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Diffstat (limited to 'examples/webchannel/shared/qwebchannel.js')
| -rw-r--r-- | examples/webchannel/shared/qwebchannel.js | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/examples/webchannel/shared/qwebchannel.js b/examples/webchannel/shared/qwebchannel.js new file mode 100644 index 0000000..5b047c2 --- /dev/null +++ b/examples/webchannel/shared/qwebchannel.js @@ -0,0 +1,427 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com> +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtWebChannel module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +"use strict"; + +var QWebChannelMessageTypes = { + signal: 1, + propertyUpdate: 2, + init: 3, + idle: 4, + debug: 5, + invokeMethod: 6, + connectToSignal: 7, + disconnectFromSignal: 8, + setProperty: 9, + response: 10, +}; + +var QWebChannel = function(transport, initCallback) +{ + if (typeof transport !== "object" || typeof transport.send !== "function") { + console.error("The QWebChannel expects a transport object with a send function and onmessage callback property." + + " Given is: transport: " + typeof(transport) + ", transport.send: " + typeof(transport.send)); + return; + } + + var channel = this; + this.transport = transport; + + this.send = function(data) + { + if (typeof(data) !== "string") { + data = JSON.stringify(data); + } + channel.transport.send(data); + } + + this.transport.onmessage = function(message) + { + var data = message.data; + if (typeof data === "string") { + data = JSON.parse(data); + } + switch (data.type) { + case QWebChannelMessageTypes.signal: + channel.handleSignal(data); + break; + case QWebChannelMessageTypes.response: + channel.handleResponse(data); + break; + case QWebChannelMessageTypes.propertyUpdate: + channel.handlePropertyUpdate(data); + break; + default: + console.error("invalid message received:", message.data); + break; + } + } + + this.execCallbacks = {}; + this.execId = 0; + this.exec = function(data, callback) + { + if (!callback) { + // if no callback is given, send directly + channel.send(data); + return; + } + if (channel.execId === Number.MAX_VALUE) { + // wrap + channel.execId = Number.MIN_VALUE; + } + if (data.hasOwnProperty("id")) { + console.error("Cannot exec message with property id: " + JSON.stringify(data)); + return; + } + data.id = channel.execId++; + channel.execCallbacks[data.id] = callback; + channel.send(data); + }; + + this.objects = {}; + + this.handleSignal = function(message) + { + var object = channel.objects[message.object]; + if (object) { + object.signalEmitted(message.signal, message.args); + } else { + console.warn("Unhandled signal: " + message.object + "::" + message.signal); + } + } + + this.handleResponse = function(message) + { + if (!message.hasOwnProperty("id")) { + console.error("Invalid response message received: ", JSON.stringify(message)); + return; + } + channel.execCallbacks[message.id](message.data); + delete channel.execCallbacks[message.id]; + } + + this.handlePropertyUpdate = function(message) + { + for (var i in message.data) { + var data = message.data[i]; + var object = channel.objects[data.object]; + if (object) { + object.propertyUpdate(data.signals, data.properties); + } else { + console.warn("Unhandled property update: " + data.object + "::" + data.signal); + } + } + channel.exec({type: QWebChannelMessageTypes.idle}); + } + + this.debug = function(message) + { + channel.send({type: QWebChannelMessageTypes.debug, data: message}); + }; + + channel.exec({type: QWebChannelMessageTypes.init}, function(data) { + for (var objectName in data) { + var object = new QObject(objectName, data[objectName], channel); + } + // now unwrap properties, which might reference other registered objects + for (var objectName in channel.objects) { + channel.objects[objectName].unwrapProperties(); + } + if (initCallback) { + initCallback(channel); + } + channel.exec({type: QWebChannelMessageTypes.idle}); + }); +}; + +function QObject(name, data, webChannel) +{ + this.__id__ = name; + webChannel.objects[name] = this; + + // List of callbacks that get invoked upon signal emission + this.__objectSignals__ = {}; + + // Cache of all properties, updated when a notify signal is emitted + this.__propertyCache__ = {}; + + var object = this; + + // ---------------------------------------------------------------------- + + this.unwrapQObject = function(response) + { + if (response instanceof Array) { + // support list of objects + var ret = new Array(response.length); + for (var i = 0; i < response.length; ++i) { + ret[i] = object.unwrapQObject(response[i]); + } + return ret; + } + if (!response + || !response["__QObject*__"] + || response.id === undefined) { + return response; + } + + var objectId = response.id; + if (webChannel.objects[objectId]) + return webChannel.objects[objectId]; + + if (!response.data) { + console.error("Cannot unwrap unknown QObject " + objectId + " without data."); + return; + } + + var qObject = new QObject( objectId, response.data, webChannel ); + qObject.destroyed.connect(function() { + if (webChannel.objects[objectId] === qObject) { + delete webChannel.objects[objectId]; + // reset the now deleted QObject to an empty {} object + // just assigning {} though would not have the desired effect, but the + // below also ensures all external references will see the empty map + // NOTE: this detour is necessary to workaround QTBUG-40021 + var propertyNames = []; + for (var propertyName in qObject) { + propertyNames.push(propertyName); + } + for (var idx in propertyNames) { + delete qObject[propertyNames[idx]]; + } + } + }); + // here we are already initialized, and thus must directly unwrap the properties + qObject.unwrapProperties(); + return qObject; + } + + this.unwrapProperties = function() + { + for (var propertyIdx in object.