(#) Scaffold content should use the padding provided as a lambda parameter !!! ERROR: Scaffold content should use the padding provided as a lambda parameter This is an error. Id : `UnusedMaterial3ScaffoldPaddingParameter` Summary : Scaffold content should use the padding provided as a lambda parameter Severity : Error Category : Correctness Platform : Any Vendor : Jetpack Compose Identifier : androidx.compose.material3 Feedback : https://issuetracker.google.com/issues/new?component=612128 Min : Lint 8.0 and 8.1 Compiled : Lint 8.7+ Artifact : [androidx.compose.material3:material3-android](androidx_compose_material3_material3-android.md.html) Since : 1.2.0 Affects : Kotlin and Java files and test sources Editing : This check runs on the fly in the IDE editor Implementation : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/compose/material3/material3-lint/src/main/java/androidx/compose/material3/lint/ScaffoldPaddingDetector.kt) Tests : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/compose/material3/material3-lint/src/test/java/androidx/compose/material3/lint/ScaffoldPaddingDetectorTest.kt) Copyright Year : 2022 The `content` lambda in Scaffold has a padding parameter which will include any inner padding for the content due to app bars. If this parameter is ignored, then content may be obscured by the app bars resulting in visual issues or elements that can't be interacted with. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text src/foo/test.kt:10:Error: Content padding parameter it is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold { /**/ } -------- src/foo/test.kt:11:Error: Content padding parameter it is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold(Modifier) { /**/ } -------- src/foo/test.kt:12:Error: Content padding parameter it is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold(Modifier, topBar = {}, bottomBar = {}) { /**/ } -------- src/foo/test.kt:13:Error: Content padding parameter it is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold(Modifier, topBar = {}, bottomBar = {}, content = { /**/ }) -------- src/foo/test.kt:14:Error: Content padding parameter _ is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold(Modifier, topBar = {}, bottomBar = {}) { _ -> /**/ } - src/foo/test.kt:15:Error: Content padding parameter innerPadding is not used [UnusedMaterial3ScaffoldPaddingParameter] Scaffold(Modifier, topBar = {}, bottomBar = {}) { innerPadding -> /**/ } ------------ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `src/foo/test.kt`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers package foo import androidx.compose.material3.* import androidx.compose.runtime.* import androidx.compose.ui.* @Composable fun Test() { Scaffold { /**/ } Scaffold(Modifier) { /**/ } Scaffold(Modifier, topBar = {}, bottomBar = {}) { /**/ } Scaffold(Modifier, topBar = {}, bottomBar = {}, content = { /**/ }) Scaffold(Modifier, topBar = {}, bottomBar = {}) { _ -> /**/ } Scaffold(Modifier, topBar = {}, bottomBar = {}) { innerPadding -> /**/ } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/compose/material3/material3-lint/src/test/java/androidx/compose/material3/lint/ScaffoldPaddingDetectorTest.kt) for the unit tests for this check to see additional scenarios. The above example was automatically extracted from the first unit test found for this lint check, `ScaffoldPaddingDetector.unreferencedParameters`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=612128. (##) Including !!! This is not a built-in check. To include it, add the below dependency to your project. ``` // build.gradle.kts implementation("androidx.compose.material3:material3-android:1.4.0-alpha13") // build.gradle implementation 'androidx.compose.material3:material3-android:1.4.0-alpha13' // build.gradle.kts with version catalogs: implementation(libs.material3.android) # libs.versions.toml [versions] material3-android = "1.4.0-alpha13" [libraries] # For clarity and text wrapping purposes the following declaration is # shown split up across lines, but in TOML it needs to be on a single # line (see https://github.com/toml-lang/toml/issues/516) so adjust # when pasting into libs.versions.toml: material3-android = { module = "androidx.compose.material3:material3-android", version.ref = "material3-android" } ``` 1.4.0-alpha13 is the version this documentation was generated from; there may be newer versions available. NOTE: These lint checks are **also** made available separate from the main library. You can also use `androidx.compose.material3:material3-lint:1.4.0-alpha13`. [Additional details about androidx.compose.material3:material3-android](androidx_compose_material3_material3-android.md.html). (##) Suppressing You can suppress false positives using one of the following mechanisms: * Using a suppression annotation like this on the enclosing element: ```kt // Kotlin @Suppress("UnusedMaterial3ScaffoldPaddingParameter") fun method() { Scaffold(...) } ``` or ```java // Java @SuppressWarnings("UnusedMaterial3ScaffoldPaddingParameter") void method() { Scaffold(...); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection UnusedMaterial3ScaffoldPaddingParameter problematicStatement() ``` * Using a special `lint.xml` file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this: ```xml <?xml version="1.0" encoding="UTF-8"?> <lint> <issue id="UnusedMaterial3ScaffoldPaddingParameter" severity="ignore" /> </lint> ``` Instead of `ignore` you can also change the severity here, for example from `error` to `warning`. You can find additional documentation on how to filter issues by path, regular expression and so on [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html). * In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like ```gradle lintOptions { disable 'UnusedMaterial3ScaffoldPaddingParameter' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore UnusedMaterial3ScaffoldPaddingParameter ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).