Left & right buttons for display size & text preview

Test: manually open page and verify buttons work. Make sure to check the buttons during setup wizard.
Bug: 386906497
Flag: EXEMPT xml-dependent change
Change-Id: I488d74591d698ad918fd864cf39b2f3133abd463

res/drawable/keyboard_arrow_left.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2025 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="960" android:viewportHeight="960" android:tint="?attr/colorControlNormal" android:autoMirrored="true">
+    <path android:fillColor="@color/settingslib_materialColorPrimary" android:pathData="M560,720L320,480L560,240L616,296L432,480L616,664L560,720Z"/>
+</vector>

res/drawable/keyboard_arrow_right.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2025 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="960" android:viewportHeight="960" android:tint="?attr/colorControlNormal" android:autoMirrored="true">
+    <path android:fillColor="@color/settingslib_materialColorPrimary" android:pathData="M504,480L320,296L376,240L616,480L376,720L320,664L504,480Z" />
+</vector>

res/layout/accessibility_text_reading_preview.xml

@@ -38,20 +38,47 @@
             android:text="@string/screen_zoom_preview_title"
             style="@style/AccessibilityTextReadingPreviewTitle" />
 
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
             <com.android.settings.accessibility.TextReadingPreviewPager
                 android:id="@+id/preview_pager"
-            android:layout_width="match_parent"
+                android:layout_width="wrap_content"
                 android:layout_height="217dp"
                 android:contentDescription="@string/preview_pager_content_description"
                 android:nestedScrollingEnabled="true" />
-
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="horizontal"
+                android:layout_gravity="center_horizontal"
+                android:gravity="center_horizontal">
+                <ImageButton
+                    android:id="@+id/preview_left_button"
+                    android:src="@drawable/keyboard_arrow_left"
+                    android:layout_width="48dp"
+                    android:layout_height="48dp"
+                    android:layout_gravity="center_vertical"
+                    android:contentDescription="@string/preview_pager_previous_button"
+                    style="?android:attr/borderlessButtonStyle" />
                 <com.android.settings.widget.DotsPageIndicator
                     android:id="@+id/page_indicator"
                     style="@style/PreviewPagerPageIndicator"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
-            android:layout_gravity="center_horizontal"
+                    android:layout_gravity="center_vertical"
                     android:padding="6dp"
                     android:visibility="gone" />
+                <ImageButton
+                    android:id="@+id/preview_right_button"
+                    android:src="@drawable/keyboard_arrow_right"
+                    android:layout_width="48dp"
+                    android:layout_height="48dp"
+                    android:layout_gravity="center_vertical"
+                    android:contentDescription="@string/preview_pager_next_button"
+                    style="?android:attr/borderlessButtonStyle" />
+            </LinearLayout>
+        </LinearLayout>
     </LinearLayout>
 </FrameLayout>

res/values/strings.xml

@@ -80,6 +80,10 @@
     <string name="preview_pager_content_description">Preview</string>
     <!-- Content description for qrcode image. [CHAR LIMIT=none]-->
     <string name="qr_code_content_description">QR code</string>
+    <!-- Previous button for preview pager. [CHAR LIMIT=NONE] -->
+    <string name="preview_pager_previous_button">Previous preview</string>
+    <!-- Next button for preview pager. [CHAR LIMIT=NONE] -->
+    <string name="preview_pager_next_button">Next preview</string>
 
     <!-- Description for the button that makes interface elements smaller. [CHAR_LIMIT=NONE] -->
     <string name="font_size_make_smaller_desc">Make smaller</string>

src/com/android/settings/accessibility/TextReadingPreviewPreference.java

@@ -22,6 +22,7 @@ import android.os.Parcelable;
 import android.util.AttributeSet;
 import android.view.View;
 import android.widget.FrameLayout;
+import android.widget.ImageButton;
 import android.widget.LinearLayout;
 
 import androidx.preference.Preference;
@@ -99,6 +100,28 @@ public class TextReadingPreviewPreference extends Preference {
                 (DotsPageIndicator) holder.findViewById(R.id.page_indicator);
         updateAdapterIfNeeded(viewPager, pageIndicator, mPreviewAdapter);
         updatePagerAndIndicator(viewPager, pageIndicator);
+        viewPager.setClipToOutline(true);
+
+        int layoutDirection =
+                getContext().getResources().getConfiguration().getLayoutDirection();
+        int previousId = (layoutDirection == View.LAYOUT_DIRECTION_RTL)
+                ? R.id.preview_right_button : R.id.preview_left_button;
+        int nextId = (layoutDirection == View.LAYOUT_DIRECTION_RTL)
+                ? R.id.preview_left_button : R.id.preview_right_button;
+        final ImageButton previousButton = previewLayout.findViewById(previousId);
+        final ImageButton nextButton = previewLayout.findViewById(nextId);
+
+        // These call ViewPager#setCurrentItem directly
+        // because that doesn't force a refresh through notifyChanged().
+        // We found this avoids a crash in SUW (See b/386906497).
+        previousButton.setOnClickListener((view) ->
+                viewPager.setCurrentItem(getCurrentItem() - 1));
+        previousButton.setContentDescription(getContext().getString(
+                R.string.preview_pager_previous_button));
+        nextButton.setOnClickListener((view) ->
+                viewPager.setCurrentItem(getCurrentItem() + 1));
+        previousButton.setContentDescription(getContext().getString(
+                R.string.preview_pager_next_button));
     }
 
     @Override