Support accessibility for battery chart (3)

Support accessibilty read out full timestamp labels instead of the short one, e.g "Sunday" instead of "Sun".

Bug: 242989585
Test: manual
Change-Id: Ica2176ef3f07849d278327b9301f8c318782c2d5
diff --git a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceController.java b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceController.java
index 6d2c1a1..64d7b1c 100644
--- a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceController.java
+++ b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceController.java
@@ -108,10 +108,6 @@
     private View mBatteryChartViewGroup;
     private PreferenceScreen mPreferenceScreen;
     private FooterPreference mFooterPreference;
-    // Daily view model only saves abbreviated day of week texts (e.g. MON). This field saves the
-    // full day of week texts (e.g. Monday), which is used in category title and battery detail
-    // page.
-    private List<String> mDailyTimestampFullTexts;
     private BatteryChartViewModel mDailyViewModel;
     private List<BatteryChartViewModel> mHourlyViewModels;
 
@@ -122,6 +118,13 @@
     private final MetricsFeatureProvider mMetricsFeatureProvider;
     private final Handler mHandler = new Handler(Looper.getMainLooper());
 
+    @VisibleForTesting
+    final DailyChartLabelTextGenerator mDailyChartLabelTextGenerator =
+            new DailyChartLabelTextGenerator();
+    @VisibleForTesting
+    final HourlyChartLabelTextGenerator mHourlyChartLabelTextGenerator =
+            new HourlyChartLabelTextGenerator();
+
     // Preference cache to avoid create new instance each time.
     @VisibleForTesting
     final Map<String, Preference> mPreferenceCache = new HashMap<>();
@@ -279,29 +282,24 @@
                 getTotalHours(batteryLevelData));
 
         if (batteryLevelData == null) {
-            mDailyTimestampFullTexts = null;
             mDailyViewModel = null;
             mHourlyViewModels = null;
             refreshUi();
             return;
         }
-        mDailyTimestampFullTexts = generateTimestampDayOfWeekTexts(
-                mContext, batteryLevelData.getDailyBatteryLevels().getTimestamps(),
-                /* isAbbreviation= */ false);
         mDailyViewModel = new BatteryChartViewModel(
                 batteryLevelData.getDailyBatteryLevels().getLevels(),
-                generateTimestampDayOfWeekTexts(
-                        mContext, batteryLevelData.getDailyBatteryLevels().getTimestamps(),
-                        /* isAbbreviation= */ true),
-                BatteryChartViewModel.AxisLabelPosition.CENTER_OF_TRAPEZOIDS);
+                batteryLevelData.getDailyBatteryLevels().getTimestamps(),
+                BatteryChartViewModel.AxisLabelPosition.CENTER_OF_TRAPEZOIDS,
+                mDailyChartLabelTextGenerator);
         mHourlyViewModels = new ArrayList<>();
         for (BatteryLevelData.PeriodBatteryLevelData hourlyBatteryLevelsPerDay :
                 batteryLevelData.getHourlyBatteryLevelsPerDay()) {
             mHourlyViewModels.add(new BatteryChartViewModel(
                     hourlyBatteryLevelsPerDay.getLevels(),
-                    generateTimestampHourTexts(
-                            mContext, hourlyBatteryLevelsPerDay.getTimestamps()),
-                    BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS));
+                    hourlyBatteryLevelsPerDay.getTimestamps(),
+                    BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS,
+                    mHourlyChartLabelTextGenerator));
         }
         refreshUi();
     }
@@ -543,8 +541,7 @@
 
     @VisibleForTesting
     String getSlotInformation() {
-        if (mDailyTimestampFullTexts == null || mDailyViewModel == null
-                || mHourlyViewModels == null) {
+        if (mDailyViewModel == null || mHourlyViewModels == null) {
             // No data
             return null;
         }
@@ -552,17 +549,13 @@
             return null;
         }
 
-        final String selectedDayText = mDailyTimestampFullTexts.get(mDailyChartIndex);
+        final String selectedDayText = mDailyViewModel.getFullText(mDailyChartIndex);
         if (mHourlyChartIndex == BatteryChartViewModel.SELECTED_INDEX_ALL) {
             return selectedDayText;
         }
 
