How Qt platform plugin could be initialized in Google Colab? - image

I got the following error while using Google Colab:
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/usr/local/lib/python3.7/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: xcb.
Please help me find a replacement for qt?

Having the same problem, and I think I found the answer.
Basically not possible to run QT on the cloud!
"QT is a GUI library that can run only on your local machine. You cannot run it in the cloud and then let it open a QT window on your machine.
You may need to find another labeling library that use web-interface instead."
check this out:
Could not connect to any X display: Google Colab Run-time

Actually you could make it work with the right platform plugin. By passing for example -platform vnc to your application you should be able to start it in "headless mode". (actually your GUI is drawn to a VNC server you can connect to)
Your error is caused by the absence of a window manager, the xcb platform is trying to access.

Related

How to get macos app signing set up for packages

I am new to macOS development and am having a terrible time trying to get my code signed. The documentation to me seems to be horrible.
My specific situation...
I am building a cross-platform app that runs on Linux, Windows, macOS and eventually iOS and Android.
It is a console app that runs as a service or LaunchDaemon
It has a UI served by WebView, http, or console commands depending on the scenario.
It is built with Go 17 in VScode.
I am not using xCode other than the command line tools.
My goal on macOS it to distribute it as a package (pkg) and not as an app.
I have been using MunkiPkg to build it
I am hung up on understanding how the various certificates need to be set up. I have not been able to get a successfully signed package notarized.
Can someone please point me to some documentation that explains how my scenario works? Most of what I found requires it to be built in xCode. And the Apple docs seem mostly to focus on how great their tools are without actually explaining how to use them.
Help!

Mono.ZeroConf Mac, No Zeroconf providers can be found

I have recently built a bonjour system using Mono.ZeroConf on Windows and wanted to try and convert it to mac. I am running into issues with this error:
No Zeroconf providers could be found or initialized. Necessary daemon may not be running.
I have tried the sample code provided by http://www.mono-project.com/Mono.Zeroconf and have tried using my own dlls with my own project that were built on the Windows machine. Both run into the same errors.
Now to resolve this on Windows, I installed Bonjour Print Services. I can't see an equivalent for Mac and imagined that the latest version of Bonjour should be installed anyway.
Was just wondering if anybody had any ideas why this error could occur?
Cheers
You can find the solution on this other StackOverflow thread:
OSX port of Mono.Zeroconf
Best regards.

How to install application on real android phone

I have created one SMSapplication and i need to test it on my android phone.
i have already tried other options like enable USB debugging in manifest file and also device
but it's not working.. any other option. pls help me..
Install USB drivers on system, you can use following link for refence of steps and driver links:
http://developer.android.com/sdk/win-usb.html
If you still facing issue, see following article.
http://appsandroid.in/connect-android-phone-to-pc-laptop-computer-mac-vi-usb-cablea
Once connected to system, To install application on device see, link:
http://www.talkandroid.com/guides/beginner/install-apk-files-on-android/#.TzZn2chG2nA
first of all, you need to get the driver of your phone.
then, you need to set your phone on debugging mode as follows:
settings > applications > development > check the debugging mode box.
if you are using eclipse then, go to run > debug configurations > testing >under the target tap make it manual to be able to choose your device ....
if still not working, connect your phone to the pc as a mass storage and copy the .apk file to it and then install it.
You have to package the application to an .apk file.
About that, the best solution is probably to take a look at the developpers' documentation -- the Preparing for release section should be kind of a good start.
Then, upload that .apk to your phone (using the USB-mass storage feature, for example ; or using FTP/samba applications) like you would do for any other file.
And, finally, open that .apk using some file-explorer application ; which will propose you to install it.
Note that it is also possible to debug on a real device (instead of using the emulator) ; Using Hardware Devices should be what you'll want to read, about that.

