InfoBar Compose

Additional

Language
Kotlin
Version
v1.0.0 (Aug 19, 2021)
Created
Jul 23, 2021
Updated
Aug 27, 2021
Owner
Radu Salagean (radusalagean)
Contributor
Radu Salagean (radusalagean)
1
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Commercial

InfoBar Compose

An Android Jetpack Compose library for displaying on-screen messages. Unlike the built-in Snackbar from the Compose Material library, the InfoBar can be properly displayed without additional requirements, like Scaffold, SnackbarHost / SnackbarHostState, or manually starting new coroutines to show the on-screen message.

Although the InfoBar composable is inspired by the Snackbar, it does not aim to entirely copy its design or behavior.

Test drive this library, demo app available on Google Play!

Usage

Include the library in your module-level build.gradle file:

repositories {
    mavenCentral()
}

dependencies {
    implementation 'com.radusalagean:info-bar-compose:1.0.0'
}

The simplest configuration of an InfoBar is showcased below:

var message: InfoBarMessage? by remember { mutableStateOf(null) }

// Assign the message on an event callback (button click, download complete, message received, etc.):
// message = InfoBarMessage(text = "Example message")

InfoBar(offeredMessage = message) {
    // ⚠️ Important step: We are nulling out the message in the trailing lambda (onDismiss function)
    message = null
}

A complete working example:

setContent {
    YourAppTheme {
        Box(Modifier.fillMaxSize().padding(16.dp)) {
            var message: InfoBarMessage? by remember { mutableStateOf(null) }
            Button(
                modifier = Modifier.align(Alignment.Center),
                onClick = { message = InfoBarMessage(text = "Example message") }
            ) {
                Text("Show message")
            }
            InfoBar(offeredMessage = message) {
                message = null
            }
        }
    }
}

InfoBar types

The InfoBar composable has 2 signatures:

  • One for a standard version, which already has a layout defined, inspired by the Material design Snackbar. This composable has multiple parameters exposed, allowing for increased customizability of the predefined standard layout.
  • One for a generic version, allowing to pass a composable layout defined in the client app.

Configuration parameters

InfoBar composable:

S G
Available in the Standard InfoBar Available in the Generic InfoBar
Parameter Description Type S G
modifier Modifier to be applied to the InfoBar surface Modifier ✔️ ✔️
offeredMessage InfoBarMessage or BaseInfoBarMessage subclass instance, describing the message that should be displayed InfoBarMessage? ✔️ ✔️
elevation Elevation to be applied to the InfoBar surface Dp ✔️ ✔️
shape Shape to be applied to the InfoBar surface Shape ✔️ ✔️
backgroundColor Background color to be applied to the InfoBar surface Color? ✔️ ✔️
content The content composable to use in the InfoBar surface @Composable (T) -> Unit ✔️
textVerticalPadding Vertical padding for the message text Dp ✔️
textColor Color for the message text Color? ✔️
textFontSize Font size for the message text TextUnit ✔️
textFontStyle Font style for the message text FontStyle? ✔️
textFontWeight Font weight for the message text FontWeight? ✔️
textFontFamily Font family for the message text FontFamily? ✔️
textLetterSpacing Letter spacing for the message text TextUnit ✔️
textDecoration Decoration for the message text TextDecoration? ✔️
textAlign Alignment for the message text TextAlign? ✔️
textLineHeight Line height for the message text TextUnit ✔️
textMaxLines Maximum number of lines for the message text Int ✔️
textStyle Style for the message text TextStyle ✔️
actionColor Color for the action button text Color? ✔️
fadeEffect Use fading effect when the message appears and disappears? (controls the alpha property) Boolean ✔️ ✔️
fadeEffectEasing Easing style of the fade effect InfoBarEasing ✔️ ✔️
scaleEffect Use scaling effect when the message appears and disappears? (controls the scaleX / scaleY properties) Boolean ✔️ ✔️
scaleEffectEasing Easing style of the scale effect InfoBarEasing ✔️ ✔️
slideEffect Which sliding effect to use when the message appears and disappears? (controls the translationY property) InfoBarSlideEffect ✔️ ✔️
slideEffectEasing Easing style of the slide effect InfoBarEasing ✔️ ✔️
enterTransitionMillis Enter animation duration in milliseconds Int ✔️ ✔️
exitTransitionMillis Exit animation duration in milliseconds Int ✔️ ✔️
wrapInsideExpandedBox Maintain the shadow of the InfoBar even when animating the alpha property, by wrapping the InfoBar content inside a Box layout that fills the maximum available space. The alpha property is then animated on the outer Box instead of the InfoBar surface, thus not clipping the shadow when alpha is less than 1f. Note: Any modifier you pass from the outside is applied to the InfoBar surface, not the outer Box layout! Boolean ✔️ ✔️
onDismiss Function which is called when the InfoBar is either timed out or dismissed by the user. Don't forget to always null out the InfoBarMessage / BaseInfoBarMessage subclass instance here! (see usage example from above) () -> Unit ✔️ ✔️

