Is there a terse introduction to GUI programming with Qt, meant for programmers with a decade's worth of experience (but who don't have any exposure to Qt). I am looking for something that gets one started quickly, and covers all the advanced stuff (including best-practices and patterns). Was looking for something like this book - Advanced Qt Programming - which alas, isn't out yet.
I would start with Qt Architecture, Graphics if you need it, IO and Networking, Model/View (learn and love it), Various other APIs, and finally How To's and Best Practices. The Qt Documentation is one of the major strengths of the toolkit. In many cases you won't need other resources. They even give a quick overview of tips for learning here.
Note: I'm linking you to the next release documentation since I think it looks better, the current release is here. When reading things over, just look for the comment on when the feature was introduced to make sure it will be available for the release you are using.
Programming with Qt, Second Edition
Related
The QT dev kit comes with some good examples of how to code features via trivial apps, but nothing comes close to showing how to structure a complex program in QT. What, if anything, should be global, etc? Pitfalls in designing your classes that would turn out to need a lot of eventual refactoring?
I'm sure there are plenty of open source KDE apps that would serve nicely, so I guess my question is what't the minimal amount of source code I'd need to download and set up in order to work with, say, Dolphin as a sample app? If the answer is 'all of KDE', then I guess this isn't practical (unless downloading and building all of KDE from source is easy enough to make that practical).
Any suggestions? Personally, I'm looking to build a browser-like app, but much simpler. So for an example to follow, something that handles sockets and multiple tabbed viewports would be nice.
Thanks,
Rob
The main advice regarding Qt itself is I would give is to try to spend as much effort as possible in learning to use Qt's Model View Delegate functionality. It can be a lot of work to wrap your head around, but once you get there, you can do very powerful things with it. Another relatively tricky topic you will want to invest learning resources in is memory management and how Qt facilitates (and doesn't facilitate) it.
One of the most confusing things to me was though that when your model is very complex, you might not want to have your core model class be a Qt model at all. Instead, I nowadays see Qt models as something that primarily provide data to views. If your model is very complex, you might want to use your actual, more complex model as a data source for the Qt model class (an QAbstractItemModel derivative), which in turn attaches to the UI view.
Also, Qt documentation is your friend. Qt is a wide framework and contains LOTS of useful functionality. I love the data structures in their ease of use, for example: QHash, QList, etc.
Project scaffolding features for beginners, for different project types in Qt Creator might indeed be useful. For now, the Qt Examples actually are quite good ones, and contain lots of good practices. You just need to pick and choose what you need.
I have been developing our Qt desktop app family for five years now. Our directory structure is quite unorthodox - the main thing is that we have lib/ under which we have grouped different related functionality in subdirectories. The thinking goes, if something is in lib, it is general-purpose and atomic enough to be used in several of the actual desktop applications in our software family.
Your question seems more general level than Qt. It is difficult to tell if you are looking for a more general level computer science education. Globals in general should be avoided, sure. OTOH, we do have a constants.h and other immutable configuration data that is global-like, since it is needed in many places. This adds state though, so it can have unpredictable consequences if you don't do it carefully.
You could look for directory structures in places like this, though I don't really follow this advice myself. http://hiltmon.com/blog/2013/07/03/a-simple-c-plus-plus-project-structure/
Unless you are planning to contribute directly to KDE, I would advice against learning KDE way of doing things. Not necessarily because they are doing things badly, but because it is a world of its own - the best practice for KDE development might not be the best practice for a stand-alone Qt app. (Disclaimer: I, as a UI developer, don't actually like KDE, so I do not know the project very well - aside from the fact that it indeed seems a bit monolithic to the outsider.)
So I wonder if something like Qupzilla would fit the bill for you? (Found via qt-apps.)
HTH.
I am making an interface for a free-and-open project I'm working on. I know that eventually I'll need it to do some heavy lifting with 3D graphics, so I'll need access to the GPU. I stumbled upon the Qt framework and its use of OpenGL. Their cross-platform properties are very appealing to me, and I've learned a lot about building run of the mill / plumbing kinda stuff on Qt, but using OpenGL is more challenging than I'd have hoped.
