Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [qt]

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

1
vote
4answers
188 views

How would I add up enumerator values such that any combination provides a unique number?

Backstory (You can skip) I am writing a pronunciation library for irregular words. Take something like the following: T1E1s // tee one E one es | tee one E ones 1994-1995// 1994 (minus|dash|to|) ...
1
vote
1answer
89 views

Architecture/Design for Hardware Control Software

I'm currently working on the control software for a system that includes a lot of user controllable hardware and also has many configurations. Configurations in this context refers to a specific ...
0
votes
1answer
88 views

Do I need to make my code open source or buy a license? [closed]

I want to develop a GUI in python for my company in order to sell it to the customer. Being fresh from the university where I used pyQt, I promptly started programming using that library, just to ...
1
vote
1answer
27 views

Organizing and Creating a Custom Qt Widget

I am looking to create a digital Rolodex to keep track of contacts in Qt 5.9 and am uncertain how to efficiently create custom widgets. Examples online like the classic clock example show to ...
3
votes
3answers
249 views

In c++, is there a way inside a function block, to execute cleanup code after the value has been returned?

Backstory (You can skip) I am building an API for managing Files and Directories in a consistent manner across a project. This is for deduplication and consistency when performing a task, and in this ...
1
vote
0answers
31 views

Save data from multiple Qt components scattered around multiple QML files

I would like to save the current "value" property of several components (e.g. a Slider) as a configuration profile when the user clicks on the Save button in my application. However, the Save button ...
0
votes
2answers
122 views

Should I always allocate QObject and derived classes to the heap?

I was in #Qt irc channel, and I showed a small snippet of my code in a style that I heavily rely upon. It looks like this: /* Get Reply from Server */ QPointer<QNetworkReply> reply; { ...
1
vote
1answer
126 views

How to understand and design functions with enumeration arguments that work in tandem with bitwise operators in C++ and Qt?

In the C++, there are 6 bitwise operators: Symbol Operator & bitwise AND | bitwise inclusive OR ^ bitwise XOR (eXclusive OR) << left shift >> right shift ~...
0
votes
1answer
131 views

How to manually model a UML activity Diagram to JSON with Qt C++?

Suppose I have a kind of UML activity diagram with 1-n forks and joins. The assignment of the individual nodes relative to each other is defined by an XML relationship table via UUIDs where each ...
-3
votes
1answer
120 views

QElapsedTimer hasExpired() - Is it one msec off?

Here is a a part of the documentation of Qt's QElapsedTimer: bool QElapsedTimer::hasExpired(qint64 timeout) const Returns true if this QElapsedTimer has already expired by timeout milliseconds (...
1
vote
1answer
182 views

Remove duplicated switch statements caused by not knowing type at compile time of opencv matrix?

I have a situation that occurs 5 times in my code, and continues to grow. Basically I have the same switch statement structure every time I need to perform an operation that involves my matrix and ...
-2
votes
1answer
153 views

What Is the Best (Conventional) Way to Format Code for PyQt5

I was looking into PyQt5 for one of my side-projects and would really like to get to learn it better. However, I wasn't sure how to correctly format the code. I've seen tutorials do class definitions ...
3
votes
3answers
218 views

How to separate serialization, visualization and computation from GUI editable code objects?

This might be an X Y problem, but here's my situation. I've got a QT5 C++ code base whose task it is to allow for the configuration of a "process chain". A "process chain" here means a list of ...
5
votes
3answers
3k views

Moving from Qt/C++ to C#/WPF - Productivity Gain?

I created a small Desktop application (approx 15000 lines of code, so not that large) written in C++/Qt. This is non-commerical, just a hobby project and I am coding on my free time. The larger the ...
0
votes
2answers
557 views

What is the safest practice in handling QWidget pointer lifespan in a QObject oriented environment?

Consider the following constructor: NetworkTools::NetworkTools(QObject *parent) : QObject(parent) { view = new QWebEngineView(); view->setParent(parent); // Produces an error, shown below. ...
1
vote
3answers
770 views

Architecture of gui application

I am writing gui application. I want to implement following structure: project tree with nodes of different type and behavior (i.e. when right clicking or selecting there can be different menu ...
2
votes
1answer
103 views

Reusing UI elements between two different QWidgets

I am writing a utility in C++ with Qt which communicates with an embedded device. The program was originally going to be used to just plot data from the device, but a new requirement has been added (...
2
votes
1answer
707 views

When writing a Qt application is good practice to ALWAYS prefer Qt function implementations, data types, and classes when they are available?

I'm just starting out with Qt and I really want to try and keep my application as separated from Qt as possible in case I decide to use a different toolset later, but at the same time don't want to ...
1
vote
2answers
354 views

How should I structure my C++ project to allow for starting, stopping, and pausing my program?

