[A11y] Prevent hide on scroll when Talkback is on

PiperOrigin-RevId: 728848785

Author: imhappi

catalog/java/io/material/catalog/bottomappbar/BottomAppBarMainDemoFragment.java

@@ -18,6 +18,8 @@
 
 import io.material.catalog.R;
 
+import android.os.Build.VERSION;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
@@ -28,6 +30,8 @@
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityManager;
+import android.widget.LinearLayout;
 import androidx.activity.BackEventCompat;
 import androidx.activity.OnBackPressedCallback;
 import androidx.annotation.LayoutRes;
@@ -55,6 +59,8 @@
 /** A fragment that displays the main Bottom App Bar demos for the Catalog app. */
 public class BottomAppBarMainDemoFragment extends DemoFragment {
 
+  private AccessibilityManager am;
+
   private final OnBackPressedCallback bottomDrawerOnBackPressedCallback =
       new OnBackPressedCallback(/* enabled= */ false) {
         @Override
@@ -125,6 +131,7 @@ public View onCreateDemoView(
     toolbar.setNavigationOnClickListener(v -> getActivity().onBackPressed());
 
     coordinatorLayout = view.findViewById(R.id.coordinator_layout);
+    LinearLayout content = view.findViewById(R.id.bottomappbar_content);
     bar = view.findViewById(R.id.bar);
     ((AppCompatActivity) getActivity()).setSupportActionBar(bar);
     barNavView = bar.getChildAt(0);
@@ -140,9 +147,16 @@ public View onCreateDemoView(
           return false;
         });
 
+    if (VERSION.SDK_INT >= VERSION_CODES.M) {
+      am = getContext().getSystemService(AccessibilityManager.class);
+      if (am != null && am.isTouchExplorationEnabled()) {
+        bar.setHideOnScroll(false);
+        bar.post(() -> content.setPadding(0, content.getPaddingTop(), 0, bar.getMeasuredHeight()));
+      }
+    }
+    
     setUpDemoControls(view);
     setUpBottomAppBarShapeAppearance();
-
     return view;
   }
 
@@ -173,7 +187,13 @@ private void setUpDemoControls(@NonNull View view) {
     MaterialSwitch barScrollSwitch = view.findViewById(R.id.bar_scroll_switch);
     barScrollSwitch.setChecked(bar.getHideOnScroll());
     barScrollSwitch.setOnCheckedChangeListener(
-        (buttonView, isChecked) -> bar.setHideOnScroll(isChecked));
+        (buttonView, isChecked) -> {
+          if (am != null && am.isTouchExplorationEnabled()) {
+            bar.setHideOnScroll(false);
+          } else {
+            bar.setHideOnScroll(isChecked);
+          }
+        });
   }
 
   @Override

catalog/java/io/material/catalog/bottomappbar/res/layout/cat_bottomappbar_content.xml

@@ -23,6 +23,7 @@
     app:layout_behavior="@string/appbar_scrolling_view_behavior">
 
     <LinearLayout
+      android:id="@+id/bottomappbar_content"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:paddingTop="16dp"
@@ -65,7 +66,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:padding="10dp"
-        android:text="@string/cat_bottomappbar_lorem_ipsum" />
+        android:text="@string/cat_bottomappbar_lorem_ipsum"/>
     </LinearLayout>
   </androidx.core.widget.NestedScrollView>
 

catalog/java/io/material/catalog/dockedtoolbar/DockedToolbarMainDemoFragment.java

@@ -17,18 +17,23 @@
 
 import io.material.catalog.R;
 
+import android.os.Build.VERSION;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.PopupMenu;
 import androidx.appcompat.widget.Toolbar;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.accessibility.AccessibilityManager;
 import android.widget.Button;
+import android.widget.LinearLayout;
 import androidx.annotation.LayoutRes;
 import androidx.annotation.MenuRes;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import com.google.android.material.dockedtoolbar.DockedToolbarLayout;
 import com.google.android.material.snackbar.Snackbar;
 import io.material.catalog.feature.DemoFragment;
@@ -59,10 +64,21 @@ public View onCreateDemoView(
     setupSnackbarOnClick(addButton);
     setupSnackbarOnClick(tabButton);
 
+    LinearLayout bodyContainer = view.findViewById(R.id.body_container);
+
     Button overflowClick = view.findViewById(R.id.docked_toolbar_button_overflow_button);
 
     overflowClick.setOnClickListener(v -> showMenu(v, R.menu.overflow_menu));
 
+    if (VERSION.SDK_INT >= VERSION_CODES.M) {
+      AccessibilityManager am = getContext().getSystemService(AccessibilityManager.class);
+      if (am != null && am.isTouchExplorationEnabled()) {
+        ((CoordinatorLayout.LayoutParams) dockedToolbar.getLayoutParams()).setBehavior(null);
+        dockedToolbar.post(
+            () -> bodyContainer.setPadding(0, 0, 0, dockedToolbar.getMeasuredHeight()));
+      }
+    }
+
     return view;
   }
 

