Merge "LS Wallpaper Sampling for LS Smartspace" into udc-dev

core/java/android/app/WallpaperColors.java

@@ -588,7 +588,7 @@ public final class WallpaperColors implements Parcelable {
 
         int hints = 0;
         double meanLuminance = totalLuminance / pixels.length;
-        if (meanLuminance > BRIGHT_IMAGE_MEAN_LUMINANCE && darkPixels < maxDarkPixels) {
+        if (meanLuminance > BRIGHT_IMAGE_MEAN_LUMINANCE && darkPixels <= maxDarkPixels) {
             hints |= HINT_SUPPORTS_DARK_TEXT;
         }
         if (meanLuminance < DARK_THEME_MEAN_LUMINANCE) {

core/java/android/app/WallpaperManager.java

@@ -1680,14 +1680,14 @@ public class WallpaperManager {
      * @hide
      */
     public void addOnColorsChangedListener(@NonNull LocalWallpaperColorConsumer callback,
-            List<RectF> regions) throws IllegalArgumentException {
+            List<RectF> regions, int which) throws IllegalArgumentException {
         for (RectF region : regions) {
             if (!LOCAL_COLOR_BOUNDS.contains(region)) {
                 throw new IllegalArgumentException("Regions must be within bounds "
                         + LOCAL_COLOR_BOUNDS);
             }
         }
-        sGlobals.addOnColorsChangedListener(callback, regions, FLAG_SYSTEM,
+        sGlobals.addOnColorsChangedListener(callback, regions, which,
                                                  mContext.getUserId(), mContext.getDisplayId());
     }
 

packages/SystemUI/shared/src/com/android/systemui/shared/regionsampling/RegionSampler.kt

@@ -21,9 +21,9 @@ import android.graphics.Color
 import android.graphics.Point
 import android.graphics.Rect
 import android.graphics.RectF
+import android.util.Log
 import android.view.View
 import androidx.annotation.VisibleForTesting
-import com.android.systemui.shared.navigationbar.RegionSamplingHelper
 import java.io.PrintWriter
 import java.util.concurrent.Executor
 
@@ -31,20 +31,21 @@ import java.util.concurrent.Executor
 open class RegionSampler
 @JvmOverloads
 constructor(
-    val sampledView: View?,
+    val sampledView: View,
     mainExecutor: Executor?,
     val bgExecutor: Executor?,
     val regionSamplingEnabled: Boolean,
+    val isLockscreen: Boolean = false,
+    val wallpaperManager: WallpaperManager? = WallpaperManager.getInstance(sampledView.context),
     val updateForegroundColor: UpdateColorCallback,
-    val wallpaperManager: WallpaperManager? = WallpaperManager.getInstance(sampledView?.context)
 ) : WallpaperManager.LocalWallpaperColorConsumer {
     private var regionDarkness = RegionDarkness.DEFAULT
     private var samplingBounds = Rect()
     private val tmpScreenLocation = IntArray(2)
-    @VisibleForTesting var regionSampler: RegionSamplingHelper? = null
     private var lightForegroundColor = Color.WHITE
     private var darkForegroundColor = Color.BLACK
-    private val displaySize = Point()
+    @VisibleForTesting val displaySize = Point()
+    private var initialSampling: WallpaperColors? = null
 
     /**
      * Sets the colors to be used for Dark and Light Foreground.
@@ -57,6 +58,36 @@ constructor(
         darkForegroundColor = darkColor
     }
 
+    private val layoutChangedListener =
+        object : View.OnLayoutChangeListener {
+
+            override fun onLayoutChange(
+                view: View?,
+                left: Int,
+                top: Int,
+                right: Int,
+                bottom: Int,
+                oldLeft: Int,
+                oldTop: Int,
+                oldRight: Int,
+                oldBottom: Int
+            ) {
+
+                // don't pass in negative bounds when region is in transition state
+                if (sampledView.locationOnScreen[0] < 0 || sampledView.locationOnScreen[1] < 0) {
+                    return
+                }
+
+                val currentViewRect = Rect(left, top, right, bottom)
+                val oldViewRect = Rect(oldLeft, oldTop, oldRight, oldBottom)
+
+                if (currentViewRect != oldViewRect) {
+                    stopRegionSampler()
+                    startRegionSampler()
+                }
+            }
+        }
+
     /**
      * Determines which foreground color to use based on region darkness.
      *
@@ -84,40 +115,57 @@ constructor(
 
