Merge "Replace DateView with VariableDateView (1/2)" into sc-qpr1-dev
diff --git a/packages/SystemUI/res-keyguard/values/donottranslate.xml b/packages/SystemUI/res-keyguard/values/donottranslate.xml
index a4d0ff7..1934457 100644
--- a/packages/SystemUI/res-keyguard/values/donottranslate.xml
+++ b/packages/SystemUI/res-keyguard/values/donottranslate.xml
@@ -21,6 +21,9 @@
     <!-- Skeleton string format for displaying the date when an alarm is set. -->
     <string name="abbrev_wday_month_day_no_year_alarm">EEEMMMd</string>
 
+    <!-- Skeleton string format for displaying the date shorter. -->
+    <string name="abbrev_month_day_no_year">MMMd</string>
+
     <!-- Skeleton string format for displaying the time in 12-hour format. -->
     <string name="clock_12hr_format">hm</string>
 
diff --git a/packages/SystemUI/res/layout/quick_qs_status_icons.xml b/packages/SystemUI/res/layout/quick_qs_status_icons.xml
index 5b9ca1b..966f992 100644
--- a/packages/SystemUI/res/layout/quick_qs_status_icons.xml
+++ b/packages/SystemUI/res/layout/quick_qs_status_icons.xml
@@ -26,17 +26,38 @@
     android:focusable="true"
     android:theme="@style/Theme.SystemUI.QuickSettings.Header">
 
-    <com.android.systemui.statusbar.policy.Clock
-        android:id="@+id/clock"
+    <LinearLayout
+        android:id="@+id/clock_container"
         android:layout_width="wrap_content"
         android:layout_height="match_parent"
-        android:minWidth="48dp"
-        android:minHeight="48dp"
+        android:orientation="horizontal"
+        android:layout_gravity="center_vertical|start"
         android:gravity="center_vertical|start"
-        android:paddingStart="@dimen/status_bar_left_clock_starting_padding"
-        android:paddingEnd="@dimen/status_bar_left_clock_end_padding"
-        android:singleLine="true"
-        android:textAppearance="@style/TextAppearance.QS.Status" />
+        >
+
+        <com.android.systemui.statusbar.policy.Clock
+            android:id="@+id/clock"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:minWidth="48dp"
+            android:minHeight="48dp"
+            android:gravity="center_vertical|start"
+            android:paddingStart="@dimen/status_bar_left_clock_starting_padding"
+            android:paddingEnd="@dimen/status_bar_left_clock_end_padding"
+            android:singleLine="true"
+            android:textAppearance="@style/TextAppearance.QS.Status" />
+
+        <com.android.systemui.statusbar.policy.VariableDateView
+            android:id="@+id/date_clock"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:gravity="center_vertical|start"
+            android:singleLine="true"
+            android:textAppearance="@style/TextAppearance.QS.Status"
+            systemui:longDatePattern="@string/abbrev_wday_month_day_no_year_alarm"
+            systemui:shortDatePattern="@string/abbrev_month_day_no_year"
+        />
+    </LinearLayout>
 
     <include layout="@layout/qs_carrier_group"
         android:id="@+id/carrier_group"
diff --git a/packages/SystemUI/res/layout/quick_status_bar_header_date_privacy.xml b/packages/SystemUI/res/layout/quick_status_bar_header_date_privacy.xml
index bff93a9..cc44b5e 100644
--- a/packages/SystemUI/res/layout/quick_status_bar_header_date_privacy.xml
+++ b/packages/SystemUI/res/layout/quick_status_bar_header_date_privacy.xml
@@ -36,7 +36,7 @@
         android:layout_weight="1"
         android:gravity="center_vertical|start" >
 
-        <com.android.systemui.statusbar.policy.DateView
+        <com.android.systemui.statusbar.policy.VariableDateView
             android:id="@+id/date"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
@@ -44,7 +44,9 @@
             android:gravity="center_vertical"
             android:singleLine="true"
             android:textAppearance="@style/TextAppearance.QS.Status"
-            systemui:datePattern="@string/abbrev_wday_month_day_no_year_alarm" />
+            systemui:longDatePattern="@string/abbrev_wday_month_day_no_year_alarm"
+            systemui:shortDatePattern="@string/abbrev_month_day_no_year"
+        />
     </FrameLayout>
 
