)) {
break;
}
return;
}
channel.port1.postMessage({
type: 'sendKeyEvent',
keyEvent: {
keyCode: e.keyCode,
code: e.code,
key: e.key,
shiftKey: e.shiftKey,
ctrlKey: e.ctrlKey,
altKey: e.altKey,
metaKey: e.metaKey,
},
});
});
// Suppress extra scroll by preventing the default "keypress" handler for Space.
// TODO(crbug.com/40208546): Ideally would prevent "keydown" instead, but this
// doesn't work when a plugin element has focus.
document.addEventListener('keypress', e => {
switch (e.key) {
case ' ':
// Don't prevent Space in form fields.
if (!isFormFieldFocused) {
e.preventDefault();
}
break;
}
});
// TODO(crbug.com/40792950): Load from pdf_viewer_utils.js instead.
function hasCtrlModifier(e: KeyboardEvent): boolean {
let hasModifier = e.ctrlKey;
// <if expr="is_macosx">
hasModifier = e.metaKey; // AKA Command.
// </if>
return hasModifier;
}
// TODO(crbug.com/40792950): Load from pdf_viewer_utils.js instead.
function hasCtrlModifierOnly(e: KeyboardEvent): boolean {
let metaModifier = e.metaKey;
// <if expr="is_macosx">
metaModifier = e.ctrlKey;
// </if>
return hasCtrlModifier(e) && !e.shiftKey && !e.altKey && !metaModifier;
}
// TODO(crbug.com/40792950): Load from chrome://resources/js/util.js instead.
function hasKeyModifiers(e: KeyboardEvent): boolean {
return !!(e.altKey || e.ctrlKey || e.metaKey || e.shiftKey);
}
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