     /** Start region sampler */
     fun startRegionSampler() {
-        if (!regionSamplingEnabled || sampledView == null) {
+
+        if (!regionSamplingEnabled) {
+            if (DEBUG) Log.d(TAG, "startRegionSampler() | RegionSampling flag not enabled")
             return
         }
 
-        val sampledRegion = calculateSampledRegion(sampledView)
+        sampledView.addOnLayoutChangeListener(layoutChangedListener)
-        val regions = ArrayList<RectF>()
-        val sampledRegionWithOffset = convertBounds(sampledRegion)
 
+        val screenLocationBounds = calculateScreenLocation(sampledView)
+        if (screenLocationBounds == null) {
+            if (DEBUG) Log.d(TAG, "startRegionSampler() | passed in null region")
+            return
+        }
+        if (screenLocationBounds.isEmpty) {
+            if (DEBUG) Log.d(TAG, "startRegionSampler() | passed in empty region")
+            return
+        }
+
+        val sampledRegionWithOffset = convertBounds(screenLocationBounds)
         if (
             sampledRegionWithOffset.left < 0.0 ||
                 sampledRegionWithOffset.right > 1.0 ||
                 sampledRegionWithOffset.top < 0.0 ||
                 sampledRegionWithOffset.bottom > 1.0
         ) {
-            android.util.Log.e(
+            if (DEBUG)
-                "RegionSampler",
+                Log.d(
-                "view out of bounds: $sampledRegion | " +
+                    TAG,
+                    "startRegionSampler() | view out of bounds: $screenLocationBounds | " +
                         "screen width: ${displaySize.x}, screen height: ${displaySize.y}",
                     Exception()
                 )
             return
         }
 
+        val regions = ArrayList<RectF>()
         regions.add(sampledRegionWithOffset)
 
-        wallpaperManager?.removeOnColorsChangedListener(this)
+        wallpaperManager?.addOnColorsChangedListener(
-        wallpaperManager?.addOnColorsChangedListener(this, regions)
+            this,
+            regions,
+            if (isLockscreen) WallpaperManager.FLAG_LOCK else WallpaperManager.FLAG_SYSTEM
+        )
 
-        // TODO(b/265969235): conditionally set FLAG_LOCK or FLAG_SYSTEM once HS smartspace
-        // implemented
         bgExecutor?.execute(
             Runnable {
-                val initialSampling =
+                initialSampling =
-                    wallpaperManager?.getWallpaperColors(WallpaperManager.FLAG_LOCK)
+                    wallpaperManager?.getWallpaperColors(
+                        if (isLockscreen) WallpaperManager.FLAG_LOCK
+                        else WallpaperManager.FLAG_SYSTEM
+                    )
                 onColorsChanged(sampledRegionWithOffset, initialSampling)
             }
         )
@@ -126,6 +174,7 @@ constructor(
     /** Stop region sampler */
     fun stopRegionSampler() {
         wallpaperManager?.removeOnColorsChangedListener(this)
+        sampledView.removeOnLayoutChangeListener(layoutChangedListener)
     }
 
