noVNC/core/input/keyboard.js
Pierre Ossman 3a7c0c67c1 Work around broken Alt keyup in Firefox
Firefox no longer sends keyup events properly for the Alt keys. Try
to sniff out the state of the Alt key by monitoring other events that
include its state.
2018-03-13 16:01:38 +01:00

359 lines
12 KiB
JavaScript

/*
* noVNC: HTML5 VNC client
* Copyright (C) 2012 Joel Martin
* Copyright (C) 2013 Samuel Mannehed for Cendio AB
* Licensed under MPL 2.0 or any later version (see LICENSE.txt)
*/
import * as Log from '../util/logging.js';
import { stopEvent } from '../util/events.js';
import * as KeyboardUtil from "./util.js";
import KeyTable from "./keysym.js";
import * as browser from "../util/browser.js";
//
// Keyboard event handler
//
export default function Keyboard(target) {
this._target = target || null;
this._keyDownList = {}; // List of depressed keys
// (even if they are happy)
this._pendingKey = null; // Key waiting for keypress
// keep these here so we can refer to them later
this._eventHandlers = {
'keyup': this._handleKeyUp.bind(this),
'keydown': this._handleKeyDown.bind(this),
'keypress': this._handleKeyPress.bind(this),
'blur': this._allKeysUp.bind(this),
'checkalt': this._checkAlt.bind(this),
};
};
Keyboard.prototype = {
// ===== EVENT HANDLERS =====
onkeyevent: function () {}, // Handler for key press/release
// ===== PRIVATE METHODS =====
_sendKeyEvent: function (keysym, code, down) {
Log.Debug("onkeyevent " + (down ? "down" : "up") +
", keysym: " + keysym, ", code: " + code);
// Windows sends CtrlLeft+AltRight when you press
// AltGraph, which tends to confuse the hell out of
// remote systems. Fake a release of these keys until
// there is a way to detect AltGraph properly.
var fakeAltGraph = false;
if (down && browser.isWindows()) {
if ((code !== 'ControlLeft') &&
(code !== 'AltRight') &&
('ControlLeft' in this._keyDownList) &&
('AltRight' in this._keyDownList)) {
fakeAltGraph = true;
this.onkeyevent(this._keyDownList['AltRight'],
'AltRight', false);
this.onkeyevent(this._keyDownList['ControlLeft'],
'ControlLeft', false);
}
}
this.onkeyevent(keysym, code, down);
if (fakeAltGraph) {
this.onkeyevent(this._keyDownList['ControlLeft'],
'ControlLeft', true);
this.onkeyevent(this._keyDownList['AltRight'],
'AltRight', true);
}
},
_getKeyCode: function (e) {
var code = KeyboardUtil.getKeycode(e);
if (code !== 'Unidentified') {
return code;
}
// Unstable, but we don't have anything else to go on
// (don't use it for 'keypress' events thought since
// WebKit sets it to the same as charCode)
if (e.keyCode && (e.type !== 'keypress')) {
// 229 is used for composition events
if (e.keyCode !== 229) {
return 'Platform' + e.keyCode;
}
}
// A precursor to the final DOM3 standard. Unfortunately it
// is not layout independent, so it is as bad as using keyCode
if (e.keyIdentifier) {
// Non-character key?
if (e.keyIdentifier.substr(0, 2) !== 'U+') {
return e.keyIdentifier;
}
var codepoint = parseInt(e.keyIdentifier.substr(2), 16);
var char = String.fromCharCode(codepoint);
// Some implementations fail to uppercase the symbols
char = char.toUpperCase();
return 'Platform' + char.charCodeAt();
}
return 'Unidentified';
},
_handleKeyDown: function (e) {
var code = this._getKeyCode(e);
var keysym = KeyboardUtil.getKeysym(e);
// We cannot handle keys we cannot track, but we also need
// to deal with virtual keyboards which omit key info
// (iOS omits tracking info on keyup events, which forces us to
// special treat that platform here)
if ((code === 'Unidentified') || browser.isIOS()) {
if (keysym) {
// If it's a virtual keyboard then it should be
// sufficient to just send press and release right
// after each other
this._sendKeyEvent(keysym, code, true);
this._sendKeyEvent(keysym, code, false);
}
stopEvent(e);
return;
}
// Alt behaves more like AltGraph on macOS, so shuffle the
// keys around a bit to make things more sane for the remote
// server. This method is used by RealVNC and TigerVNC (and
// possibly others).
if (browser.isMac()) {
switch (keysym) {
case KeyTable.XK_Super_L:
keysym = KeyTable.XK_Alt_L;
break;
case KeyTable.XK_Super_R:
keysym = KeyTable.XK_Super_L;
break;
case KeyTable.XK_Alt_L:
keysym = KeyTable.XK_Mode_switch;
break;
case KeyTable.XK_Alt_R:
keysym = KeyTable.XK_ISO_Level3_Shift;
break;
}
}
// Is this key already pressed? If so, then we must use the
// same keysym or we'll confuse the server
if (code in this._keyDownList) {
keysym = this._keyDownList[code];
}
// macOS doesn't send proper key events for modifiers, only
// state change events. That gets extra confusing for CapsLock
// which toggles on each press, but not on release. So pretend
// it was a quick press and release of the button.
