(#) Suspicious 0dp dimension !!! ERROR: Suspicious 0dp dimension This is an error. Id : `Suspicious0dp` Summary : Suspicious 0dp dimension Severity : Error Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : Initial 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/InefficientWeightDetector.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/InefficientWeightDetectorTest.java) Copyright Year : 2011 Using 0dp as the width in a horizontal `LinearLayout` with weights is a useful trick to ensure that only the weights (and not the intrinsic sizes) are used when sizing the children. However, if you use 0dp for the opposite dimension, the view will be invisible. This can happen if you change the orientation of a layout without also flipping the `0dp` dimension in all the children. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text res/layout/wrong0dp.xml:19:Error: Suspicious size: this will make the view invisible, should be used with layout_weight [Suspicious0dp] android:layout_width="0dp" -------------------------- res/layout/wrong0dp.xml:25:Error: Suspicious size: this will make the view invisible, should be used with layout_weight [Suspicious0dp] android:layout_height="0dp" --------------------------- res/layout/wrong0dp.xml:34:Error: Suspicious size: this will make the view invisible, probably intended for layout_height [Suspicious0dp] android:layout_width="0dp" -------------------------- res/layout/wrong0dp.xml:67:Error: Suspicious size: this will make the view invisible, probably intended for layout_width [Suspicious0dp] android:layout_height="0dp" --------------------------- res/layout/wrong0dp.xml:90:Error: Suspicious size: this will make the view invisible, probably intended for layout_width [Suspicious0dp] android:layout_height="0dp" --------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `res/layout/wrong0dp.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <?xml version="1.0" encoding="utf-8"?> <FrameLayout 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" > <!-- Vertical Layout --> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <!-- No weight: Always an error --> <Button android:layout_width="0dp" android:layout_height="wrap_content" android:text="Button" /> <Button android:layout_width="wrap_content" android:layout_height="0dp" android:text="Button" /> <!-- 0dp not along the orientation axis is wrong; here layout_height is okay, layout_width is not --> <Button android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:text="Button" /> <!-- OK --> <Button android:layout_width="wrap_content" android:layout_height="0dp" android:layout_weight="1.0" android:text="Button" /> </LinearLayout> <!-- Horizontal Layout --> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <!-- OK --> <Button android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:text="Button" /> <!-- Not OK --> <Button android:layout_width="wrap_content" android:layout_height="0dp" android:layout_weight="1.0" android:text="Button" /> </LinearLayout> <!-- No orientation specified, so horizontal --> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" > <!-- OK --> <Button android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:text="Button" /> <!-- Not OK --> <Button android:layout_width="wrap_content" android:layout_height="0dp" android:layout_weight="1.0" android:text="Button" /> <!-- Check suppressed --> <Button android:layout_width="0dp" android:layout_height="wrap_content" android:text="Button" tools:ignore="Suspicious0dp" /> </LinearLayout> </FrameLayout> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/InefficientWeightDetectorTest.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, `InefficientWeightDetector.testWrong0Dp`. 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="Suspicious0dp"` 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"?> <LinearLayout xmlns:tools="http://schemas.android.com/tools" tools:ignore="Suspicious0dp" ...> ... </LinearLayout> ``` * 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="Suspicious0dp" 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 'Suspicious0dp' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore Suspicious0dp ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).