     /** Dump region sampler */
@@ -138,22 +187,23 @@ constructor(
         pw.println("passed-in sampledView: $sampledView")
         pw.println("calculated samplingBounds: $samplingBounds")
         pw.println(
-            "sampledView width: ${sampledView?.width}, sampledView height: ${sampledView?.height}"
+            "sampledView width: ${sampledView.width}, sampledView height: ${sampledView.height}"
         )
         pw.println("screen width: ${displaySize.x}, screen height: ${displaySize.y}")
         pw.println(
-            "sampledRegionWithOffset: ${convertBounds(calculateSampledRegion(sampledView!!))}"
+            "sampledRegionWithOffset: ${convertBounds(
+                    calculateScreenLocation(sampledView) ?: RectF())}"
         )
-        // TODO(b/265969235): mock initialSampling based on if component is on HS or LS wallpaper
-        // HS Smartspace - wallpaperManager?.getWallpaperColors(WallpaperManager.FLAG_SYSTEM)
-        // LS Smartspace, clock - wallpaperManager?.getWallpaperColors(WallpaperManager.FLAG_LOCK)
         pw.println(
-            "initialSampling for lockscreen: " +
+            "initialSampling for ${if (isLockscreen) "lockscreen" else "homescreen" }" +
-                "${wallpaperManager?.getWallpaperColors(WallpaperManager.FLAG_LOCK)}"
+                ": $initialSampling"
         )
     }
 
-    fun calculateSampledRegion(sampledView: View): RectF {
+    fun calculateScreenLocation(sampledView: View): RectF? {
+
+        if (!sampledView.isLaidOut) return null
+
         val screenLocation = tmpScreenLocation
         /**
          * The method getLocationOnScreen is used to obtain the view coordinates relative to its
@@ -181,7 +231,8 @@ constructor(
      */
     fun convertBounds(originalBounds: RectF): RectF {
 
-        // TODO(b/265969235): GRAB # PAGES + CURRENT WALLPAPER PAGE # FROM LAUNCHER
+        // TODO(b/265969235): GRAB # PAGES + CURRENT WALLPAPER PAGE # FROM LAUNCHER (--> HS
+        // Smartspace always on 1st page)
         // TODO(b/265968912): remove hard-coded value once LS wallpaper supported
         val wallpaperPageNum = 0
         val numScreens = 1
@@ -214,6 +265,11 @@ constructor(
             )
         updateForegroundColor()
     }
+
+    companion object {
+        private const val TAG = "RegionSampler"
+        private const val DEBUG = false
+    }
 }
 
 typealias UpdateColorCallback = () -> Unit

packages/SystemUI/src/com/android/keyguard/ClockEventController.kt

@@ -21,13 +21,11 @@ import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
 import android.content.res.Resources
-import android.graphics.Rect
 import android.text.format.DateFormat
 import android.util.TypedValue
 import android.view.View
 import android.view.View.OnAttachStateChangeListener
 import android.view.ViewTreeObserver
-import android.widget.FrameLayout
 import androidx.annotation.VisibleForTesting
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.repeatOnLifecycle
@@ -55,16 +53,16 @@ import com.android.systemui.statusbar.policy.BatteryController
 import com.android.systemui.statusbar.policy.BatteryController.BatteryStateChangeCallback
 import com.android.systemui.statusbar.policy.ConfigurationController
 import com.android.systemui.util.concurrency.DelayableExecutor
-import java.util.Locale
-import java.util.TimeZone
-import java.util.concurrent.Executor
-import javax.inject.Inject
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.DisposableHandle
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.launch
+import java.util.Locale
+import java.util.TimeZone
+import java.util.concurrent.Executor
+import javax.inject.Inject
 
 /**
  * Controller for a Clock provided by the registry and used on the keyguard. Instantiated by
@@ -98,12 +96,7 @@ constructor(
 
                 value.initialize(resources, dozeAmount, 0f)
 
-                if (regionSamplingEnabled) {
+                if (!regionSamplingEnabled) {
-                    clock?.run {
-                        smallClock.view.addOnLayoutChangeListener(mLayoutChangedListener)
-                        largeClock.view.addOnLayoutChangeListener(mLayoutChangedListener)
-                    }
-                } else {
                     updateColors()
                 }
                 updateFontSizes()
@@ -140,44 +133,10 @@ constructor(
     private var disposableHandle: DisposableHandle? = null
     private val regionSamplingEnabled = featureFlags.isEnabled(REGION_SAMPLING)
 
