[Feat Req] Change wallpaper based on contents of workspace

[edrozenberg]

Idea:
It would be nice to be able to spec for ex. "kitty.jpg" if a workspace is empty (no windows) vs. "gradient.jpg" if a workspace has one or more windows (workspace not empty).

Motivation:

• When a workspace is empty, it's nice to properly view a wallpaper in its entirety
• When a workspace has window(s), it's sometimes preferable to use a simple gradient wallpaper so that window gaps don't show lines and other partially cut-off content of an image wallpaper

One way to use this feature would be to modify some image wallpaper to contain a gradient border of some thickness. Then "image 1" would be the original image with the gradient border, and "image 2" would be a full-screen gradient that includes the same gradient border from "image 1". When adding a window to an empty workspace, the transition from "image 1" to "image 2" would be a visually seamless transition where the outside window gap continues to show the same gradient colors, while the contents of the original wallpaper are now replaced with a full-screen gradient/color.

I looked at https://wiki.hypr.land/Configuring/Advanced-and-Cool/Expanding-functionality/ and pseudocode-wise something like:

for each existing workspace x
    if workspace[x].hl.get_windows() is NULL 
    then workspace[x].wallpaper = "image 1"
    otherwise workspace[x].wallpaper = "image 2"

Don't believe it's possible to achieve this today. Also, this isn't the most important thing in the world. Definitely toward the bottom of the "nice-to-have / what else can we possibly think of" list.