     <android.widget.Space
diff --git a/packages/SystemUI/res/values/attrs.xml b/packages/SystemUI/res/values/attrs.xml
index b5337d3..3121ce3 100644
--- a/packages/SystemUI/res/values/attrs.xml
+++ b/packages/SystemUI/res/values/attrs.xml
@@ -69,6 +69,10 @@
     <declare-styleable name="DateView">
         <attr name="datePattern" format="string" />
     </declare-styleable>
+    <declare-styleable name="VariableDateView">
+        <attr name="longDatePattern" format="string" />
+        <attr name="shortDatePattern" format="string" />
+    </declare-styleable>
     <declare-styleable name="PseudoGridView">
         <attr name="numColumns" format="integer" />
         <attr name="verticalSpacing" format="dimension" />
diff --git a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
index 77906ab..19d5fa0 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
@@ -42,6 +42,7 @@
 import com.android.systemui.statusbar.phone.StatusBarWindowView;
 import com.android.systemui.statusbar.phone.StatusIconContainer;
 import com.android.systemui.statusbar.policy.Clock;
+import com.android.systemui.statusbar.policy.VariableDateView;
 
 import java.util.List;
 
@@ -62,11 +63,14 @@
     protected QuickQSPanel mHeaderQsPanel;
     private View mDatePrivacyView;
     private View mDateView;
+    // DateView next to clock. Visible on QQS
+    private VariableDateView mClockDateView;
     private View mSecurityHeaderView;
     private View mClockIconsView;
     private View mContainer;
 
     private View mQSCarriers;
+    private ViewGroup mClockContainer;
     private Clock mClockView;
     private Space mDatePrivacySeparator;
     private View mClockIconsSeparator;
@@ -86,7 +90,6 @@
     private int mWaterfallTopInset;
     private int mCutOutPaddingLeft;
     private int mCutOutPaddingRight;
-    private float mViewAlpha = 1.0f;
     private float mKeyguardExpansionFraction;
     private int mTextColorPrimary = Color.TRANSPARENT;
     private int mTopViewMeasureHeight;
@@ -123,12 +126,14 @@
         mIconContainer = findViewById(R.id.statusIcons);
         mPrivacyChip = findViewById(R.id.privacy_chip);
         mDateView = findViewById(R.id.date);
+        mClockDateView = findViewById(R.id.date_clock);
         mSecurityHeaderView = findViewById(R.id.header_text_container);
         mClockIconsSeparator = findViewById(R.id.separator);
         mRightLayout = findViewById(R.id.rightLayout);
         mDateContainer = findViewById(R.id.date_container);
         mPrivacyContainer = findViewById(R.id.privacy_container);
 
+        mClockContainer = findViewById(R.id.clock_container);
         mClockView = findViewById(R.id.clock);
         mDatePrivacySeparator = findViewById(R.id.space);
         // Tint for the battery icons are handled in setupHost()
@@ -177,7 +182,7 @@
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         if (mDatePrivacyView.getMeasuredHeight() != mTopViewMeasureHeight) {
             mTopViewMeasureHeight = mDatePrivacyView.getMeasuredHeight();
-            updateAnimators();
+            post(this::updateAnimators);
         }
     }
 
@@ -280,7 +285,8 @@
         TouchAnimator.Builder builder = new TouchAnimator.Builder()
                 .addFloat(mSecurityHeaderView, "alpha", 0, 1)
                 // These views appear on expanding down
-                .addFloat(mClockView, "alpha", 0, 1)
+                .addFloat(mDateView, "alpha", 0, 0, 1)
+                .addFloat(mClockDateView, "alpha", 1, 0, 0)
                 .addFloat(mQSCarriers, "alpha", 0, 1)
                 .setListener(new TouchAnimator.ListenerAdapter() {
                     @Override
@@ -289,10 +295,14 @@
                         if (!mIsSingleCarrier) {
                             mIconContainer.addIgnoredSlots(mRssiIgnoredSlots);
                         }
+                        // Make it gone so there's enough room for carrier names
+                        mClockDateView.setVisibility(View.GONE);
                     }
 
