edge-to-edge（边到边）

Prerequisites

• Project MUST use Android Jetpack Compose.
• Project MUST target SDK 35 or later. If the SDK is lower than 35, increase the SDK to 35.

Step 1: plan

1. Locate and analyze all Activity classes to detect which have existing edge-to-edge support. For every Activity without edge-to-edge, plan to make each Activity edge-to-edge.
2. In each Activity, Locate and analyze all lists and FAB components to detect which have existing edge-to-edge support. For every component without edge-to-edge support, plan to make each of these components edge-to-edge.
3. In each Activity, scan for TextField, OutlinedTextField, or BasicTextField. If found, then you MUST verify the IME doesn't hide the input field by following the IME section of this skill.

Step 2: add edge-to-edge support

1. Add enableEdgeToEdge before setContent in onCreate in each Activity that does not already call enableEdgeToEdge.
2. Add android:windowSoftInputMode="adjustResize" in the AndroidManifest.xml for all Activities that use a soft keyboard.

Step 3: apply insets

• The app MUST apply system insets, or align content to rulers, so critical

UI remains tappable. Choose only one method to avoid double padding:

1. PREFERRED: When available, use Scaffolds and pass PaddingValues to the content lambda.

  Scaffold { innerPadding ->
      // innerPadding accounts for system bars and any Scaffold components
      LazyColumn(
          modifier = Modifier
              .fillMaxSize()
              .consumeWindowInsets(innerPadding),
          contentPadding = innerPadding
      ) { /* Content */ }
  }

<br />

1. PREFERRED: When available, use the automatic inset handling or padding modifiers in material components.

- Material 3 Components manages safe areas for its own components, including: - TopAppBar - SmallTopAppBar - CenterAlignedTopAppBar - MediumTopAppBar - LargeTopAppBar - BottomAppBar - ModalDrawerSheet - DismissibleDrawerSheet - PermanentDrawerSheet - ModalBottomSheet - NavigationBar - NavigationRail - For Material 2 Components, use the windowInsetsparameter to apply insets manually for BottomAppBar, TopAppBar and BottomNavigation. DO NOT apply padding to the parent container; instead, pass insets directly to the App Bar component. Applying padding to the parent container prevents the App Bar background from drawing into the system bar area. For example, for TopAppBar, choose only one of the following options: 1. PREFERRED: TopAppBar(windowInsets = AppBarDefaults.topAppBarWindowInsets) 2. TopAppBar(windowInsets = WindowInsets.systemBars.exclude(WindowInsets.navigationBars)) 3. TopAppBar(windowInsets = WindowInsets.systemBars.add(WindowInsets.captionBar)) 2. For components outside a Scaffold, use padding modifiers, such as Modifier.safeDrawingPadding() or Modifier.windowInsetsPadding(WindowInsets.safeDrawing).

     Box(
         modifier = Modifier
             .fillMaxSize()
             .safeDrawingPadding()
     ) {
         Button(
             onClick = {},
             modifier = Modifier.align(Alignment.BottomCenter)
         ) {
             Text("Login")
         }
     }

<br />

3. For deeply nested components with excessive padding, use WindowInsetsRulers (e.g. Modifier.fitInside(WindowInsetsRulers.SafeDrawing.current)). See the *IME* section for a code sample.

4. When you need an element (e.g. a custom header or decorative scrim) to equal the dimensions of a system bar, use inset size modifiers (e.g. Modifier.windowInsetsTopHeight(WindowInsets.systemBars)). See the *Lists* section for a code sample.

Adaptive Scaffolds

• NavigationSuiteScaffold manages safe areas for its own components, like the NavigationRail or NavigationBar. However, the adaptive scaffolds (e.g. NavigationSuiteScaffold, ListDetailPaneScaffold) don't propagate PaddingValues to their inner contents. You MUST apply insets to individual screens or components (e.g., list contentPadding or FAB padding) as described in *Step 3* . DO NOT apply safeDrawingPadding or similar modifiers to the NavigationSuiteScaffold parent. This clips and prevents an edge-to-edge screen.

