Adds swipe to delete tab

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayFragment.kt

@@ -21,6 +21,7 @@ import org.mozilla.fenix.ext.requireComponents
 import androidx.navigation.fragment.findNavController
 import mozilla.components.browser.session.Session
 import mozilla.components.browser.session.SessionManager
+import mozilla.components.browser.tabstray.BrowserTabsTray
 import mozilla.components.concept.tabstray.Tab
 import mozilla.components.concept.tabstray.TabsTray
 import org.mozilla.fenix.BrowserDirection
@@ -51,6 +52,10 @@ class TabTrayFragment : Fragment(R.layout.fragment_tab_tray), TabsTray.Observer,
         showToolbar(getString(R.string.tab_tray_title))
         onTabsChanged()
 
+        (tabsTray as? BrowserTabsTray)?.also { tray ->
+            TabsTouchHelper(tray.tabsAdapter).attachToRecyclerView(tray)
+        }
+
         sessionManager.register(observer = object : SessionManager.Observer {
             override fun onSessionAdded(session: Session) {
                 onTabsChanged()

app/src/main/java/org/mozilla/fenix/tabtray/TabsTouchHelper.kt

@@ -0,0 +1,17 @@
+/* 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 org.mozilla.fenix.tabtray
+
+import androidx.recyclerview.widget.ItemTouchHelper
+import mozilla.components.browser.tabstray.TabTouchCallback
+import mozilla.components.concept.tabstray.TabsTray
+import mozilla.components.support.base.observer.Observable
+
+class TabsTouchHelper(observable: Observable<TabsTray.Observer>) :
+    ItemTouchHelper(object : TabTouchCallback(observable) {
+        override fun alphaForItemSwipe(dX: Float, distanceToAlphaMin: Int): Float {
+            return 1f - 2f * Math.abs(dX) / distanceToAlphaMin
+        }
+    })

app/src/main/res/layout/tab_tray_item.xml

@@ -44,7 +44,6 @@
         android:textSize="16sp"
         android:paddingTop="22dp"
         android:paddingStart="16dp"
-        android:layout_marginEnd="20dp"
         app:layout_constraintHorizontal_bias="0.0"
         app:layout_constraintEnd_toStartOf="@id/mozac_browser_tabstray_close"
         app:layout_constraintStart_toEndOf="@id/mozac_browser_tabstray_card"
@@ -59,18 +58,15 @@
         android:lines="1"
         android:textSize="14sp"
         android:paddingStart="16dp"
-        android:layout_marginEnd="20dp"
         app:layout_constraintHorizontal_bias="0.0"
         app:layout_constraintEnd_toStartOf="@id/mozac_browser_tabstray_close"
         app:layout_constraintStart_toEndOf="@id/mozac_browser_tabstray_card"
         app:layout_constraintTop_toBottomOf="@id/mozac_browser_tabstray_title" />
 
     <androidx.appcompat.widget.AppCompatImageButton
         android:id="@+id/mozac_browser_tabstray_close"
-        android:layout_width="24dp"
-        android:layout_height="24dp"
-        android:layout_marginTop="32dp"
-        android:layout_marginEnd="16dp"
+        android:layout_width="56dp"
+        android:layout_height="match_parent"
         app:layout_constraintHorizontal_bias="0.0"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintTop_toTopOf="parent"