                     @Override
                     public void onAnimationStarted() {
+                        mClockDateView.setVisibility(View.VISIBLE);
+                        mClockDateView.setFreezeSwitching(true);
                         setSeparatorVisibility(false);
                         if (!mIsSingleCarrier) {
                             mIconContainer.addIgnoredSlots(mRssiIgnoredSlots);
@@ -302,6 +312,7 @@
                     @Override
                     public void onAnimationAtStart() {
                         super.onAnimationAtStart();
+                        mClockDateView.setFreezeSwitching(false);
                         setSeparatorVisibility(mShowClockIconsSeparator);
                         // In QQS we never ignore RSSI.
                         mIconContainer.removeIgnoredSlots(mRssiIgnoredSlots);
@@ -434,10 +445,11 @@
         mClockIconsSeparator.setVisibility(visible ? View.VISIBLE : View.GONE);
         mQSCarriers.setVisibility(visible ? View.GONE : View.VISIBLE);
 
-        LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) mClockView.getLayoutParams();
+        LinearLayout.LayoutParams lp =
+                (LinearLayout.LayoutParams) mClockContainer.getLayoutParams();
         lp.width = visible ? 0 : WRAP_CONTENT;
         lp.weight = visible ? 1f : 0f;
-        mClockView.setLayoutParams(lp);
+        mClockContainer.setLayoutParams(lp);
 
         lp = (LinearLayout.LayoutParams) mRightLayout.getLayoutParams();
         lp.width = visible ? 0 : WRAP_CONTENT;
diff --git a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeaderController.java b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeaderController.java
index da75c9e..18d6e64 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeaderController.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeaderController.java
@@ -41,6 +41,7 @@
 import com.android.systemui.statusbar.phone.StatusBarIconController;
 import com.android.systemui.statusbar.phone.StatusIconContainer;
 import com.android.systemui.statusbar.policy.Clock;
+import com.android.systemui.statusbar.policy.VariableDateViewController;
 import com.android.systemui.util.ViewController;
 
 import java.util.List;
@@ -71,6 +72,9 @@
     private final QSExpansionPathInterpolator mQSExpansionPathInterpolator;
     private final FeatureFlags mFeatureFlags;
 
+    private final VariableDateViewController mVariableDateViewControllerDateView;
+    private final VariableDateViewController mVariableDateViewControllerClockDateView;
+
     private boolean mListening;
     private boolean mMicCameraIndicatorsEnabled;
     private boolean mLocationIndicatorsEnabled;
@@ -134,7 +138,8 @@
             SysuiColorExtractor colorExtractor,
             PrivacyDialogController privacyDialogController,
             QSExpansionPathInterpolator qsExpansionPathInterpolator,
-            FeatureFlags featureFlags) {
+            FeatureFlags featureFlags,
+            VariableDateViewController.Factory variableDateViewControllerFactory) {
         super(view);
         mPrivacyItemController = privacyItemController;
         mActivityStarter = activityStarter;
@@ -154,6 +159,12 @@
         mPrivacyChip = mView.findViewById(R.id.privacy_chip);
         mClockView = mView.findViewById(R.id.clock);
         mIconContainer = mView.findViewById(R.id.statusIcons);
+        mVariableDateViewControllerDateView = variableDateViewControllerFactory.create(
+                mView.requireViewById(R.id.date)
+        );
+        mVariableDateViewControllerClockDateView = variableDateViewControllerFactory.create(
+                mView.requireViewById(R.id.date_clock)
+        );
 
         mIconManager = new StatusBarIconController.TintedIconManager(mIconContainer, featureFlags);
         mDemoModeReceiver = new ClockDemoModeReceiver(mClockView);
@@ -205,6 +216,9 @@
         mView.onAttach(mIconManager, mQSExpansionPathInterpolator, rssiIgnoredSlots);
 
