(#) Monochrome icon is not defined !!! WARNING: Monochrome icon is not defined This is a warning. Id : `MonochromeLauncherIcon` Summary : Monochrome icon is not defined Severity : Warning Category : Usability: Icons Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 7.4.0 (January 2023) Affects : Resource files Editing : This check runs on the fly in the IDE editor 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/MonochromeLauncherIconDetector.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/MonochromeLauncherIconDetectorTest.kt) The system may use the coloring of the user's chosen wallpaper and theme to tint app icons. Providing a `` layer (which will be used for tinting) for every adaptive icon is strongly recommended, otherwise Android 16 QPR 2 and above will simply tint the color version of the icon, which may look unusual. Devices running earlier Android versions will (with no monochrome layer) show the untinted color icon for your app, which will look inconsistent. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text res/drawable-ldpi/ic_icon.xml:2:Warning: The application adaptive icon is missing a monochrome tag [MonochromeLauncherIcon] <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> ^ res/drawable-ldpi/ic_round_icon.xml:2:Warning: The application adaptive roundIcon is missing a monochrome tag [MonochromeLauncherIcon] <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `res/drawable-ldpi/ic_icon.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> <background android:drawable="@drawable/ic_launcher_background" /> <foreground android:drawable="@drawable/ic_launcher_foreground" /> </adaptive-icon> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `res/drawable-ldpi/ic_round_icon.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android"> <background android:drawable="@drawable/ic_launcher_background" /> <foreground android:drawable="@drawable/ic_launcher_foreground" /> </adaptive-icon> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `src/AndroidManifest.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="test.pkg"> <application android:icon="@drawable/ic_icon" android:roundIcon="@drawable/ic_round_icon" android:label="@string/app_name" > </application> </manifest> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/MonochromeLauncherIconDetectorTest.kt) for the unit tests for this check to see additional scenarios. (##) Suppressing You can suppress false positives using one of the following mechanisms: * Adding the suppression attribute `tools:ignore="MonochromeLauncherIcon"` 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"`. ```xml <?xml version="1.0" encoding="UTF-8"?> <adaptive-icon xmlns:tools="http://schemas.android.com/tools" tools:ignore="MonochromeLauncherIcon" ...> ... </adaptive-icon> ``` * 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="MonochromeLauncherIcon" 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 'MonochromeLauncherIcon' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore MonochromeLauncherIcon ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).