I am a C++ programmer, but for some reason, I have to develop a website by myself(My own commercial project). I don't want to take a lot of time to study JavaScript and something else. It is possible to just use QT and WebAssembly (instead of HTML + CSS + JavaScript) to develop a front-end web?
Yes, it's absolutely possible and I'm currently doing it for a project but you should do it carefully based on the project requirements, running environment and your own backgrounds.
Here are some problems you may encounter:
The output .wasm file may get too large. Generally, it won't be suitable for public domain applications.
In low-end devices, maybe you find it laggy if you don't do enough code level optimizations.
Threads are not officially supported yet (as of Dec. 2019) by major browsers but tech-preview is available. This is not a real big problem as it would be a standard feature soon.
Native virtual keyboard won't work on mobile devices but the work is in progress.
These were my own major problems with Qt for WebAssembly.
Despite this, I find it much more flexible than HTML+CSS. QML is really a nice language for UI development. Creating animated UIs is quite easy and straight-forward.
You can also use many JavaScript libraries in your QML code like Lodash and Moment or any other js library that does not refer or manipulate window DOM.
Yes, it is possible. But you should do not do it if only reason is reject for learning new technologies.
For now (I'am writing this answer when Qt 5.14 is present) Qt for webassembly is deployed as official platform. Unfortunately it is young platform support with a lot of problems and possible future changes. Qt team do really good job so next version will be better. 5.14 is much better than 5.13 in webassembly context but still need fixes.
You should know Qt for webassembly will support only a few Qt modules, excluding widget. Yes, you can only use QML for GUI.
Qt for webassembly was created for the purpose of port one code base in other platform (it it generally Qt develop way, please see Qt for MCU). With other technologies in this stack like QRemoteObject is very interesting technologies. It was not created for websites in normal network. Main Qt for webassembly target are internal network systems and remote control of devices. Pay attention about this.
Unfortunately, not all browser will support webassembly right. Please see Qt for weassembly support notes.
Additional, in Qt you can't find build-in rest-API handle or other standard web technologies to integrate with your existing backed.
Related
My long term goal is to make HCI development for embedded devices, and by embedded I really mean it, not phone devices.
I've been working on Qt Widgets for a month now, avoiding Qt Quick for some reasons (I feared that QML code wasn't optimize), but yesterday I have watched this video :Youtube
The speaker says at the end : "If you're making an embedded product these days, use Qt Quick, especially now in 5.8. There's no excuse not to use Qt Quick"
But on the contrary, he explains that for embedded devices we should use c++ code, not JavaScript.
I don't really get it, does it means that I have to create all my objects in c++ code and make my architecture using Qt Quick ?
I don't really get what Qt want us to do. Is it just communication, since they don't want to optimize the old and stable Qt widgets, or is Qt Quick really the solution for embedded devices ?
I personally think that Qt is not the solution for embedded devices, as they keep evolving, changing strategy, and seems not to know where they are going.
I apologize for this non-algorithmic question, and thank you for all your answers.
I can't speak to the developer's intent, nor can I speak for other developers. I can only speak to what I understand, as a developer that has been designing embedded devices for 40 years (sorry for being a number dropper).
C++ or JavaScript? I don't feel that question has too much to do with whether you use QtQuick or not. Sure, you can embed some JaveScript in QML code (with limitations), but you can also use C++ in the same code base (just not embedded in the QML). Then there's Python. Both Qt and QtQuick are programming frameworks, and are somewhat language agnostic.
My perspective is that QtQuick is a good, portable way to create your user-interface code. In my current project (a multi-axis industrial servo-control system) I use QML for the user-interface (with a little JavaScript where needed), C++ for the bulk of the higher level processing (like network control and data-streaming), C and assembly language for the lower levels (those routines executed in uC's and DSP's). QML and C++ interface together nicely, in my opinion.
I believe the speaker is getting at the idea that most if not all your business logic should be done using a C++ model back-end. It is possible to do all your logic just in QML with embedded JavaScript however, because JS is an interpreted language its performance at run-time can possibly be less than compiled C++ code(dependent on how well the C++ is written).