-        final String fromHourText = mHourlyViewModels.get(mDailyChartIndex).texts().get(
+        final String selectedHourText = mHourlyViewModels.get(mDailyChartIndex).getFullText(
                 mHourlyChartIndex);
-        final String toHourText = mHourlyViewModels.get(mDailyChartIndex).texts().get(
-                mHourlyChartIndex + 1);
-        final String selectedHourText =
-                String.format("%s%s%s", fromHourText, mIs24HourFormat ? "-" : " - ", toHourText);
         if (isBatteryLevelDataInOneDay()) {
             return selectedHourText;
         }
@@ -663,25 +656,6 @@
                 / DateUtils.HOUR_IN_MILLIS);
     }
 
-    private static List<String> generateTimestampDayOfWeekTexts(@NonNull final Context context,
-            @NonNull final List<Long> timestamps, final boolean isAbbreviation) {
-        final ArrayList<String> texts = new ArrayList<>();
-        for (Long timestamp : timestamps) {
-            texts.add(ConvertUtils.utcToLocalTimeDayOfWeek(context, timestamp, isAbbreviation));
-        }
-        return texts;
-    }
-
-    private static List<String> generateTimestampHourTexts(
-            @NonNull final Context context, @NonNull final List<Long> timestamps) {
-        final boolean is24HourFormat = DateFormat.is24HourFormat(context);
-        final ArrayList<String> texts = new ArrayList<>();
-        for (Long timestamp : timestamps) {
-            texts.add(ConvertUtils.utcToLocalTimeHour(context, timestamp, is24HourFormat));
-        }
-        return texts;
-    }
-
     /** Used for {@link AppBatteryPreferenceController}. */
     public static List<BatteryDiffEntry> getAppBatteryUsageData(Context context) {
         final long start = System.currentTimeMillis();
@@ -727,4 +701,36 @@
         }
         return null;
     }
+
+    private final class DailyChartLabelTextGenerator implements
+            BatteryChartViewModel.LabelTextGenerator {
+        @Override
+        public String generateText(List<Long> timestamps, int index) {
+            return ConvertUtils.utcToLocalTimeDayOfWeek(mContext,
+                    timestamps.get(index), /* isAbbreviation= */ true);
+        }
+
+        @Override
+        public String generateFullText(List<Long> timestamps, int index) {
+            return ConvertUtils.utcToLocalTimeDayOfWeek(mContext,
+                    timestamps.get(index), /* isAbbreviation= */ false);
+        }
+    }
+
+    private final class HourlyChartLabelTextGenerator implements
+            BatteryChartViewModel.LabelTextGenerator {
+        @Override
+        public String generateText(List<Long> timestamps, int index) {
+            return ConvertUtils.utcToLocalTimeHour(mContext, timestamps.get(index),
+                    mIs24HourFormat);
+        }
+
+        @Override
+        public String generateFullText(List<Long> timestamps, int index) {
+            return index == timestamps.size() - 1
+                    ? generateText(timestamps, index)
+                    : String.format("%s%s%s", generateText(timestamps, index),
+                            mIs24HourFormat ? "-" : " - ", generateText(timestamps, index + 1));
+        }
+    }
 }
diff --git a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartView.java b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartView.java
index 40e3167..f84ced7 100644
--- a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartView.java
+++ b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartView.java
@@ -158,7 +158,7 @@
             if (mViewModel != null) {
                 int maxTop = 0;
                 for (int index = 0; index < mViewModel.size(); index++) {
-                    final String text = mViewModel.texts().get(index);
+                    final String text = mViewModel.getText(index);
                     mTextPaint.getTextBounds(text, 0, text.length(), mAxisLabelsBounds.get(index));
                     maxTop = Math.max(maxTop, -mAxisLabelsBounds.get(index).top);
                 }
@@ -490,7 +490,7 @@
             Canvas canvas, final int index, final Rect displayArea, final float baselineY) {
         mTextPaint.setTextAlign(Paint.Align.CENTER);
         canvas.drawText(
-                mViewModel.texts().get(index),
+                mViewModel.getText(index),
                 displayArea.centerX(),
                 baselineY,
                 mTextPaint);
@@ -524,9 +524,9 @@
             mTrapezoidPaint.setColor(isHoverState ? mTrapezoidHoverColor : trapezoidColor);
 
