Preview doesn't render BottomAppBar cutout [158551084]

Fixed

Bug

Status Update

No update yet.

Description

cl...@google.com

created issue #1

Jun 9, 2020 11:28AM

Component used: BottomAppBar

Version used: AS 4.1 Canary 8 + Compose snapshot at 6557927

I created a BottomAppBar with a FAB and cutout, and running the emulator it appears correct but in the preview the cutout is not rendered correctly.

Code:

@Composable
fun ReplyScaffold(content: @Composable () -> Unit) {
    Scaffold(
        backgroundColor = AppBackground,
        bottomBar = { ReplyBottomBar() },
        floatingActionButton = { ReplyFAB() },
        floatingActionButtonPosition = Scaffold.FabPosition.Center,
        isFloatingActionButtonDocked = true
    ) {
        content()
    }
}

@Composable
fun ReplyBottomBar() {
    // TODO: cutout doesn't work on preview
    BottomAppBar(cutoutShape = RoundedCornerShape(50)) {
        IconButton(onClick = {}) {
            Icon(Icons.Default.KeyboardArrowUp)
        }
        Spacer(modifier = Modifier.weight(1f))
        IconButton(onClick = {}) {
            Icon(Icons.Default.Search)
        }
    }
}

@Composable
fun ReplyFAB() {
    FloatingActionButton(
        onClick = {}
    ) {
        Icon(Icons.Default.Edit)
    }
}

@Preview
@Composable
fun ScaffoldPreview() {
    AppTheme {
        ReplyScaffold {
            Text("Hello")
        }
    }
}

Screenshot 2020-06-09 at 12.25.42.png

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Comments

lp...@google.com <lp...@google.com> #2Jun 9, 2020 11:30AM

There is a report about it in kotlinlang Slack: https://kotlinlang.slack.com/archives/C01D6HTPATV/p1706005056105739

an...@google.com <an...@google.com> #3Jun 9, 2020 11:36AM

Thanks for the report!

[Deleted User] <[Deleted User]> #4Jun 11, 2020 02:32PM

The release notes documentation has been edited to clarify this change in behavior for line height.

To support non-standard text sizes, we encourage users to follow the Material design system and use a different type scale rather than changing the font size directly. Alternatively, users can overwrite the line height like so: style = LocalTextStyle.current.copy(lineHeight = TextUnit.Unspecified), or create a custom Typography entirely.

[Deleted User] <[Deleted User]> #5Jun 11, 2020 02:35PM

deleted

an...@google.com <an...@google.com> Jul 21, 2020 05:09PM

Reassigned to an...@google.com.

an...@google.com <an...@google.com> #6Aug 4, 2020 04:27PM

Reassigned to ma...@google.com.

In my case, I have multiple font sizes in the same Text (using SpanStyle in AnnotatedString). There are legitimate reasons for this. For example, when combining Chinese and English (phonetic) together (for language-learning purposes).

lp...@google.com <lp...@google.com> Sep 16, 2020 04:26PM

Reassigned to lp...@google.com.

lp...@google.com <lp...@google.com> Sep 29, 2020 07:50PM

Marked as fixed.

ap...@google.com <ap...@google.com> #7Sep 29, 2020 07:50PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit e243833b9705e35184bb8aec84cb9ef49f66eb76
Author: Louis Pullen-Freilich <lpf@google.com>
Date: Mon Sep 14 16:10:51 2020

Refactors Scaffold to use SubcomposeLayout, avoiding frame delays in calculating the content padding / FAB cutout location

Also removes nullable type from Composable lambda parameters, these now just default to emptyContent()

Bug:

b/157633857

Bug:

b/158551084

Test: ScaffoldTest
Test: ScaffoldScreenshotTest
Relnote: "Removes nullable type from Scaffold lambda parameters, you can use emptyContent() to represent no content for a given parameter."
Change-Id: I2b3181de9314b8b0dd48c30e2f663cddc0d62448

M compose/material/material/api/current.txt
M compose/material/material/api/public_plus_experimental_current.txt
M compose/material/material/api/restricted_current.txt
M compose/material/material/integration-tests/material-demos/src/main/java/androidx/compose/material/demos/MaterialDemos.kt
M compose/material/material/src/androidAndroidTest/kotlin/androidx/compose/material/ScaffoldScreenshotTest.kt
M compose/material/material/src/androidAndroidTest/kotlin/androidx/compose/material/ScaffoldTest.kt
M compose/material/material/src/commonMain/kotlin/androidx/compose/material/AppBar.kt
M compose/material/material/src/commonMain/kotlin/androidx/compose/material/Scaffold.kt

https://android-review.googlesource.com/1426753