Qt is a cross-platform application development framework widely used for the development of GUI programs.

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passing by refernce

I am study c++ and c languages, i was writing in javascript before. Im trying to understand the ideas of pointer and refernces. So im stuck with following, what would be the specific behaviour in this ...
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0answers
58 views

Do I need a commercial license for Qt if I'm going to sell on the Mac App store?

I would like to build an os x app and sell it on the Mac App Store. I'm going to build this in C++ and use the Qt library. I'm wondering if I can use the free version or if I need a commercial license....
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0answers
19 views

QSqlDatabase member inside QRunnable - yes or no

I am working on Async multithreaded Tcp Server in Qt and I am wondering, which approach is beeter: To encapsulate QSqlDatabase as member inside QRunnable To create local QSqlDatabase variable inside ...
0
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1answer
251 views

Can Qt desktop programs be recompiled for Android/iOS as-is?

One of the advantages of open-source programs is that they can be ported easily to any platform simply by recompiling. Qt is also a cross-platform toolkit that can work on several platforms simply by ...
13
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1answer
7k views

raw, weak_ptr, unique_ptr, shared_ptr etc… How to choose them wisely?

There is a lot of pointers in C++ but to be honest in 5 years or so in C++ programming (specifically with the Qt Framework) I only use the old raw pointer: SomeKindOfObject *someKindOfObject = new ...
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0answers
48 views

Qt Quick dynamic QML vs Apple's App Store rules

Imagine that I've got a piece of custom audio hardware that I'd like to be able to control in a multitude of ways via a tablet/touchscreen GUI. In particular, my goals are to have the tablet's ...
3
votes
2answers
174 views

Building and Debugging an IDE using the same IDE

This may be a question more suited some Programming Meta Discussions. I was trying to delve deeper into the inner plugin management feature for QT Creator 2.x IDE provided by Digia Inc. So I ...
4
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2answers
104 views

How to facilitate thread-safe access to large set of shared variables?

I have 2 sets--inputs and outputs--of 70 32-bit integer variables and 70 bools (140 vars altogether). These need to be accessed and modified from 3 threads. What is an appropriate design pattern to ...
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1answer
111 views

Client-Server app architecture with custom communication protocol

I am working on Qt/QML/C++ based Client-Server software system with custom protocol. Now, in both projects inside QtCreator I have same header and implementation files inside both projects. What is ...
0
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1answer
32 views

Sharing Project configuration files for an application with Qt IDE using Cmake and sharing via Git?

Imagine that you are starting to work in a project with a group of people. You want to share your code and the full configuration files of CMake, Qt IDE configuration. So you if you want to test or ...
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0answers
36 views

Qt network app sockets vs. QtNetwork library dilemma

I am working Qt network app which basically opens some sockets, for start, one QUdpScoket and one QTcpSocket. Now, through these two socket data stream is read and written to, that is all ok. However, ...
6
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2answers
379 views

Why is threading platform-dependent?

I am reading book "Foundations of Qt Development", Chapter 12, and I read that threading is platform-dependent, can someone explain, why? I know how to use threads but that what they said is not so ...
0
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1answer
165 views

Find if certain files have been added or removed in large directory structure

I have a larger directory structure (dir + sub directories) with files. It contains files of certain types. For one particular type (let's say with appendix .foo) I need to figure out if files have ...
7
votes
4answers
4k views

What are some standard design methods to add GUI to a command line app? [closed]

I have an embedded linux c application that runs with a simple CLI. I am now tasked with creating a GUI that accomplishes the same functionality as the command line program. I am not an accomplished ...
-1
votes
1answer
87 views

(Re)structuring a Qt Project [closed]

A PySide project I've been working on for a while now has started to grow to a point where it's becoming large enough that I've had to step back and re-think the overall design. I've spent some time ...
3
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3answers
247 views

I want to overload a function with the same type parameter; what should I do?

I'm creating an API, and I want to overload a function for strip: QString MyClass::strip(); QString MyClass::strip(QRegularExpression open); QString MyClass::strip(QRegularExpression close); QString ...
2
votes
2answers
449 views

Is it good practice to have your C++/Qt functions always check all its arguments for null values?