             final float leftTop = round(
-                    trapezoidBottom - requireNonNull(mViewModel.levels().get(index)) * unitHeight);
+                    trapezoidBottom - requireNonNull(mViewModel.getLevel(index)) * unitHeight);
             final float rightTop = round(trapezoidBottom
-                    - requireNonNull(mViewModel.levels().get(index + 1)) * unitHeight);
+                    - requireNonNull(mViewModel.getLevel(index + 1)) * unitHeight);
             trapezoidPath.reset();
             trapezoidPath.moveTo(mTrapezoidSlots[index].mLeft, trapezoidBottom);
             trapezoidPath.lineTo(mTrapezoidSlots[index].mLeft, leftTop);
@@ -564,8 +564,8 @@
 
     private static boolean isTrapezoidValid(
             @NonNull BatteryChartViewModel viewModel, int trapezoidIndex) {
-        return viewModel.levels().get(trapezoidIndex) != null
-                && viewModel.levels().get(trapezoidIndex + 1) != null;
+        return viewModel.getLevel(trapezoidIndex) != null
+                && viewModel.getLevel(trapezoidIndex + 1) != null;
     }
 
     private static boolean isTrapezoidIndexValid(
@@ -617,8 +617,8 @@
                     new AccessibilityNodeInfo(BatteryChartView.this, index);
             onInitializeAccessibilityNodeInfo(childInfo);
             childInfo.setClickable(isValidToDraw(mViewModel, index));
-            childInfo.setText(mViewModel.texts().get(index));
-            childInfo.setContentDescription(mViewModel.texts().get(index));
+            childInfo.setText(mViewModel.getFullText(index));
+            childInfo.setContentDescription(mViewModel.getFullText(index));
 
             final Rect bounds = new Rect();
             getBoundsOnScreen(bounds, true);
diff --git a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewModel.java b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewModel.java
index ac01bfd..f58d241 100644
--- a/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewModel.java
+++ b/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewModel.java
@@ -19,6 +19,7 @@
 import androidx.annotation.NonNull;
 import androidx.core.util.Preconditions;
 
+import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
@@ -38,34 +39,59 @@
         CENTER_OF_TRAPEZOIDS,
     }
 
+    interface LabelTextGenerator {
+        /** Generate the label text. The text may be abbreviated to save space. */
+        String generateText(List<Long> timestamps, int index);
+
+        /** Generate the full text for accessibility. */
+        String generateFullText(List<Long> timestamps, int index);
+    }
+
     private final List<Integer> mLevels;
-    private final List<String> mTexts;
+    private final List<Long> mTimestamps;
     private final AxisLabelPosition mAxisLabelPosition;
+    private final LabelTextGenerator mLabelTextGenerator;
+    private final String[] mTexts;
+    private final String[] mFullTexts;
+
     private int mSelectedIndex = SELECTED_INDEX_ALL;
 
-    BatteryChartViewModel(
-            @NonNull List<Integer> levels, @NonNull List<String> texts,
-            @NonNull AxisLabelPosition axisLabelPosition) {
+    BatteryChartViewModel(@NonNull List<Integer> levels, @NonNull List<Long> timestamps,
+            @NonNull AxisLabelPosition axisLabelPosition,
+            @NonNull LabelTextGenerator labelTextGenerator) {
         Preconditions.checkArgument(
-                levels.size() == texts.size() && levels.size() >= MIN_LEVELS_DATA_SIZE,
+                levels.size() == timestamps.size() && levels.size() >= MIN_LEVELS_DATA_SIZE,
                 String.format(Locale.ENGLISH,
-                        "Invalid BatteryChartViewModel levels.size: %d, texts.size: %d.",
-                        levels.size(), texts.size()));
+                        "Invalid BatteryChartViewModel levels.size: %d, timestamps.size: %d.",
+                        levels.size(), timestamps.size()));
         mLevels = levels;
-        mTexts = texts;
+        mTimestamps = timestamps;
         mAxisLabelPosition = axisLabelPosition;
+        mLabelTextGenerator = labelTextGenerator;
+        mTexts = new String[size()];
+        mFullTexts = new String[size()];
     }
 
     public int size() {
         return mLevels.size();
     }
 
-    public List<Integer> levels() {
-        return mLevels;
+    public Integer getLevel(int index) {
+        return mLevels.get(index);
     }
 
