How should i build my GUI in Qt? - c++

I am wondering which way is the best to start building a GUI+SOFT in Qt. I am trying to build a sound media player based on a MVC pattern. Until now i have found 3 ways to do so.
1- Should I use a .ui file thanks to Qt designer, is it flexible enough ?
2- Should I use QML to make the design than integrate it to a C++ development ?
3- Should I just start from scratch and do it by hand without Qt Designer and using Qt library ?
Thank you very much for your answers.

NOTE: I'm using PyQt, so my comment may not be the most relevant.
I found Qt Designer to be great to create UIs, but then, when comes the time to modify them later, it becomes somewhat of a problem. Inserting new elements in an existing layout is often tricky, and you have to break all your layouts and re-assemble them (hoping you didn't mess anything up). Moreover, if your app is not trivial, you'll likely end up with code "fixing" what the .ui can't do. There are other tricky cases like that, but I don't remember them right now.
I ended up getting rid of my .ui files. So what I'd recommend is to initially use the designer to create the UI, and then use only the generated code from that point forward.

If you want your UI to be animated and it is not a requirement to follow platform UI appearance, QML is by far the best way to achieve this. If you want a UI that appears like any other application on your system and has limited animation then stick with QtDesigner and standard widgets.

I prefer building UI completely from scratch. This gives a lot of flexibility and better understanding of what is where, but on the other hand changing layout sometimes is a big headache.

I would use Qt Designer, as this is the easiest method IMHO.

Related

QT many layers of window

Recently I've been working on my project in QT creator. I wanted to build it only on one window but I find it difficult. I've not found something like layers, that I can apply to the window.
What i mean is that I'd like to hide actual content of my window and replace it with other. How could I make many layers in Designer mode?
You might want to look at QStackedWidget:
The QStackedWidget class provides a stack of widgets where only one widget is visible at a time.
But don’t overdo it. After a certain point complexity tends to kill you quickly in Qt Designer. One simple solution is to design each of the “layers” in their own QWidget-derived class and just combine them on the final QStackedWidget. That last step is probably simple enough that you don’t even need Designer for it.

Setting up a QMainWindow's corner to belong to a docking widget area (QMainWindow::setCorner) using Qt Designer

Well, subj.
I use dock widgets in my desktop Qt4 application, but I don't like the layout the docks form. I want the right dock to occupy the upper right corner which is by default occupied by the top dock.
I've googled (seriously!) what can I do with this and I've found an article where the use of QMainWindow::setCorner is described. It is pretty simple, and I've ended up with the following code that I've added to my window's constructor:
this->setCorner(Qt::TopRightCorner,Qt::RightDockWidgetArea);
It works perfectly, but here comes my question.
The code seems to describe the UI in the application's logic code section, which is, I think, not quite good. In my case the UI is described using .ui files I create with Qt Designer, so the UI things are separated from the application's main logic things.
The question is, is there a way to make Qt generate such code from .ui files?
The second reason is that the form in Qt Designer looks different from what I get when I run the application (this behavior is perfectly legal and obvious, of course).
If I'm unclear, please let me know.
Thank you.
Qt generates C++ header file ui_foo.h from foo.ui(XML file format) through UI compiler(uic) during the time qmake is working. In other words, eventually those .ui files will inevitably become part of your logic code, and it's quite normal to interact with those UI instance in code editor.
Personally, I feel Qt Designer's job is helping create a basic body of chiffon and leaving the rest of decoration to logic code, depends on personal appetite so you can add your own flavor and make it a delicious cake. That's why I started to use Qt Creator, which allows me to switch back and forth between the built-in UI designer and code editor. Hence, though I like the way of how Qt Designer simplifies the programming, I'd rather take it just as a supporter.
Let's just say the ability of Qt Deisgner is limited. For example , it's almost impossible to make a table with clickable button only by Qt Designer:
In brief, it is not worthwhile to seek a way to make Qt generate such code from .ui files because it depends on how UI complier is designed. Just code it!

How to develop nice-looking, visually modern applications in QT?