-    private val mLayoutChangedListener =
-        object : View.OnLayoutChangeListener {
-
-            override fun onLayoutChange(
-                view: View?,
-                left: Int,
-                top: Int,
-                right: Int,
-                bottom: Int,
-                oldLeft: Int,
-                oldTop: Int,
-                oldRight: Int,
-                oldBottom: Int
-            ) {
-                view?.removeOnLayoutChangeListener(this)
-
-                val parent = (view?.parent) as FrameLayout
-
-                // don't pass in negative bounds when clocks are in transition state
-                if (view.locationOnScreen[0] < 0 || view.locationOnScreen[1] < 0) {
-                    return
-                }
-
-                val currentViewRect = Rect(left, top, right, bottom)
-                val oldViewRect = Rect(oldLeft, oldTop, oldRight, oldBottom)
-
-                if (
-                    currentViewRect.width() != oldViewRect.width() ||
-                        currentViewRect.height() != oldViewRect.height()
-                ) {
-                    updateRegionSampler(view)
-                }
-            }
-        }
 
     private fun updateColors() {
         val wallpaperManager = WallpaperManager.getInstance(context)
-        if (regionSamplingEnabled && !wallpaperManager.lockScreenWallpaperExists()) {
+        if (regionSamplingEnabled) {
             regionSampler?.let { regionSampler ->
                 clock?.let { clock ->
                     if (regionSampler.sampledView == clock.smallClock.view) {
@@ -212,6 +171,7 @@ constructor(
                     mainExecutor,
                     bgExecutor,
                     regionSamplingEnabled,
+                    isLockscreen = true,
                     ::updateColors
                 )
                 ?.apply { startRegionSampler() }
@@ -220,10 +180,11 @@ constructor(
     }
 
     protected open fun createRegionSampler(
-        sampledView: View?,
+        sampledView: View,
         mainExecutor: Executor?,
         bgExecutor: Executor?,
         regionSamplingEnabled: Boolean,
+        isLockscreen: Boolean,
         updateColors: () -> Unit
     ): RegionSampler? {
         return RegionSampler(
@@ -231,8 +192,8 @@ constructor(
             mainExecutor,
             bgExecutor,
             regionSamplingEnabled,
-            updateColors
+            isLockscreen,
-        )
+        ) { updateColors() }
     }
 
     var regionSampler: RegionSampler? = null

packages/SystemUI/src/com/android/systemui/statusbar/lockscreen/LockscreenSmartspaceController.kt

@@ -17,7 +17,6 @@
 package com.android.systemui.statusbar.lockscreen
 
 import android.app.PendingIntent
-import android.app.WallpaperManager
 import android.app.smartspace.SmartspaceConfig
 import android.app.smartspace.SmartspaceManager
 import android.app.smartspace.SmartspaceSession
@@ -56,7 +55,6 @@ import com.android.systemui.plugins.WeatherData
 import com.android.systemui.plugins.statusbar.StatusBarStateController
 import com.android.systemui.settings.UserTracker
 import com.android.systemui.shared.regionsampling.RegionSampler
-import com.android.systemui.shared.regionsampling.UpdateColorCallback
 import com.android.systemui.smartspace.dagger.SmartspaceModule.Companion.DATE_SMARTSPACE_DATA_PLUGIN
 import com.android.systemui.smartspace.dagger.SmartspaceModule.Companion.WEATHER_SMARTSPACE_DATA_PLUGIN
 import com.android.systemui.statusbar.phone.KeyguardBypassController
@@ -120,7 +118,7 @@ constructor(
 
     private val regionSamplingEnabled =
             featureFlags.isEnabled(Flags.REGION_SAMPLING)
-    private var isContentUpdatedOnce = false
+    private var isRegionSamplersCreated = false
     private var showNotifications = false
     private var showSensitiveContentForCurrentUser = false
     private var showSensitiveContentForManagedUser = false
@@ -128,7 +126,6 @@ constructor(
 
