Override the state description of volume seekbar.

This overrides the state description of seekbar in order to adjust the
progress percentage. The percentage of seekbar is not matching with the
percentage said by talkback feature when the volume changes. This CL
rounds the percentage to match what is said by talkback.

Bug: 285458191
Test: Enabled talkback and checked percentages of sliders of all sounds
and vibrations volumes. Video attached in bug link.
Test: atest VolumeSeekBarPreferenceTest.

Change-Id: Iedcf3eccb13b7f8ee1a4ca521f0783c55d7a1902

src/com/android/settings/notification/SeekBarVolumizerFactory.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+package com.android.settings.notification;
+
+import android.content.Context;
+import android.net.Uri;
+import android.preference.SeekBarVolumizer;
+
+/**
+ * Testable wrapper around {@link SeekBarVolumizer} constructor.
+ */
+public class SeekBarVolumizerFactory {
+    private final Context mContext;
+
+    public SeekBarVolumizerFactory(Context context) {
+        mContext = context;
+    }
+
+    /**
+     * Creates a new SeekBarVolumizer.
+     *
+     * @param streamType of the audio manager.
+     * @param defaultUri of the volume.
+     * @param sbvc callback of the seekbar volumizer.
+     * @return a SeekBarVolumizer.
+     */
+    public SeekBarVolumizer create(int streamType, Uri defaultUri, SeekBarVolumizer.Callback sbvc) {
+        return new SeekBarVolumizer(mContext, streamType, defaultUri, sbvc);
+    }
+}

src/com/android/settings/notification/VolumeSeekBarPreference.java

@@ -37,6 +37,8 @@ import com.android.internal.jank.InteractionJankMonitor;
 import com.android.settings.R;
 import com.android.settings.widget.SeekBarPreference;
 
+import java.text.NumberFormat;
+import java.util.Locale;
 import java.util.Objects;
 
 /** A slider preference that directly controls an audio stream volume (no dialog) **/
@@ -47,8 +49,9 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
 
     protected SeekBar mSeekBar;
     private int mStream;
+    private SeekBarVolumizer mVolumizer;
     @VisibleForTesting
-    SeekBarVolumizer mVolumizer;
+    SeekBarVolumizerFactory mSeekBarVolumizerFactory;
     private Callback mCallback;
     private Listener mListener;
     private ImageView mIconView;
@@ -62,30 +65,36 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
     private boolean mStopped;
     @VisibleForTesting
     AudioManager mAudioManager;
+    private Locale mLocale;
+    private NumberFormat mNumberFormat;
 
     public VolumeSeekBarPreference(Context context, AttributeSet attrs, int defStyleAttr,
             int defStyleRes) {
         super(context, attrs, defStyleAttr, defStyleRes);
         setLayoutResource(R.layout.preference_volume_slider);
         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+        mSeekBarVolumizerFactory = new SeekBarVolumizerFactory(context);
     }
 
     public VolumeSeekBarPreference(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         setLayoutResource(R.layout.preference_volume_slider);
         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+        mSeekBarVolumizerFactory = new SeekBarVolumizerFactory(context);
     }
 
     public VolumeSeekBarPreference(Context context, AttributeSet attrs) {
         super(context, attrs);
         setLayoutResource(R.layout.preference_volume_slider);
         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+        mSeekBarVolumizerFactory = new SeekBarVolumizerFactory(context);
     }
 
     public VolumeSeekBarPreference(Context context) {
         super(context);
         setLayoutResource(R.layout.preference_volume_slider);
         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+        mSeekBarVolumizerFactory = new SeekBarVolumizerFactory(context);
     }
 
     public void setStream(int stream) {
@@ -143,6 +152,7 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
                 if (mCallback != null) {
                     mCallback.onStreamValueChanged(mStream, progress);
                 }
+                overrideSeekBarStateDescription(formatStateDescription(progress));
             }
             @Override
             public void onMuted(boolean muted, boolean zenMuted) {
@@ -170,7 +180,7 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
         };
         final Uri sampleUri = mStream == AudioManager.STREAM_MUSIC ? getMediaVolumeUri() : null;
         if (mVolumizer == null) {
-            mVolumizer = new SeekBarVolumizer(getContext(), mStream, sampleUri, sbvc);
+            mVolumizer = mSeekBarVolumizerFactory.create(mStream, sampleUri, sbvc);
         }
         mVolumizer.start();
         mVolumizer.setSeekBar(mSeekBar);
@@ -216,6 +226,33 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
                 + "/" + R.raw.media_volume);
     }
 
+    @VisibleForTesting
+    CharSequence formatStateDescription(int progress) {
+        // This code follows the same approach in ProgressBar.java, but it rounds down the percent
+        // to match it with what the talkback feature says after any progress change. (b/285458191)
+        // Cache the locale-appropriate NumberFormat.  Configuration locale is guaranteed
+        // non-null, so the first time this is called we will always get the appropriate
+        // NumberFormat, then never regenerate it unless the locale changes on the fly.
+        Locale curLocale = getContext().getResources().getConfiguration().getLocales().get(0);
+        if (mLocale == null || !mLocale.equals(curLocale)) {
+            mLocale = curLocale;
+            mNumberFormat = NumberFormat.getPercentInstance(mLocale);
+        }
+        return mNumberFormat.format(getPercent(progress));
+    }
+
+    @VisibleForTesting
+    double getPercent(float progress) {
+        final float maxProgress = getMax();
+        final float minProgress = getMin();
+        final float diffProgress = maxProgress - minProgress;
+        if (diffProgress <= 0.0f) {
+            return 0.0f;
+        }
+        final float percent = (progress - minProgress) / diffProgress;
+        return Math.floor(Math.max(0.0f, Math.min(1.0f, percent)) * 100) / 100;
+    }
+
     public void setSuppressionText(String text) {
         if (Objects.equals(text, mSuppressionText)) return;
         mSuppressionText = text;