Do you any materials to better understand how to r...

# compose

[Olivier Patry]

Do you any materials to better understand how to reach "low level" related to """""view bounds"""""" in the Compose world?
I need 2 distinct things
• where is the "view" on the Window (I'd like to anchor a dialog to a view)
• what is the size of my "view" (≃`View.getMeasuredWidth()` or the value we get from View.onSizeChanged()), what is the DPI of the screen where my "view" is (≃`Context.resources.displayMetrics`)
→ I'm aware there is no such "view" in the 100% Compose world, what I'd like is the have such thing within the layout for the result of a given composable

[Halil Ozercan]

onGloballyPositioned would help you with "position in window". To get the size, there are BoxConstraints and onSizeChanged

[Olivier Patry]

Thanks I'll start to look at this

[Adam Powell]

You can also look at Popup which already can anchor to a specific location in a parent layout

[Olivier Patry]

I tried DropdownMenu (which I needed to something else, but also requiring to be anchored to a toolbar button).
I now better understand such concepts and I'll be able to go further 👍

[Olivier Patry]

Do you know how one can get the screen DPI? I found LocalDensity for font scale and density but nothing for DPI

[Adam Powell]

density is a function of dpi. density = screenDpi / 160.0

[Olivier Patry]

I might miss something then…

LocalDensity.current.density == 1

So, the DPI is 160 with your suggestion.
My computation based on my screen returns 102f and

AwtToolkit.getDefaultToolkit().screenResolution == 102

So, I'm confused 🤔

[Adam Powell]

Are you running on desktop? Sounds like there may be a bug in not propagating density from the host system.

[Adam Powell]

The density system compose uses is inherited from Android where it's a function of screen dpi but rounded into buckets. It's not exact by design, but I would have expected 102 to be rounded into a 120dpi bucket or similar.

[Olivier Patry]

I'm running on Jetbrains Compose on macOS yes, sorry I thought I told it 😬

[Adam Powell]

No worries, I missed it in the thread scrollback

[Adam Powell]

Please file a bug, we should get a standard of compatible buckets worked out for desktop sooner rather than later. A lot of people are probably going to be surprised by the change in existing code behavior for any fix we do

[Olivier Patry]

I'll dot 👍

[Olivier Patry]

In the JetBrains tracker? https://github.com/JetBrains/compose-jb/issues

[Adam Powell]

either there or the google issue tracker

[Olivier Patry]

done https://github.com/JetBrains/compose-jb/issues/531