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
Related
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.
I am trying to make a decision for what to use to continue developing my application.
I have some experience with C++ in the MFC Document/View architecture and have found it very frustrating. I felt I was always fighting the framework and also felt that my application didn't fit the doc/view architecture. (I now know that it probably would have fit, if I had known how to structure it that way.)
So I decided to try Python and ended up using tkinter. That was easier to learn and didn't have as many frustrations. (Though it had a few different new ones.) I think I learned a bit more about object orientation and setting up classes along the way. But am now concerned about the fact that it is an interpreted language and much slower than C++ for my purpose.
So I have been wanting to go back to C++ but not MFC. I have read a little about wxWidgets and Qt.
So here are the things I want to know:
For wxWidgets and Qt, do they use a resource editor for setting up the layout of a GUI or directly expose the code the way Python and tkinter do.
Do either wxWidgets or Qt produce any interpreted code or is everything ultimately compiled into native machine code?
Thanks
1. Both
Qt and wxWidgets have GUI builders available. In the case of Qt, an XML file is produced that is parsed by the uic to produce C++ code. wxWidgets has several designers available, they will differ between them, but I'll be surprised if they don't all follow the same pattern.
However many people, myself included, choose to hand code - there is no requirement to use the UI designers. Be careful using the term 'resource editor', as Qt has a Resource Editor and it is not used for designing GUIs.
2. Both
Qt and wxWidgets are not just GUI frameworks - they're cross-platform toolkits. In view of this, Qt is pushing for a clear separation between GUI and backend by using QtQuick and the QML language for GUI development. Qt5 still has full support for C++ widget-based development of course. wxWidgets has no equivalent that I'm aware of.
Also, if you liked Python but not tkinter, both Qt and wxWidgets have Python bindings.
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.
I have a significant codebase written in MFC and am tasked with creating a port for Mac OS X. I know that I'm going to have to roll up my sleeves at some point and do alot of grunt work to get everything working correctly, but are there any tools out there that might get me partway?
I'm working on one.
From the GUI point of view, the new version of AppMaker is based around an import/generate model. Most of commercial work I've done with AppMaker has been the other way, porting Macintosh applications to Windows. However, there's no reason why the same principles can't be applied in reverse.
AppMaker v2 had a very good importer for PowerPlant UI resources and traditional Mac dialogs. As it is only able to run on Classic, that code base has been discarded (you really don't want to know) and the final generator languge I wrote for AppMaker v2 is an XML exporter which dumps the entire object model to an extended XAML.
I already have a XAML UI generator and am currently working on a Cocoa xib generator - one of the reasons for going to WWDC in June. The focus at this time is on import/generator suites before returning my attention to a GUI editor.
I wrote PP2MFC to allow PowerPlant applications to be compiled for Windows - a cross-platform solution needed because no other framework or cross-platform tool at the time (1997) would perform well enough for the hardware requirements. I've since discussed an opposite program with someone I could chase up and I'm sure an MFC portability layer could be created to map to Cocoa objects. Whilst many developers have a poor opinion of MFC's message-map architecture, the heavily macro-based API sits on top of a reasonably clean OO framework.
This is the kind of project where you need to think about long-term maintainability - do you want something which ends up as large chunks of MFC code working with Cocoa or do you want to migrate to an idiomatic Cocoa program.
Any further discussion should probably be taken off SO - contact me at dent at oofile.com.au but I'm happy to debate technicalities and feasibility on here. The combination of code generation and skinny framework adaptor layers works better than most people expect.
Honestly, the models are so different that I suspect you're going to need to do a nearly complete re-code at least of most of the UI parts.
No, Such a tool would be pretty much impossible to write.
MFC and Cocoa are such fundamentally different platforms there is no easy way to convert between the two.
Depending on how you've written your applications, you will either need to write the GUI portion of your code or even the whole codebase.