(#) Layout Inflation without a Parent !!! WARNING: Layout Inflation without a Parent This is a warning. Id : `InflateParams` Summary : Layout Inflation without a Parent Severity : Warning Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : Initial Affects : Kotlin and Java files and resource files Editing : This check runs on the fly in the IDE editor See : https://www.bignerdranch.com/blog/understanding-androids-layoutinflater-inflate/ Implementation : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/LayoutInflationDetector.kt) Tests : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/LayoutInflationDetectorTest.java) Copyright Year : 2014 When inflating a layout, avoid passing in null as the parent view, since otherwise any layout parameters on the root of the inflated layout will be ignored. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text src/test/pkg/LayoutInflationTest.java:13:Warning: Avoid passing null as the view root (needed to resolve layout parameters on the inflated layout's root element) [InflateParams] convertView = mInflater.inflate(R.layout.your_layout, null); ---- src/test/pkg/LayoutInflationTest.java:14:Warning: Avoid passing null as the view root (needed to resolve layout parameters on the inflated layout's root element) [InflateParams] convertView = mInflater.inflate(R.layout.your_layout, null, true); ---- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `src/test/pkg/LayoutInflationTest.java`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers package test.pkg; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.annotation.SuppressLint; import java.util.ArrayList; public abstract class LayoutInflationTest extends BaseAdapter { public View getView(int position, View convertView, ViewGroup parent) { convertView = mInflater.inflate(R.layout.your_layout, null); convertView = mInflater.inflate(R.layout.your_layout, null, true); //convertView = mInflater.inflate(R.layout.your_layout); convertView = mInflater.inflate(R.layout.your_layout, parent); convertView = WeirdInflater.inflate(convertView, null); return convertView; } @SuppressLint("InflateParams") public View getView2(int position, View convertView, ViewGroup parent) { convertView = mInflater.inflate(R.layout.your_layout, null); convertView = mInflater.inflate(R.layout.your_layout, null, true); convertView = mInflater.inflate(R.layout.your_layout, parent); convertView = WeirdInflater.inflate(convertView, null); return convertView; } private LayoutInflater mInflater; private static class R { private static class layout { public static final int your_layout = 1; } } private static class WeirdInflater { public static View inflate(View view, Object params) { return null; } } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `res/layout/your_layout.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/LinearLayout1" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" /> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `res/layout-port/your_layout.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@id/text1" style="?android:attr/listSeparatorTextViewStyle" /> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/LayoutInflationDetectorTest.java) 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, `LayoutInflationDetector.testFull`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=192708. (##) 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("InflateParams") fun method() { inflate(...) } ``` or ```java // Java @SuppressWarnings("InflateParams") void method() { inflate(...); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection InflateParams problematicStatement() ``` * Adding the suppression attribute `tools:ignore="InflateParams"` on the problematic XML element (or one of its enclosing elements). You may also need to add the following namespace declaration on the root element in the XML file if it's not already there: `xmlns:tools="http://schemas.android.com/tools"`. * 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="InflateParams" 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 'InflateParams' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore InflateParams ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).