[DO NOT MERGE] Separate Region Sampling Instance

This change abstracts out the creation of a region sampling helper
and the initialization of all its fields. It adds test coverage
for the new class.

Bug: 202758428
Test: atest RegionSamplingInstanceTest
Change-Id: Ife2aafccc20466e81f481d1764210806dffc3123

packages/SystemUI/shared/src/com/android/systemui/shared/navigationbar/RegionSamplingHelper.java

@@ -128,6 +128,13 @@ public class RegionSamplingHelper implements View.OnAttachStateChangeListener,
         mCallback = samplingCallback;
     }
 
+    /**
+     * Make callback accessible
+     */
+    @VisibleForTesting
+    public SamplingCallback getCallback() {
+        return mCallback;
+    }
     private void onDraw() {
         if (mWaitingOnDraw) {
             mWaitingOnDraw = false;

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

@@ -0,0 +1,10 @@
+package com.android.systemui.shared.regionsampling
+
+/**
+ * Enum for whether clock region is dark or light.
+ */
+enum class RegionDarkness(val isDark: Boolean) {
+    DEFAULT(false),
+    DARK(true),
+    LIGHT(false)
+}

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

@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2022 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.shared.regionsampling
+
+import android.graphics.Rect
+import android.view.View
+import androidx.annotation.VisibleForTesting
+import com.android.systemui.shared.navigationbar.RegionSamplingHelper
+import com.android.systemui.shared.navigationbar.RegionSamplingHelper.SamplingCallback
+import java.io.PrintWriter
+import java.util.concurrent.Executor
+
+/**
+ * Class for instance of RegionSamplingHelper
+ */
+open class RegionSamplingInstance(
+        sampledView: View?,
+        mainExecutor: Executor?,
+        bgExecutor: Executor?,
+        regionSamplingEnabled: Boolean,
+        updateFun: UpdateColorCallback
+) {
+    private var isDark = RegionDarkness.DEFAULT
+    private var samplingBounds = Rect()
+    @VisibleForTesting var regionSampler: RegionSamplingHelper? = null
+
+    /**
+     * Interface for method to be passed into RegionSamplingHelper
+     */
+    @FunctionalInterface
+    interface UpdateColorCallback {
+        /**
+         * Method to update the text colors after clock darkness changed.
+         */
+        fun updateColors()
+    }
+
+    @VisibleForTesting
+    open fun createRegionSamplingHelper(
+            sampledView: View,
+            callback: SamplingCallback,
+            mainExecutor: Executor?,
+            bgExecutor: Executor?
+    ): RegionSamplingHelper {
+        return RegionSamplingHelper(sampledView, callback, mainExecutor, bgExecutor)
+    }
+
+    private fun convertToClockDarkness(isRegionDark: Boolean): RegionDarkness {
+        return if (isRegionDark) {
+            RegionDarkness.DARK
+        } else {
+            RegionDarkness.LIGHT
+        }
+    }
+
+    fun currentRegionDarkness(): RegionDarkness {
+        return isDark
+    }
+
+    /**
+     * Start region sampler
+     */
+    fun startRegionSampler() {
+        regionSampler?.start(samplingBounds)
+    }
+
+    /**
+     * Stop region sampler
+     */
+    fun stopRegionSampler() {
+        regionSampler?.stop()
+    }
+
+    /**
+     * Dump region sampler
+     */
+    fun dump(pw: PrintWriter) {
+        regionSampler?.dump(pw)
+    }
+
+    init {
+        if (regionSamplingEnabled && sampledView != null) {
+            regionSampler = createRegionSamplingHelper(sampledView,
+                    object : SamplingCallback {
+                        override fun onRegionDarknessChanged(isRegionDark: Boolean) {
+                            isDark = convertToClockDarkness(isRegionDark)
+                            updateFun.updateColors()
+                        }
+
+                        override fun getSampledRegion(sampledView: View): Rect {
+                            samplingBounds = Rect(sampledView.left, sampledView.top,
+                                    sampledView.right, sampledView.bottom)
+                            return samplingBounds
+                        }
+
+                        override fun isSamplingEnabled(): Boolean {
+                            return regionSamplingEnabled
+                        }
+                    }, mainExecutor, bgExecutor)
+        }
+        regionSampler?.setWindowVisible(true)
+    }
+}