I've rooted around in several books and on Google for good tutorials, but they jump around, or don't seem to quite work when I try to implement them. The examples presented in the IDE have a lot of bells and whistles, and almost none of it is explained. When I tried implementing the example from "C++ GUI Programming with Qt 4", it didn't compile properly. There are a set of somewhat famous "NeHe" tutorials on OpenGL, but they are not implemented with Qt and the companion series on made by "The Independent Qt Tutorial" is very brief.
I would be very grateful for an example that goes very slowly and introduces Qt and OpenGL together. There is a blog entry that made things a lot clearer when I read it from a man named Daniel Eder. But he hasn't actually written code in that part of the discussion.
Specifically, if I could just get something really simple working in Qt like a cube I could rotate or maybe something more sophisticated like a sphere, I'd have enough traction to understand other tutorials. I definitely want to do the coding myself, but I'm having trouble even getting to the place where I can fool around, haha.
Here are some places with tutorials and examples:
There is also a Wiki in the Qt Dev network that you may find useful. I particularly suggest Wesley Stessens's blog that helped me personally a lot.
Nehe website provide a good tutorial where you can find some of the examples given ported to Qt.
There are also many QtOpenGL examples in Qt Creator/SDK that can be handy. I strongly suggest you take a look at them as they are very simple to understand and to play around with.
With that my next step was to read these two books:
C++ GUI Programming with Qt 4, 3rd edition
OpenGL Programming Guide: The Official Guide to Learning OpenGL, 7th edition
I have also been very happy when looking for help in the related Doc's/Reference manuals, etc.:
Qt Documentation
QtOpenGL module
OpenGL Documentation
At this level, you may solve your implementation problem straight away : )
Good luck.
I am currently considering writing a small game. It is essentially a map where you can zoom out and in, and in certain places click on info boxes where, at some point, I hope to integrate minigames. Granted, game might be overstating it. Think of it as an interactive map. The theme is how mathematics can be applied in peoples every day life to raise awareness on the usefullness of mathematics.
The question is how I as fast as possible can make a reasonable prototype. If I recieve enough positive response on this I might try to code "the real thing" and use the prototype to obtain funding.
However, I am at a crossroad. I want something to work rather fast and have some C++ experience coding optimization problems, mainly in c-style. I am not convienced, though, that coding it in C++ is the fast way to obtain a prototype. Though I have some experience coding in C++, but have no experience in coding any sort of GUI.
As I see it there is a number of possibilites:
C++, possibly using some library, such as boost or ???.
Start out purely webbased, using e.g. HTML 5 and java.
Python
C#/.NET
Others, such as?
I have to admit I have little experience with anything besides C++ and the STL.
So my question to this wonderful forum is basically, is there a language that provides a significant advantage? Also, any additional insight or comments is more than welcome!
Python is a simpler language than C++, and for prototyping it will help you focus on the task at hand. You can use Pygame, a game library built on the excellent cross-platform SDL library. It provides 2D graphics, input, and audio mixing features. SDL is mainly a C library (and thus compatible with C++), and there are a number of very useful libraries that integrate with it:
SDL_image for loading images in various formats
SDL_ttf for rendering text using TrueType fonts
SDL_mixer for audio mixing
SDL_net for networking
SDL_gfx for graphics drawing primitives
So if you prototype in Python using Pygame, there is a reasonable chance you’ll be able to port what you make over to C++ with minimal hassle, if and when you choose to do so.
Possible options:
Go with what you know the best. Anything else will require a learning curve, which may be weeks to months long. If you're willing to take that road in order to make your prototype, then there are some really great tools available.
BlitzBasic is a good way to go, and is basically designed to be for games
I've done little games in Java using Slick2D - but you'll need good grounding in object-oriented coding to work effectively in Java. If you've got that from C++, then you can see a tech demo I built in Slick2D called Pedestrians. It's open source, and has demo videos here.
