Cannot set stylesheet within method body, but can inside constructor

SGaist

Did you try to let QPixmap operate a format conversion ?

ejm1

There is no change. I set the format to MonoOnly and nothing changed. If I load the Pixmap from data using any format it will break it as the incoming format is RAW which Qt cannot handle. Which is why I turned to loading directly from a Qimage even if it's slowler.

SGaist

What exactly do you mean by RAW ?

ejm1

Its just the pixel values there's no header. It's simply the width x height of pixels given as an unsigned char*. Either way it doesn't display the pixmap I just had more success loading it from an image than the raw data.

ejm1

I'm not sure the problem is even with the pixmap. That's why I attempted to change the style sheet of the label in there too. The style sheet does not get changed despite the code executing. Whereas, if I change the stylesheet in the constructor that code works. So something beyond my understanding is going on here.

SGaist

I would try with loading a known image from the disk.

ejm1

I've attempted that as well. I placed the image in the directory with the ui files. Was that incorrect?

Bonnie

Hey, did you try not setting any format parameter (leaving it as auto) and see if it can show? Just

QPixmap::fromImage(qt_g_image)

And if you try to test with a image from the disk, better to load it by the full path, then it doesn't matter where you put it.

ejm1

@Bonnie I'll try both of those tomorrow and let ya know how it goes.

SGaist

Use the full path to the test image. If you use a relative path it won't work because your executable is not built in the same folder as your sources.

ejm1

I think I figured out why the code doesn't work. The function calling this method is activated by a slot in my application. However, this slot is essentially a while(true) loop that doesn't stop acquiring pictures until I press the space bar. I just noticed while acquiring images none of the other buttons on my GUI are clickable, which makes sense since that loop is still running. I thought that Qt slots were asynchronous, but I guess I'm understanding something wrong?? If anyone has ideas as to how I can fix this because I can't simply throw the function in another thread of execution.

ejm1

Ok I added QCoreApplication::processEvents(); into the blocking event and all of the buttons are unblocked; however, the pixmap still did not display so I guess that was not the issue.

SGaist

Asynchronous does not mean that several threads are running in parallel. A while loop will always "block" the execution of the thread it runs in inside the body of the loop.

Did you check with the full path to a test image like I suggested ?

ejm1

I fixed the issue. It turns out it was not fully Qt related. I did add a call to update() however.

SGaist

What was the issue ?