docs/components/BottomAppBar.md

@@ -71,6 +71,34 @@ in the menu:
 </menu>
 ```
 
+#### Talkback
+
+Bottom app bar can optionally hide on scroll with the `app:hideOnScroll`
+attribute. When this attribute is set to true, scrolling will hide the bottom
+app bar and prevent it from being seen by any screen readers which may be
+confusing for users.
+
+When Talkback is enabled, this behavior should be disabled by setting
+`bottomAppBar.setHideOnScroll(false)`. Additionally, disabling this behavior
+causes any content to be obscured, make sure to add the appropriate bottom
+padding of the height of the bottom app bar to the content. See below for an
+example:
+
+```
+val am = context.getSystemService(AccessibilityManager::class.java)
+if (am != null && am.isTouchExplorationEnabled) {
+    bar.setHideOnScroll(false)
+    bar.post {
+        content.setPadding(
+            content.paddingLeft,
+            content.paddingTop,
+            content.paddingRight,
+            content.paddingBottom + bar.measuredHeight
+        )
+    }
+}
+```
+
 ## Bottom app bar
 
 Bottom app bars provide access to up to four actions, including the

docs/components/FloatingToolbar.md

@@ -112,7 +112,9 @@ Here's what a typical layout would look like:
 A Floating Toolbar is a `FrameLayout` that provides additional styling and functionality.
 You may add children to it as you would to a `FrameLayout`.
 
-Floating toolbars can hide on scroll if inside a `CoordinatorLayout` by setting the following `CoordinatorLayout.Behavior` through the `app:layout_behavior` attribute:
+Floating toolbars can hide on scroll if inside a `CoordinatorLayout` by setting
+the following `CoordinatorLayout.Behavior` through the `app:layout_behavior`
+attribute:
 
 ```xml
   <com.google.android.material.floatingtoolbar.FloatingToolbarLayout
@@ -125,6 +127,8 @@ Floating toolbars can hide on scroll if inside a `CoordinatorLayout` by setting
 </com.google.android.material.floatingtoolbar.FloatingToolbarLayout>
 ```
 
+This behavior will be disabled when Talkback is enabled for a11y reasons. See [how to make floating toolbars accessible](#making-floating-toolbar-accessible).
+
 Note that the default M3 style is the horizontal standard color styling. Vibrant color or vertical styles should be explicitly set on the `FloatingToolbarLayout`. M3 stylings for specific components may also be defined, such as for icon buttons. These are recommended to be set explicitly on the corresponding components inside `FloatingToolbarLayout`. See the full list of [styles](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/floatingtoolbar/res/values/styles.xml).
 
 API and source code:
@@ -135,12 +139,15 @@ API and source code:
 
 ### Making Floating Toolbar accessible
 
-You should set a `contentDescription` on all the actions in the Floating Toolbar so that screen
-readers like TalkBack can properly announce what each action represents.
+You should set a `contentDescription` on all the actions in the Floating Toolbar
+so that screen readers like TalkBack can properly announce what each action
+represents.
 
-You can also control the ordering of the Talkback focus through the `accessibilityTraversalBefore` and `accessibilityTraversalAfter` flags.
+You can also control the ordering of the Talkback focus through the
+`accessibilityTraversalBefore` and `accessibilityTraversalAfter` flags.
 
-For example, if you want the Floating Toolbar to gain Talkback focus first, you can set these accessibility flags like below:
+For example, if you want the Floating Toolbar to gain Talkback focus first, you
+can set these accessibility flags like below:
 
 ```xml
   <!-- sample screen content -->
@@ -161,14 +168,43 @@ For example, if you want the Floating Toolbar to gain Talkback focus first, you
   </androidx.core.widget.NestedScrollView>
 
   <com.google.android.material.floatingtoolbar.FloatingToolbarLayout
-    android:id="@+id/floating_toolbar"
+android:id="@+id/floating_toolbar"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:accessibilityTraversalBefore="@id/content">
     ...
   </com.google.android.material.floatingtoolbar.FloatingToolbarLayout>
 ```
 
+#### Talkback
+
+If optionally using the `CoordinatorLayout.Behavior` `HideViewOnScrollBehavior`
+to hide the floating toolbar on scroll, make sure to disable it when Talkback
+is enabled. Screen readers such as Talkback will not be able to see it if the
+floating toolbar is hidden when scrolled.
+
+If using a Floating toolbar in a layout that obscures any content when
+hide on scroll is disabled, make sure to add the appropriate padding to the
+content. For example, if the floating toolbar is on the bottom and it is
+obscuring the content, bottom padding should be added to the content.
+
+See below for an example:
+
+```
+val am = context.getSystemService(AccessibilityManager::class.java)
+if (am != null && am.isTouchExplorationEnabled) {
+    (bar.layoutParams as? CoordinatorLayout.LayoutParams)?.behavior = null
+    bar.post {
+        content.setPadding(
+            content.paddingLeft,
+            content.paddingTop,
+            content.paddingRight,
+            content.paddingBottom + bar.measuredHeight
+        )
+    }
+}
+```
+
 ### Anatomy and key properties
 
 The following is an anatomy diagram for the floating toolbar:

lib/java/com/google/android/material/behavior/HideBottomViewOnScrollBehavior.java

@@ -44,6 +44,10 @@
  * The {@link Behavior} for a View within a {@link CoordinatorLayout} to hide the view off the
  * bottom of the screen when scrolling down, and show it when scrolling up.
  *
+ * <p> If Talkback is enabled, the hide on scroll behavior should be disabled until Talkback
+ * is disabled. Ensure that the content is not obscured due to disabling this behavior by
+ * adding padding to the content.
+ *
  * @deprecated Use {@link HideViewOnScrollBehavior} instead.
  *     <p>TODO(b/378132394): Migrate usages of this class to {@link HideViewOnScrollBehavior}.
  */

lib/java/com/google/android/material/behavior/HideViewOnScrollBehavior.java

@@ -52,6 +52,10 @@
  *
  * <p>Supports hiding the View off of three screen edges: {@link HideOnScrollView#EDGE_RIGHT},
  * {@link HideOnScrollView#EDGE_BOTTOM} and {@link HideOnScrollView#EDGE_LEFT}.
+ *
+ * <p>If Talkback is enabled, the hide on scroll behavior should be disabled until Talkback is
+ * disabled. Ensure that the content is not obscured due to disabling this behavior by adding
+ * padding to the content.
  */
 public class HideViewOnScrollBehavior<V extends View> extends Behavior<V> {