[Media TTT] Allow swiping up to dismiss the chipbar.

Bug: 262584940 Test: with flag off, verify that you can't swipe up to dismiss the chipbar Test: with flag on, verify that starting a swipe around the chipbar area and swiping up will dismiss the chipbar Test: atest ChipbarCoordinatorTest SwipeChipbarAwayGestureHandlerTest Change-Id: I8440b9b2d7d715981bbf8ee9e44d9202068d4a88 Change-Id: I38aa257855eacaaae6708c796f3f91ea4584342a
2022-12-22 19:12:23 +00:00
parent b7ec39e18d
commit b4314f1e4f
13 changed files with 351 additions and 3 deletions
--- a/packages/SystemUI/src/com/android/systemui/flags/Flags.kt
+++ b/packages/SystemUI/src/com/android/systemui/flags/Flags.kt
@@ -341,6 +341,10 @@ object Flags {
    // TODO(b/263512203): Tracking Bug
    val MEDIA_EXPLICIT_INDICATOR = unreleasedFlag(911, "media_explicit_indicator", teamfood = true)

+    // TODO(b/265813373): Tracking Bug
+    val MEDIA_TAP_TO_TRANSFER_DISMISS_GESTURE =
+        unreleasedFlag(912, "media_ttt_dismiss_gesture", teamfood = true)
+
    // 1000 - dock
    val SIMULATE_DOCK_THROUGH_CHARGING = releasedFlag(1000, "simulate_dock_through_charging")

--- a/packages/SystemUI/src/com/android/systemui/media/taptotransfer/MediaTttFlags.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/taptotransfer/MediaTttFlags.kt
@@ -30,4 +30,8 @@ class MediaTttFlags @Inject constructor(private val featureFlags: FeatureFlags)
    /** Check whether the flag for the receiver success state is enabled. */
    fun isMediaTttReceiverSuccessRippleEnabled(): Boolean =
        featureFlags.isEnabled(Flags.MEDIA_TTT_RECEIVER_SUCCESS_RIPPLE)
+
+    /** True if the media transfer chip can be dismissed via a gesture. */
+    fun isMediaTttDismissGestureEnabled(): Boolean =
+        featureFlags.isEnabled(Flags.MEDIA_TAP_TO_TRANSFER_DISMISS_GESTURE)
 }
--- a/packages/SystemUI/src/com/android/systemui/media/taptotransfer/sender/MediaTttSenderCoordinator.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/taptotransfer/sender/MediaTttSenderCoordinator.kt
@@ -185,6 +185,7 @@ constructor(
                    }
                },
            vibrationEffect = chipStateSender.transferStatus.vibrationEffect,
+            allowSwipeToDismiss = true,
            windowTitle = MediaTttUtils.WINDOW_TITLE_SENDER,
            wakeReason = MediaTttUtils.WAKE_REASON_SENDER,
            timeoutMs = chipStateSender.timeout,
--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/TemporaryViewDisplayController.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/TemporaryViewDisplayController.kt
@@ -31,6 +31,7 @@ import android.view.accessibility.AccessibilityManager.FLAG_CONTENT_CONTROLS
 import android.view.accessibility.AccessibilityManager.FLAG_CONTENT_ICONS
 import android.view.accessibility.AccessibilityManager.FLAG_CONTENT_TEXT
 import androidx.annotation.CallSuper
+import androidx.annotation.VisibleForTesting
 import com.android.systemui.CoreStartable
 import com.android.systemui.Dumpable
 import com.android.systemui.dagger.qualifiers.Main
@@ -108,9 +109,10 @@ abstract class TemporaryViewDisplayController<T : TemporaryViewInfo, U : Tempora
     * Whenever the current view disappears, the next-priority view will be displayed if it's still
     * valid.
     */
+    @VisibleForTesting
    internal val activeViews: MutableList<DisplayInfo> = mutableListOf()

-    private fun getCurrentDisplayInfo(): DisplayInfo? {
+    internal fun getCurrentDisplayInfo(): DisplayInfo? {
        return activeViews.getOrNull(0)
    }