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

@@ -0,0 +1,113 @@
+package com.android.systemui.shared.regionsampling
+
+import android.graphics.Rect
+import android.testing.AndroidTestingRunner
+import android.view.View
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.shared.navigationbar.RegionSamplingHelper
+import java.io.PrintWriter
+import java.util.concurrent.Executor
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.clearInvocations
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.`when` as whenever
+import org.mockito.junit.MockitoJUnit
+
+@RunWith(AndroidTestingRunner::class)
+@SmallTest
+class RegionSamplingInstanceTest : SysuiTestCase() {
+
+    @JvmField @Rule
+    val mockito = MockitoJUnit.rule()
+
+    @Mock private lateinit var sampledView: View
+    @Mock private lateinit var mainExecutor: Executor
+    @Mock private lateinit var bgExecutor: Executor
+    @Mock private lateinit var regionSampler: RegionSamplingHelper
+    @Mock private lateinit var updateFun: RegionSamplingInstance.UpdateColorCallback
+    @Mock private lateinit var pw: PrintWriter
+    @Mock private lateinit var callback: RegionSamplingHelper.SamplingCallback
+
+    private lateinit var regionSamplingInstance: RegionSamplingInstance
+
+    @Before
+    fun setUp() {
+        whenever(sampledView.isAttachedToWindow).thenReturn(true)
+        whenever(regionSampler.callback).thenReturn(this@RegionSamplingInstanceTest.callback)
+
+        regionSamplingInstance = object : RegionSamplingInstance(
+                sampledView,
+                mainExecutor,
+                bgExecutor,
+                true,
+                updateFun
+        ) {
+            override fun createRegionSamplingHelper(
+                    sampledView: View,
+                    callback: RegionSamplingHelper.SamplingCallback,
+                    mainExecutor: Executor?,
+                    bgExecutor: Executor?
+            ): RegionSamplingHelper {
+                return this@RegionSamplingInstanceTest.regionSampler
+            }
+        }
+    }
+
+    @Test
+    fun testStartRegionSampler() {
+        regionSamplingInstance.startRegionSampler()
+
+        verify(regionSampler).start(Rect(0, 0, 0, 0))
+    }
+
+    @Test
+    fun testStopRegionSampler() {
+        regionSamplingInstance.stopRegionSampler()
+
+        verify(regionSampler).stop()
+    }
+
+    @Test
+    fun testDump() {
+        regionSamplingInstance.dump(pw)
+
+        verify(regionSampler).dump(pw)
+    }
+
+    @Test
+    fun testUpdateColorCallback() {
+        regionSampler.callback.onRegionDarknessChanged(false)
+        verify(regionSampler.callback).onRegionDarknessChanged(false)
+        clearInvocations(regionSampler.callback)
+        regionSampler.callback.onRegionDarknessChanged(true)
+        verify(regionSampler.callback).onRegionDarknessChanged(true)
+    }
+
+    @Test
+    fun testFlagFalse() {
+        regionSamplingInstance = object : RegionSamplingInstance(
+                sampledView,
+                mainExecutor,
+                bgExecutor,
+                false,
+                updateFun
+        ) {
+            override fun createRegionSamplingHelper(
+                    sampledView: View,
+                    callback: RegionSamplingHelper.SamplingCallback,
+                    mainExecutor: Executor?,
+                    bgExecutor: Executor?
+            ): RegionSamplingHelper {
+                return this@RegionSamplingInstanceTest.regionSampler
+            }
+        }
+
+        Assert.assertEquals(regionSamplingInstance.regionSampler, null)
+    }
+}