Backstory While developing with Qt Signal/Slots, I came across a few segmentation faults that had me puzzled as to what was causing it. Eventually I figured out that you could actually pass a slot ...
2
votes
1answer
319 views

Model-View-Controller design question (One vs. multiple models for multiple view+controller)

I have an issue with shared code in a MVC application. Application controllers/views ABC are different classes but use a common framework. It is a single class reused multiple times. Let me introduce ...
8
votes
2answers
416 views

Merits of copy-on-write semantics

I am wondering what possible merits does copy-on-write have? Naturally, I don't expect personal opinions, but real-world practical scenarios where it can be technically and practically beneficial in a ...
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votes
1answer
159 views

Can I use Qt open-source for my web-scraping website? [closed]

I apologize if I should be understanding this more readily but I'm a little new to this and dont understand the LGPL license. Here is the FAQ for it: http://www.qt.io/qt-licensing-terms/ I am making ...
3
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2answers
211 views

Design pattern for fetching data in chunks

I am creating Qt application that uses database with huge amount of data to draw some charts. Fetching data from the database is time consuming, so is blocking the application thread or worker thread ...
3
votes
2answers
668 views

Qt, LGPL, Android and GooglePlay licensing

So, you can build Qt apps and deploy them to android. Taking a look at this post, I was wondering if making a game using Qt would be fine with LGPL legal terms given the following facts: The app ...
1
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1answer
48 views

Fill widget with data retrieved from internet

I want to retrieve data from internet and show them into a widget. In particular, I've a widget with a QComboBox containing some service from which I can retrieve a list of exchange markets. When I ...
7
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1answer
583 views

Is hardware accelerated GUI data kept on the GPU

I am doing some research as to how most hardware accelerated GUI libraries work. I am actually only care about the rendering backends of them here. I am trying to figure out what would be the best way ...
0
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0answers
154 views

Qt / C++ internal API design for slightly similar web services

in my application I provide a Qt/C++ wrapper to certain web services based on the Danbooru software. Basically the API wraps a series of REST calls and produces / parses the JSON responses to display ...
2
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0answers
65 views

Should the order of definitions correspond to the order of declarations in header/source files? [closed]

If my header looks like this: class foo { public: foo(); ~foo(); QString b(); QString c(); QString a(); void setB(QString s); void setC(QString s); void setA(...
6
votes
2answers
882 views

Deploying Qt-based app on Mac OS X

I wrote a cross platform application and I distributed it successfully for Windows and Linux (and tested them on "clean" virtual systems, with no other additional software and/or libraries installed). ...
2
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1answer
1k views

How is C++ in QT different from the standard C++ libraries?

I want my app to be able to manipulate images and create watermarks and also needs to run on both windows and mac. Hence I've been investigating QT. Does QT ship with all the libraries I will need to ...
1
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1answer
254 views

how can i make a program written in c++ with qt to text and graphic mode?

I have seen in many programs, almost only on linux, that when you run the program with a graphical manager(Clicking the executable) the program runs in a graphical window and when you run it from the ...
7
votes
1answer
471 views

Should I build undo stack in model or its wrapper?

I am building an application (Python/PyQt). The first-order item will be a tree view/model with many helper functions to add new items, move them around in the tree, etc.. Then I will have a main ...
25
votes
10answers
4k views

Qt's future in the light of Nokia-Microsoft partnership [closed]

In case you missed it, a lot has happened in the last two day that could potentially impact the Qt framework, for the worse. :-( It will impact the mobile sector in several and probably not currently ...
30
votes
8answers
15k views

Is Learning C++ Through The Qt Framework Really Learning C++ [closed]

The problem I have, is that most of the C++ books I read spend almost forever on syntax and the basics of the language, e.g. for and loops while, arrays, lists, pointers, etc. But they never seem to ...
3
votes
1answer
808 views

Is it OK to use the MIT license for a project that uses Qt?