     // TODO(b/202758428): refactor so that we can test color updates via region samping, similar to
     //  how we test color updates when theme changes (See testThemeChangeUpdatesTextColor).
-    private val updateFun: UpdateColorCallback = { updateTextColorFromRegionSampler() }
 
     // TODO: Move logic into SmartspaceView
     var stateChangeListener = object : View.OnAttachStateChangeListener {
@@ -144,6 +141,9 @@ constructor(
         override fun onViewDetachedFromWindow(v: View) {
             smartspaceViews.remove(v as SmartspaceView)
 
+            regionSamplers[v]?.stopRegionSampler()
+            regionSamplers.remove(v as SmartspaceView)
+
             if (smartspaceViews.isEmpty()) {
                 disconnect()
             }
@@ -170,7 +170,7 @@ constructor(
 
         val filteredTargets = targets.filter(::filterSmartspaceTarget)
         plugin?.onTargetsAvailable(filteredTargets)
-        if (!isContentUpdatedOnce) {
+        if (!isRegionSamplersCreated) {
             for (v in smartspaceViews) {
                 if (regionSamplingEnabled) {
                     var regionSampler = RegionSampler(
@@ -178,15 +178,14 @@ constructor(
                         uiExecutor,
                         bgExecutor,
                         regionSamplingEnabled,
-                        updateFun
+                        isLockscreen = true,
-                    )
+                    ) { updateTextColorFromRegionSampler() }
                     initializeTextColors(regionSampler)
                     regionSamplers[v] = regionSampler
                     regionSampler.startRegionSampler()
                 }
-                updateTextColorFromWallpaper()
             }
-            isContentUpdatedOnce = true
+            isRegionSamplersCreated = true
         }
     }
 
@@ -504,18 +503,16 @@ constructor(
     }
 
     private fun updateTextColorFromRegionSampler() {
-        smartspaceViews.forEach {
+        regionSamplers.forEach { (view, region) ->
-            val textColor = regionSamplers.get(it)?.currentForegroundColor()
+            val textColor = region.currentForegroundColor()
             if (textColor != null) {
-                it.setPrimaryTextColor(textColor)
+                view.setPrimaryTextColor(textColor)
             }
         }
     }
 
     private fun updateTextColorFromWallpaper() {
-        val wallpaperManager = WallpaperManager.getInstance(context)
+        if (!regionSamplingEnabled || regionSamplers.isEmpty()) {
-        if (!regionSamplingEnabled || wallpaperManager.lockScreenWallpaperExists() ||
-            regionSamplers.isEmpty()) {
             val wallpaperTextColor =
                     Utils.getColorAttrDefaultColor(context, R.attr.wallpaperTextColor)
             smartspaceViews.forEach { it.setPrimaryTextColor(wallpaperTextColor) }

packages/SystemUI/tests/src/com/android/systemui/shared/regionsampling/RegionSamplerTest.kt

@@ -1,17 +1,30 @@
 package com.android.systemui.shared.regionsampling
 
+import android.app.WallpaperColors
 import android.app.WallpaperManager
+import android.graphics.Color
+import android.graphics.RectF
 import android.testing.AndroidTestingRunner
 import android.view.View
 import androidx.test.filters.SmallTest
 import com.android.systemui.SysuiTestCase
+import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.capture
+import com.google.common.truth.Truth.assertThat
 import java.io.PrintWriter
 import java.util.concurrent.Executor
+import org.junit.Assert.assertTrue
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.eq
+import org.mockito.Captor
 import org.mockito.Mock
+import org.mockito.Mockito.clearInvocations
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
 import org.mockito.Mockito.`when` as whenever
 import org.mockito.junit.MockitoJUnit
 
@@ -26,25 +39,188 @@ class RegionSamplerTest : SysuiTestCase() {
     @Mock private lateinit var bgExecutor: Executor
     @Mock private lateinit var pw: PrintWriter
     @Mock private lateinit var wallpaperManager: WallpaperManager
+    @Mock private lateinit var updateForegroundColor: UpdateColorCallback
 