--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarCoordinator.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarCoordinator.kt
@@ -80,6 +80,7 @@ constructor(
    powerManager: PowerManager,
    private val falsingManager: FalsingManager,
    private val falsingCollector: FalsingCollector,
+    private val swipeChipbarAwayGestureHandler: SwipeChipbarAwayGestureHandler?,
    private val viewUtil: ViewUtil,
    private val vibratorHelper: VibratorHelper,
    wakeLockBuilder: WakeLock.Builder,
@@ -105,6 +106,8 @@ constructor(
        commonWindowLayoutParams.apply { gravity = Gravity.TOP.or(Gravity.CENTER_HORIZONTAL) }

    override fun updateView(newInfo: ChipbarInfo, currentView: ViewGroup) {
+        updateGestureListening()
+
        logger.logViewUpdate(
            newInfo.windowTitle,
            newInfo.text.loadText(context),
@@ -228,6 +231,42 @@ constructor(
            includeMargins = true,
            onAnimationEnd,
        )
+
+        updateGestureListening()
+    }
+
+    private fun updateGestureListening() {
+        if (swipeChipbarAwayGestureHandler == null) {
+            return
+        }
+
+        val currentDisplayInfo = getCurrentDisplayInfo()
+        if (currentDisplayInfo != null && currentDisplayInfo.info.allowSwipeToDismiss) {
+            swipeChipbarAwayGestureHandler.setViewFetcher { currentDisplayInfo.view }
+            swipeChipbarAwayGestureHandler.addOnGestureDetectedCallback(TAG) {
+                onSwipeUpGestureDetected()
+            }
+        } else {
+            swipeChipbarAwayGestureHandler.resetViewFetcher()
+            swipeChipbarAwayGestureHandler.removeOnGestureDetectedCallback(TAG)
+        }
+    }
+
+    private fun onSwipeUpGestureDetected() {
+        val currentDisplayInfo = getCurrentDisplayInfo()
+        if (currentDisplayInfo == null) {
+            logger.logSwipeGestureError(id = null, errorMsg = "No info is being displayed")
+            return
+        }
+        if (!currentDisplayInfo.info.allowSwipeToDismiss) {
+            logger.logSwipeGestureError(
+                id = currentDisplayInfo.info.id,
+                errorMsg = "This view prohibits swipe-to-dismiss",
+            )
+            return
+        }
+        removeView(currentDisplayInfo.info.id, SWIPE_UP_GESTURE_REASON)
+        updateGestureListening()
    }

