From e0d4d96cc8523186b759dd3baae39b2d6f9fde10 Mon Sep 17 00:00:00 2001
From: Kevin Hufnagle <khufnagle@google.com>
Date: Sat, 24 Aug 2019 01:04:09 +0000
Subject: docs: Modernized AccessibilityNodeProvider example

Uses a delegate and more realistic method contents. Also added
language switcher for Kotlin-based and Java-based code.

Test: make ds-docs -j32

Bug: 138849874
Change-Id: Id31cf944f4adab2f09cf5004d68434b445da6eeb
---
 .../accessibility/AccessibilityNodeProvider.java   | 130 ++++++++++++++++++---
 1 file changed, 114 insertions(+), 16 deletions(-)

diff --git a/core/java/android/view/accessibility/AccessibilityNodeProvider.java b/core/java/android/view/accessibility/AccessibilityNodeProvider.java
index 4b25378755f1..f4c7b96b8edc 100644
--- a/core/java/android/view/accessibility/AccessibilityNodeProvider.java
+++ b/core/java/android/view/accessibility/AccessibilityNodeProvider.java
@@ -44,28 +44,126 @@ import java.util.List;
  * View itself. Similarly the returned instance is responsible for performing accessibility
  * actions on any virtual view or the root view itself. For example:
  * </p>
- * <pre>
- *     getAccessibilityNodeProvider(
- *         if (mAccessibilityNodeProvider == null) {
- *             mAccessibilityNodeProvider = new AccessibilityNodeProvider() {
- *                 public boolean performAction(int action, int virtualDescendantId) {
- *                     // Implementation.
- *                     return false;
+ * <div>
+ * <div class="ds-selector-tabs"><section><h3 id="kotlin">Kotlin</h3>
+ * <pre class="prettyprint lang-kotlin">
+ * // "view" is the View instance on which this class performs accessibility functions.
+ * class MyCalendarViewAccessibilityDelegate(
+ *       private var view: MyCalendarView) : AccessibilityDelegate() {
+ *     override fun getAccessibilityNodeProvider(host: View): AccessibilityNodeProvider {
+ *         return object : AccessibilityNodeProvider() {
+ *             override fun createAccessibilityNodeInfo(virtualViewId: Int):
+ *                     AccessibilityNodeInfo? {
+ *                 when (virtualViewId) {
+ *                     <var>host-view-id</var> -&gt; {
+ *                         val node = AccessibilityNodeInfo.obtain(view)
+ *                         node.addChild(view, <var>child-view-id</var>)
+ *                         // Set other attributes like screenReaderFocusable
+ *                         // and contentDescription.
+ *                         return node
+ *                     }
+ *                     <var>child-view-id</var> -&gt; {
+ *                         val node = AccessibilityNodeInfo
+ *                                 .obtain(view, virtualViewId)
+ *                         node.setParent(view)
+ *                         node.addAction(ACTION_SCROLL_UP)
+ *                         node.addAction(ACTION_SCROLL_DOWN)
+ *                         // Set other attributes like focusable and visibleToUser.
+ *                         node.setBoundsInScreen(
+ *                                 Rect(<var>coords-of-edges-relative-to-screen</var>))
+ *                         return node
+ *                     }
+ *                     else -&gt; return null
  *                 }
+ *             }
  *
- *                 public List<AccessibilityNodeInfo> findAccessibilityNodeInfosByText(String text,
- *                         int virtualDescendantId) {
- *                     // Implementation.
- *                     return null;
+ *             override fun performAction(
+ *                 virtualViewId: Int,
+ *                 action: Int,
+ *                 arguments: Bundle
+ *             ): Boolean {
+ *                 if (virtualViewId == <var>host-view-id</var>) {
+ *                     return view.performAccessibilityAction(action, arguments)
  *                 }
+ *                 when (action) {
+ *                     ACTION_SCROLL_UP.id -&gt; {
+ *                         // Implement logic in a separate method.
+ *                         navigateToPreviousMonth()
  *
- *                 public AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualDescendantId) {
- *                     // Implementation.
- *                     return null;
+ *                         return true
+ *                     }
+ *                     ACTION_SCROLL_DOWN.id -&gt;
+ *                         // Implement logic in a separate method.
+ *                         navigateToNextMonth()
+ *
+ *                         return true
+ *                     else -&gt; return false
  *                 }
- *             });
- *     return mAccessibilityNodeProvider;
+ *             }
+ *         }
+ *     }
+ * }
  * </pre>
+ * </section><section><h3 id="java">Java</h3>
+ * <pre class="prettyprint lang-java">
+ * final class MyCalendarViewAccessibilityDelegate extends AccessibilityDelegate {
+ *     // The View instance on which this class performs accessibility functions.
+ *     private final MyCalendarView view;
+ *
+ *     MyCalendarViewAccessibilityDelegate(MyCalendarView view) {
+ *         this.view = view;
+ *     }
+ *
+ *     &#64;Override
+ *     public AccessibilityNodeProvider getAccessibilityNodeProvider(View host) {
+ *         return new AccessibilityNodeProvider() {
+ *             &#64;Override
+ *             &#64;Nullable
+ *             public AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualViewId) {
+ *                 if (virtualViewId == <var>host-view-id</var>) {
+ *                     AccessibilityNodeInfo node = AccessibilityNodeInfo.obtain(view);
+ *                     node.addChild(view, <var>child-view-id</var>);
+ *                     // Set other attributes like screenReaderFocusable and contentDescription.
+ *                     return node;
+ *                 } else if (virtualViewId == <var>child-view-id</var>) {
+ *                     AccessibilityNodeInfo node =
+ *                         AccessibilityNodeInfo.obtain(view, virtualViewId);
+ *                     node.setParent(view);
+ *                     node.addAction(ACTION_SCROLL_UP);
+ *                     node.addAction(ACTION_SCROLL_DOWN);
+ *                     // Set other attributes like focusable and visibleToUser.
+ *                     node.setBoundsInScreen(
+ *                         new Rect(<var>coordinates-of-edges-relative-to-screen</var>));
+ *                     return node;
+ *                 } else {
+ *                     return null;
+ *                 }
+ *             }
+ *
+ *             &#64;Override
+ *             public boolean performAction(int virtualViewId, int action, Bundle arguments) {
+ *                 if (virtualViewId == <var>host-view-id</var>) {
+ *                     return view.performAccessibilityAction(action, arguments);
+ *                 }
+ *
+ *                 if (action == ACTION_SCROLL_UP.getId()) {
+ *                     // Implement logic in a separate method.
+ *                     navigateToPreviousMonth();
+ *
+ *                     return true;
+ *                 } else if (action == ACTION_SCROLL_DOWN.getId()) {
+ *                     // Implement logic in a separate method.
+ *                     navigateToNextMonth();
+ *
+ *                     return true;
+ *                 } else {
+ *                     return false;
+ *                 }
+ *             }
+ *         };
+ *     }
+ * }
+ * </pre></section></div></div>
  */
 public abstract class AccessibilityNodeProvider {
 
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