-    private lateinit var mRegionSampler: RegionSampler
+    private lateinit var regionSampler: RegionSampler // lockscreen
-    private var updateFun: UpdateColorCallback = {}
+    private lateinit var homescreenRegionSampler: RegionSampler
+
+    @Captor
+    private lateinit var colorsChangedListener:
+        ArgumentCaptor<WallpaperManager.LocalWallpaperColorConsumer>
+
+    @Captor private lateinit var layoutChangedListener: ArgumentCaptor<View.OnLayoutChangeListener>
 
     @Before
     fun setUp() {
         whenever(sampledView.isAttachedToWindow).thenReturn(true)
+        whenever(sampledView.width).thenReturn(100)
+        whenever(sampledView.height).thenReturn(100)
+        whenever(sampledView.isLaidOut).thenReturn(true)
+        whenever(sampledView.locationOnScreen).thenReturn(intArrayOf(0, 0))
 
-        mRegionSampler =
+        regionSampler =
-            RegionSampler(sampledView, mainExecutor, bgExecutor, true, updateFun, wallpaperManager)
+            RegionSampler(
+                sampledView,
+                mainExecutor,
+                bgExecutor,
+                regionSamplingEnabled = true,
+                isLockscreen = true,
+                wallpaperManager,
+                updateForegroundColor
+            )
+        regionSampler.displaySize.set(1080, 2050)
+
+        // TODO(b/265969235): test sampling on home screen via WallpaperManager.FLAG_SYSTEM
+        homescreenRegionSampler =
+            RegionSampler(
+                sampledView,
+                mainExecutor,
+                bgExecutor,
+                regionSamplingEnabled = true,
+                isLockscreen = false,
+                wallpaperManager,
+                updateForegroundColor
+            )
     }
 