    private fun ViewGroup.getInnerView(): ViewGroup {
@@ -250,3 +289,5 @@ constructor(
 private const val ANIMATION_IN_DURATION = 500L
 private const val ANIMATION_OUT_DURATION = 250L
@IdRes private val INFO_TAG = R.id.tag_chipbar_info
+private const val SWIPE_UP_GESTURE_REASON = "SWIPE_UP_GESTURE_DETECTED"
+private const val TAG = "ChipbarCoordinator"
--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarInfo.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarInfo.kt
@@ -33,12 +33,14 @@ import com.android.systemui.temporarydisplay.ViewPriority
 * @property endItem an optional end item to display at the end of the chipbar (on the right in LTR
 * locales; on the left in RTL locales).
 * @property vibrationEffect an optional vibration effect when the chipbar is displayed
+ * @property allowSwipeToDismiss true if users are allowed to swipe up to dismiss this chipbar.
 */
 data class ChipbarInfo(
    val startIcon: TintedIcon,
    val text: Text,
    val endItem: ChipbarEndItem?,
    val vibrationEffect: VibrationEffect? = null,
+    val allowSwipeToDismiss: Boolean = false,
    override val windowTitle: String,
    override val wakeReason: String,
    override val timeoutMs: Int,
--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarLogger.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/ChipbarLogger.kt
@@ -46,4 +46,16 @@ constructor(
            { "Chipbar updated. window=$str1 text=$str2 endItem=$str3" }
        )
    }
+
+    fun logSwipeGestureError(id: String?, errorMsg: String) {
+        buffer.log(
+            tag,
+            LogLevel.WARNING,
+            {
+                str1 = id
+                str2 = errorMsg
+            },
+            { "Chipbar swipe gesture detected for incorrect state. id=$str1 error=$str2" }
+        )
+    }
 }
--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/SwipeChipbarAwayGestureHandler.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/chipbar/SwipeChipbarAwayGestureHandler.kt
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui.temporarydisplay.chipbar
+
+import android.content.Context
+import android.view.MotionEvent
+import android.view.View
+import com.android.systemui.statusbar.gesture.SwipeUpGestureHandler
+import com.android.systemui.statusbar.gesture.SwipeUpGestureLogger
+import com.android.systemui.util.boundsOnScreen
+
+/**
+ * A class to detect when a user has swiped the chipbar away.
+ *
+ * Effectively [SysUISingleton]. But, this shouldn't be created if the gesture isn't enabled. See
+ * [TemporaryDisplayModule.provideSwipeChipbarAwayGestureHandler].
+ */
+class SwipeChipbarAwayGestureHandler(
+    context: Context,
+    logger: SwipeUpGestureLogger,
+) : SwipeUpGestureHandler(context, logger, loggerTag = LOGGER_TAG) {
+
+    private var viewFetcher: () -> View? = { null }
+
+    override fun startOfGestureIsWithinBounds(ev: MotionEvent): Boolean {
+        val view = viewFetcher.invoke() ?: return false
+        // Since chipbar is in its own window, we need to use [boundsOnScreen] to get an accurate
+        // bottom. ([view.bottom] would be relative to its window, which would be too small.)
+        val viewBottom = view.boundsOnScreen.bottom
+        // Allow the gesture to start a bit below the chipbar
+        return ev.y <= 1.5 * viewBottom
+    }
+
+    /**
+     * Sets a fetcher that returns the current chipbar view. The fetcher will be invoked whenever a
+     * gesture starts to determine if the gesture is near the chipbar.
+     */
+    fun setViewFetcher(fetcher: () -> View?) {
+        viewFetcher = fetcher
+    }
+
+    /** Removes the current view fetcher. */
+    fun resetViewFetcher() {
+        viewFetcher = { null }
+    }
+}
+
+private const val LOGGER_TAG = "SwipeChipbarAway"
--- a/packages/SystemUI/src/com/android/systemui/temporarydisplay/dagger/TemporaryDisplayModule.kt
+++ b/packages/SystemUI/src/com/android/systemui/temporarydisplay/dagger/TemporaryDisplayModule.kt
@@ -16,22 +16,38 @@

 package com.android.systemui.temporarydisplay.dagger

+import android.content.Context
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.log.LogBufferFactory
+import com.android.systemui.media.taptotransfer.MediaTttFlags
 import com.android.systemui.plugins.log.LogBuffer
+import com.android.systemui.statusbar.gesture.SwipeUpGestureLogger
+import com.android.systemui.temporarydisplay.chipbar.SwipeChipbarAwayGestureHandler
 import dagger.Module
 import dagger.Provides

