Qt for Embedded Linux or Qt Enterprise Embedded? [closed] - qt

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I need to develop an application for a board (ARM 8), running embedded Linux (probably Angstrom – yet to be decided). I’ve been Googling and I’m confused about a few things.
It seems for embedded, I have to use Qt for Embedded Linux (qt-4.8). I also see a Qt Enterprise Embedded.
I’m confused between the two. What’s the more current way to go with Qt for embedded linux and what’s the major difference between the two?
Also, I downloaded the Qt SDK and followed the instructions to build and install the SDK on my Ubuntu 12.04 LTS system. However, I do not see QtCreator, QtDesigner, and QtQuick Designer anywhere on my system. According to the documentation I should have gotten all of these tools, including qtdemo application after building the sdk.
Finally, I do not see a version 4.8 of the QtCreator. The link in the documentation page (Tools to Install) is broken. Can I use the latest QtCreator with Qt 4.8 SDK?
Can someone please help?

The Qt Enterprise Embedded is a commercial version of Qt for embedded devices If you need support you can buy it from Digia.
The Qt libraries 4.8.5 for embedded Linux is also available for download. It uses Compact and Efficient Windowing System (QWS). It writes directly to the Linux framebuffer, eliminating the need for the X11 windowing system and saving memory.
You can use Qt5 for embedded devices as long as you have a good graphics stack. There is no specific Embedded prebuild available for Qt5 because QWS was dropped in favour for Qt Platform Abstraction. So, Qt does not ship with a windowing system anymore, it expects the OS to provide one (or at least some display devices like directFB etc.).

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Is there a recommended path to upgrade from Qt Extended to a newer Qt framework? [closed]

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I'm looking at a Qt Extended application built circa 2006-2008 and upgrading to a newer Qt framework. What direction(s) are recommended to upgrade / rewrite this application to get on the latest supported version of some Qt framework?
I assume this is an embedded platform, and in this is case first of all you need to get Linux BSP with newer Qt version (you can look into Buildroot or Yocto or even a distribution like Debian, all of these have excellent support for Qt), and make sure that you have full HW supported for your platform. This is pretty much platform and product dependent, so i can't really be more specific.
After you got the OS up and running, you can start to port your application to port to Qt5. This can be pretty straightforward (see for example https://wiki.qt.io/Transition_from_Qt_4.x_to_Qt5), but can be rather complicated if a lot of Qt Extended related features were used. Again, this depends a lot on the application itself, so hard to give guidelines.

Can I publish free GUI software with Qt GPL license? [closed]

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I'm about to publish a free software written with Qt 4.8 GUI, can I publish the stand-alone version with dlls such as QtCore? Do I have to publish my code also?
If possible, could you make some examples of using GPL license legally?
Thanks very much!
If you want to publish your software using GPL then you have to provide the source code no matter is it free or you charge money for it. In GPL "Free" doesn't mean cost free but freedom to change the code etc.
In your case if you don't wish to give away your source code, then you you should use LGPL license. Qt is available under LGPL license too. The only restriction it puts is that you cannot statically link with Qt libs. You ought to use dlls as you are using. And if you only use Qt dlls then you can even charge money for your application.
http://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License#Differences_from_the_GPL
You can use LGPL library in your commercial, closed source, non-free/free application provided you link to the LGPL library dynamically (using .dlls, .so etc.).

What development tool to use for develop cross-platform application using Python and Qt? [closed]

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I'm a Delphi developer I only used to develop application on Windows platform only.
From now on, I wish to develop a GUI based database applications which target Windows, Ubuntu, OSX.
I don't have much knowledge about cross platform solution, I know I little about Java, I know almost nothing about Python and Qt.
Anyway, I prefer to use Python as the programming language and use Qt for GUI, my question is I'm not quite sure about...
What development tool and version (prefer latest if possible) do I need to install on my development machine which is running Ubuntu 13.04?
What are major differences between PyQt, Qt Designer?
Did you read basic Qt documentation?
You should write platform independed code to make it portable ;). Do not use OS-specific features, use Qt classes. You need a compiler for each platform. You need a Qt for each platform.
Visit qt-project.org and get latest versions. (And a lot of other information about Qt)
PyQt - is port of Qt libraries to python. Qt Designer - is software (tool) for making .ui files. Others??

How can I reuse part of the QtCreator source in a commercial application? [closed]

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Suppose I have a commercial license for Qt (say, for 4.5.2 ), is it possible to reuse part of the QtCreator (say, version 2.0) source code to develop a completely proprietary software? I read the QtLicensing information, but it doesn't provide any information about QtCreator licensing.
QtCreator is licensed under the LGPL just like Qt - check the Gitorious QtCreator source tree for details, specifically LICENSE.LGPL, LGPL_EXCEPTION.TXT, and the README where the various third party libraries used by QtCreator are detailed.)
Thus you can reuse the QtCreator source code in the same conditions that apply to any other LGPL-licensed product - see my answer here for additional details.
As klez said, the best thing to do would be to ask Nokia. However, if your commercial license is for Qt 4.5.2, I seriously doubt you can apply the same license to QtCreator 2.0, because QtCreator 2.0 is based on Qt 4.7. You will want to stick to QtCreator 1.3 with Qt 4.5.
Using the LGPL, you can include unmodified code from Qt Creator in a proprietary application, but if you modify any of the Qt Creator code, you must make that code (just the modified code, not your entire application) available under the LGPL.

Should I base my Embedded Linux product on Qt? [closed]

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My company is developing a medical product. One of the components is a pda-like platform that will run embedded linux.
We were considering Qt as the UI framework but found out that Qt is a lot more than that (we are not familiar with Qt). We intend to program in C++.
In general, the device needs to do the following:
Receive measurements over USB HID from another device (USB HID is used for convenience).
Process the measurements.
Store them in a database.
Interact with the user using the device's touch screen lcd.
Communicate (wi-fi, tcp-ip) with a central management station that collects the data and configures the device.
Include a web server to allow accessing the device via a browser.
My questions are:
Is that a good choice for such a device?
Assuming we choose Qt, how do we build our product?
Do we use Qt just as a GUI framework and write the application code in a separate process (passing messages between Qt and the application process)?
Do we write the entire application inside Qt, using all of the services the tool has to offer?
Another approach?
To answer the question if it's a good choice one needs to know what other choices you have. What other possibilities do you have to write GUI for this embedded linux system? Do they support C++? Are they any good? Are they likely to be portable to any other devices you might want to write for in the future?
Another reason to choose Qt is that it has an emulator for some embedded devices so at least for the GUI front end you might be able do to most of the development on your normal windows machine.
Yes, you build a complete application with Qt. There is no need to divide into more than one process. The GUI part is integrated seamlessly with the rest of your functionality. There is nothing that will prevent you from making whatever calls you make to communicate with the USB.

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