Bug 1783561 - Stop BrowserToolbarBehavior positioning the snackbar

The snackbar is placed depending on the toolbar so the relation should be
reversed. The toolbar should not know about and control the snackbar.
There could be other siblings that the snackbar wants to position itself by
and so removing this responsability from BrowserToolbarBehavior will help
better support current and future flows.

android-components/components/browser/toolbar/src/main/java/mozilla/components/browser/toolbar/behavior/BrowserToolbarBehavior.kt

@@ -6,20 +6,16 @@ package mozilla.components.browser.toolbar.behavior
 
 import android.content.Context
 import android.util.AttributeSet
-import android.view.Gravity
 import android.view.MotionEvent
 import android.view.View
 import androidx.annotation.VisibleForTesting
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.view.ViewCompat
-import com.google.android.material.snackbar.Snackbar
 import mozilla.components.browser.toolbar.BrowserToolbar
 import mozilla.components.concept.base.crash.CrashReporting
 import mozilla.components.concept.engine.EngineView
 import mozilla.components.support.ktx.android.view.findViewInHierarchy
 
-private const val SMALL_ELEVATION_CHANGE = 0.01f
-
 /**
  * Where the toolbar is placed on the screen.
  */
@@ -36,7 +32,6 @@ enum class ToolbarPosition {
  *
  * This implementation will:
  * - Show/Hide the [BrowserToolbar] automatically when scrolling vertically.
- * - On showing a [Snackbar] position it above the [BrowserToolbar].
  * - Snap the [BrowserToolbar] to be hidden or visible when the user stops scrolling.
  */
 class BrowserToolbarBehavior(
@@ -130,14 +125,6 @@ class BrowserToolbarBehavior(
         return false // allow events to be passed to below listeners
     }
 
-    override fun layoutDependsOn(parent: CoordinatorLayout, child: BrowserToolbar, dependency: View): Boolean {
-        if (toolbarPosition == ToolbarPosition.BOTTOM && dependency is Snackbar.SnackbarLayout) {
-            positionSnackbar(child, dependency)
-        }
-
-        return super.layoutDependsOn(parent, child, dependency)
-    }
-
     override fun onLayoutChild(
         parent: CoordinatorLayout,
         child: BrowserToolbar,
@@ -181,23 +168,6 @@ class BrowserToolbarBehavior(
         isScrollEnabled = false
     }
 
-    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
-    internal fun positionSnackbar(child: View, snackbarLayout: Snackbar.SnackbarLayout) {
-        val params = snackbarLayout.layoutParams as CoordinatorLayout.LayoutParams
-
-        // Position the snackbar above the toolbar so that it doesn't overlay the toolbar.
-        params.anchorId = child.id
-        params.anchorGravity = Gravity.TOP or Gravity.CENTER_HORIZONTAL
-        params.gravity = Gravity.TOP or Gravity.CENTER_HORIZONTAL
-
-        snackbarLayout.layoutParams = params
-
-        // In order to avoid the snackbar casting a shadow on the toolbar we adjust the elevation of the snackbar here.
-        // We still place it slightly behind the toolbar so that it will not animate over the toolbar but instead pop
-        // out from under the toolbar.
-        snackbarLayout.elevation = child.elevation - SMALL_ELEVATION_CHANGE
-    }
-
     @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
     internal fun tryToScrollVertically(distance: Float) {
         browserToolbar?.let { toolbar ->

android-components/components/browser/toolbar/src/test/java/mozilla/components/browser/toolbar/behavior/BrowserToolbarBehaviorTest.kt

@@ -6,14 +6,12 @@ package mozilla.components.browser.toolbar.behavior
 
 import android.content.Context
 import android.graphics.Bitmap
-import android.view.Gravity
 import android.view.MotionEvent.ACTION_DOWN
 import android.view.MotionEvent.ACTION_MOVE
 import android.widget.FrameLayout
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.view.ViewCompat
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.google.android.material.snackbar.Snackbar
 import mozilla.components.browser.toolbar.BrowserToolbar
 import mozilla.components.concept.engine.EngineSession
 import mozilla.components.concept.engine.EngineView
@@ -474,29 +472,6 @@ class BrowserToolbarBehaviorTest {
         verify(yTranslator).collapseWithAnimation(toolbar)
     }
 
-    @Test
-    fun `Behavior will position snackbar above toolbar`() {
-        val behavior = BrowserToolbarBehavior(testContext, null, ToolbarPosition.BOTTOM)
-
-        val toolbar: BrowserToolbar = mock()
-        doReturn(4223).`when`(toolbar).id
-
-        val layoutParams: CoordinatorLayout.LayoutParams = CoordinatorLayout.LayoutParams(0, 0)
-
-        val snackbarLayout: Snackbar.SnackbarLayout = mock()
-        doReturn(layoutParams).`when`(snackbarLayout).layoutParams
-
-        behavior.layoutDependsOn(
-            parent = mock(),
-            child = toolbar,
-            dependency = snackbarLayout,
-        )
-
-        assertEquals(4223, layoutParams.anchorId)
-        assertEquals(Gravity.TOP or Gravity.CENTER_HORIZONTAL, layoutParams.anchorGravity)
-        assertEquals(Gravity.TOP or Gravity.CENTER_HORIZONTAL, layoutParams.gravity)
-    }
-
     @Test
     fun `Behavior will forceExpand when scrolling up and !shouldScroll if the touch was handled in the browser`() {
         val behavior = spy(BrowserToolbarBehavior(testContext, null, ToolbarPosition.BOTTOM))

docs/changelog.md

@@ -9,6 +9,9 @@ permalink: /changelog/
 * [Gecko](https://github.com/mozilla-mobile/firefox-android/blob/main/android-components/plugins/dependencies/src/main/java/Gecko.kt)
 * [Configuration](https://github.com/mozilla-mobile/firefox-android/blob/main/android-components/.config.yml)
 
+* **browser-toolbar**
+  * ⚠️ **This is a breaking change**: `BrowserToolbarBehavior` will not position the `Snackbar.SnackbarLayout` anymore. The ownership for the positioning behavior should be reversed with the snackbar choosing whether it want to be shown above the toolbar and exactly how.
+
 # 110.0.0
 * [Commits](https://github.com/mozilla-mobile/firefox-android/compare/v109.0.0...v110.0.0)
 * [Dependencies](https://github.com/mozilla-mobile/firefox-android/blob/v110.0.0/android-components/plugins/dependencies/src/main/java/DependenciesPlugin.kt)