You might also ask your question on https://gamedev.stackexchange.com/ - a Q/A site dedicated to game programming
A book "ASP.NET MVC 1.0 Test Driven Development" contains pictures like
and
Unfortunately Emad Ibrahim (the book's author) doesn't know what software was used, he told the publisher did it for him.
Maybe you know what it is. I believe it isn't Balsamiq Mockups.
Many thanks!
While I don't know what program the author used to create these specific mock-ups, but I know of two programs you can use to create similar prototypes and diagrams.
For diagrams, I've found that SimpleDiagrams is an excellent "virtual pen and paper" program for creating freestyle diagrams without getting in your way. It's also very cheap as far as prototyping tools go: $19 for a personal use license.
For prototyping, there are plenty of tools to choose from. Pencil (there is also a standalone version of the application) seems to be a fairly useful tool if you're only looking for a tool to do rough sketches of the UI when detailing the UI requirements. This tool and many others have been discussed in detail elsewhere already, and won't be re-hashed here.
Hope this helps!
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I am new to programming. I have some Knowledge Of C++ and have learned Python.
Now i want to develop a Qt Gui Application. Which language should i use for Qt development C++ or Python with PyQt. I found Python to be easy language.
There is no definite answer to this question. With that said...
Pros and cons you often hear
Python is easy, C++ is hard (in
comparison to Python)
C++ is fast, Python is slow (so to
speak) performance wise.
In reality...
Both arguments can be true or false, you can make slow C++ program, but you can also make fast Python program, you could also say C++ is not that hard if you know it really good etc.
Qt is written in C++ so the documentation examples are in C++. This is not really a problem since it is easy to port this to Python. Although I've found that for example animations with state machine cause segmentation faults with PyQt and PySide is not all that stable yet.
So which one to pick?
Depends on your skill and assignment. If it is work you are doing go with what you know best and asses how much speed you actually need, not every app has a need for lower level code.
If you know Python, you could start building your prototype in Python, then port to C++ parts that you deemed slow and bind them back to the Python (using SIP for example) or even port the whole application to C++. This approach also makes good exercise.
But even if you wrote your whole app in Python I doubt you and your clients would ever notice the "slowness" or "fastness" if you go with C++. These things usually depend on skill of a programmer.
Conclusion
It's entirely up to you to choose what are you are most comfortable with and to understand what your app really needs, but both languages will do the job in most cases.
My subjective advice would be to go with Python and port to C++ if you really need to. Sole reason for this advice is that you do not need to type as much in Python as you do in C++ but this can also be seen as a silly reason.
I just finished a reasonably large project with PyQT... I think your choice should depend on three factors:
How big is your audience (less
than 100 installations? More?)
How much functionality do you need?
(Databases + graphics + plotting +
signal analysis + network access +
blah blah blah)?
How rapidly do
you need to develop, both now and in
the future?
C++/QT is great for 1) Big audience, 2) Low to medium functionality, and 3) Slow to medium development speed. Of course, you can do anything with C++ given enough time and money.
Python/PyQt is great for 1) Small Audience, 2) Any level (including high) functionality, and 3) Medium to fast development speed.
The benefits of Python/PyQt are that:
you needn't worry too much about datatypes, header files, and numerous other headaches that slow development, and you get to work in a world-class interpreted environment known for its ability to foster fast and robust development.
you can pull in massive 3rd party libraries like matplotlib, scipy, sqlalchemy, and configobj that can make complex tasks stupidly easy.
The downsides of Python/PyQt, IMHO, are that:
it may have slower performance in some applications (who cares? How often does that really matter?)
it may be substantially harder to deploy. Py2exe requires quite a bit of tweaking to get 3rd party libraries to work, and then you still need to build an installer and get that working. Then, every time someone installs your app you might have 10 to 100MB of unnecessary dependencies built into the thing.
Personally, I work in an engineering R&D environment where fast turnaround and extensive data analysis/visualization is key, and deployment is often to only a few dozen (tech-savvy) people. Python/Pyqt is the clear choice. But, if I were to be developing a simple, widely-deployed application like a bittorrent client or something, I'd go C++ all the way.