I'm wondering how to develop visually modern, with attractive GUI applications in QT. When I run QT Creator and start new project, the GUI looks very basic and "pure", just like simple win32 apps. But look for example at Allegorithmic Substance Designer 2, where GUI looks somehow similar to WPF. There are many other applications with nice-looking GUI. So, the question is: how to do this? Is there any extension/library to QT, which provide richer GUI experience? Or it must be developed from scratch? Thanks for replies in advance.
As well as Nano's answer, I think it would be worth your while to search around for any Qt stylesheets others have made.
For example, this one that mimics Microsoft Office.
Unfortunately, there doesn't seem to be very many of them available.
I found these useful links, some of whose links may give some ideas:
Qt Stylesheet Snippet Repository
Another idea might be to search for example qml files in Google Code Search. This search for .qml files has plenty of hits. Before using any of them, you would obviously need to check its license.
Have you tried Nokia's Qt Creator? If you're looking for something "similar" to WPF I assume you're referring to its declarative nature, QML being XAML's counterpart in such regard.

Integrating Qt into legacy MFC applications

We currently maintain a suit of MFC applications that are fairly well designed, however the user interface is beginning to look tired and a lot of the code is in need quite a bit of refactoring to tidy up some duplication and/or performance problems. We make use of quite a few custom controls that handle all their own drawing (all written using MFC).
Recently I've been doing more research into Qt and the benefits it provides (cross-platform and supports what you might call a more "professional" looking framework for UI development).
My question is - what would be the best approach to perhaps moving to the Qt framework? Does Qt play nice with MFC? Would it be better to start porting some of our custom controls to Qt and gradually integrate more and more into our existing MFC apps? (is this possible?).
Any advice or previous experience is appreciated.
In my company, we are currently using Qt and are very happy with it.
I personnally never had to move a MFC-app into using the Qt framework, but here is something which might be of some interest for you :
Qt/MFC Migration Framework
Qt/MFC Migration Framework
It's part of Qt-Solutions, so this means you'll have to buy a Qt license along with a Qt-Solutions license. (edit: not any more)
I hope this helps !
(This doesn't really answer your specific questions but...)
I haven't personally used Qt, but it's not free for commercial Windows development.
Have you looked at wxWindows which is free? Nice article here. Just as an aside, if you wanted a single code base for all platforms, then you may have to migrate away from MFC - I am pretty sure (someone will correct if wrong) that MFC only targets Windows.
One other option would be to look at the Feature Pack update to MFC in SP1 of VS2008 - it includes access to new controls, including the Office style ribbon controls.
It's a tricky problem, and I suspect that the answer depends on how much time you have. You will get a much better result if you port your custom controls to Qt - if you use the QStyle classes to do the actual drawing then you'll end up with theme-able code right out of the box.
In general, my advice would be to bite the bullet and go the whole way at once. Sure, it might take longer, but the alternative is to spend an age trying to debug code that doesn't quite play ball, and end up writing more code to deal with minor incompatibilities between the two systems (been there, done that).
So, to summarise, my advice is to start a branch and rip out all your old MFC code and replace it with Qt. You'll get platform independence (almost) for free, and while it will take a while, you'll end up with a much nicer product at the end of it.
One final word of warning: make sure you take the time to understand the "Qt way of doing things" - in some cases it can be quite different to the MFC approach - the last thing you want to do is to end up with MFC-style Qt code.
I have lead a team doing this kind of thing before (not MFC to QT but the principles should work).
First we documented the dialogs and what their inputs, controls and outputs were. Also, we create several test cases especially for any clever logic inside the GUI.
Sometimes we had to refactor some business logic to provide a clean interface the GUIs but this is the way it should have been done in the first place tbh.
Now we had a list of GUIs, inputs, outputs, tests and an interface that the encapsulated GUI had to match.
We began, project by project, to create equivilant GUIs to the old ones. Once we did that we could slot the GUI in where the old one was, rebuild and test it. At first we tripped a lot but we soon worked out the common errors and fixed them. We navigated (I think) 612 dialogs although there was a team of about a dozen of us working on it.