@Module
 interface TemporaryDisplayModule {
-    @Module
    companion object {
-        @JvmStatic
        @Provides
        @SysUISingleton
        @ChipbarLog
        fun provideChipbarLogBuffer(factory: LogBufferFactory): LogBuffer {
            return factory.create("ChipbarLog", 40)
        }
+
+        @Provides
+        @SysUISingleton
+        fun provideSwipeChipbarAwayGestureHandler(
+            mediaTttFlags: MediaTttFlags,
+            context: Context,
+            logger: SwipeUpGestureLogger,
+        ): SwipeChipbarAwayGestureHandler? {
+            return if (mediaTttFlags.isMediaTttDismissGestureEnabled()) {
+                SwipeChipbarAwayGestureHandler(context, logger)
+            } else {
+                null
+            }
+        }
    }
 }
--- a/packages/SystemUI/tests/src/com/android/systemui/media/taptotransfer/sender/MediaTttSenderCoordinatorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/taptotransfer/sender/MediaTttSenderCoordinatorTest.kt
@@ -50,6 +50,7 @@ import com.android.systemui.temporarydisplay.chipbar.ChipbarCoordinator
 import com.android.systemui.temporarydisplay.chipbar.ChipbarInfo
 import com.android.systemui.temporarydisplay.chipbar.ChipbarLogger
 import com.android.systemui.temporarydisplay.chipbar.FakeChipbarCoordinator
+import com.android.systemui.temporarydisplay.chipbar.SwipeChipbarAwayGestureHandler
 import com.android.systemui.util.concurrency.FakeExecutor
 import com.android.systemui.util.mockito.any
 import com.android.systemui.util.mockito.argumentCaptor
@@ -98,6 +99,7 @@ class MediaTttSenderCoordinatorTest : SysuiTestCase() {
    @Mock private lateinit var viewUtil: ViewUtil
    @Mock private lateinit var windowManager: WindowManager
    @Mock private lateinit var vibratorHelper: VibratorHelper
+    @Mock private lateinit var swipeHandler: SwipeChipbarAwayGestureHandler
    private lateinit var fakeWakeLockBuilder: WakeLockFake.Builder
    private lateinit var fakeWakeLock: WakeLockFake
    private lateinit var chipbarCoordinator: ChipbarCoordinator
@@ -148,6 +150,7 @@ class MediaTttSenderCoordinatorTest : SysuiTestCase() {
                powerManager,
                falsingManager,
                falsingCollector,
+                swipeHandler,
                viewUtil,
                vibratorHelper,
                fakeWakeLockBuilder,
--- a/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/ChipbarCoordinatorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/ChipbarCoordinatorTest.kt
@@ -20,6 +20,7 @@ import android.os.PowerManager
 import android.os.VibrationEffect
 import android.testing.AndroidTestingRunner
 import android.testing.TestableLooper
+import android.view.MotionEvent
 import android.view.View
 import android.view.ViewGroup
 import android.view.WindowManager
@@ -43,6 +44,8 @@ import com.android.systemui.statusbar.policy.ConfigurationController
 import com.android.systemui.temporarydisplay.ViewPriority
 import com.android.systemui.util.concurrency.FakeExecutor
 import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.argumentCaptor
+import com.android.systemui.util.mockito.capture
 import com.android.systemui.util.mockito.eq
 import com.android.systemui.util.time.FakeSystemClock
 import com.android.systemui.util.view.ViewUtil
@@ -54,6 +57,7 @@ import org.junit.runner.RunWith
 import org.mockito.ArgumentCaptor
 import org.mockito.ArgumentMatchers.anyInt
 import org.mockito.Mock
+import org.mockito.Mockito.never
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.`when` as whenever
 import org.mockito.MockitoAnnotations
@@ -74,6 +78,7 @@ class ChipbarCoordinatorTest : SysuiTestCase() {
    @Mock private lateinit var falsingCollector: FalsingCollector
    @Mock private lateinit var viewUtil: ViewUtil
    @Mock private lateinit var vibratorHelper: VibratorHelper
+    @Mock private lateinit var swipeGestureHandler: SwipeChipbarAwayGestureHandler
    private lateinit var fakeWakeLockBuilder: WakeLockFake.Builder
    private lateinit var fakeWakeLock: WakeLockFake
    private lateinit var fakeClock: FakeSystemClock
@@ -106,6 +111,7 @@ class ChipbarCoordinatorTest : SysuiTestCase() {
                powerManager,
                falsingManager,
                falsingCollector,
+                swipeGestureHandler,
                viewUtil,
                vibratorHelper,
                fakeWakeLockBuilder,
@@ -430,17 +436,101 @@ class ChipbarCoordinatorTest : SysuiTestCase() {
        verify(logger).logViewUpdate(eq(WINDOW_TITLE), eq("new title text"), any())
    }