IME

• For each Activity with a soft keyboard, check that android:windowSoftInputMode="adjustResize" is set in the AndroidManifest.xml. DO NOT use SOFT_INPUT_ADJUST_RESIZE because it is deprecated. Then, maintain focus on the input field. Choose one:

- 1. PREFERRED: Add Modifier.fitInside(WindowInsetsRulers.Ime.current) to the content container. This is preferred over imePadding() because it reduces jank and extra padding caused by forgetting to consume insets upstream in the hierarchy. - 2. Add imePadding to the content container. The padding modifier MUST be placed before Modifier.verticalScroll(). Do NOT use Modifier.imePadding() if the parent already accounts for the IME with contentWindowInsets (e.g. contentWindowInsets = WindowInsets.safeDrawing). Doing so will cause double padding.

IMEs with Scaffolds code patterns

RIGHT

RIGHT because contentWindowInsets contains IME insets, which are passed to the content lambda as innerPadding.

// RIGHT
Scaffold(contentWindowInsets = WindowInsets.safeDrawing) { innerPadding ->
    Column(
        modifier = Modifier
            .padding(innerPadding)
            .consumeWindowInsets(innerPadding)
            .verticalScroll(rememberScrollState())
    ) { /* Content */ }
}

<br />

* * *

RIGHT because fitInside fits the content to the IME insets regardless of contentWindowInsets.

// RIGHT
Scaffold() { innerPadding ->
    Column(
        modifier = Modifier
            .padding(innerPadding)
            .consumeWindowInsets(innerPadding)
            .fitInside(WindowInsetsRulers.Ime.current)
            .verticalScroll(rememberScrollState())
    ) { /* Content */ }
}

<br />

* * *

RIGHT because the default contentWindowInsets does not contain IME insets, and imePadding() applies IME insets:

// RIGHT
Scaffold() { innerPadding ->
    Column(
        modifier = Modifier
            .padding(innerPadding)
            .consumeWindowInsets(innerPadding)
            .imePadding()
            .verticalScroll(rememberScrollState())
    ) { /* Content */ }
}

<br />

WRONG

WRONG because there will be excess padding when the IME opens. IME insets are applied twice, once with innerPadding, which contains IME insets from the passed contentWindowInsets values, and once with imePadding:

// WRONG
Scaffold( contentWindowInsets = WindowInsets.safeDrawing ) { innerPadding ->
    Column(
        modifier = Modifier
            .padding(innerPadding)
            .imePadding()
            .verticalScroll(rememberScrollState())
    ) { /* Content */ }
}

<br />

* * *

WRONG because the IME will cover up the content. Scaffold's default contentWindowInsets does NOT contain IME insets.

// WRONG
Scaffold() { innerPadding ->
    Column(
        modifier = Modifier
            .padding(innerPadding)
            .verticalScroll(rememberScrollState())
    ) { /* Content */ }
}

<br />

IMEs without Scaffolds code patterns

RIGHT

The following code samples WILL NOT cause excessive padding.

// RIGHT
Box(
    // Insets consumed
    modifier = Modifier.safeDrawingPadding() // or imePadding(), safeContentPadding(), safeGesturesPadding()
) {
    Column(
        modifier = Modifier.imePadding()
    ) { /* Content */ }
}

<br />

* * *

// RIGHT
Box(
    // Insets consumed
    modifier = Modifier.windowInsetsPadding(WindowInsets.safeDrawing) // or WindowInsets.ime, WindowInsets.safeContent, WindowInsets.safeGestures
) {
    Column(
        modifier = Modifier.imePadding()
    ) { /* Content */ }
}

<br />

* * *

// RIGHT
Box(
    // Insets not consumed, but irrelevant due to fitInside
    modifier = Modifier.padding(WindowInsets.safeDrawing.asPaddingValues()) // or WindowInsets.ime.asPaddingValues(), WindowInsets.safeContent.asPaddingValues(), WindowInsets.safeGestures.asPaddingValues()
) {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .fitInside(WindowInsetsRulers.Ime.current)
    ) { /* Content */ }
}

<br />

WRONG

The following code sample WILL cause excessive padding because IME insets are applied twice:

// WRONG
Box(
    // Insets not consumed
    modifier = Modifier.padding(WindowInsets.safeDrawing.asPaddingValues()) // or WindowInsets.ime.asPaddingValues(), WindowInsets.safeContent.asPaddingValues(), WindowInsets.safeGestures.asPaddingValues()
) {
    Column(
        modifier = Modifier.imePadding()
    ) { /* Content */ }
}

<br />

Navigation Bar Contrast \& System Bar Icons

• If the Activity uses enableEdgeToEdge from WindowCompat, you MUST set

isAppearanceLightNavigationBars and isAppearanceLightStatusBars to the inverse of the device theme for apps that support light and dark theme so the system bar icons are legible. It's recommended to do this in your theme file. DO NOT do this if the Activities use enableEdgeToEdge from ComponentActivity because it handles the icon colors automatically.