     @Test
-    fun testStartRegionSampler() {
+    fun testCalculatedBounds_inRange() {
-        mRegionSampler.startRegionSampler()
+        // test calculations return region within [0,1]
+        sampledView.setLeftTopRightBottom(100, 100, 200, 200)
+        var fractionalBounds =
+            regionSampler.calculateScreenLocation(sampledView)?.let {
+                regionSampler.convertBounds(it)
+            }
+
+        assertTrue(fractionalBounds?.left!! >= 0.0f)
+        assertTrue(fractionalBounds.right <= 1.0f)
+        assertTrue(fractionalBounds.top >= 0.0f)
+        assertTrue(fractionalBounds.bottom <= 1.0f)
+    }
+
+    @Test
+    fun testEmptyView_returnsEarly() {
+        sampledView.setLeftTopRightBottom(0, 0, 0, 0)
+        whenever(sampledView.width).thenReturn(0)
+        whenever(sampledView.height).thenReturn(0)
+        regionSampler.startRegionSampler()
+        // returns early so should never call this function
+        verify(wallpaperManager, never())
+            .addOnColorsChangedListener(
+                any(WallpaperManager.LocalWallpaperColorConsumer::class.java),
+                any(),
+                any()
+            )
+    }
+
+    @Test
+    fun testLayoutChange_notifiesListener() {
+        regionSampler.startRegionSampler()
+        // don't count addOnColorsChangedListener() call made in startRegionSampler()
+        clearInvocations(wallpaperManager)
+
+        verify(sampledView).addOnLayoutChangeListener(capture(layoutChangedListener))
+        layoutChangedListener.value.onLayoutChange(
+            sampledView,
+            300,
+            300,
+            400,
+            400,
+            100,
+            100,
+            200,
+            200
+        )
+        verify(sampledView).removeOnLayoutChangeListener(layoutChangedListener.value)
+        verify(wallpaperManager)
+            .removeOnColorsChangedListener(
+                any(WallpaperManager.LocalWallpaperColorConsumer::class.java)
+            )
+        verify(wallpaperManager)
+            .addOnColorsChangedListener(
+                any(WallpaperManager.LocalWallpaperColorConsumer::class.java),
+                any(),
+                any()
+            )
+    }
+
+    @Test
+    fun testColorsChanged_triggersCallback() {
+        regionSampler.startRegionSampler()
+        verify(wallpaperManager)
+            .addOnColorsChangedListener(
+                capture(colorsChangedListener),
+                any(),
+                eq(WallpaperManager.FLAG_LOCK)
+            )
+        setWhiteWallpaper()
+        verify(updateForegroundColor).invoke()
+    }
+
+    @Test
+    fun testRegionDarkness() {
+        regionSampler.startRegionSampler()
+        verify(wallpaperManager)
+            .addOnColorsChangedListener(
+                capture(colorsChangedListener),
+                any(),
+                eq(WallpaperManager.FLAG_LOCK)
+            )
+
+        // should detect dark region
+        setBlackWallpaper()
+        assertThat(regionSampler.currentRegionDarkness()).isEqualTo(RegionDarkness.DARK)
+
+        // should detect light region
+        setWhiteWallpaper()
+        assertThat(regionSampler.currentRegionDarkness()).isEqualTo(RegionDarkness.LIGHT)
+    }
+
+    @Test
+    fun testForegroundColor() {
+        regionSampler.setForegroundColors(Color.WHITE, Color.BLACK)
+        regionSampler.startRegionSampler()
+        verify(wallpaperManager)
+            .addOnColorsChangedListener(
+                capture(colorsChangedListener),
+                any(),
+                eq(WallpaperManager.FLAG_LOCK)
+            )
+
+        // dark background, light text
+        setBlackWallpaper()
+        assertThat(regionSampler.currentForegroundColor()).isEqualTo(Color.WHITE)
+
+        // light background, dark text
+        setWhiteWallpaper()
+        assertThat(regionSampler.currentForegroundColor()).isEqualTo(Color.BLACK)
+    }
+
+    private fun setBlackWallpaper() {
+        val wallpaperColors =
+            WallpaperColors(Color.valueOf(Color.BLACK), Color.valueOf(Color.BLACK), null)
+        colorsChangedListener.value.onColorsChanged(
+            RectF(100.0f, 100.0f, 200.0f, 200.0f),
+            wallpaperColors
+        )
+    }
+    private fun setWhiteWallpaper() {
+        val wallpaperColors =
+            WallpaperColors(
+                Color.valueOf(Color.WHITE),
+                Color.valueOf(Color.WHITE),
+                null,
+                WallpaperColors.HINT_SUPPORTS_DARK_TEXT
+            )
+        colorsChangedListener.value.onColorsChanged(
+            RectF(100.0f, 100.0f, 200.0f, 200.0f),
+            wallpaperColors
+        )
     }
 
     @Test
     fun testDump() {
-        mRegionSampler.dump(pw)
+        regionSampler.dump(pw)
+        homescreenRegionSampler.dump(pw)
     }
 }

tests/Internal/src/android/app/WallpaperColorsTest.java

@@ -48,10 +48,10 @@ public class WallpaperColorsTest {
     }
 
     /**
-     * Check that white supports dark text and black doesn't
+     * Check that white surface supports dark text
      */
     @Test
-    public void colorHintsTest() {
+    public void whiteSurfaceColorHintsTest() {
         Bitmap image = Bitmap.createBitmap(30, 30, Bitmap.Config.ARGB_8888);
         Canvas canvas = new Canvas(image);
 
