I have X_Compiled Qt for BeagleBone Black and everything works fine. I've compiled Qt virtual keyboard plugin and I can load keyboard example on the device. I want to use this virtual keyboard in my C++ app. Can anyone show me the right way to do so?
I've also downloaded a plugin and compiled it but I don't know how to use it. Can any one tell me how to use Qt plugins like the two I mentioned above?
first of all make sure that the plugin is in the plugin folfer of Qt installation path and in main file add this line before creating QApplication object.
qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
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Greetings for the first time:
Usually I can work my way through problems like this but I think I need help for this one.
I have developed a small utility for myself to plot some data using Qt and Qwt under Mint. When I run the application from Qt Creator everything works fine. Once I added (export LD_LIBRARY_PATH="/usr/local/qwt-6.1.3/lib") to my .bashrc file, I can invoke the application from the terminal with “./PlotAccountsChange” and it woks. Also the ldd command shows all dependencies have been found.
The problem I am having is that the application can not be invoked from the Nemo file manager, or from the menu system if I add the link to the executable in the menu, or from a link to the executable placed on the desktop. In all of these cases I get no indication at all, just nothing happens. Any other application that I have created using Qt but that doesn’t use Qwt invokes without problems.
Thank you, regards,
B Kace
So here is my question I have been trying to create a small "software" which would control my arduino card. For this I decide to use qt so I used this tutorial to add arduino to qt :
http://www.lucidarme.me/?p=3287
I am very sorry the page is only in French. I basicly get 3 files config files and includes for my arduino. And a Makefile. The problem I have is that I want to add GUI such as Windows but whenever I add a gui file to my project it says it cannot find the "QMainWindow". However I think the problem is deeper and that it doesn't find any Qt class.
I think this is because I don't have any pro files but I tried adding one and it didn't work. I hope you guys understood my problem I am very new to QT ...
Thank you !
The GUI project is completely unrelated to anything Arduino. The page you linked to shows how to use Qt Creator as an IDE to work on Arduino projects, as a replacement to the Arduino IDE. This has nothing to do with GUIs or Qt, you'd be reusing Qt Creator as a general-purpose IDE that it is.
What you need and want is to create a standard Qt project in Qt Creator and go from there. You can also leverage Qt to "simulate" Arduino code without running real Arduino hardware, see this answer for an example.
I created a Qt Application with Qt Creator 3.3.1, using Qt embedded 4.8.6 for a Cortex A5.
It runs on a board with Linux embedded and a touchscreen.
The filesystem was created with Buildroot 2015.08.
I'm using a resistive touchscreen calibrated with ts_calibrate.
The Qt Application works, but I often get the wrong coordinates. For example, when I push on a button, sometimes the program takes the coordinates related to another point of the touchscreen, giving the idea that the button pushed doesn't work properly.
My Qt enviroment variable are:
export TSLIB_CALIBFILE='/etc/pointercal'
export TSLIB_CONFFILE='/etc/ts.conf'
export TSLIB_PLUGINDIR='/usr/lib/ts'
export TSLIB_TSDEVICE=`cat /etc/ts.dev 2>/dev/null`
export QWS_DISPLAY=LinuxFB:mmWidth=800:mmHeight=480
export QWS_MOUSE_PROTO=Tslib:/dev/input/event0
If I try to use another Qt Application (for example the Qt demos created with Buildroot) I get the same problem.
Is it a bug of Qt 4.8.6 or something?
Can anyone help me? Thank you
Sounds like playing with your activated filters or their parameters in ts.conf might help.
Since you asked your question, there is tslib 1.2 and (if you need multitouch) tslib 1.3-rc3, both with new and improved filters, see tslib's project page
I'm trying to make a simple videoplayer using qt. However, I can't get the videowidget example that comes with qt to work, instead I get an error: "The QMediaPlayer object does not have a valid service". I'm using windows vista. Can I get the videos to play normally, even if that example isn't working? Is there any other simple way to test playing videos? Or is this a problem with qt?
Check this VideoWidget I created: https://github.com/MaximAlien/VideoWidget. The main thing here is that the video should be in web and QMediaPlayer handles everything for you. Example works with Qt 5 and higher.
This is expected on your Vista, unfortunately. See the relevant post from the maintainer:
On Windows XP, Qt Multimedia uses DirectShow (and WMF for Windows Vista and later). The DirectShow plugin binary is not included in the Qt 5.0 package (only the WMF plugin is). You need to compile QtMultimedia yourself, or just the DirectShow plugin in qtmultimedia/src/plugins/directshow
... in the following report on the Qt issue tracker:
Qt 5.0 and QMediaPlayer failure on Windows XP
The steps to build it on your would be:
grab the tarball
unpack it
move into the qtmultimedia folder
run qmake -r
(n)make
(n)make install
Please make sure qmake is properly in your PATH before doing this.
I am having problems with a Qt GUI application I created. Basically I created the application in my ubuntu to check if it compiles and works properly, however, if I set up the cross compiler (followed a tutorial and tried a hello world which works properly) and execute my code in the pi the UI does not display properly and basically I cant do anything:
· Text disappears from buttons
· Mouse disappears from screen (therefore cant click buttons)
· Cant navigate buttons using tab key
Any clues? maybe I cant use .ui files in the pi and have to use qml? Thank you in advance.
2 Screenshots of what I get with the pi and what the program should actually look like (ignore the second LCD display):
what I get http://imageshack.us/a/img17/9986/img20130508093318.jpg
I’ve been told that Qt5 has different rendering platforms, the standard for my compiled version is “eglfs”, which is fullscreen EGL accelerated mobile application style. I need to run it another platform for example xcb or x11 with the command “./myprogram -platform xcb”. Unfortunatelly i only have the following platform options and none of them work: eglfs,linuxfb,minimal,minimalegl,offscreen. I dont now how to install these, i’ll google it see if i can find anything.
http://www.raspberrypi.org/phpBB3/viewtopic.php?t=26590&p=321556