  // Only use if calling `enableEdgeToEdge` from `WindowCompat`.
  // Apply to your theme file.
  @Composable
  fun MyTheme(
      darkTheme: Boolean = isSystemInDarkTheme(),
      content: @Composable () -> Unit
  ) {
      val view = LocalView.current
      if (!view.isInEditMode) {
          SideEffect {
              val window = (view.context as? Activity)?.window ?: return@SideEffect
              val controller = WindowCompat.getInsetsController(window, view)

              // Dark icons for Light Mode (!darkTheme), Light icons for Dark Mode
              controller.isAppearanceLightStatusBars = !darkTheme
              controller.isAppearanceLightNavigationBars = !darkTheme
          }
      }

      MaterialTheme(content = content)
  }

<br />

• If any screen uses a Scaffold or a NavigationSuiteScaffold with a bottom

bar (e.g., BottomAppBar, NavigationBar), set window.isNavigationBarContrastEnforced = false in the corresponding Activity for SDK 29+. This prevents the system from adding a translucent background to the navigation bar, verifying your bottom bar colors extend to the bottom of the screen.

Lists

• Apply inset padding (like Scaffold's innerPadding) to the contentPadding parameter of scrollable components (e.g. LazyColumn, LazyRow). DO NOT apply it as a Modifier.padding() to the list's parent container, as this clips the content and prevents it from scrolling behind the system bars.
• Create a translucent composable covering the system bar so that the icons are still legible.

class SystemBarProtectionSnippets : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // enableEdgeToEdge sets window.isNavigationBarContrastEnforced = true
        // which is used to add a translucent scrim to three-button navigation
        enableEdgeToEdge()

        setContent {
            MyTheme {
                // Main content
                MyContent()

                // After drawing main content, draw status bar protection
                StatusBarProtection()
            }
        }
    }
}

@Composable
private fun StatusBarProtection(
    color: Color = MaterialTheme.colorScheme.surfaceContainer,
) {
    Spacer(
        modifier = Modifier
            .fillMaxWidth()
            .height(
                with(LocalDensity.current) {
                    (WindowInsets.statusBars.getTop(this) * 1.2f).toDp()
                }
            )
            .background(
                brush = Brush.verticalGradient(
                    colors = listOf(
                        color.copy(alpha = 1f),
                        color.copy(alpha = 0.8f),
                        Color.Transparent
                    )
                )
            )
    )
}

<br />

Dialogs

If both the following conditions are true, then the Dialog is full screen and must be made edge-to-edge:

1. The DialogProperties contains usePlatformDefaultWidth = false.
2. The Dialog calls Modifier.fillMaxSize().

To make a full screen Dialog edge-to-edge, set decorFitsSystemWindows = false in the DialogProperties.

Dialog(
    onDismissRequest = { /* Handle dismiss */ },
    properties = DialogProperties(
        // 1. Allows the dialog to span the full width of the screen
        usePlatformDefaultWidth = false,
        // 2. Allows the dialog to draw behind status and navigation bars
        decorFitsSystemWindows = false
    )
) { /* Content */ }

<br />

Checklist

• \[ \] Does every Activity call enableEdgeToEdge()?
• \[ \] Is adjustResize set in the AndroidManifest.xml?
• \[ \] Does every TextField, OutlinedTextField, or BasicTextField have a parent with imePadding(), fitInside, Modifier.safeDrawingPadding(), Modifier.safeContentPadding(), Modifier.safeGesturesPadding(), or contentWindowInsets set to WindowInsets.safeDrawing or WindowInsets.ime?
• \[\] Does the first and last list item draw away from the system bars by passing insets to contentPadding?
• \[\] Do FABs draw above the navigation bars by either being inside a Scaffold or by applying Modifier.safeDrawingPadding()?
• \[\] Does the project build? Run ./gradlew build to be sure.