Hand Coded GUI Versus Qt Designer GUI [closed]

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I'm spending these holidays learning to write Qt applications. I was reading about Qt Designer just a few hours ago, which made me wonder : what do people writing real world applications in Qt use to design their GUIs? In fact, how do people design GUIs in general?
I, for one, found that writing the code by hand was conceptually simpler than using Qt Designer, although for complex GUIs Designer might make sense. Large GUIs might be possible using Designer, but with time they might become very difficult to manage as complexity increases (this is just my opinion). I also downloaded the AmaroK source code to take a peek at what those guys were doing, and found many calls to addWidget() and friends, but none of those XML files created by Designer (aside: AmaroK has to be my favorite application ever on any platform).
What, then, is the "right" way to create a GUI? Designer or code? Let us, for this discussion, consider the following types of GUIs :
Simple dialogs that just need to take input, show some result and exit. Let's assume an application that takes a YouTube URL and downloads the video to the user's hard disk. The sort of applications a newbie is likely to start out with.
Intermediate level GUIs like, say, a sticky notes editor with a few toolbar/menu items. Let's take xPad for example (http://getxpad.com/). I'd say most applications falling in the category of "utilities".
Very complex GUIs, like AmaroK or OpenOffice. You know 'em when you see 'em because they make your eyes bleed.
Our experience with Designer started in Qt3.
Qt3
At that point, Designer was useful mainly to generate code that you would then compile into your application. We started using for that purpose but with all generated code, once you edit it, you can no longer go back and regenerate it without losing your edits. We ended up just taking the generated code and doing everything by hand henceforth.
Qt4
Qt4 has improved on Designer significantly. No longer does it only generate code, but you can dynamically load in your Designer files (in xml) and dynamically connect them to the running objects in your program -- no generated code however, you do have to name the items in Designer and stick with the names to not break your code.
My assessment is that it's nowhere near as useful as Interface Builder on Mac OS X, but at this point, I could see using the Designer files directly in a program.
We haven't moved back to Designer since Qt3, but still use it to prototype, and debug layouts.
For your problems:
You could probably get away with using the standard dialogs that Qt offers.
QInputDialog or if you subclass QDialog, make sure to use QButtonDialogBox
to make sure your buttons have the proper platform-layout.
You could probably do something more limited like xPad with limited Designer functionality.
I wouldn't think you could write something like OpenOffice solely with Designer but maybe that's not the point.
I'd use Designer as another tool, just like your text editor. Once you find the limitations, try a different tool for that new problem. I totally agree with Steve S that one advantage of Designer is that someone else who's not a programmer can do the layout.
In my experience with Qt Designer and other toolkits/UI-tools:
UI tools speed up the work.
UI tools make it easier to tweak the layout later.
UI tools make it easier/possible for non-programmers to work on the UI design.
Complexity can often be dealt with in a UI tool by breaking the design into multiple UI files. Include small logical groups of components in each file and treat each group as a single widget that is used to build the complete UI. Qt Designer's concept of promoted widgets can help with this.
I haven't found that the scale of the project makes any difference. Your experience may vary.
The files created with UI tools (I guess you could write them by hand if you really wanted to) can often be dynamically loaded at run-time (Qt and GTK+ both provide this feature). This means that you can make layout changes and test them without recompiling.
Ultimately, I think both raw code and UI tools can be effective. It probably depends a lot on the environment, the toolkit/UI-tool, and of course personal preference. I like UI tools because they get me up and running fast and allow easy changes later.
The organisation I work for has ported its GUI application to Qt several years ago.
I think there are several aspects that are worth mentioning:
Working with Qt Designer, at least at that point, was not a realistic option: there were too many features that couldn't be done with Qt Designer;
Conventions and structure that had to be preserved prevented the use of Qt Designer;
Once you've started without Designer, it is probably difficult to return to it;
the most important aspect, though, was that the programmers were very much used to programming using vi or emacs, rather than using a GUI IDE.
My own experience, which goes back approx. 4 years, using Qt3.3, is that dynamic behavior in dialogs was not possible to realise in Designer.
Just to say I've written and maintained complex GUIs in Qt without using Qt Designer -- not because I don't like Qt Designer, but because I never got around to working that way.
It's partly a matter of style and where you're coming from: when I started on Qt, I'd had horrible experiences of Dreamweaver and Frontpage and other visual HTML tools,and far preferred writing code with HomeSite and resorting to Photoshop for tricky layout problems.
There's a danger with visual code IDEs that you try to keep within the visual tools, but end up having to tweak code as well -- in ways that aren't well understood.