Other notes:
PySide (a free LGPL alternative to PyQt) is rapidly progressing and seems sure to blow PyQt out of the water; I'm planning to switch within the next few months but as of now some 3rd party libraries still aren't set up for it.
The documentation for Pyside is much better than for PyQt; if you need help on, say, "QListView", just search google for "Pyside QListView".
I'd recommend only using PyQt where you need to. E.g., don't mess with QtSQL (debugging is a nightmare) when you could just use SqlAlchemy, and don't screw with Qt's configuration system when you can use the awesome library ConfigObj.
The clear way to install Python/Pyqt/etc is using the distribution Python(x,y) ... it includes, among other things: Python, PyQt, Qt, Eclipse, PyDev, QtDesigner, Spyder, iPython, and many dozens of useful scientific and computing libraries. Compiling and installing this stuff on your own is not fun.
In addition to the arguments given by rebus, I would add that the development and maintenance time in Python is considered to be about 2-10 times faster than in C++ (in papers by Prechelt and Ousterhout). This is another significant advantage of Python, that you might want to consider.
My main reasons for choosing Python and PyQt4 are:
Readability: I can't think in C++. I truthfully cannot. Python, on the other hand, is pretty close to English, so I find it easier to skim and debug.
Speed: I find that Qt4 works almost identically in both C++ and Python when you're using it for simple applications that do little work on the inside. I coded a book binding application with Python, and since it is basically a frontend to bunch of CLI tools, there is no noticeable performance lag.
Rapid Development: If you can write it in words, you can probably write it in Python. When I had to implement a new feature in my program, I just opened up the source folder (which consists of only a few files. Compare that to C++'s header mayhem), and added it in. Sure I had to tweak it to work faster later on, but my main point is that because the language is readable, it is easy to code in, and hence increases productivity.
But just to weigh both sides equally, here's what I don't like about Python and Qt4:
Example Code: Good luck trying to find some sample PyQt4 applications. The community is pretty small compared to the C++ Qt community, so don't expect tons and tons of examples.
IDE: I code with Gedit, so this was not a big issue for me, but it did take some hacking while I was designing the GUI. You have to trick Qt Designer into promoting your widgets in Python-compatible ways (like proving fake header file names so that the modules import properly), and other things like that. Nothing to serious. My regret was the inability to use Qt Creator IDE. It's basically a GUI designer on steroids, but it looks nice and is like Visual Studio for Qt.
Speed: If your application does some serious heavy lifting, I'd stick with C++. Python is good for algorithmic things, but for raw number-crunching power, C++ is the winner.
Deployment: To compile Python applications into binaries, you need to do some magical stuff with PyInstaller, Py2exe, and Py2App. It's a pretty painful process (for me at least), but it's the price you pay for an interpreted language. C++ just compiles and is ready to go.
I hope this helps in your decision. Good luck!
Learn C++. C++ executes faster than Python, and the fact that Qt is not native to Python will also slow things down slightly. Also, there is at this point far more 3rd party software in C/C++ than in Python. You might not need it now but down the road you might want to link to some of this.
EDIT: Looking a little harder I see that EOL is right, there is a lot of Python support for major libraries, though not for everything as lunayorn points out. Nonetheless in all these cases the Python user is reliant on bindings, which by their nature may lag the library developments and add extra possibility for bugs.
And since I don't yet have the cred to respond to others' posts, let me say here that rebus' claim that it's all programmer relative and C++ or Python can be just as fast is completely (and dangerously, where speed is important!) wrong. Python's ease of use comes at an unavoidable performance cost, see the wikipedia entries on interpreted vs. directly executed languages. I know from direct experience that Matlab, which is interpreted in the way Python is, executes line for line 2 full orders of magnitude more slowly than C++. Python and Matlab are best considered as (and in the case of Matlab at least, originally intended as) interfaces to libraries coded in languages like C or Fortran. For serious, large programs where performance matters use C++.