(#) When using `setHasFixedSize()` in an `RecyclerView`, `wrap_content` cannot be used as a value for `size` in the scrolling direction. !!! ERROR: When using `setHasFixedSize()` in an `RecyclerView`, `wrap_content` cannot be used as a value for `size` in the scrolling direction. This is an error, and is also enforced at build time when supported by the build system. For Android this means it will run during release builds. Id : `InvalidSetHasFixedSize` Summary : When using `setHasFixedSize()` in an `RecyclerView`, `wrap_content` cannot be used as a value for `size` in the scrolling direction. Severity : Fatal Category : Correctness Platform : Android Vendor : Android Open Source Project Identifier : androidx.recyclerview Feedback : https://issuetracker.google.com/issues/new?component=460887 Min : Lint 8.0 and 8.1 Compiled : Lint 8.0 and 8.1 Artifact : [androidx.recyclerview:recyclerview](androidx_recyclerview_recyclerview.md.html) Since : 1.2.0 Affects : Kotlin and Java files and resource files Editing : This check can *not* run live in the IDE editor Implementation : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/recyclerview/recyclerview-lint/src/main/java/androidx/recyclerview/lint/InvalidSetHasFixedSizeDetector.kt) Tests : [Source Code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/recyclerview/recyclerview-lint/src/test/java/androidx/recyclerview/lint/InvalidSetHasFixedSizeTest.kt) Copyright Year : 2020 When a RecyclerView uses `setHasFixedSize(...)` you cannot use `wrap_content` for size in the scrolling direction. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text com/example/Example.kt:10:Error: When using `setHasFixedSize() in an RecyclerView, wrap_content cannot be used as a value for size in the scrolling direction. [InvalidSetHasFixedSize] recyclerView?.setHasFixedSize(true) ----------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `layout/recycler_view.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <?xml version="1.0" encoding="utf-8"?> <androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/my_recycler_view" android:layout_width="match_parent" android:layout_height="wrap_content"/> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `com/example/R.kt`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers package com.example object R { object id { const val my_recycler_view = 0 } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `com/example/Example.kt`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers package com.example import android.view.View import androidx.recyclerview.widget.RecyclerView class Example { fun main() { val view: View = TODO() val recyclerView = view.findViewById(R.id.my_recycler_view) recyclerView?.setHasFixedSize(true) } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:/recyclerview/recyclerview-lint/src/test/java/androidx/recyclerview/lint/InvalidSetHasFixedSizeTest.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, `InvalidSetHasFixedSizeDetector.testInCorrectUsageOfFixedSize`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=460887. (##) Including !!! This is not a built-in check. To include it, add the below dependency to your project. ``` // build.gradle.kts implementation("androidx.recyclerview:recyclerview:1.4.0-rc01") // build.gradle implementation 'androidx.recyclerview:recyclerview:1.4.0-rc01' // build.gradle.kts with version catalogs: implementation(libs.recyclerview) # libs.versions.toml [versions] recyclerview = "1.4.0-rc01" [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: recyclerview = { module = "androidx.recyclerview:recyclerview", version.ref = "recyclerview" } ``` 1.4.0-rc01 is the version this documentation was generated from; there may be newer versions available. [Additional details about androidx.recyclerview:recyclerview](androidx_recyclerview_recyclerview.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("InvalidSetHasFixedSize") fun method() { setHasFixedSize(...) } ``` or ```java // Java @SuppressWarnings("InvalidSetHasFixedSize") void method() { setHasFixedSize(...); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection InvalidSetHasFixedSize 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="InvalidSetHasFixedSize" 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 'InvalidSetHasFixedSize' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore InvalidSetHasFixedSize ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).