I built a Qt application. Am I allowed to LICENSE it under the MIT license? Qt is a cross-platform application and UI framework for developers using C++ or QML, a CSS & JavaScript like ...
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1answer
98 views

Releasing Qt-based controls under University of Illinois/NCSA

Qt is a graphic framework which has a double license: commercial (statically link and modify at your wish) LGPL (you should either dynamically link against it or release your source code, any ...
0
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1answer
220 views

Difference between Signal/Slot and DataBusPattern

I'm just trying to figure out what makes the Signal/Slot (Pattern?). Wikipedia tells me not so much and calls it an implementation of the ObserverPattern* while I would think it has much more ...
3
votes
4answers
975 views

In C++ Good reasons for NOT using symmetrical memory management (i.e. new and delete)

I try to learn C++ and programming in general. Currently I am studying open source with help of UML. Learning is my hobby and great one too. My understanding of memory allocation in C++ is that it ...
3
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5answers
2k views

Web technologies on GUI apps

I developed many GUI applications for the Windows platform during my early professional career, and saw several GUI frameworks come, have whole magazines devoted to them, and then fade away. MFC is ...
5
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2answers
7k views

Are Nested Static Library dependencies possible?

I am working in QT . Can a static library depend on another static library?(Static Lib is made by linking another static lib) If yes, is it possible that after linking to lib2, the generated lib(...
17
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7answers
2k views

To rewrite or slowly refactor old C++ project [duplicate]

Our team has recently inherited a relatively large project from another company (~250k lines). It was developed using C++Builder and we intend to port the Ui side to Qt. Most of the Ui code is ...
118
votes
14answers
131k views

Why aren't more desktop apps written with Qt? [closed]

As far as I know and have understood in my experience with Qt, it's a very good and easy to learn library. It has a very well designed API and is cross-platform, and these are just two of the many ...
0
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1answer
564 views

How QT Framework handles Events Coming from OS?

When we call QApplication::exec() at the end of our main() function, the application enters Qt's event loop. Conceptually, the event loop looks like this: while (!exit_was_called) { while (!...
7
votes
2answers
11k views

Open source projects, how to choose? [closed]

I would like to join an open source project since I think I am good enough at programming to progress onto reading others code and to modify it. But the problem is, how would I choose an open source ...
0
votes
2answers
202 views

Design Question: Keep 1000 newest items; DB vs. application

I have a Qt application, which sends and receives messages. Messages are stored in a local MongoDB. The application has a message list window, which shows sent, received and all messages (depending ...
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vote
4answers
3k views

Help with learning the C++ Qt Framework [closed]

I've been a longtime PHP web developer. But now I've reached the limits and web doesn't fascinate me anymore. I am interested in learning cross-platform development. I have learned Java for almost a ...
13
votes
3answers
8k views

QT-C++ vs Generic C++ and STL [closed]

Been brushing up on my C++ lately, on Ubuntu QQ. I love the Qt framework for everything, especially building GUI's. I became quite familiar with it when using PyQt over the last few years. When ...
2
votes
2answers
916 views

How do objects fit into modern C++ (stl, policy-classes, functional) style?

I'm a bit confused so the question is a bit confusing. TL;dr: how to mix STL and OOP? From the comment to Best overview to modern C++ paradigms? and http://www.boost.org/community/generic_programming....
2
votes
2answers
2k views

C++ Typecasting VS performance

Let's say we're designing a video game. We have some sprites on the map and we want to call some method of the particular sprite at some particular position. We are using one broadly-known C++ ...
3
votes
1answer
852 views

How to structure unit testing of huge libraries?

I am writing unit tests for a library written in Qt/C++. The library is rather big, with lots of functionalities. I have a separate unitTest folder which I have my UnitTest.cpp in there. Having all ...
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1answer
2k views

Automated Qt testing framework

Can someone recommend a good robust "Free" testing framework for Qt? Our requirements: Should be able to test basic mouse click / mouse move events Should be able to handle non-widget view ...
7
votes
3answers
609 views

Architecture of interaction modes (“paint tools”) for a 3D paint program

We are developing a Qt-based application to navigate through and paint on a volume treated as a 3D pixel graphic. The layout of the app consists of three orthogonal slice views on which the user may ...