+    @Test
+    fun swipeToDismiss_false_neverListensForGesture() {
+        underTest.displayView(
+            createChipbarInfo(
+                Icon.Resource(R.drawable.ic_cake, contentDescription = null),
+                Text.Loaded("title text"),
+                endItem = ChipbarEndItem.Loading,
+                allowSwipeToDismiss = false,
+            )
+        )
+
+        verify(swipeGestureHandler, never()).addOnGestureDetectedCallback(any(), any())
+    }
+
+    @Test
+    fun swipeToDismiss_true_listensForGesture() {
+        underTest.displayView(
+            createChipbarInfo(
+                Icon.Resource(R.drawable.ic_cake, contentDescription = null),
+                Text.Loaded("title text"),
+                endItem = ChipbarEndItem.Loading,
+                allowSwipeToDismiss = true,
+            )
+        )
+
+        verify(swipeGestureHandler).addOnGestureDetectedCallback(any(), any())
+    }
+
+    @Test
+    fun swipeToDismiss_swipeOccurs_viewDismissed() {
+        underTest.displayView(
+            createChipbarInfo(
+                Icon.Resource(R.drawable.ic_cake, contentDescription = null),
+                Text.Loaded("title text"),
+                endItem = ChipbarEndItem.Loading,
+                allowSwipeToDismiss = true,
+            )
+        )
+        val view = getChipbarView()
+
+        val callbackCaptor = argumentCaptor<(MotionEvent) -> Unit>()
+        verify(swipeGestureHandler).addOnGestureDetectedCallback(any(), capture(callbackCaptor))
+
+        callbackCaptor.value.invoke(MotionEvent.obtain(0L, 0L, 0, 0f, 0f, 0))
+
+        verify(windowManager).removeView(view)
+    }
+
+    @Test
+    fun swipeToDismiss_viewUpdatedToFalse_swipeOccurs_viewNotDismissed() {
+        underTest.displayView(
+            createChipbarInfo(
+                Icon.Resource(R.drawable.ic_cake, contentDescription = null),
+                Text.Loaded("title text"),
+                endItem = ChipbarEndItem.Loading,
+                allowSwipeToDismiss = true,
+            )
+        )
+        val view = getChipbarView()
+        val callbackCaptor = argumentCaptor<(MotionEvent) -> Unit>()
+        verify(swipeGestureHandler).addOnGestureDetectedCallback(any(), capture(callbackCaptor))
+
+        // WHEN the view is updated to not allow swipe-to-dismiss
+        underTest.displayView(
+            createChipbarInfo(
+                Icon.Resource(R.drawable.ic_cake, contentDescription = null),
+                Text.Loaded("title text"),
+                endItem = ChipbarEndItem.Loading,
+                allowSwipeToDismiss = false,
+            )
+        )
+
+        // THEN the callback is removed
+        verify(swipeGestureHandler).removeOnGestureDetectedCallback(any())
+
+        // And WHEN the old callback is invoked
+        callbackCaptor.value.invoke(MotionEvent.obtain(0L, 0L, 0, 0f, 0f, 0))
+
+        // THEN it is ignored and view isn't removed
+        verify(windowManager, never()).removeView(view)
+    }
+
    private fun createChipbarInfo(
        startIcon: Icon,
        text: Text,
        endItem: ChipbarEndItem?,
        vibrationEffect: VibrationEffect? = null,
+        allowSwipeToDismiss: Boolean = false,
    ): ChipbarInfo {
        return ChipbarInfo(
            TintedIcon(startIcon, tintAttr = null),
            text,
            endItem,
            vibrationEffect,
+            allowSwipeToDismiss,
            windowTitle = WINDOW_TITLE,
            wakeReason = WAKE_REASON,
            timeoutMs = TIMEOUT,
--- a/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/FakeChipbarCoordinator.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/FakeChipbarCoordinator.kt
@@ -43,6 +43,7 @@ class FakeChipbarCoordinator(