-    public List<String> texts() {
-        return mTexts;
+    public String getText(int index) {
+        if (mTexts[index] == null) {
+            mTexts[index] = mLabelTextGenerator.generateText(mTimestamps, index);
+        }
+        return mTexts[index];
+    }
+
+    public String getFullText(int index) {
+        if (mFullTexts[index] == null) {
+            mFullTexts[index] = mLabelTextGenerator.generateFullText(mTimestamps, index);
+        }
+        return mFullTexts[index];
     }
 
     public AxisLabelPosition axisLabelPosition() {
@@ -82,7 +108,7 @@
 
     @Override
     public int hashCode() {
-        return Objects.hash(mLevels, mTexts, mSelectedIndex, mAxisLabelPosition);
+        return Objects.hash(mLevels, mTimestamps, mSelectedIndex, mAxisLabelPosition);
     }
 
     @Override
@@ -94,16 +120,26 @@
         }
         final BatteryChartViewModel batteryChartViewModel = (BatteryChartViewModel) other;
         return Objects.equals(mLevels, batteryChartViewModel.mLevels)
-                && Objects.equals(mTexts, batteryChartViewModel.mTexts)
+                && Objects.equals(mTimestamps, batteryChartViewModel.mTimestamps)
                 && mAxisLabelPosition == batteryChartViewModel.mAxisLabelPosition
                 && mSelectedIndex == batteryChartViewModel.mSelectedIndex;
     }
 
     @Override
     public String toString() {
-        return String.format(Locale.ENGLISH,
-                "levels: %s,\ntexts: %s,\naxisLabelPosition: %s, selectedIndex: %d",
-                Objects.toString(mLevels), Objects.toString(mTexts), mAxisLabelPosition,
-                mSelectedIndex);
+        // Generate all the texts and full texts.
+        for (int i = 0; i < size(); i++) {
+            getText(i);
+            getFullText(i);
+        }
+
+        return new StringBuilder()
+                .append("levels: " + Objects.toString(mLevels))
+                .append(", timestamps: " + Objects.toString(mTimestamps))
+                .append(", texts: " + Arrays.toString(mTexts))
+                .append(", fullTexts: " + Arrays.toString(mFullTexts))
+                .append(", axisLabelPosition: " + mAxisLabelPosition)
+                .append(", selectedIndex: " + mSelectedIndex)
+                .toString();
     }
 }
diff --git a/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceControllerTest.java
index 20af849..26e0f50 100644
--- a/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartPreferenceControllerTest.java
@@ -19,6 +19,7 @@
 import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.atLeast;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.never;
@@ -173,22 +174,33 @@
 
     @Test
     public void setBatteryChartViewModel_6Hours() {
+        reset(mHourlyChartView);
         mBatteryChartPreferenceController.setBatteryHistoryMap(createBatteryHistoryMap(6));
 
         verify(mDailyChartView, atLeastOnce()).setVisibility(View.GONE);
         verify(mHourlyChartView, atLeastOnce()).setVisibility(View.VISIBLE);
-        verify(mHourlyChartView).setViewModel(new BatteryChartViewModel(
+        // Ignore fast refresh ui from the data processor callback.
+        verify(mHourlyChartView, atLeast(0)).setViewModel(null);
+        verify(mHourlyChartView, atLeastOnce()).setViewModel(new BatteryChartViewModel(
                 List.of(100, 97, 95),
-                List.of("8 AM", "10 AM", "12 PM"),
-                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS));
+                List.of(1619251200000L /* 8 AM */,
+                        1619258400000L /* 10 AM */,
+                        1619265600000L /* 12 PM */),
+                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS,
+                mBatteryChartPreferenceController.mHourlyChartLabelTextGenerator));
     }
 
     @Test
     public void setBatteryChartViewModel_60Hours() {
         BatteryChartViewModel expectedDailyViewModel = new BatteryChartViewModel(
                 List.of(100, 83, 59, 41),
-                List.of("Sat", "Sun", "Mon", "Mon"),
-                BatteryChartViewModel.AxisLabelPosition.CENTER_OF_TRAPEZOIDS);
+                // "Sat", "Sun", "Mon", "Mon"
+                List.of(1619251200000L /* Sat */,
+                        1619308800000L /* Sun */,
+                        1619395200000L /* Mon */,
+                        1619460000000L /* Mon */),
+                BatteryChartViewModel.AxisLabelPosition.CENTER_OF_TRAPEZOIDS,
+                mBatteryChartPreferenceController.mDailyChartLabelTextGenerator);
 
         mBatteryChartPreferenceController.setBatteryHistoryMap(createBatteryHistoryMap(60));
 