         mDemoModeController.addCallback(mDemoModeReceiver);
+
+        mVariableDateViewControllerDateView.init();
+        mVariableDateViewControllerClockDateView.init();
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateView.kt b/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateView.kt
new file mode 100644
index 0000000..ae9d9ee
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateView.kt
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2021 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.systemui.statusbar.policy
+
+import android.content.Context
+import android.text.StaticLayout
+import android.util.AttributeSet
+import android.widget.TextView
+import com.android.systemui.R
+
+/**
+ * View for showing a date that can toggle between two different formats depending on size.
+ *
+ * If no pattern can fit, it will display empty.
+ *
+ * @see R.styleable.VariableDateView_longDatePattern
+ * @see R.styleable.VariableDateView_shortDatePattern
+ */
+class VariableDateView(context: Context, attrs: AttributeSet) : TextView(context, attrs) {
+
+    val longerPattern: String
+    val shorterPattern: String
+
+    init {
+        val a = context.theme.obtainStyledAttributes(
+                attrs,
+                R.styleable.VariableDateView,
+                0, 0)
+        longerPattern = a.getString(R.styleable.VariableDateView_longDatePattern)
+                ?: context.getString(R.string.system_ui_date_pattern)
+        shorterPattern = a.getString(R.styleable.VariableDateView_shortDatePattern)
+                ?: context.getString(R.string.abbrev_month_day_no_year)
+
+        a.recycle()
+    }
+
+    /**
+     * Freeze the pattern switching
+     *
+     * Use during animations if the container will change its size but this view should not change
+     */
+    var freezeSwitching = false
+
+    private var onMeasureListener: OnMeasureListener? = null
+
+    fun onAttach(listener: OnMeasureListener?) {
+        onMeasureListener = listener
+    }
+
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        val availableWidth = MeasureSpec.getSize(widthMeasureSpec) - paddingStart - paddingEnd
+        if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED && !freezeSwitching) {
+            onMeasureListener?.onMeasureAction(availableWidth)
+        }
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
+    }
+
+    fun getDesiredWidthForText(text: CharSequence): Float {
+        return StaticLayout.getDesiredWidth(text, paint)
+    }
+
+    interface OnMeasureListener {
+        fun onMeasureAction(availableWidth: Int)
+    }
+}
\ No newline at end of file
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateViewController.kt b/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateViewController.kt
new file mode 100644
index 0000000..99d84c4
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/VariableDateViewController.kt
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2021 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.systemui.statusbar.policy
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.icu.text.DateFormat
+import android.icu.text.DisplayContext
+import android.icu.util.Calendar
+import android.os.Handler
+import android.os.HandlerExecutor
+import android.os.UserHandle
+import android.text.TextUtils
+import android.util.Log
+import androidx.annotation.VisibleForTesting
+import com.android.systemui.Dependency
+import com.android.systemui.broadcast.BroadcastDispatcher
+import com.android.systemui.util.ViewController
+import com.android.systemui.util.time.SystemClock
+import java.text.FieldPosition
+import java.text.ParsePosition
+import java.util.Date
+import java.util.Locale
+import javax.inject.Inject
+import javax.inject.Named
+
+@VisibleForTesting
+internal fun getTextForFormat(date: Date?, format: DateFormat): String {
+    return if (format === EMPTY_FORMAT) { // Check if same object
+        ""
+    } else format.format(date)
+}
+
+@VisibleForTesting
+internal fun getFormatFromPattern(pattern: String?): DateFormat {
+    if (TextUtils.equals(pattern, "")) {