InfoBarMessage class:

Parameter Description Type
text Message as string String?
textStringResId Message as string resource id Int?
textStringResArgs Arguments for textStringResId Array<Any>?
textColor Color for the message text (overrides textColor set in the InfoBar composable) Color?
action Action as string String?
actionStringResId Action as string resource id Int?
actionStringResArgs Arguments for actionStringResId Array<Any>?
actionColor Color for the action button text (overrides actionColor set in the InfoBar composable) Color?
backgroundColor Background color to be applied to the InfoBar surface (overrides backgroundColor set in the InfoBar composable) Color?
displayTimeSeconds The number of seconds to display the message (excluding animation time). Pass -1 if you don't want the message to time out. Int?
onAction Function which is called when the user presses the action button (() -> Unit)?

Using the generic composable

If the standard InfoBar signature does not entirely meet your requirements in terms of layout, you can use the generic InfoBar signature, which allows you to pass a custom layout composable:

  1. Extend the BaseInfoBarMessage abstract class and define your custom message data structure:

    class CustomMessage(
        val textString: String,
        val icon: ImageVector,
        val iconColor: Color,
        val textColor: Color = Color.Unspecified,
        override val backgroundColor: Color? = null,
        override val displayTimeSeconds: Int? = 4,
    ) : BaseInfoBarMessage() {
        override val containsControls: Boolean = false
    }
  2. Declare the content composable that defines your layout:

    val content: @Composable (CustomMessage) -> Unit = { message ->
        Row {
            Icon(
                modifier = Modifier.padding(8.dp).align(Alignment.CenterVertically),
                imageVector = message.icon,
                contentDescription = null,
                tint = message.iconColor
            )
            Text(
                modifier = Modifier.align(Alignment.CenterVertically),
                text = message.textString,
                color = message.textColor
            )
        }
    }
  3. Display the message:

    setContent {
        YourAppTheme {
            Box(Modifier.fillMaxSize().padding(16.dp)) {
                var message: CustomMessage? by remember { mutableStateOf(null) }
                Button(
                    modifier = Modifier.align(Alignment.Center),
                    onClick = { 
                        message = CustomMessage(
                            textString = "This is a custom message",
                            textColor = Color(0xFF414141),
                            icon = Icons.Rounded.Info,
                            iconColor = Color(0xFF27C54D),
                            backgroundColor = Color(0xFFE3F1E6)
                        )
                    }
                ) {
                    Text("Show message")
                }
                InfoBar(offeredMessage = message, content = content) {
                    message = null
                }
            }
        }
    }

Sample App

More complex usage examples are available in the sample app. Download from Google Play.

Photo credits: The sample app contains 2 photos, used under Pexels license. The authors of these photos are Kittichai Chumanee and Karolina Grabowska.

Contributions

Found a bug or have a suggestion? Please open an issue.

Support

If you use this library and enjoy it, please support it by starring it on GitHub. 🌟

Further reading

There is an article available that showcases this library in a bit more detail.

License

Apache License 2.0, see the LICENSE file for details.