Learning iPhone development, for example, I've found it frustrating to hit 'magic' visual stuff ('drag from the empty circle in the Connections inspector to the object in the Interface Builder window...') that would be simpler (for me) to understand in plain old code.
Good luck with Qt -- it's a great toolkit, however you use it, and Qt Creator looks like being a great IDE.
I'd add that one of the reasons for using graphical designer was the lack of layout managers in Win32, for instance. Only absolute positioning was possible, and doing that by hand would have just sucked.
Since I switched from Delphi to Java for GUI apps (back in 2002), I've never used designers any more. I like layout managers much more. And yeah, you get boilerplate code, but moving objects on a UI designer may take as much time as changing the boilerplate. Plus, I would be stuck with a slow IDE; that's for the Java/C# case, OK, while for Qt (especially Qt4) it doesn't apply. For Qt3, I wonder why one should edit the generated code - wasn't it possible to add code in other files? For which reason?
About the discussed cases:
1) Hand Coded GUI is likely faster to write, at least if you know your libraries. If you're a newbie and you don't know them, you may save time and learn less with a designer, since you don't need to learn the APIs you use. But "learn less" is the key factor, so in both cases I'd say Hand Coded GUI.
2) Menu bars are quite annoying to write code for. Also, think to details like accelerators and so on. Still, it depends on what you're used to. After some time, it may be faster to type that boilerplate than to point-and-click into designer to fix all those properties, but just if you can really type like into a typewriter (like those admins for which typing Unix commands is faster than using any GUI).
3) I'd extend the answer for case #2 to this one. Note that, for Win32 platforms, it may be possible that using designers which generate Win32 resources might be faster to load (no idea about that).
However, I'd like to mention a potential problem with using Qt Designer there. Real world case: it took some seconds (say 10) to load a complex Java dialog (the Preferences dialog box for a programmer's text editor) with a lot of options. The correct fix would have been to load each of the tabs only when the programmer wanted to see them (I realized that after), by adding a separate method to each preference set to build its GUI.
If you design all the tabs and the tab switcher together with a designer, can you do that as easily? I guess there might be a similar example where a hand coded GUI gives you more flexibility, and in such a big app, you're likely to need that, even if just for optimization purposes.
One of the main benefits of using designer to create GUIs is that other programmers can change or maintain forms and widgets easily without the need to delve in to a complex code.
Its strange that you're saying the writing code is simpler than manipulating objects in a graphical environment. It's a no-brainer.
The designer is there to make your life easier and in the long term it makes your code more maintainable. It's easier looking in the designer to see what the your UI looks like then reading the code and trying to imagine what it might look like.
With current Qt you can do almost everything from within the designer and the very few things you can't do, you can fix with very few lines of code in the constructor.
Take for instance the simplest example - adding a signal-slot connection. Using the designer it's as simple as a double click. Without the designer you need to go lookup the correct signature of the signal, edit the .h file and then edit write your code in the .cpp file. The designer allows you to be above these details and focus on what really matters - the functionality of your application.
I like to first turn to the designer to develop GUI widgets. As mentioned in the other posts, its faster. You also get immediate feedback to see if it "looks right" and isn't confusing to the user. The designer is a major reason I choose Qt over other toolkits.
I mostly use the designer to make the one-off dialogs.
Having said that, I do the main window and any complex widgets by hand.
I think this is the way Trolltech intended. QFormLayout is a class they provide to easily programatically create an input dialog.
By the way, the designer in Qt 4 is not an IDE like the one they had in Qt 3. It's just an editor for editing .ui files. I like it that way. The new cross platform IDE is going to be called Qt Creator.
It's an old post but I would advise you to look at Clementine - a music player which (I think) derives from Amarok. They use Qt4 and from what I can see there is a ui folder in the src folder of the project. In the ui folder as one might expect they have all sorts of .ui files. If you compile and start Clementine you will see that the GUI is fairly complex and quite nice.
For me, it depends how much logic is encapsulated in the widget/GUI. If it's just about simple forms, I prefer to use QtDesigner.
If it contains complex checks or interaction, I tend to program it.
We're using the Qt Designer if anyone needs to create a Gui.
The thing is to create just little Widgets for certain tasks (like you would do in a class-design) and then get them together into a "parent-gui".
This way your widgets are highly reusable and could be used for Guis in a modular way. You just have to specify which signals each Widget is sending and which slots they provide.
We additionally are creating .ui-Files which than could be generated during build-process. Until now there was no need to edit those files by hand.
Build different parts of your UI
in different .ui files using QtDesigner,
then bring them together (and add complications) in code.
There are things you can't do in Qt Designer, you can only do in code,
so Qt Designer is just one (great) part of the tool chain.