(#) Notification Icon Compatibility !!! WARNING: Notification Icon Compatibility This is a warning. Id : `NotificationIconCompatibility` Summary : Notification Icon Compatibility Severity : Warning Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 3.2.0 (September 2018) Affects : Kotlin and Java files, manifest files and resource files Editing : This check can *not* run live 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/IconDetector.java) 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/IconDetectorTest.java) Notification icons should define a raster image to support Android versions below 5.0 (API 21). Note that the way Lint decides whether an icon is a notification icon is based on the filename prefix `ic_stat_`. This corresponds to the naming convention documented in https://d.android.com/r/studio-ui/designer/material/iconography. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text res/drawable/icon1.xml:Warning: Notification icon icon1 has to have a raster image to support Android versions below 5.0 (API 21) [NotificationIconCompatibility] 0 errors, 1 warnings ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `src/test/pkg/NotificationTest.java`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers package test.pkg; import android.app.Notification; import android.app.Notification.Builder; import android.content.Context; import android.graphics.Bitmap; @SuppressWarnings({ "deprecation", "unused", "javadoc" }) class NotificationTest { public void test1() { Notification notification = new Notification(R.drawable.icon1, "Test1", 0); } public void test2() { int resource = R.drawable.icon2; Notification notification = new Notification(resource, "Test1", 0); } public void test3() { int icon = R.drawable.icon3; CharSequence tickerText = "Hello"; long when = System.currentTimeMillis(); Notification notification = new Notification(icon, tickerText, when); } public void test4(Context context, String sender, String subject, Bitmap bitmap) { Notification notification = new Notification.Builder(context) .setContentTitle("New mail from " + sender.toString()) .setContentText(subject).setSmallIcon(R.drawable.icon4) .setLargeIcon(bitmap).build(); } public void test5(Context context, String sender, String subject, Bitmap bitmap) { Notification notification = new Builder(context) .setContentTitle("New mail from " + sender.toString()) .setContentText(subject).setSmallIcon(R.drawable.icon5) .setLargeIcon(bitmap).build(); } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `res/drawable/icon1.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <vector/> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/IconDetectorTest.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, `IconDetector.testNotificationIconCompatibility`. 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("NotificationIconCompatibility") fun method() { problematicStatement() } ``` or ```java // Java @SuppressWarnings("NotificationIconCompatibility") void method() { problematicStatement(); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection NotificationIconCompatibility problematicStatement() ``` * Adding the suppression attribute `tools:ignore="NotificationIconCompatibility"` 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"?> <manifest xmlns:tools="http://schemas.android.com/tools"> ... <application tools:ignore="NotificationIconCompatibility" .../> ... </manifest> ``` * 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="NotificationIconCompatibility" 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 'NotificationIconCompatibility' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore NotificationIconCompatibility ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).