Jetpack compose - change bottom bar cutout color

Question

How to change the color of the cut out for the bottom bar?

I know it takes the color from MaterialTheme.colors.background, but I don't want to change the background color for all components, only for the bottom bar. (The white color in the cut out in the picture.)

I have tried different things, for example setting a new theme just for the bottom bar, but that doesn't work.

val bottomBarColors = MaterialTheme.colors.copy(background = Color.LightGray)
...

bottomBar = {
    MaterialTheme(
        colors = bottomBarColors,
        typography = MaterialTheme.typography,
        shapes = MaterialTheme.shapes
    ) {
        BottomAppBar(
            cutoutShape = fabShape,
            content = {
                MyBottomNavigation(navController, bottomNavigationItems)
            })
    }
}

would you pleas share your codes? – Mostafa Imani Dec 29 '22 at 05:25 — Mostafa Imani, Dec 29 '22 at 05:25

score 3 · Accepted Answer · answered Jul 28 '21 at 19:37

3

In your case you can apply the Modifier.background to the BottomAppBar:

    bottomBar = {
        BottomAppBar(
            modifier = Modifier.background(Color.Red),
            cutoutShape = fabShape) {

            BottomNavigation {
                /* .... */
            }
        }
    }

answered Jul 28 '21 at 19:37

Gabriele Mariotti

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how to make that color to be transparent? – mrzbn Aug 19 '23 at 15:03

score -1 · Answer 2 · answered Jul 28 '21 at 18:26

-1

The solution was easier than I thought. Just add something below the bottom bar:

bottomBar = {
        Box {
            Spacer(modifier = Modifier.matchParentSize().background(color = Color.Blue))
            BottomAppBar(
                cutoutShape = fabShape,
                content = {
                    MyBottomNavigation(navController, bottomNavigationItems)
                })
    }
}

answered Jul 28 '21 at 18:26

Mackan

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Check out Gabriele's answer. That is appropriate. – Richard Onslow Roper Jul 29 '21 at 04:51
More official way of doing it – Richard Onslow Roper Jul 29 '21 at 04:51

Jetpack compose - change bottom bar cutout color

2 Answers2