Hmm, why Icon with painter not changing on recompose? I have mechanics to change dark theme. And lin...

# compose

[iamthevoid]

Hmm, why Icon with painter not changing on recompose? I have mechanics to change dark theme. And line below works: icons changing when app theme change (used for example just random vectors)

Icon(
    imageVector = with(Icons.Default) { if (isAppDarkTheme()) DateRange else KeyboardArrowRight },
    contentDescription = null
)

but if i replace it with resources icon not changing

Icon(
    painter = painterResource(id = if (isAppDarkTheme()) R.drawable.ic_checkbox_on_night else R.drawable.ic_checkbox_on_day),
    contentDescription = null
)

[iamthevoid]

Is it the bug or i should set vector to icon with another mechanism?

[Neal Sanche]

Is isAppDarkTheme() returning something that compose will know is changing? A state?

[Neal Sanche]

Maybe simplify this and pass a boolean into your composable function instead?

[iamthevoid]

isAppDarkTheme() returns boolean. Like this

[Neal Sanche]

It's probably going to calculate isSystemInDarkTheme() once here.

[iamthevoid]

i toggle the

darkLightThemeState

from DARK to LIGHT on button click. And if i use ImageVector instead painterResource icon changes

[Neal Sanche]

Your resources are set up with a drawable-night folder with the dark alternates in there?

[iamthevoid]

nope. isAppDarkTheme() is just a boolean value, not dependent on system anyhow. So i just store resources in drawable folder

[iamthevoid]

without any modifiers

[iamthevoid]

[Neal Sanche]

Yeah, I scrolled back up and noticed you're just using the resource names. I'm out of ideas. 🙂

[Zach Klippenstein (he/him) [MOD]]

Are you actually getting different return values from isAppDarkTheme when you’re expecting it to change? If so, sounds like it might be a bug in Icon or painterResource. If that’s the case, figure out if you’re getting a new painter when the value changes, file a bug on the affected component, and you could probably work around it by wrapping your icon with the key composable.

[nitrog42]

can you try :

Icon(
    painter = if (isAppDarkTheme()) painterResource(id = R.drawable.ic_checkbox_on_night) else painterResource(id = R.drawable.ic_checkbox_on_day),
    contentDescription = null
)

?

[iamthevoid]

@nitrog42 tried it with same result: icon not changing. I’ll try to find a time to create an app to reproduce this for bug report if it is

[Zach Klippenstein (he/him) [MOD]]

so starting with your original code, i’d do something like this:

println("resource: $res")
val painter = painterResource(id = res)
println("painter: $painter")
Icon(painter, …)

That will tell you if the painter is being updated correctly. If not, that’s probably a bug. If it is, then Icon probably has a bug. Either way, if that’s the issue, you should be able to workaround it by doing:

key(res) {
  Icon(painter = painterResource(id = res), …)
}

[iamthevoid]

I/System.out: 2131099749
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1
I/System.out: 2131099748
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1
I/System.out: 2131099749
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1
I/System.out: 2131099748
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1
I/System.out: 2131099749
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1
I/System.out: 2131099748
I/System.out: androidx.compose.ui.graphics.vector.VectorPainter@4d87db1

[Chris Sinco [G]]

@Louis Pullen-Freilich [G] may have some insights

[Chris Sinco [G]]

Does the same happen if you use Image instead of Icon?

[iamthevoid]

Image works perfect, thanks! I am new in compose and somehow missed it. But this behavior for Icon... Is it normal?

[Louis Pullen-Freilich [G]]

What is the difference between ic_checkbox_on_night and ic_checkbox_on_day - is it just a different color?

[Louis Pullen-Freilich [G]]

Icon by default applies a tint color, so the resource might be changing correctly, but Icon is just always applying a color on top that makes it look like it is the same

[iamthevoid]

Yes, only the color

[Louis Pullen-Freilich [G]]

If you use Icon, and set tint = Color.Unspecified - then this would probably work

[Louis Pullen-Freilich [G]]

But since you don’t want tint to be applied, which is the main point of Icon, probably easier just to use Image instead

[iamthevoid]

Thanks!