Essentially you only want to use JS to manipulate graphical components while using C++ with QObject models to update the QtQuick elements' individual properties.
This is mentioned in the Qt Quick Best Practices wiki,
https://wiki.qt.io/Qt_Quick_Best_Practices
Is it possible to write front-end of my application in QML and back-end in C++ and compile it somehow so that I can deploy it to a web-server like Apache or JBoss so that it is accessible from within a web browser ?
If yes, do you have any examples how to perform this ?
Thank you very much for your answers :)
I was trying to find an answer to my question on the Internet but I was not successful.
QmlWeb is a JavaScript library that is able to parse QML-code and create a website out of it using normal HTML/DOM elements and absolute positions within CSS, translating the QML properties into CSS properties.
QmlWeb is a small project started primarily by Lauri Paimen who developed it for a few years and is now a KDE project maintained by Anton Kreuzkamp.
QmlWeb of course doesn’t yet support everything Qt’s implementation of QML does, but it already supports a quite usable subset of it. It supports nearly all of the most basic QML syntax. Moreover it has support for HTML input elements (Button, TextInput, TextArea are currently supported, more to come).
Well, QmlWeb is not finished. I hope Digia help with this project to make it ready with mature features.
The javascript currently sits on top of v8 but serves the purpose of expressing complex bindings and some (preferably small) client logic. But the engine could change (http://blog.qt.digia.com/blog/2013/04/15/evolution-of-the-qml-engine-part-1/).
Like in a browser, the actual graphics are kind of orthogonal to javascript which can only interact (or instantiate) with already existing graphical objects. In a browser, the graphics are described by html/css/svg/dom, and interpreted by the web engine written in C++. In QtQuick, the graphics are written in Qml and interpreted by the qml engine (scengraph) written in C++.
The two stacks are completely different.
Exception made of the Html canvas and the Qml canvas (which almost share the same api). But those are graphics working in immediate mode (opposed to a SVG or Qml scenegraph, working in a Retained mode fashion).
That being said...
There are 3 attempts to port Qml to the web:
A Qt port to Google Nacl (never heard of it from a long time, most likely dead)
Qt port through Emscripten/asm.js (awesome project, but not viable for production, and I don't think QtQuick is even supported... might require a huge effort to be actively maintained)
QmlWeb (Javascript apis to translate Qml files and interpret those on top of the HTML5 stack). Work in progress and only a subset of the whole QtQuick ecosystem might be supported in the long term. But still a really interesting project and maybe the most promising of all three. At least, it is the youngest one, and it might get some traction from the KDE community. http://akreuzkamp.de/2013/07/10/webapps-written-in-qml-not-far-from-reality-anymore/
You might also be interested in other scenegraphs technologies sitting on top of the web stack (amino, cake.js, rapahel.js...).
Last but not least, you might be interested by Wt (http://www.webtoolkit.eu/wt).
No. You cannot compile QML, and in any form it cannot be deployed onto a Java Application server such as JBoss. Qml is strictly for creating applications to run on a local machine. It sounds like you want to build a Web Application out of HTML with some sort of backend like .Net.
We have existing WPF application with complicated graphics (rounded edges of the window, speedometer style indicators etc).
Since we rely on .NET our application needs .NET framework. Some users are unwilling to install .NET and we want to provide them with a version that does not need .NET and runs of Windows only (XP,Vista,W7).
Which graphical toolkit we should use to for this scenario?
So far I think Codejock Toolkit Pro is a good adept as we already have GUI in XAML and it could be easier to port GUI to C++.
However, another aspect is download size of the toolkit. We don't want to end up in the situation where toolkit size is so big (e.g. 20-40MB) that's comparable with .NET 4.0 framework size.
I know some of you might think that going back from WPF to C++ is a bad idea, but for our scenario it is absolutely crucial to make user's installation process as easy as possible and .NET framework is a big stumbling block which we are trying to remove.
