Decided to try writing a Wayland compositor for fun.
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Turns out, there's a lot of details to get right when implementing a floating window space. For example, dialog windows should always show above their parent window. Otherwise, it's easy to lose them under the (usually much bigger) parent.
The WIP floating branch in niri now handles this properly, even for xdg-desktop-portal dialogs (like file chooser) as long as the app correctly parents them via xdg-foreign.
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Turns out, there's a lot of details to get right when implementing a floating window space. For example, dialog windows should always show above their parent window. Otherwise, it's easy to lose them under the (usually much bigger) parent.
The WIP floating branch in niri now handles this properly, even for xdg-desktop-portal dialogs (like file chooser) as long as the app correctly parents them via xdg-foreign.
Another piece of the floating puzzle: keeping windows on screen. When you change your monitor scale or resolution, you don't want your floating windows to suddenly go unreachable behind the monitor's new borders.
Here I'm resizing a nested niri with three windows, simulating resolution changes. No matter what I do, they always remain partially visible and reachable. Even for more unusual cases like trying to resize a window into out of bounds.
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Another piece of the floating puzzle: keeping windows on screen. When you change your monitor scale or resolution, you don't want your floating windows to suddenly go unreachable behind the monitor's new borders.
Here I'm resizing a nested niri with three windows, simulating resolution changes. No matter what I do, they always remain partially visible and reachable. Even for more unusual cases like trying to resize a window into out of bounds.
In the tiling layout, niri is constantly asking windows to assume their expected size. In contrast, floating windows should be able to freely change size as they see fit.
The logic turns out to be quite tricky. On the one hand we want a window to keep its latest size, but on the other we still want to be able to resize the window, which means asking it for a different size. The window can take a second to respond, or respond with a yet another size, and nothing must break.
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In the tiling layout, niri is constantly asking windows to assume their expected size. In contrast, floating windows should be able to freely change size as they see fit.
The logic turns out to be quite tricky. On the one hand we want a window to keep its latest size, but on the other we still want to be able to resize the window, which means asking it for a different size. The window can take a second to respond, or respond with a yet another size, and nothing must break.
While trying to make this work, I realized that this is the time when I *really really* want to be able to test this stuff. So I got on a sidetrack adventure to write testing infra for running real Wayland clients inside unit tests.
I've got it working! In these tests, I'm creating a new niri instance along with test clients, all on the same test-local event loop. No global state, no threads needed.
What's really cool is that this lets me test the weirdest client-server event timings.
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While trying to make this work, I realized that this is the time when I *really really* want to be able to test this stuff. So I got on a sidetrack adventure to write testing infra for running real Wayland clients inside unit tests.
I've got it working! In these tests, I'm creating a new niri instance along with test clients, all on the same test-local event loop. No global state, no threads needed.
What's really cool is that this lets me test the weirdest client-server event timings.
This morning I worked on remembering the size for floating windows when they go to the tiling layout and back.
The whole sizing code must be at the top by logic complexity in niri. I have to juggle, all at once:
- new size I haven't sent to the window yet,
- size changes I sent, but window hasn't acked yet (0, 1, or more in-flight),
- size change window acked but hasn't committed for yet,
- size change window acked and responded to with a commit (maybe with a different size entirely). -
This morning I worked on remembering the size for floating windows when they go to the tiling layout and back.
The whole sizing code must be at the top by logic complexity in niri. I have to juggle, all at once:
- new size I haven't sent to the window yet,
- size changes I sent, but window hasn't acked yet (0, 1, or more in-flight),
- size change window acked but hasn't committed for yet,
- size change window acked and responded to with a commit (maybe with a different size entirely).The diff is 85 lines of change and 243 lines of new tests, and I already found a few weirder edge cases that I've missed. No way I could do this well without that client-server testing setup that I posted about yesterday.
Btw I pushed the testing setup if you're curious, along with the entirety of 1215 snapshot files for a powerset of new window workspace/output target settings: https://github.com/YaLTeR/niri/commit/771ea1e81557ffe7af9cbdbec161601575b64d81
The WIP floating branch caused them to update in several commits already.
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The diff is 85 lines of change and 243 lines of new tests, and I already found a few weirder edge cases that I've missed. No way I could do this well without that client-server testing setup that I posted about yesterday.