+        return EMPTY_FORMAT
+    }
+    val l = Locale.getDefault()
+    val format = DateFormat.getInstanceForSkeleton(pattern, l)
+    format.setContext(DisplayContext.CAPITALIZATION_FOR_STANDALONE)
+    return format
+}
+
+private val EMPTY_FORMAT: DateFormat = object : DateFormat() {
+    override fun format(
+        cal: Calendar,
+        toAppendTo: StringBuffer,
+        fieldPosition: FieldPosition
+    ): StringBuffer? {
+        return null
+    }
+
+    override fun parse(text: String, cal: Calendar, pos: ParsePosition) {}
+}
+
+private const val DEBUG = false
+private const val TAG = "VariableDateViewController"
+
+class VariableDateViewController(
+    private val systemClock: SystemClock,
+    private val broadcastDispatcher: BroadcastDispatcher,
+    private val timeTickHandler: Handler,
+    view: VariableDateView
+) : ViewController<VariableDateView>(view) {
+
+    private var dateFormat: DateFormat? = null
+    private var datePattern = view.longerPattern
+        set(value) {
+            if (field == value) return
+            field = value
+            dateFormat = null
+            if (isAttachedToWindow) {
+                post(::updateClock)
+            }
+        }
+    private var lastWidth = Integer.MAX_VALUE
+    private var lastText = ""
+    private var currentTime = Date()
+
+    // View class easy accessors
+    private val longerPattern: String
+        get() = mView.longerPattern
+    private val shorterPattern: String
+        get() = mView.shorterPattern
+    private fun post(block: () -> Unit) = mView.handler?.post(block)
+
+    private val intentReceiver: BroadcastReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context, intent: Intent) {
+            // If the handler is null, it means we received a broadcast while the view has not
+            // finished being attached or in the process of being detached.
+            // In that case, do not post anything.
+            val handler = mView.handler ?: return
+            val action = intent.action
+            if (
+                    Intent.ACTION_TIME_TICK == action ||
+                    Intent.ACTION_TIME_CHANGED == action ||
+                    Intent.ACTION_TIMEZONE_CHANGED == action ||
+                    Intent.ACTION_LOCALE_CHANGED == action
+            ) {
+                if (
+                        Intent.ACTION_LOCALE_CHANGED == action ||
+                        Intent.ACTION_TIMEZONE_CHANGED == action
+                ) {
+                    // need to get a fresh date format
+                    handler.post { dateFormat = null }
+                }
+                handler.post(::updateClock)
+            }
+        }
+    }
+
+    private val onMeasureListener = object : VariableDateView.OnMeasureListener {
+        override fun onMeasureAction(availableWidth: Int) {
+            if (availableWidth != lastWidth) {
+                // maybeChangeFormat will post if the pattern needs to change.
+                maybeChangeFormat(availableWidth)
+                lastWidth = availableWidth
+            }
+        }
+    }
+
+    override fun onViewAttached() {
+        val filter = IntentFilter().apply {
+            addAction(Intent.ACTION_TIME_TICK)
+            addAction(Intent.ACTION_TIME_CHANGED)
+            addAction(Intent.ACTION_TIMEZONE_CHANGED)
+            addAction(Intent.ACTION_LOCALE_CHANGED)
+        }
+
+        broadcastDispatcher.registerReceiver(intentReceiver, filter,
+                HandlerExecutor(timeTickHandler), UserHandle.SYSTEM)
+
+        post(::updateClock)
+        mView.onAttach(onMeasureListener)
+    }
+
+    override fun onViewDetached() {
+        dateFormat = null
+        mView.onAttach(null)
+        broadcastDispatcher.unregisterReceiver(intentReceiver)
+    }
+
+    private fun updateClock() {
+        if (dateFormat == null) {
+            dateFormat = getFormatFromPattern(datePattern)
+        }
+
+        currentTime.time = systemClock.currentTimeMillis()
+
+        val text = getTextForFormat(currentTime, dateFormat!!)