@@ -208,9 +220,17 @@
         verify(mDailyChartView).setViewModel(expectedDailyViewModel);
         verify(mHourlyChartView).setViewModel(new BatteryChartViewModel(
                 List.of(100, 97, 95, 93, 91, 89, 87, 85, 83),
-                List.of("8 AM", "10 AM", "12 PM", "2 PM", "4 PM", "6 PM", "8 PM", "10 PM",
-                        "12 AM"),
-                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS));
+                List.of(1619251200000L /* 8 AM */,
+                        1619258400000L /* 10 AM */,
+                        1619265600000L /* 12 PM */,
+                        1619272800000L /* 2 PM */,
+                        1619280000000L /* 4 PM */,
+                        1619287200000L /* 6 PM */,
+                        1619294400000L /* 8 PM */,
+                        1619301600000L /* 10 PM */,
+                        1619308800000L /* 12 AM */),
+                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS,
+                mBatteryChartPreferenceController.mHourlyChartLabelTextGenerator));
 
         reset(mDailyChartView);
         reset(mHourlyChartView);
@@ -224,9 +244,21 @@
         verify(mDailyChartView).setViewModel(expectedDailyViewModel);
         BatteryChartViewModel expectedHourlyViewModel = new BatteryChartViewModel(
                 List.of(83, 81, 79, 77, 75, 73, 71, 69, 67, 65, 63, 61, 59),
-                List.of("12 AM", "2 AM", "4 AM", "6 AM", "8 AM", "10 AM", "12 PM", "2 PM",
-                        "4 PM", "6 PM", "8 PM", "10 PM", "12 AM"),
-                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS);
+                List.of(1619308800000L /* 12 AM */,
+                        1619316000000L /* 2 AM */,
+                        1619323200000L /* 4 AM */,
+                        1619330400000L /* 6 AM */,
+                        1619337600000L /* 8 AM */,
+                        1619344800000L /* 10 AM */,
+                        1619352000000L /* 12 PM */,
+                        1619359200000L /* 2 PM */,
+                        1619366400000L /* 4 PM */,
+                        1619373600000L /* 6 PM */,
+                        1619380800000L /* 8 PM */,
+                        1619388000000L /* 10 PM */,
+                        1619395200000L /* 12 AM */),
+                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS,
+                mBatteryChartPreferenceController.mHourlyChartLabelTextGenerator);
         expectedHourlyViewModel.setSelectedIndex(6);
         verify(mHourlyChartView).setViewModel(expectedHourlyViewModel);
 
@@ -243,9 +275,18 @@
         verify(mDailyChartView).setViewModel(expectedDailyViewModel);
         verify(mHourlyChartView).setViewModel(new BatteryChartViewModel(
                 List.of(59, 57, 55, 53, 51, 49, 47, 45, 43, 41),
-                List.of("12 AM", "2 AM", "4 AM", "6 AM", "8 AM", "10 AM", "12 PM", "2 PM",
-                        "4 PM", "6 PM"),
-                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS));
+                List.of(1619395200000L /* 12 AM */,
+                        1619402400000L /* 2 AM */,
+                        1619409600000L /* 4 AM */,
+                        1619416800000L /* 6 AM */,
+                        1619424000000L /* 8 AM */,
+                        1619431200000L /* 10 AM */,
+                        1619438400000L /* 12 PM */,
+                        1619445600000L /* 2 PM */,
+                        1619452800000L /* 4 PM */,
+                        1619460000000L /* 6 PM */),
+                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS,
+                mBatteryChartPreferenceController.mHourlyChartLabelTextGenerator));
     }
 
     @Test
diff --git a/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewTest.java b/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewTest.java
index 7e423e0..5213199 100644
--- a/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewTest.java
+++ b/tests/robotests/src/com/android/settings/fuelgauge/batteryusage/BatteryChartViewTest.java
@@ -63,8 +63,8 @@
     public void onClick_invokesCallback() {
         final int originalSelectedIndex = 2;
         BatteryChartViewModel batteryChartViewModel = new BatteryChartViewModel(
-                List.of(90, 80, 70, 60), List.of("", "", "", ""),
-                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS);
+                List.of(90, 80, 70, 60), List.of(0L, 0L, 0L, 0L),
+                BatteryChartViewModel.AxisLabelPosition.BETWEEN_TRAPEZOIDS, null);
         batteryChartViewModel.setSelectedIndex(originalSelectedIndex);
         mBatteryChartView.setViewModel(batteryChartViewModel);
         for (int i = 0; i < mBatteryChartView.mTrapezoidSlots.length; i++) {