AccessibilityScrollActions.md.html

<meta charset="utf-8">
(#) Incomplete Scroll Action support

!!! WARNING: Incomplete Scroll Action support
   This is a warning.

Id
:   `AccessibilityScrollActions`
Summary
:   Incomplete Scroll Action support
Severity
:   Warning
Category
:   Accessibility
Platform
:   Android
Vendor
:   Android Open Source Project
Feedback
:   https://issuetracker.google.com/issues/new?component=192708
Since
:   8.6.0 (August 2024)
Affects
:   Kotlin and Java 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/AccessibilityViewScrollActionsDetector.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/AccessibilityViewScrollActionsDetectorTest.kt)

Views that behave like `ScrollView` and support
`ACTION_SCROLL_{FORWARD,BACKWARD}` should also support
`ACTION_SCROLL_{LEFT,RIGHT}` and/or `ACTION_SCROLL_{UP,DOWN}`.

(##) Example

Here is an example of lint warnings produced by this check:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text
src/com/my/app/MyView.kt:11:Warning: Views that behave like ScrollView
and support ACTION_SCROLL_{FORWARD,BACKWARD} should also support
ACTION_SCROLL_{LEFT,RIGHT} and/or ACTION_SCROLL_{UP,DOWN}
[AccessibilityScrollActions]
  override fun onInitializeAccessibilityNodeInfo(info: AccessibilityNodeInfo) {
  ^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Here is the source file referenced above:

`src/com/my/app/MyView.kt`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers
package com.my.app

import android.content.Context
import android.view.View
import android.view.accessibility.AccessibilityEvent
import android.view.accessibility.AccessibilityNodeInfo
import android.widget.ScrollView

class MyView(context: Context) : View(context) {

  override fun onInitializeAccessibilityNodeInfo(info: AccessibilityNodeInfo) {
    super.onInitializeAccessibilityNodeInfo(info)
    info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_FORWARD)
    info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_BACKWARD)
  }

  override fun getAccessibilityClassName(): CharSequence {
    return ScrollView::class.java.name
  }
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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/AccessibilityViewScrollActionsDetectorTest.kt)
for the unit tests for this check to see additional scenarios.

(##) 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("AccessibilityScrollActions")
  fun method() {
     problematicStatement()
  }
  ```

  or

  ```java
  // Java
  @SuppressWarnings("AccessibilityScrollActions")
  void method() {
     problematicStatement();
  }
  ```

* Using a suppression comment like this on the line above:

  ```kt
  //noinspection AccessibilityScrollActions
  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
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;lint&gt;
      &lt;issue id="AccessibilityScrollActions" severity="ignore" /&gt;
  &lt;/lint&gt;
  ```
  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 'AccessibilityScrollActions'
  }
  ```
  In Android projects this should be nested inside an `android { }`
  block.

* For manual invocations of `lint`, using the `--ignore` flag:
  ```
  $ lint --ignore AccessibilityScrollActions ...`
  ```

* Last, but not least, using baselines, as discussed
  [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).

<!-- Markdeep: --><style class="fallback">body{visibility:hidden;white-space:pre;font-family:monospace}</style><script src="markdeep.min.js" charset="utf-8"></script><script src="https://morgan3d.github.io/markdeep/latest/markdeep.min.js" charset="utf-8"></script><script>window.alreadyProcessedMarkdeep||(document.body.style.visibility="visible")</script>