+        if (text != lastText) {
+            mView.setText(text)
+            lastText = text
+        }
+    }
+
+    private fun maybeChangeFormat(availableWidth: Int) {
+        if (mView.freezeSwitching ||
+                availableWidth > lastWidth && datePattern == longerPattern ||
+                availableWidth < lastWidth && datePattern == ""
+        ) {
+            // Nothing to do
+            return
+        }
+        if (DEBUG) Log.d(TAG, "Width changed. Maybe changing pattern")
+        // Start with longer pattern and see what fits
+        var text = getTextForFormat(currentTime, getFormatFromPattern(longerPattern))
+        var length = mView.getDesiredWidthForText(text)
+        if (length <= availableWidth) {
+            changePattern(longerPattern)
+            return
+        }
+
+        text = getTextForFormat(currentTime, getFormatFromPattern(shorterPattern))
+        length = mView.getDesiredWidthForText(text)
+        if (length <= availableWidth) {
+            changePattern(shorterPattern)
+            return
+        }
+
+        changePattern("")
+    }
+
+    private fun changePattern(newPattern: String) {
+        if (newPattern.equals(datePattern)) return
+        if (DEBUG) Log.d(TAG, "Changing pattern to $newPattern")
+        datePattern = newPattern
+    }
+
+    class Factory @Inject constructor(
+        private val systemClock: SystemClock,
+        private val broadcastDispatcher: BroadcastDispatcher,
+        @Named(Dependency.TIME_TICK_HANDLER_NAME) private val handler: Handler
+    ) {
+        fun create(view: VariableDateView): VariableDateViewController {
+            return VariableDateViewController(
+                    systemClock,
+                    broadcastDispatcher,
+                    handler,
+                    view
+            )
+        }
+    }
+}
\ No newline at end of file
diff --git a/packages/SystemUI/tests/src/com/android/systemui/qs/QuickStatusBarHeaderControllerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/qs/QuickStatusBarHeaderControllerTest.kt
index 35360bd..8b7e20e 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/qs/QuickStatusBarHeaderControllerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/qs/QuickStatusBarHeaderControllerTest.kt
@@ -36,6 +36,8 @@
 import com.android.systemui.statusbar.phone.StatusBarIconController
 import com.android.systemui.statusbar.phone.StatusIconContainer
 import com.android.systemui.statusbar.policy.Clock
+import com.android.systemui.statusbar.policy.VariableDateView
+import com.android.systemui.statusbar.policy.VariableDateViewController
 import com.android.systemui.util.mockito.any
 import com.android.systemui.util.mockito.argumentCaptor
 import com.android.systemui.util.mockito.capture
@@ -87,8 +89,14 @@
     @Mock
     private lateinit var privacyDialogController: PrivacyDialogController
     @Mock
+    private lateinit var variableDateViewControllerFactory: VariableDateViewController.Factory
+    @Mock
+    private lateinit var variableDateViewController: VariableDateViewController
+    @Mock
     private lateinit var clock: Clock
     @Mock
+    private lateinit var variableDateView: VariableDateView
+    @Mock
     private lateinit var mockView: View
     @Mock(answer = Answers.RETURNS_DEEP_STUBS)
     private lateinit var context: Context
@@ -109,6 +117,8 @@
         stubViews()
         `when`(iconContainer.context).thenReturn(context)
         `when`(qsCarrierGroupControllerBuilder.build()).thenReturn(qsCarrierGroupController)
+        `when`(variableDateViewControllerFactory.create(any()))
+                .thenReturn(variableDateViewController)
         `when`(view.resources).thenReturn(mContext.resources)
         `when`(view.isAttachedToWindow).thenReturn(true)
         `when`(view.context).thenReturn(context)
@@ -133,7 +143,8 @@
                 colorExtractor,
                 privacyDialogController,
                 qsExpansionPathInterpolator,
-                featureFlags
+                featureFlags,
+                variableDateViewControllerFactory
         )
     }
 
