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Comment by cosmic_cheese | Hacker News Reader

Semi-relevant, not too long ago I started tinkering around with launcher ideas and almost immediately ran into headwinds when it turned out that the only way to draw the wallpaper the user has set in Settings is to use a magic method that doesn’t let the launcher actually do anything with the image and forces you to let the system handle compositing.

This is limiting and completely rules out implementing effects like blurs or a Liquid Glass lookalike unless you want to make the user set the wallpaper in the launcher separately. Totally killed my motivation to build further.

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It also prevents your launcher from uploading your private wallpapers to servers and reading the exifs from images to datamine location data.

This is an interesting point. Couldn't the OS give access to the pixel data without access to the EXIF data? i.e. doesn't need to give direct access to the image file, just convert it first to strip the metadata.

That still gives you the image data which might be private, but we should be able to lock that behind a permission dialog "Allow access to current desktop background image" or whatever. It's a weird and very specific permission but it might be worth having.

of coure the OS could that.

It could, but there's other benefits as well of decoupling wallpaper rendering from the launcher - it allows you to switch the launcher without having to beg the developer (OEM nowadays) to support your preferred (live) wallpaper. It gives you freedom to choose while preventing what the OP is ranting about - the launcher developer deciding for you what's best for you.

> the launcher developer deciding for you what's best for you.

I don’t understand how I would be deciding what’s best for users?

The only reason why third party launchers wouldn’t support live wallpapers is if Google didn’t give devs the tools to render them. All they’d need to do is include a WallpaperView the dev can add to their view hierarchy that supports live wallpapers. Boom, the dev can do fancy effects and the user loses nothing.

Why not also provide a way to deny all network access to the app? Then there’s nothing it can do with any data of gets.

This is how third party keyboards work on iOS. No network access by default, but the user can go into settings and grant network permission if they judge it fit to.

I think this model would make a lot of sense for Android launchers, too, given how they continually run and potentially have access to much more user data than is typical.

Honestly it should be how all apps work. I hate that I can’t deny Internet access to any app.

I'm so glad that the only entity with access to this data is Google and that open source launchers can't... render an image

Maybe I'm not understanding something here, but Kvaesitso has wallpaper blur and darkening effects.

https://kvaesitso.mm20.de/

Interesting, thanks for the link. Seems like they use that same “magic” wallpaper drawing I mentioned earlier and implement the blur by setting a blur property on the activity’s window, therefore letting the system compositor do the blurring. Had no idea that was possible.

Still has some limits, though, like inability to blur specific parts of the image (e.g. under a box) and apparently the Android skin that ships with some devices disables that window blurring feature, in which case it won’t work. Better than nothing but still restricts the scope of what’s possible quite a lot.

> the only way to draw the wallpaper the user has set in Settings is to use a magic method that doesn’t let the launcher actually do anything with the image and forces you to let the system handle compositing

My guess is, this might have to do with fixed layers in the Hardware Composer HAL, which offloads compositing that otherwise (I guess) Surface Flinger would need GPU/CPU for.

Android has gone through epochs of customization option the best of which for me was 'Theamer' phase, a long gone one-click to customize the whole UI app and lot of creative people making things. Much much better than todays root needing hacks I used to enjoy opening the phone more then. Enshitification.

Whatever happens on wallpaper side under the hood on old android versions is so messed up. At some point of using my Android 11 tablet and experiencing a lot of lag when any custom wallpaper was visible on the screen (but not when default one), after lots of digging I discovered that lag was completely gone if I set my wallpaper in portrait orientation. Had to install some separate wallpaper app from google for that but at least lag's gone. Just another little example of weirdness

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