Btw I pushed the testing setup if you're curious, along with the entirety of 1215 snapshot files for a powerset of new window workspace/output target settings: https://github.com/YaLTeR/niri/commit/771ea1e81557ffe7af9cbdbec161601575b64d81
The WIP floating branch caused them to update in several commits already.
The big 1215 snapshot test powerset (actually it already grew to 1695) continues to prove its worth. Just finished a big +495 -508 cleanup of the window opening code, and verified that not a single of those 1215 window opening configurations changed its outcome. I will be sleeping well tonight
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The big 1215 snapshot test powerset (actually it already grew to 1695) continues to prove its worth. Just finished a big +495 -508 cleanup of the window opening code, and verified that not a single of those 1215 window opening configurations changed its outcome. I will be sleeping well tonight
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After three weeks of hard work, I am undrafting the floating window PR in niri. Please give it thorough testing and report any bugs or issues!
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Alright, I think I got all of the important things in for the next niri release. Today I updated Smithay for the DRM compositor changes, and added a workaround for a panic when you have two monitors with exactly matching make/model/serial.
I'll give it a week of testing (if you run niri-git, please report any problems) and if all goes well, tag next Saturday.
There are a few PRs I'll try to review in time, but they're fairly self contained.
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Alright, I think I got all of the important things in for the next niri release. Today I updated Smithay for the DRM compositor changes, and added a workaround for a panic when you have two monitors with exactly matching make/model/serial.
I'll give it a week of testing (if you run niri-git, please report any problems) and if all goes well, tag next Saturday.
There are a few PRs I'll try to review in time, but they're fairly self contained.
After a full day of writing release notes (god how'd it take so long
), niri v25.01 is out with Floating Windows and Working Layer-Shell Desktop Icons and Layer-Shell Screencast Blocking Out and so many more improvements! Yes, you read that right, we finally escaped zerover! I feel that niri is now ready to graduate from v0.1 
Read here and download when your distribution package updates: https://github.com/YaLTeR/niri/releases/tag/v25.01
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After a full day of writing release notes (god how'd it take so long
), niri v25.01 is out with Floating Windows and Working Layer-Shell Desktop Icons and Layer-Shell Screencast Blocking Out and so many more improvements! Yes, you read that right, we finally escaped zerover! I feel that niri is now ready to graduate from v0.1 Read here and download when your distribution package updates: https://github.com/YaLTeR/niri/releases/tag/v25.01
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Looking for testing and feedback for server-side shadows: https://github.com/YaLTeR/niri/pull/990
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ppl from our niri matrix playing around with the new compositor-side shadows! These screenshots are from @r4hulrosh4n and calops (no fedi)
Added shadow support for layer-shell surfaces!
Though unfortunately layer-shell has no way to signal the visual geometry, so this only looks right if the layer surface doesn't have its own margins.
https://github.com/YaLTeR/niri/wiki/Configuration:-Layer-Rules#shadow
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Added shadow support for layer-shell surfaces!
Though unfortunately layer-shell has no way to signal the visual geometry, so this only looks right if the layer surface doesn't have its own margins.
https://github.com/YaLTeR/niri/wiki/Configuration:-Layer-Rules#shadow
I'm adding tabs to niri. Instead of some separate mode, they're just changing how a column is displayed. This means all your hotkeys and everything works exactly the same with tabs. Which was a wonderful UX idea by @elkowar!
I've got a draft PR going with some design and UX questions, please feel free to try it and give feedback: https://github.com/YaLTeR/niri/pull/1085
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I'm adding tabs to niri. Instead of some separate mode, they're just changing how a column is displayed. This means all your hotkeys and everything works exactly the same with tabs. Which was a wonderful UX idea by @elkowar!
I've got a draft PR going with some design and UX questions, please feel free to try it and give feedback: https://github.com/YaLTeR/niri/pull/1085
Why would you even want tabs in niri? Occasionally it's quite useful. For example, when streaming programming, I increase the font size, so I can no longer fit editor + terminal on the screen at once. Scrolling back and forth gets annoying, and tabs feel just right for this.
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Why would you even want tabs in niri? Occasionally it's quite useful. For example, when streaming programming, I increase the font size, so I can no longer fit editor + terminal on the screen at once. Scrolling back and forth gets annoying, and tabs feel just right for this.
