Cursor image control

[hmaarrfk]

I was removing some Qt-only code from our codebase and trying to replace it with wgpu/pygfx equivalents (for unifying Qt/JupyterRFB stuff) and I couldn't find a good replacement for setCursor

from qtpy.QtCore import Qt
canvas.setCursor(Qt.SizeBDiagCursor)

https://doc.qt.io/qt-6/qwidget.html#cursor-prop

thougths? ideas? maybe i'm missing something? I tried to search for "cursor" here but couldn't find anything.

[Korijn]

There's no good way to abstract over such GUI differences. At this point it's just too specific. For the web you need to use CSS and HTML whereas for Qt you have the right method there. Just use those.

[hmaarrfk]

got it, that makes sense that certain things are likely too hard.

Could PyGFX just take over the look the of the cursor when you are hovering over the canvas?

[hmaarrfk]

I guess it would be up to my application have:

1. Front end dependent code to hide the cursor using Qt/CSS/HTML
2. PyGFX Scene cursor.

[hmaarrfk]

Honestly, the interaction I had setup for it was likely weak and buggy anyway.

Touch interfaces don't have cursors, so it doesn't work for that.

Thanks for helping me brainstorm!!! (and the awesome stuff!)

[Korijn]

You have a cursor within pygfx? That's pretty cool.

[hmaarrfk]

You have a cursor within pygfx

not yet but i could...

[kushalkolar]

Nice! I'm working on a crosshair tool but I could actually just add this to pygfx instead 🤔 . The idea is just a group of lines that share a buffer that can be added to multiple scenes, when added to a scene it creates the line world objects using the shared buffer.

some cursor stuff from jupyter_rfb

[hmaarrfk]

wow pretty cool!

[almarklein]

There's no good way to abstract over such GUI differences. At this point it's just too specific. For the web you need to use CSS and HTML whereas for Qt you have the right method there. Just use those.

That was my first impression as well. But a canvas that sits in the browser can abstract the html/css stuff, like jupyter_rfb does. I did a quick search and it looks like all our current backends support setting the cursor ...

[kushalkolar]

If anyone's interested I decided to add our cursor tool to fpl itself, it quickly got pretty tedious trying to do it directly in pygfx, this is a bit more than a simple cursor since it can be added to multiple graphics and maps the same position across graphics (so it needs to keep track of a world object's viewport and scene which is managed in fpl.PlotArea that makes it easier)
https://github.com/fastplotlib/fastplotlib/blob/7836c5d229ad8014a2a63f4da11df9964e2f1d6a/fastplotlib/tools/_cursor.py

WIP PR: fastplotlib/fastplotlib#662