(#) Using `dp` instead of `sp` for text sizes !!! WARNING: Using `dp` instead of `sp` for text sizes This is a warning. Id : `SpUsage` Summary : Using `dp` instead of `sp` for text sizes Severity : Warning 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 See : https://developer.android.com/training/multiscreen/screendensities.html 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/PxUsageDetector.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/PxUsageDetectorTest.java) Copyright Year : 2011 When setting text sizes, you should normally use `sp`, or "scale-independent pixels". This is like the `dp` unit, but it is also scaled by the user's font size preference. It is recommend you use this unit when specifying font sizes, so they will be adjusted for both the screen density and the user's preference. There **are** cases where you might need to use `dp`; typically this happens when the text is in a container with a specific dp-size. This will prevent the text from spilling outside the container. Note however that this means that the user's font size settings are not respected, so consider adjusting the layout itself to be more flexible. !!! 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/textsize.xml:11:Warning: Should use "sp" instead of "dp" for text sizes [SpUsage] android:textSize="14dp" /> ----------------------- res/layout/textsize.xml:16:Warning: Should use "sp" instead of "dp" for text sizes [SpUsage] android:textSize="14dip" /> ------------------------ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `res/layout/textsize.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" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="14dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="14dip" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="14sp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="@android/dimen/mysizedp" /> <!-- Small --> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="10sp" /> <ImageView android:layout_width="wrap_content" android:layout_height="6.5sp" /> <!-- No warnings: wrong attribute, size == 0, etc --> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="0sp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:marginTop="5sp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="11sp" /> </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/PxUsageDetectorTest.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, `PxUsageDetector.testSpWarnings`. 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="SpUsage"` 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"?> <resources xmlns:tools="http://schemas.android.com/tools"> ... <style tools:ignore="SpUsage" .../> ... </resources> ``` * 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="SpUsage" 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 'SpUsage' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore SpUsage ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).