For #357 - Changes delete text depending on the number of items selected

app/src/main/java/org/mozilla/fenix/library/history/HistoryAdapter.kt

@@ -125,12 +125,14 @@ class HistoryAdapter(
         }
 
         fun bind(mode: HistoryState.Mode) {
-            when(mode) {
-                is HistoryState.Mode.Normal ->
-                    text.text = text.context.resources.getText(R.string.delete_history)
-                is HistoryState.Mode.Editing ->
-                    text.text = text.context.resources.getString(R.string.delete_history_items, mode.selectedItems.size)
+            val text = if (mode is HistoryState.Mode.Editing && mode.selectedItems.isNotEmpty()) {
+                text.context.resources.getString(R.string.delete_history_items, mode.selectedItems.size)
+            } else {
+                text.context.resources.getString(R.string.delete_history)
             }
+
+            button.contentDescription = text
+            this.text.text = text
         }
 
         companion object {

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

@@ -4,9 +4,12 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/delete_history_button"
+    android:foreground="?android:attr/selectableItemBackground"
     android:background="@drawable/delete_history_background"
     android:layout_margin="16dp"
     android:padding="6dp"
+    android:clickable="true"
+    android:focusable="true"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">
 
@@ -19,5 +22,7 @@
         android:drawablePadding="8dp"
         android:textSize="16sp"
         android:gravity="center"
+        android:clickable="false"
+        android:focusable="false"
         android:layout_gravity="center" />
 </FrameLayout>

app/src/main/res/values/strings.xml

@@ -152,5 +152,5 @@
 
     <!-- Text for the button to clear selected history items. The first parameter
         is the number of items you have selected -->
-    <string name="delete_history_items">Delete %1$s Items</string>
+    <string name="delete_history_items">Delete %1$d Items</string>
 </resources>