(#) Using left/right instead of start/end attributes !!! WARNING: Using left/right instead of start/end attributes This is a warning. Id : `RtlHardcoded` Summary : Using left/right instead of start/end attributes Severity : Warning Category : Internationalization: Bidirectional Text Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : Initial Affects : Kotlin and Java files, manifest files and 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/RtlDetector.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/RtlDetectorTest.java) Copyright Year : 2017 Using `Gravity#LEFT` and `Gravity#RIGHT` can lead to problems when a layout is rendered in locales where text flows from right to left. Use `Gravity#START` and `Gravity#END` instead. Similarly, in XML `gravity` and `layout_gravity` attributes, use `start` rather than `left`. For XML attributes such as paddingLeft and `layout_marginLeft`, use `paddingStart` and `layout_marginStart`. **NOTE**: If your `minSdkVersion` is less than 17, you should add **both** the older left/right attributes **as well as** the new start/end attributes. On older platforms, where RTL is not supported and the start/end attributes are unknown and therefore ignored, you need the older left/right attributes. There is a separate lint check which catches that type of error. (Note: For `Gravity#LEFT` and `Gravity#START`, you can use these constants even when targeting older platforms, because the `start` bitmask is a superset of the `left` bitmask. Therefore, you can use `gravity="start"` rather than `gravity="left|start"`.) !!! Tip This lint check has an associated quickfix available in the IDE. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text res/layout/rtl.xml:14:Warning: Use "start" instead of "left" to ensure correct behavior in right-to-left locales [RtlHardcoded] android:layout_gravity="left" ---- res/layout/rtl.xml:22:Warning: Use "end" instead of "right" to ensure correct behavior in right-to-left locales [RtlHardcoded] android:layout_gravity="right" ----- res/layout/rtl.xml:30:Warning: Use "end" instead of "right" to ensure correct behavior in right-to-left locales [RtlHardcoded] android:gravity="right" ----- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `src/AndroidManifest.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="test.rtl"> <uses-sdk android:minSdkVersion="5" android:targetSdkVersion="17" /> </manifest> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `res/layout/rtl.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:ignore="HardcodedText" > <!-- Warn: Use start instead of left --> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="left" android:text="Button" /> <!-- Warn: Use end instead of right with layout_gravity --> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="right" android:text="Button" /> <!-- Warn: Use end instead of right with gravity --> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="right" android:text="TextView" /> <!-- OK: No warning --> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="start" android:text="Button" /> <!-- OK: No warning --> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="end" android:text="Button" /> <!-- OK: No warning --> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="end" android:text="TextView" /> <!-- OK: Suppressed --> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="right" android:text="Button" tools:ignore="RtlHardcoded" /> </LinearLayout> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/RtlDetectorTest.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, `RtlDetector.testTarget17WithRtl`. 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: * Adding the suppression attribute `tools:ignore="RtlHardcoded"` 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 suppression annotation like this on the enclosing element: ```kt // Kotlin @Suppress("RtlHardcoded") fun method() { problematicStatement() } ``` or ```java // Java @SuppressWarnings("RtlHardcoded") void method() { problematicStatement(); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection RtlHardcoded 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="RtlHardcoded" 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 'RtlHardcoded' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore RtlHardcoded ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).