Compiling a Qt based NPAPI Browser Plugin on Windows

I am further developing a NPAPI Plugin in Qt. I got the source code and a precompiled windows (DLL) version of the Plugin. I added some functionality and tried to compile it using the default Build process of Qt Creator. In my edited case as well as in the original case the compiling worked perfectly well on windows and linux. The problem is, that the plugin itself is only usable on the linux machine. On Windows (XP SP3) there is an error mentioned, that my specific scriptable methods wouldn't exist. Is there a special way or toolchain for compiling on Windows? Or is there way to locate the failure?
Thanks in anticipation!
Here are some things to check and to try:
Set a breakpoint in NPP_New (you'll have to find it in QT's framework, I don't know where it is); step through until you find a problem
Make sure that NPP_GetValue is returning an NPObject on request; if not, then you definitely won't get any scripting API
Make sure that QT's framework isn't still trying to use XPCOM for scripting.

Blackberry Development on Mac OS X

I recently started creating applications for mobile devices and have successfully completed an application for the iPhone. I am now turning my attention to the Blackberry but haven't been able to find a convincing article or website that states that it can be done or a tutorial on how to do so. Can Blackberry apps be developed on Mac OS X? If yes, how do I go about doing so? Can anyone please point me in the right direction as I only have access to a Mac and really want to get this project on the road. Thanks in advance for your help.
UPDATE:
RIM has released a MacOS Eclipse plug-in for Blackberry Development: http://na.blackberry.com/eng/developers/javaappdev/macosx.jsp
While there is no built-in simulator, the plug-in DOES support USB tethered device debugging for the Torch 9800 handhelds. I plan to get one; they are ~$499 w/no contract. With a Torch and the new plug-in, Blackberry development is possible without using a VM. (Finally!)
PREVIOUS POST:
Building on MacOS works well once you set it up. I've had less luck with the simulator. On the whole though, being able to run Eclipse natively in MacOS and flip to a Windows VM only for debugging is a big win in my book.
You can get a MacOS version of preverify (see link below for details). I do my development with Eclipse on MacOS X and use Ant to build BB apps.
This blog is excellent and has many of the details to get you started:
http://www.azizuysal.com/2009/07/blackberry-development-on-mac-os-x.html (original link is dead. The "wayback machine" provides us with the original text content, but images and styling are lost to the sands of time. Still worth a read.)
The tricky part is getting the simulator to work. There is a Wine-based work-around, but on my computer, while the simulator was able to run under Wine, the LCD output was scrambled.
Currently, I build COD files from Mac, and my Ant build process drops them into a directory that is shared with a WinXP VM. I can run the simulator stand-alone in this VM. Debugging is also possible by installing Eclipse inside WinXP and pointing the debug configuration it at the source directories.
I've actually got a bit more magic. I enabled some of the Java 1.5 features by compiling against 1.5 and then translating the bytecode to 1.3 prior to the preverify script. (Blackberry only speaks a barbaric 1.3 java, flashback to circa 1992). It's not a silver bullet as some features still don't work, but it does cut down on the need to make everything an untyped Object reference.
Lately, I've been working on a x-platform framework to allow me to write app code once and build against both Android and Blackberry (both are Java). The Android part was easy. It's just a bitch to debug anything in Blackberry. Someone working at RIM decided that Blackberry didn't need to keep Exception stack traces unless there was a catch(Throwable), and then they could do something bizarre, non-standard, and undocumented (catching Throwable behaves weird). I've only kinda-sorta figured out a hack to get stack traces using JavaLoader.exe without breaking into the debugger, and it's barely worth it.
p.s., I now do x-platform development with a single code-base targeting Android, Blackberry, and Desktop. Desktop is great for testing app functionality, with very little Blackberry on-device testing needed once features work in the desktop 'simulator' (a Swing GUI built for debugging our games).
Even though certain components of the RIM development platform are java-based, such as the JDE - other components such as the preverifier and device simulators are implemented as native Windows executables.
Basically, the easiest way to do it is to install Windows on your Mac using Bootcamp or Parallels and run inside a real Windows environment on your Mac.
However, there are other "hackier" ways to do it using Wine, MacPorts, and a number of other tools - as an example see this blog post

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