Sorry I do not have the answer to your question (and I would never ever even dream that I might do such a thing), but I am compelled to tell you as an advice
implementing all the WPF functionality in C++ will take 10-20 times more
installation of a C++ would not be necessarily easier
if you need to make installation easier, use SilverLight
We used QT in one of our projects in past which is Object Oriented and Multi Platform, but QT is mostly like WinForms
As I remember QT keeps UI in xml files too, try to write XSLT from xaml to QT xml. But I don't thik you can do it in complex WPF structures like Triggers or Animation
Have you evaluated QT? Since this relies on XML for UI definition too, it might be easier to port the code to.
You've already gotten a couple of answers recommending Qt -- and I'd agree that's probably your first choice. Note, however, that while Qt does support an XML-based UI description, they seem to be moving away from it toward QML, which is based on JavaScript instead.
Another possibility would be wxWidgets, which also supports an XML-based description of the widgets using XRC.
Is Qt an interesting platform for business apps development, outside of Nokia phones ?
Why ? Strong points ?
Thanks
I like Qt because:
Very well-designed framework, e.g. signal-slot, model-view, graphics view/scene/item/proxy, painter/paint device/paint engine..., too many to be listed here!
Excellent documentation!
Cross platform language/API, as well as tools like UI designer, creator, and so on.
Rich features, e.g. graphics framework, network library, database engine, and so on.
Active community, and active development.
There should be more. If you have ever used it, you'll find it's easy to build your framework upon Qt.
I didn't have any complain to Qt. If I have to say at least one disadvantage here, "convention". You must adopt the convention of Qt, e.g. You have to use moc to make the meta object of your objects, and it's easier for developers to use Qt's vector, list, auto_ptr than STL, tr1. But I never found any issue caused by that. On the contrary, it works very well.
In my opinion, Qt is the state-of-the-art C++ framework in this modern world!
P.S. There are a lot of commercial applications built on Qt. You can find it under Qt's official website. But I'd like add one more here: Perforce, one of the top commercial source code management tools, built its client tool on Qt for Windows/Linux/Mac.
yes it is .. just look at kde apps :)
or see more applications made by qt
and it has alot of bindings in many languages
Documentation
cross-Platform IDE
further reading
may be this is not so related to the question ... but my first deal with qt was just great starting from their well organized Documentation to their great widgets
the GraphicsView is just ammazing ! :)
It's about the only current/modern C++ gui library on Windows.
MFC is so old you have to write comments in Latin
WTL would be nice if they had finished it before abandoning it.
Winforms/WPF + managed C++/CLR - all the fun of several incompatible new technologies at once.
Bad points:
To fit on lots of platforms they have invented their own solutions to things that are now in the STL/Boost
The signal/slot mechanism - tricky to debug and silently fails (with no error) with simple typos.
Although everything is possible it's sometimes a lot of effort to do simple things (they do love MVC) compared to Winforms.
Qt is simple
Qt is powerful
Qt is NATIVELY-CROSS-PLATFORM
Qt is REALLY-CROSS-PLATFORM
Qt is comprehensive (but the Media side of it still needs to grow)
Qt doesn't require Garbage Collection, but it embeds a GREAT model of memory management that makes you forget about memory deallocation
Qt is solid
Qt is modern
Qt proposes some new paradigm of programming that are really good (Signals-Slots)
Qt runs a lot of VERY successful software: (Skype, Google Earth...)
Are those points strong enough?
Maybe you have heard about Google Earth which happens to be programmed in Qt too.
That aside, I like Qt for my in-house development because it
is very well supported and documented,
allows me to write simple and decent-looking apps that are
works cross-platform for Windows and Linux with little effort, and
contains nice to have components for database access, regexps, guis, xml, ...
I also use the Qwt widgets for easy real-time plotting on top of Qt.
I really dont understand whats the point in underestimating tools/frameworks which makes things easy for programmers. Qt is too good for GUI development, I would say its much better than any current existing crossplatform app development suite.
So many advantages, I have been using it for more than three years now for a product to be deployed in Linux/Win environments. The app is thread intensive and initially we had a tough time using pthreads and its conterpart for windows. Then we switched to Qt(and QThreads eventually) and things were a breeze...
Backed by active development, a highly helpful and supportive community along with excellent documentation, training, certification programs, videos, forums... its easy, fast and effective to develop in Qt. You should see the video which they create a web browser in just five mins!