    powerManager: PowerManager,
    falsingManager: FalsingManager,
    falsingCollector: FalsingCollector,
+    swipeChipbarAwayGestureHandler: SwipeChipbarAwayGestureHandler,
    viewUtil: ViewUtil,
    vibratorHelper: VibratorHelper,
    wakeLockBuilder: WakeLock.Builder,
@@ -59,6 +60,7 @@ class FakeChipbarCoordinator(
        powerManager,
        falsingManager,
        falsingCollector,
+        swipeChipbarAwayGestureHandler,
        viewUtil,
        vibratorHelper,
        wakeLockBuilder,
--- a/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/SwipeChipbarAwayGestureHandlerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/temporarydisplay/chipbar/SwipeChipbarAwayGestureHandlerTest.kt
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui.temporarydisplay.chipbar
+
+import android.graphics.Rect
+import android.view.MotionEvent
+import android.view.View
+import androidx.test.filters.SmallTest
+import com.android.dx.mockito.inline.extended.ExtendedMockito.doAnswer
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.util.mockito.any
+import com.android.systemui.util.mockito.mock
+import com.android.systemui.util.mockito.whenever
+import com.google.common.truth.Truth.assertThat
+import org.junit.Before
+import org.junit.Test
+
+@SmallTest
+class SwipeChipbarAwayGestureHandlerTest : SysuiTestCase() {
+
+    private lateinit var underTest: SwipeChipbarAwayGestureHandler
+
+    @Before
+    fun setUp() {
+        underTest = SwipeChipbarAwayGestureHandler(context, mock())
+    }
+
+    @Test
+    fun startOfGestureIsWithinBounds_noViewFetcher_returnsFalse() {
+        assertThat(underTest.startOfGestureIsWithinBounds(createMotionEvent())).isFalse()
+    }
+
+    @Test
+    fun startOfGestureIsWithinBounds_usesViewFetcher_aboveBottom_returnsTrue() {
+        val view = createMockView()
+
+        underTest.setViewFetcher { view }
+
+        val motionEvent = createMotionEvent(y = VIEW_BOTTOM - 100f)
+        assertThat(underTest.startOfGestureIsWithinBounds(motionEvent)).isTrue()
+    }
+
+    @Test
+    fun startOfGestureIsWithinBounds_usesViewFetcher_slightlyBelowBottom_returnsTrue() {
+        val view = createMockView()
+
+        underTest.setViewFetcher { view }
+
+        val motionEvent = createMotionEvent(y = VIEW_BOTTOM + 20f)
+        assertThat(underTest.startOfGestureIsWithinBounds(motionEvent)).isTrue()
+    }
+
+    @Test
+    fun startOfGestureIsWithinBounds_usesViewFetcher_tooFarDown_returnsFalse() {
+        val view = createMockView()
+
+        underTest.setViewFetcher { view }
+
+        val motionEvent = createMotionEvent(y = VIEW_BOTTOM * 4f)
+        assertThat(underTest.startOfGestureIsWithinBounds(motionEvent)).isFalse()
+    }
+
+    @Test
+    fun startOfGestureIsWithinBounds_viewFetcherReset_returnsFalse() {
+        val view = createMockView()
+
+        underTest.setViewFetcher { view }
+
+        val motionEvent = createMotionEvent(y = VIEW_BOTTOM - 100f)
+        assertThat(underTest.startOfGestureIsWithinBounds(motionEvent)).isTrue()
+
+        underTest.resetViewFetcher()
+        assertThat(underTest.startOfGestureIsWithinBounds(motionEvent)).isFalse()
+    }
+
+    private fun createMotionEvent(y: Float = 0f): MotionEvent {
+        return MotionEvent.obtain(0, 0, MotionEvent.ACTION_DOWN, 0f, y, 0)
+    }
+
+    private fun createMockView(): View {
+        return mock<View>().also {
+            doAnswer { invocation ->
+                    val out: Rect = invocation.getArgument(0)
+                    out.set(0, 0, 0, VIEW_BOTTOM)
+                    null
+                }
+                .whenever(it)
+                .getBoundsOnScreen(any())
+        }
+    }
+
+    private companion object {
+        const val VIEW_BOTTOM = 455
+    }
+}