TL;DR: How should I structure my C++ project to allow for starting, stopping, and pausing my program? Overview: I am designing an application that needs to allow users to start, pause, and stop the ...
2
votes
1answer
225 views

Using Qt in Open Source App that Communicates with Closed Source Hardware

Preface I'm having trouble determining if I can use the Qt framework for developing a cross platform desktop app. Situation The app is open source, and the libraries it uses are also open source. ...
0
votes
1answer
103 views

For Qt, or C++, do modern standards or practices exist for designing Run Configuration files for your programs? [closed]

Backstory I am building a daemon that is to be run in the background on systems based on X11. As of right now, the settings are hardcoded, and that obviously needs to change. As such, I plan to ...
0
votes
1answer
234 views

In Qt or C++, is there a good means for creating a switch with dynamically generated cases, or should I just use a for loop (or something else)?

Presume this situation: Max Number of 256 key slots. Key slots are defined by a struct, and a variable for each (256) has to exist. User defines which keys slots are active at initiation (in my ...
0
votes
2answers
418 views

Interaction between model and self-modifying data in Qt MV

I have a tree structure that represents a system of devices that are connected to the PC via serial port. In a way, this structure was inspired by tree model example in Qt and I think that helps to ...
3
votes
2answers
804 views

What can I infer from someones code when they use direct initialization with Curly Braces as opposed to Parenthese?

Up until now, I have been initializing most of my variables as such: const QString foo("bar"); Which from my newfound understanding, is known as direct initialization. (http://en.cppreference.com/w/...
0
votes
1answer
157 views

Windows Qt5-based app porting to Linux

I'm here today, because I'd like to ask you a question about porting application built with Qt5 to linux. I have been asked to port this application to linux, I don't yet have the source code, but I ...
0
votes
2answers
401 views

Events fired when widgets are updated programmatically

In the GUI application I'm working on I have a number of custom (composite) widgets that I've created, with each widget having an update_gui function where I access my SQLite database so I can fill in ...
-1
votes
1answer
894 views

Is it required to disclose source code for custom Qt software? [closed]

I was hired to develop a custom Qt application for a customer, but I'm concerned about the licensing. My software will not be publicly distributed and it is going to be used exclusively by this ...
1
vote
3answers
150 views

How to handle custom metadata in XML?

Backstory I have an XML type document (SSML, which is used forText-To-Speech), which will be used to generate audio files when ssh transferred to a remote server. As such, I will need to include ...
1
vote
1answer
101 views

Static link GUI project as dynamic library

My app has 2 projects: logic.dll and GUI.dll. Currently, its size is 1MB, but the whole app's size is 60MB+ due to the dependency dlls. I've read about QT-LGPL license and know that to keep my app ...
7
votes
2answers
407 views

How to treat in-house libraries

I am facing problems structuring projects and libraries. In the company I am working for I often see, that things would be more maintainable and less error prone, if we could extract common code and ...
7
votes
1answer
112 views

Database Model description using constants

I want to create a class with static constants which are used whenever a part of an application want to access the database in any way. This way I want to remove all magic numbers and string inside my ...
0
votes
1answer
139 views

What is the proper way to track my build versions in Qt?

Basically what I need in my project is a number of some sort that iterates itself every time I build my project, and that I can output by my program. So for example, when generating audio, I need to ...
0
votes
0answers
108 views

Qt Naming Schemes for returns of boolean member variables: enabled(); vs isEnabled(); ?

In building my classes, I have noticed that I have not been very consistent about naming my boolean returns. In Qt; I notice that many of their classes use the is prefix, but checking their coding ...
0
votes
1answer
142 views

How to play audio samples while generating them

I am trying to write a simple live sine wave generator from scratch in Qt. I try not to use any external APIs like ASIO or VST. And I want to generate new audio while playing. (As opposed to the Qt ...
4
votes
2answers
1k views

Not understanding the concept of how to make my GUI application

I am making a program that primarily deals with heavy data mining and analysis. It is primarily a back-end type algorithm, with no GUI elements or console windows seen as it runs. Occasionally though, ...
2
votes
2answers
1k views

In Qt or C++, how should I check whether my `int` variable has been defined?

Short Problem: How should I check if integers are undefined, just as I can check QStrings for having NULL values? Backstory: This is my coding style when I am trying to avoid overloading my ...
1
vote
1answer
1k views

Creating a private in-house application with Qt

I want to create an application using the Qt framework, but can not at all afford a commercial license. While looking at the licensing comparison table, I noticed that the LGPLV3 license said this: ...
0
votes
2answers
679 views

Passing by refernce

I am trying to understand the ideas of pointers and references in C++. I am stuck with the following, what would be the specific behaviour in this case? I have a class like this: class MyClass{ ...
4
votes
1answer
648 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 ...
5
votes
2answers
3k 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 ...
0
votes
1answer
62 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 ...
6
votes
2answers
512 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
votes
1answer
2k 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 ...
1
vote
1answer
614 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 ...
2
votes
1answer
2k 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 ...
-1
votes
1answer
454 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 ...
4
votes
3answers
2k 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 ...
5
votes
3answers
3k 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
563 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 ...
10
votes
2answers
2k 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 ...