if (browser.isMac() && (code === 'CapsLock')) {
this._sendKeyEvent(KeyTable.XK_Caps_Lock, 'CapsLock', true);
this._sendKeyEvent(KeyTable.XK_Caps_Lock, 'CapsLock', false);
stopEvent(e);
return;
}
// If this is a legacy browser then we'll need to wait for
// a keypress event as well
// (IE and Edge has a broken KeyboardEvent.key, so we can't
// just check for the presence of that field)
if (!keysym && (!e.key || browser.isIE() || browser.isEdge())) {
this._pendingKey = code;
// However we might not get a keypress event if the key
// is non-printable, which needs some special fallback
// handling
setTimeout(this._handleKeyPressTimeout.bind(this), 10, e);
return;
}
this._pendingKey = null;
stopEvent(e);
this._keyDownList[code] = keysym;
this._sendKeyEvent(keysym, code, true);
},
// Legacy event for browsers without code/key
_handleKeyPress: function (e) {
stopEvent(e);
// Are we expecting a keypress?
if (this._pendingKey === null) {
return;
}
var code = this._getKeyCode(e);
var keysym = KeyboardUtil.getKeysym(e);
// The key we were waiting for?
if ((code !== 'Unidentified') && (code != this._pendingKey)) {
return;
}
code = this._pendingKey;
this._pendingKey = null;
if (!keysym) {
Log.Info('keypress with no keysym:', e);
return;
}
this._keyDownList[code] = keysym;
this._sendKeyEvent(keysym, code, true);
},
_handleKeyPressTimeout: function (e) {
// Did someone manage to sort out the key already?
if (this._pendingKey === null) {
return;
}
var code, keysym;
code = this._pendingKey;
this._pendingKey = null;
// We have no way of knowing the proper keysym with the
// information given, but the following are true for most
// layouts
if ((e.keyCode >= 0x30) && (e.keyCode <= 0x39)) {
// Digit
keysym = e.keyCode;
} else if ((e.keyCode >= 0x41) && (e.keyCode <= 0x5a)) {
// Character (A-Z)
var char = String.fromCharCode(e.keyCode);
// A feeble attempt at the correct case
if (e.shiftKey)
char = char.toUpperCase();
else
char = char.toLowerCase();
keysym = char.charCodeAt();
} else {
// Unknown, give up
keysym = 0;
}
this._keyDownList[code] = keysym;
this._sendKeyEvent(keysym, code, true);
},
_handleKeyUp: function (e) {
stopEvent(e);
var code = this._getKeyCode(e);
// See comment in _handleKeyDown()
if (browser.isMac() && (code === 'CapsLock')) {
this._sendKeyEvent(KeyTable.XK_Caps_Lock, 'CapsLock', true);
this._sendKeyEvent(KeyTable.XK_Caps_Lock, 'CapsLock', false);
return;
}
// Do we really think this key is down?
if (!(code in this._keyDownList)) {
return;
}
this._sendKeyEvent(this._keyDownList[code], code, false);
delete this._keyDownList[code];
},
_allKeysUp: function () {
Log.Debug(">> Keyboard.allKeysUp");
for (var code in this._keyDownList) {
this._sendKeyEvent(this._keyDownList[code], code, false);
};
this._keyDownList = {};
Log.Debug("<< Keyboard.allKeysUp");
},
// Firefox Alt workaround, see below
_checkAlt: function (e) {
if (e.altKey) {
return;
}
let target = this._target;
let downList = this._keyDownList;
['AltLeft', 'AltRight'].forEach(function (code) {
if (!(code in downList)) {
return;
}
let event = new KeyboardEvent('keyup',
{ key: downList[code],
code: code });
target.dispatchEvent(event);
});
},
// ===== PUBLIC METHODS =====
grab: function () {
//Log.Debug(">> Keyboard.grab");
var c = this._target;
c.addEventListener('keydown', this._eventHandlers.keydown);
c.addEventListener('keyup', this._eventHandlers.keyup);
c.addEventListener('keypress', this._eventHandlers.keypress);
// Release (key up) if window loses focus
window.addEventListener('blur', this._eventHandlers.blur);
// Firefox has broken handling of Alt, so we need to poll as
// best we can for releases (still doesn't prevent the menu
// from popping up though as we can't call preventDefault())
if (browser.isWindows() && browser.isFirefox()) {
let handler = this._eventHandlers.checkalt;
['mousedown', 'mouseup', 'mousemove', 'wheel',
'touchstart', 'touchend', 'touchmove',
'keydown', 'keyup'].forEach(function (type) {
document.addEventListener(type, handler,
{ capture: true,
passive: true });
});
}
//Log.Debug("<< Keyboard.grab");
},
ungrab: function () {
//Log.Debug(">> Keyboard.ungrab");
var c = this._target;
if (browser.isWindows() && browser.isFirefox()) {
let handler = this._eventHandlers.checkalt;
['mousedown', 'mouseup', 'mousemove', 'wheel',
'touchstart', 'touchend', 'touchmove',
'keydown', 'keyup'].forEach(function (type) {
document.removeEventListener(type, handler);
});
}
c.removeEventListener('keydown', this._eventHandlers.keydown);
c.removeEventListener('keyup', this._eventHandlers.keyup);
c.removeEventListener('keypress', this._eventHandlers.keypress);
window.removeEventListener('blur', this._eventHandlers.blur);
// Release (key up) all keys that are in a down state
this._allKeysUp();
//Log.Debug(">> Keyboard.ungrab");
},
};