@@ -274,6 +285,8 @@
         `when`(view.findViewById<StatusIconContainer>(R.id.statusIcons)).thenReturn(iconContainer)
         `when`(view.findViewById<OngoingPrivacyChip>(R.id.privacy_chip)).thenReturn(privacyChip)
         `when`(view.findViewById<Clock>(R.id.clock)).thenReturn(clock)
+        `when`(view.requireViewById<VariableDateView>(R.id.date)).thenReturn(variableDateView)
+        `when`(view.requireViewById<VariableDateView>(R.id.date_clock)).thenReturn(variableDateView)
     }
 
     private fun setPrivacyController(micCamera: Boolean, location: Boolean) {
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/VariableDateViewControllerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/VariableDateViewControllerTest.kt
new file mode 100644
index 0000000..871a48c
--- /dev/null
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/VariableDateViewControllerTest.kt
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2021 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.systemui.statusbar.policy
+
+import android.os.Handler
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.broadcast.BroadcastDispatcher
+import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.capture
+import com.android.systemui.util.time.FakeSystemClock
+import com.google.common.truth.Truth.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.Captor
+import org.mockito.Mock
+import org.mockito.Mockito.`when`
+import org.mockito.Mockito.anyString
+import org.mockito.Mockito.verify
+import org.mockito.MockitoAnnotations
+import java.util.Date
+
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper
+@SmallTest
+class VariableDateViewControllerTest : SysuiTestCase() {
+
+    companion object {
+        private const val TIME_STAMP = 1_500_000_000_000
+        private const val LONG_PATTERN = "EEEMMMd"
+        private const val SHORT_PATTERN = "MMMd"
+        private const val CHAR_WIDTH = 10f
+    }
+
+    @Mock
+    private lateinit var broadcastDispatcher: BroadcastDispatcher
+    @Mock
+    private lateinit var view: VariableDateView
+    @Captor
+    private lateinit var onMeasureListenerCaptor: ArgumentCaptor<VariableDateView.OnMeasureListener>
+
+    private var lastText: String? = null
+
+    private lateinit var systemClock: FakeSystemClock
+    private lateinit var testableLooper: TestableLooper
+    private lateinit var testableHandler: Handler
+    private lateinit var controller: VariableDateViewController
+
+    private lateinit var longText: String
+    private lateinit var shortText: String
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        testableLooper = TestableLooper.get(this)
+        testableHandler = Handler(testableLooper.looper)
+
+        systemClock = FakeSystemClock()
+        systemClock.setCurrentTimeMillis(TIME_STAMP)
+
+        `when`(view.longerPattern).thenReturn(LONG_PATTERN)
+        `when`(view.shorterPattern).thenReturn(SHORT_PATTERN)
+        `when`(view.handler).thenReturn(testableHandler)
+
+        `when`(view.setText(anyString())).thenAnswer {
+            lastText = it.arguments[0] as? String
+            Unit
+        }
+        `when`(view.isAttachedToWindow).thenReturn(true)
+
+        val date = Date(TIME_STAMP)
+        longText = getTextForFormat(date, getFormatFromPattern(LONG_PATTERN))
+        shortText = getTextForFormat(date, getFormatFromPattern(SHORT_PATTERN))
+
+        // Assume some sizes for the text, the controller doesn't need to know if these sizes are
+        // the true ones
+        `when`(view.getDesiredWidthForText(any())).thenAnswer {
+            getTextLength(it.arguments[0] as CharSequence)
+        }
+
+        controller = VariableDateViewController(
+                systemClock,
+                broadcastDispatcher,
+                testableHandler,
+                view
+        )
+
+        controller.init()
+        testableLooper.processAllMessages()
+
+        verify(view).onAttach(capture(onMeasureListenerCaptor))
+    }
+
+    @Test
+    fun testViewStartsWithLongText() {
+        assertThat(lastText).isEqualTo(longText)
+    }
+
+    @Test
+    fun testListenerNotNull() {
+        assertThat(onMeasureListenerCaptor.value).isNotNull()
+    }
+
+    @Test
+    fun testLotsOfSpaceUseLongText() {
+        onMeasureListenerCaptor.value.onMeasureAction(10000)
+
+        testableLooper.processAllMessages()
+        assertThat(lastText).isEqualTo(longText)
+    }
+
+    @Test
+    fun testSmallSpaceUseEmpty() {
+        onMeasureListenerCaptor.value.onMeasureAction(1)
+        testableLooper.processAllMessages()
+
+        assertThat(lastText).isEmpty()
+    }
+
+    @Test
+    fun testSpaceInBetweenUseShortText() {
+        val average = ((getTextLength(longText) + getTextLength(shortText)) / 2).toInt()
+
+        onMeasureListenerCaptor.value.onMeasureAction(average)
+        testableLooper.processAllMessages()
+
+        assertThat(lastText).isEqualTo(shortText)
+    }
+
+    @Test
+    fun testSwitchBackToLonger() {
+        onMeasureListenerCaptor.value.onMeasureAction(1)
+        testableLooper.processAllMessages()
+
+        onMeasureListenerCaptor.value.onMeasureAction(10000)
+        testableLooper.processAllMessages()
+
+        assertThat(lastText).isEqualTo(longText)
+    }
+
+    @Test
+    fun testNoSwitchingWhenFrozen() {
+        `when`(view.freezeSwitching).thenReturn(true)
+
+        val average = ((getTextLength(longText) + getTextLength(shortText)) / 2).toInt()
+        onMeasureListenerCaptor.value.onMeasureAction(average)
+        testableLooper.processAllMessages()
+        assertThat(lastText).isEqualTo(longText)
+
+        onMeasureListenerCaptor.value.onMeasureAction(1)
+        testableLooper.processAllMessages()
+        assertThat(lastText).isEqualTo(longText)
+    }
+
+    private fun getTextLength(text: CharSequence): Float {
+        return text.length * CHAR_WIDTH
+    }
+}
\ No newline at end of file