__propertyCache__) { + object.__propertyCache__[propertyIdx] = object.unwrapQObject(object.__propertyCache__[propertyIdx]); + } + } + + function addSignal(signalData, isPropertyNotifySignal) + { + var signalName = signalData[0]; + var signalIndex = signalData[1]; + object[signalName] = { + connect: function(callback) { + if (typeof(callback) !== "function") { + console.error("Bad callback given to connect to signal " + signalName); + return; + } + + object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || []; + object.__objectSignals__[signalIndex].push(callback); + + if (!isPropertyNotifySignal && signalName !== "destroyed") { + // only required for "pure" signals, handled separately for properties in propertyUpdate + // also note that we always get notified about the destroyed signal + webChannel.exec({ + type: QWebChannelMessageTypes.connectToSignal, + object: object.__id__, + signal: signalIndex + }); + } + }, + disconnect: function(callback) { + if (typeof(callback) !== "function") { + console.error("Bad callback given to disconnect from signal " + signalName); + return; + } + object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || []; + var idx = object.__objectSignals__[signalIndex].indexOf(callback); + if (idx === -1) { + console.error("Cannot find connection of signal " + signalName + " to " + callback.name); + return; + } + object.__objectSignals__[signalIndex].splice(idx, 1); + if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 0) { + // only required for "pure" signals, handled separately for properties in propertyUpdate + webChannel.exec({ + type: QWebChannelMessageTypes.disconnectFromSignal, + object: object.__id__, + signal: signalIndex + }); + } + } + }; + } + + /** + * Invokes all callbacks for the given signalname. Also works for property notify callbacks. + */ + function invokeSignalCallbacks(signalName, signalArgs) + { + var connections = object.__objectSignals__[signalName]; + if (connections) { + connections.forEach(function(callback) { + callback.apply(callback, signalArgs); + }); + } + } + + this.propertyUpdate = function(signals, propertyMap) + { + // update property cache + for (var propertyIndex in propertyMap) { + var propertyValue = propertyMap[propertyIndex]; + object.__propertyCache__[propertyIndex] = propertyValue; + } + + for (var signalName in signals) { + // Invoke all callbacks, as signalEmitted() does not. This ensures the + // property cache is updated before the callbacks are invoked. + invokeSignalCallbacks(signalName, signals[signalName]); + } + } + + this.signalEmitted = function(signalName, signalArgs) + { + invokeSignalCallbacks(signalName, this.unwrapQObject(signalArgs)); + } + + function addMethod(methodData) + { + var methodName = methodData[0]; + var methodIdx = methodData[1]; + object[methodName] = function() { + var args = []; + var callback; + for (var i = 0; i < arguments.length; ++i) { + var argument = arguments[i]; + if (typeof argument === "function") + callback = argument; + else if (argument instanceof QObject && webChannel.objects[argument.__id__] !== undefined) + args.push({ + "id": argument.__id__ + }); + else + args.push(argument); + } + + webChannel.exec({ + "type": QWebChannelMessageTypes.invokeMethod, + "object": object.__id__, + "method": methodIdx, + "args": args + }, function(response) { + if (response !== undefined) { + var result = object.unwrapQObject(response); + if (callback) { + (callback)(result); + } + } + }); + }; + } + + function bindGetterSetter(propertyInfo) + { + var propertyIndex = propertyInfo[0]; + var propertyName = propertyInfo[1]; + var notifySignalData = propertyInfo[2]; + // initialize property cache with current value + // NOTE: if this is an object, it is not directly unwrapped as it might + // reference other QObject that we do not know yet + object.__propertyCache__[propertyIndex] = propertyInfo[3]; + + if (notifySignalData) { + if (notifySignalData[0] === 1) { + // signal name is optimized away, reconstruct the actual name + notifySignalData[0] = propertyName + "Changed"; + } + addSignal(notifySignalData, true); + } + + Object.defineProperty(object, propertyName, { + configurable: true, + get: function () { + var propertyValue = object.__propertyCache__[propertyIndex]; + if (propertyValue === undefined) { + // This shouldn't happen + console.warn("Undefined value in property cache for property \"" + propertyName + "\" in object " + object.__id__); + } + + return propertyValue; + }, + set: function(value) { + if (value === undefined) { + console.warn("Property setter for " + propertyName + " called with undefined value!"); + return; + } + object.__propertyCache__[propertyIndex] = value; + var valueToSend = value; + if (valueToSend instanceof QObject && webChannel.objects[valueToSend.__id__] !== undefined) + valueToSend = { "id": valueToSend.__id__ }; + webChannel.exec({ + "type": QWebChannelMessageTypes.setProperty, + "object": object.__id__, + "property": propertyIndex, + "value": valueToSend + }); + } + }); + + } + + // ---------------------------------------------------------------------- + + data.methods.forEach(addMethod); + + data.properties.forEach(bindGetterSetter); + + data.signals.forEach(function(signal) { addSignal(signal, false); }); + + for (var name in data.enums) { + object[name] = data.enums[name]; + } +} + +//required for use with nodejs +if (typeof module === 'object') { + module.exports = { + QWebChannel: QWebChannel + }; +} |