@@ -59,28 +59,68 @@ public class WallpaperColorsTest {
         int hints = WallpaperColors.fromBitmap(image).getColorHints();
         boolean supportsDarkText = (hints & WallpaperColors.HINT_SUPPORTS_DARK_TEXT) != 0;
         boolean supportsDarkTheme = (hints & WallpaperColors.HINT_SUPPORTS_DARK_THEME) != 0;
-        boolean fromBitmap = (hints & WallpaperColors.HINT_FROM_BITMAP) != 0;
         Assert.assertTrue("White surface should support dark text.", supportsDarkText);
         Assert.assertFalse("White surface shouldn't support dark theme.", supportsDarkTheme);
-        Assert.assertTrue("From bitmap should be true if object was created "
-                + "using WallpaperColors#fromBitmap.", fromBitmap);
-
-        canvas.drawColor(Color.BLACK);
-        hints = WallpaperColors.fromBitmap(image).getColorHints();
-        supportsDarkText = (hints & WallpaperColors.HINT_SUPPORTS_DARK_TEXT) != 0;
-        supportsDarkTheme = (hints & WallpaperColors.HINT_SUPPORTS_DARK_THEME) != 0;
-        Assert.assertFalse("Black surface shouldn't support dark text.", supportsDarkText);
-        Assert.assertTrue("Black surface should support dark theme.", supportsDarkTheme);
 
         Paint paint = new Paint();
         paint.setStyle(Paint.Style.FILL);
         paint.setColor(Color.BLACK);
-        canvas.drawColor(Color.WHITE);
         canvas.drawRect(0, 0, 8, 8, paint);
         supportsDarkText = (WallpaperColors.fromBitmap(image)
                 .getColorHints() & WallpaperColors.HINT_SUPPORTS_DARK_TEXT) != 0;
         Assert.assertFalse("Light surface shouldn't support dark text "
                 + "when it contains dark pixels.", supportsDarkText);
+    }
+
+    /**
+     * Check that x-small white region supports dark text when max number of dark pixels = 0
+     */
+    @Test
+    public void xSmallWhiteSurfaceColorHintsTest() {
+        Bitmap xsmall_image = Bitmap.createBitmap(1, 5, Bitmap.Config.ARGB_8888);
+        Canvas xsmall_canvas = new Canvas(xsmall_image);
+
+        xsmall_canvas.drawColor(Color.WHITE);
+        int hints = WallpaperColors.fromBitmap(xsmall_image).getColorHints();
+        boolean supportsDarkText = (hints & WallpaperColors.HINT_SUPPORTS_DARK_TEXT) != 0;
+        boolean supportsDarkTheme = (hints & WallpaperColors.HINT_SUPPORTS_DARK_THEME) != 0;
+        Assert.assertTrue("X-small white surface should support dark text.",
+                supportsDarkText);
+        Assert.assertFalse("X-small white surface shouldn't support dark theme.",
+                supportsDarkTheme);
+    }
+
+    /**
+     * Check that black surface doesn't support dark text
+     */
+    @Test
+    public void blackSurfaceColorHintsTest() {
+        Bitmap image = Bitmap.createBitmap(30, 30, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(image);
+
+        canvas.drawColor(Color.BLACK);
+        int hints = WallpaperColors.fromBitmap(image).getColorHints();
+        boolean supportsDarkText = (hints & WallpaperColors.HINT_SUPPORTS_DARK_TEXT) != 0;
+        boolean supportsDarkTheme = (hints & WallpaperColors.HINT_SUPPORTS_DARK_THEME) != 0;
+        Assert.assertFalse("Black surface shouldn't support dark text.", supportsDarkText);
+        Assert.assertTrue("Black surface should support dark theme.", supportsDarkTheme);
+    }
+
+    /**
+     * Check that bitmap hint properly indicates when object created via WallpaperColors#fromBitmap
+     * versus WallpaperColors() public constructor
+     */
+    @Test
+    public void bitmapHintsTest() {
+        Bitmap image = Bitmap.createBitmap(30, 30, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(image);
+
+        canvas.drawColor(Color.WHITE);
+        int hints = WallpaperColors.fromBitmap(image).getColorHints();
+
+        boolean fromBitmap = (hints & WallpaperColors.HINT_FROM_BITMAP) != 0;
+        Assert.assertTrue("From bitmap should be true if object was created "
+                + "using WallpaperColors#fromBitmap.", fromBitmap);
 
         WallpaperColors colors = new WallpaperColors(Color.valueOf(Color.GREEN), null, null);
         fromBitmap = (colors.getColorHints() & WallpaperColors.HINT_FROM_BITMAP) != 0;