Allow text links to be navigatable via keyboard by default v2 (#49381)

Summary:
Pull Request resolved: #49381

A much improved version of my previous attempt in D68306316 (#48773).

Instead of LinkMovementMethod which makes TextViews scrollable if they overflow, this implementation uses `ExploreByTouchHelper`'s `onVirtualViewKeyboardFocusChanged` and `onPerformActionForVirtualView` to handle focus changes and clicks on virtual views (aka spans in our case). This impl will correctly ellipsize text and allow tab to nav through the links.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D69551206

fbshipit-source-id: 6a88ccd507dc5534c1f494e3303c6bfc2bae5e9f

Author: joevilches

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -6856,13 +6856,15 @@ public final class com/facebook/react/views/text/ReactTextUpdate$Companion {
 public class com/facebook/react/views/text/ReactTextView : androidx/appcompat/widget/AppCompatTextView, com/facebook/react/uimanager/ReactCompoundView {
 	public fun <init> (Landroid/content/Context;)V
 	protected fun dispatchHoverEvent (Landroid/view/MotionEvent;)Z
+	public fun dispatchKeyEvent (Landroid/view/KeyEvent;)Z
 	public fun getSpanned ()Landroid/text/Spannable;
 	public fun hasOverlappingRendering ()Z
 	public fun invalidateDrawable (Landroid/graphics/drawable/Drawable;)V
 	public fun onAttachedToWindow ()V
 	public fun onDetachedFromWindow ()V
 	protected fun onDraw (Landroid/graphics/Canvas;)V
 	public fun onFinishTemporaryDetach ()V
+	public final fun onFocusChanged (ZILandroid/graphics/Rect;)V
 	protected fun onLayout (ZIIII)V
 	protected fun onMeasure (II)V
 	public fun onStartTemporaryDetach ()V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextView.java

@@ -9,6 +9,7 @@
 
 import android.content.Context;
 import android.graphics.Canvas;
+import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.text.Layout;
@@ -19,6 +20,7 @@
 import android.text.util.Linkify;
 import android.util.TypedValue;
 import android.view.Gravity;
+import android.view.KeyEvent;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
@@ -756,6 +758,30 @@ protected boolean dispatchHoverEvent(MotionEvent event) {
     return super.dispatchHoverEvent(event);
   }
 
+  @Override
+  public final void onFocusChanged(
+      boolean gainFocus, int direction, @Nullable Rect previouslyFocusedRect) {
+    super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
+    AccessibilityDelegateCompat accessibilityDelegateCompat =
+        ViewCompat.getAccessibilityDelegate(this);
+    if (accessibilityDelegateCompat != null
+        && accessibilityDelegateCompat instanceof ReactTextViewAccessibilityDelegate) {
+      ((ReactTextViewAccessibilityDelegate) accessibilityDelegateCompat)
+          .onFocusChanged(gainFocus, direction, previouslyFocusedRect);
+    }
+  }
+
+  @Override
+  public boolean dispatchKeyEvent(KeyEvent event) {
+    AccessibilityDelegateCompat accessibilityDelegateCompat =
+        ViewCompat.getAccessibilityDelegate(this);
+    return (accessibilityDelegateCompat != null
+            && accessibilityDelegateCompat instanceof ReactTextViewAccessibilityDelegate
+            && ((ReactTextViewAccessibilityDelegate) accessibilityDelegateCompat)
+                .dispatchKeyEvent(event))
+        || super.dispatchKeyEvent(event);
+  }
+
   private void applyTextAttributes() {
     // Workaround for an issue where text can be cut off with an ellipsis when
     // using certain font sizes and padding. Sets the provided text size and

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextViewAccessibilityDelegate.kt

@@ -9,6 +9,7 @@ package com.facebook.react.views.text
 
 import android.graphics.Paint
 import android.graphics.Rect
+import android.os.Bundle
 import android.text.Spannable
 import android.text.Spanned
 import android.text.style.AbsoluteSizeSpan
@@ -20,6 +21,7 @@ import androidx.core.view.accessibility.AccessibilityNodeInfoCompat
 import androidx.core.view.accessibility.AccessibilityNodeProviderCompat
 import com.facebook.react.R
 import com.facebook.react.uimanager.ReactAccessibilityDelegate
+import com.facebook.react.views.text.internal.span.ReactClickableSpan
 import kotlin.math.ceil
 
 internal class ReactTextViewAccessibilityDelegate : ReactAccessibilityDelegate {
@@ -68,6 +70,49 @@ internal class ReactTextViewAccessibilityDelegate : ReactAccessibilityDelegate {
     }
   }
 
+  override fun onVirtualViewKeyboardFocusChanged(virtualViewId: Int, hasFocus: Boolean) {
+    if (accessibilityLinks == null) {
+      return
+    }
+
+    val link = accessibilityLinks?.getLinkById(virtualViewId) ?: return
+
+    val span = getFirstSpan(link.start, link.end, ClickableSpan::class.java)
+    if (span == null || span !is ReactClickableSpan || hostView !is ReactTextView) {
+      return
+    }
+
+    // TODO: When we refactor ReactTextView, implement this using
+    // https://developer.android.com/reference/android/text/Layout
+    span.isKeyboardFocused = hasFocus
+    span.focusBgColor = (hostView as TextView).highlightColor
+    hostView.invalidate()
+  }
+
+  override fun onPerformActionForVirtualView(
+      virtualViewId: Int,
+      action: Int,
+      arguments: Bundle?
+  ): Boolean {
+    if (accessibilityLinks == null) {
+      return false
+    }
+
+    val link = accessibilityLinks?.getLinkById(virtualViewId) ?: return false
+
+    val span = getFirstSpan(link.start, link.end, ClickableSpan::class.java)
+    if (span == null || span !is ReactClickableSpan) {
+      return false
+    }
+
+    if (action == AccessibilityNodeInfoCompat.ACTION_CLICK) {
+      span.onClick(hostView)
+      return true
+    }
+
+    return false
+  }
+
   override fun getVisibleVirtualViews(virtualViewIds: MutableList<Int?>) {
     val accessibilityLinks = accessibilityLinks ?: return
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/text/internal/span/ReactClickableSpan.kt

@@ -7,6 +7,7 @@
 
 package com.facebook.react.views.text.internal.span
 
+import android.graphics.Color
 import android.text.TextPaint
 import android.text.style.ClickableSpan
 import android.view.View
@@ -35,6 +36,9 @@ import com.facebook.react.views.view.ViewGroupClickEvent
  * menu).
  */
 public class ReactClickableSpan(public val reactTag: Int) : ClickableSpan(), ReactSpan {
+  public var isKeyboardFocused: Boolean = false
+  public var focusBgColor: Int = Color.TRANSPARENT
+
   public override fun onClick(view: View) {
     val context = view.context as ReactContext
     val eventDispatcher = UIManagerHelper.getEventDispatcherForReactTag(context, reactTag)
@@ -43,7 +47,10 @@ public class ReactClickableSpan(public val reactTag: Int) : ClickableSpan(), Rea
   }
 
   public override fun updateDrawState(ds: TextPaint) {
-    // no-op to make sure we don't change the link color or add an underline by default, as the
+    // no super call so we don't change the link color or add an underline by default, as the
     // superclass does.
+    if (isKeyboardFocused) {
+      ds.bgColor = focusBgColor
+    }
   }
 }