Its really 'cross platform', and it doesnt have a software wrapper(like Java does) to enable this which makes it faster. Cmon, we all know java apps have buttons which takes a second to respond to even a simple 'click'.
I hope Qt will someday do a take on Java. :D
after all, 350000 developers cant be wrong when they chose Qt.
Pixar uses Qt (or at least, used, as of 2005) internally for certain parts of their tool suite (called "Marionette" in the marketing) collectively called Menv, ("men-vee" for Modelling ENVironment)---at least for their lighting sub-tool Lumos.
Is there any browser I could embedd in C++ application on Windows?
I need all features typical browser has (HTTP client, cookies support, DOM style HTML parser, JavaScript engine) except rendering.
Because I don't need rendering capability (and that's rather big part of a browser) I would prefer a browser with non monolithic design so I wouldn't have to include rendering stuff into my project.
It would be nice if it had C++ rather than C API.
I need this embedded browser mainly because I have much trouble finding C++ HTML parser which could handle broken HTML like browsers do.
If you know any, please answer Library Recommendation: C++ HTML Parser SO question or at least vote on it to increase a chance someone will give a good answer.
Sounds like all you need is something like libcurl which is an HTTP library and will let you do GET/POST/etc.
When I think browser I generally think rendering/JavaScript and not HTTP library.
Edit
In that case I'd look at WebKit (which I think has a C++ API) and hope you don't have to pull too much in.
Edit Again
On second thought (since rendering is such a big part of what browsers do), you might be better off using a stand-alone JS engine like SpiderMonkey and a stand-alone XML parser like Xerces-C (plus maybe tidy to make your HTML into XML).
I'm a bit confused by your question regarding embedding a web browser for which you don't need rendering capabilities. A web browser is rendering web pages by definition, unless you just need HTTP and XML with JavaScript capabilities which is a subset of a browser functionalities?
If you need a web browser to embed in your C++ application, I would suggest to consider Qt that comes with the WebKit plugin. It is C++, LGPL and has a very nice IDE (Qt Creator). I tried Qt with Qt Creator on unix (Ubuntu) and it was very impressive. The debugger is a bit light but it is just the first version. The adapter of Qt into visual c++ 2008 is now free.
You might also want to check out Awesomium-- it's free for non-commercial use and has all of the features you're looking for (if you don't need rendering, simply don't use it).
There is a project called CEF = The Chromium Embedded Framework - it is:
a simple framework for
embedding Chromium-based browsers in other applications. It is a
BSD-licensed open source project founded by Marshall Greenblatt in
2008 and based on the Google Chromium project. Unlike the Chromium
project itself, which focuses mainly on Google Chrome application
development, CEF focuses on facilitating embedded browser use cases in
third-party applications.
and yes:
The base CEF framework includes support for the C and C++ programming
languages.
Including javascript support and html parsing makes this non-trivial task - you have to use one of the available browsers.
IE is usable through its COM model - you can create instance of it in your window be it invisible or not and call its javascript/html capabilities.
It has been designed to be used like that since the beginning and certainly it is working fine.
The other options are:
Gecko/Mozilla - a couple of years ago it wasn't usable like this, currently I think it is.
WebKit/V8 - no public API has been released for chrome yet, you could use webkit itself, but it doesn't have javascript engine. Another option is to take a look at the Chrome codebase and see if you could get out of it what you need.
I would probably go for IE, since it is maybe the easiest option and I have already used it. The other options seem to me more like building a browser instead of just using it.
How about Gecko ? You may not need the entire engine but you may find some its components useful like SpiderMonkey which is a JavaScript engine written in C.
I'd recommend picking up Qt for C++ programming. It has a built-in library that embeds Webkit with all the bells'n'whistles, and Qt is a great C++ library in general.
Old question, I know, but take a look on
http://msdn.microsoft.com/en-us/library/ky29ffxd%28v=vs.94%29.aspx
IActiveScript and family COM interfaces allows script execution (not only JS, any language that registers as script interpeter, for that matter) in-memory.