Bug 1991654 - part 3 - Use new EngineViewScrollingDataBehavior r=android-reviewers,Roger

This will animate the bottom toolbar based on scroll data
exposed by GeckoView instead of inferring the scroll distances
based on intercepted MotionEvents.
As a result the dynamic toolbar will be always kept in sync
with the engine view being scrolled.

Differential Revision: https://phabricator.services.mozilla.com/D267223

Author: Mugurell

mobile/android/android-components/components/ui/widgets/build.gradle

@@ -29,6 +29,7 @@ dependencies {
     testImplementation project(':components:support-test-fakes')
 
     testImplementation libs.androidx.test.junit
+    testImplementation libs.kotlinx.coroutines.test
     testImplementation libs.robolectric
 }
 

mobile/android/android-components/components/ui/widgets/src/main/java/mozilla/components/ui/widgets/behavior/EngineViewScrollingBehaviorFactory.kt

@@ -7,11 +7,14 @@ package mozilla.components.ui.widgets.behavior
 import android.view.View
 import mozilla.components.concept.base.crash.CrashReporting
 import mozilla.components.concept.engine.EngineView
+import mozilla.components.ui.widgets.behavior.DependencyGravity.Bottom
 
 /**
  * Factory for [EngineViewScrollingBehavior] instances.
  */
-object EngineViewScrollingBehaviorFactory {
+class EngineViewScrollingBehaviorFactory(
+    private val useScrollData: Boolean = false,
+) {
     /**
      * Create a new [EngineViewScrollingBehavior] instance.
      *
@@ -25,10 +28,18 @@ object EngineViewScrollingBehaviorFactory {
         dependency: View,
         dependencyGravity: DependencyGravity,
         crashReporting: CrashReporting? = null,
-    ) = EngineViewScrollingGesturesBehavior(
-        engineView = engineView,
-        dependency = dependency,
-        dependencyGravity = dependencyGravity,
-        crashReporting = crashReporting,
-    )
+    ) = when (useScrollData && dependencyGravity is Bottom) {
+        true -> EngineViewScrollingDataBehavior(
+            engineView = engineView,
+            dependency = dependency,
+            dependencyGravity = dependencyGravity,
+        )
+
+        false -> EngineViewScrollingGesturesBehavior(
+            engineView = engineView,
+            dependency = dependency,
+            dependencyGravity = dependencyGravity,
+            crashReporting = crashReporting,
+        )
+    }
 }

mobile/android/android-components/components/ui/widgets/src/main/java/mozilla/components/ui/widgets/behavior/EngineViewScrollingDataBehavior.kt

@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.ui.widgets.behavior
+
+import android.view.View
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.view.isVisible
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import mozilla.components.concept.engine.EngineView
+import mozilla.components.support.ktx.android.view.toScope
+
+/**
+ * A [CoordinatorLayout.Behavior] implementation to be used for moving [dependency] up/down
+ * depending on scroll data exposed by [engineView].
+ *
+ * This is safe to use even if [dependency] has it's visibility modified.
+ *
+ * This implementation will:
+ * - Show/Hide the [View] automatically when scrolling vertically.
+ * - Snap the [View] to be hidden or visible when the user stops scrolling.
+ */
+class EngineViewScrollingDataBehavior(
+    private val engineView: EngineView,
+    private val dependency: View,
+    dependencyGravity: DependencyGravity,
+    private val scrollListenerScope: CoroutineScope = engineView.asView().toScope(),
+) : EngineViewScrollingBehavior(engineView, dependency, dependencyGravity) {
+    private var scrollUpdatesJob: Job? = null
+
+    override fun onStartNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: View,
+        directTargetChild: View,
+        target: View,
+        axes: Int,
+        type: Int,
+    ): Boolean = when (dependency.isVisible && isScrollEnabled) {
+        true -> {
+            yTranslator.cancelInProgressTranslation()
+
+            scrollUpdatesJob = scrollListenerScope.launch {
+                engineView.verticalScrollDelta.collect {
+                    if (isActive) { yTranslator.translate(dependency, it) }
+                }
+            }
+            true
+        }
+        false -> false // not interested in subsequent scroll events
+    }
+
+    override fun onStopNestedScroll(
+        coordinatorLayout: CoordinatorLayout, child: View, target: View, type: Int,
+    ) {
+        scrollUpdatesJob?.cancel()
+
+        if (dependency.isVisible) {
+            yTranslator.snapWithAnimation(dependency)
+        }
+    }
+}

mobile/android/android-components/components/ui/widgets/src/test/java/mozilla/components/ui/widgets/behavior/EngineViewScrollingBehaviorFactoryTest.kt

@@ -0,0 +1,72 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.ui.widgets.behavior
+
+import android.view.View
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import mozilla.components.concept.engine.EngineView
+import mozilla.components.support.test.mock
+import mozilla.components.support.test.robolectric.testContext
+import mozilla.components.ui.widgets.behavior.DependencyGravity.Bottom
+import mozilla.components.ui.widgets.behavior.DependencyGravity.Top
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.doReturn
+
+@RunWith(AndroidJUnit4::class)
+class EngineViewScrollingBehaviorFactoryTest {
+    private val engineView: EngineView = mock()
+
+    @Before
+    fun setUp() {
+        doReturn(View(testContext)).`when`(engineView).asView()
+    }
+
+    @Test
+    fun `GIVEN should use scroll data and dependency is at bottom WHEN building a scrolling behavior THEN return one using scroll data`() {
+        val result = EngineViewScrollingBehaviorFactory(true).build(
+            engineView = engineView,
+            dependency = mock(),
+            dependencyGravity = Bottom,
+        )
+
+        assertTrue(result is EngineViewScrollingDataBehavior)
+    }
+
+    @Test
+    fun `GIVEN should not use scroll data and dependency is at bottom WHEN building a scrolling behavior THEN return one using scroll gestures`() {
+        val result = EngineViewScrollingBehaviorFactory(false).build(
+            engineView = engineView,
+            dependency = mock(),
+            dependencyGravity = Bottom,
+        )
+
+        assertTrue(result is EngineViewScrollingGesturesBehavior)
+    }
+
+    @Test
+    fun `GIVEN should use scroll data and dependency is at top WHEN building a scrolling behavior THEN return one using scroll gestures`() {
+        val result = EngineViewScrollingBehaviorFactory(true).build(
+            engineView = engineView,
+            dependency = mock(),
+            dependencyGravity = Top,
+        )
+
+        assertTrue(result is EngineViewScrollingGesturesBehavior)
+    }
+
+    @Test
+    fun `GIVEN should not use scroll data and dependency is at top WHEN building a scrolling behavior THEN return one using scroll gestures`() {
+        val result = EngineViewScrollingBehaviorFactory(false).build(
+            engineView = engineView,
+            dependency = mock(),
+            dependencyGravity = Top,
+        )
+
+        assertTrue(result is EngineViewScrollingGesturesBehavior)
+    }
+}