Adjust reader seekbar design

- Revert back to old prev/next chapter icons
- Make views taller for easier actions
- Use more consistent spacing
- Add ripples to prev/next chapter buttons

app/src/main/res/drawable/ic_skip_next_24dp.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/black"
+        android:pathData="M6,18l8.5,-6L6,6v12zM16,6v12h2V6h-2z" />
+</vector>

app/src/main/res/drawable/ic_skip_previous_24dp.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/black"
+        android:pathData="M6,6h2v12L6,18zM9.5,12l8.5,6L18,6z" />
+</vector>

app/src/main/res/drawable/reader_seekbar_background.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <shape xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
-    <corners android:radius="15dp" />
+    <corners android:radius="48dp" />
     <solid android:color="?attr/colorPrimary" />
 </shape>

app/src/main/res/drawable/reader_seekbar_button.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/reader_seekbar_ripple" android:state_pressed="true" />
+    <item android:drawable="@drawable/reader_seekbar_ripple" android:state_focused="true" />
+    <item android:drawable="@drawable/reader_seekbar_ripple" android:state_selected="true" />
+    <item android:drawable="@drawable/reader_seekbar_background" />
+</selector>

app/src/main/res/drawable/reader_seekbar_ripple.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="?attr/colorOnPrimary">
+    <item android:id="@android:id/mask">
+        <shape android:shape="rectangle">
+            <solid android:color="@android:color/white" />
+            <corners android:radius="48dp" />
+        </shape>
+    </item>
+</ripple>

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

@@ -68,33 +68,31 @@
                 android:id="@+id/reader_nav"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:layout_gravity="bottom"
                 android:layout_marginStart="8dp"
                 android:layout_marginEnd="8dp"
                 android:layout_marginBottom="16dp"
-                android:gravity="center"
+                android:layoutDirection="ltr"
                 android:orientation="horizontal">
 
                 <ImageButton
                     android:id="@+id/left_chapter"
-                    android:layout_width="40dp"
-                    android:layout_height="40dp"
-                    android:layout_gravity="center"
-                    android:layout_marginStart="50dp"
+                    android:layout_width="48dp"
+                    android:layout_height="48dp"
                     android:layout_marginEnd="8dp"
                     android:background="@drawable/reader_seekbar_background"
                     android:contentDescription="@string/action_previous_chapter"
                     android:padding="@dimen/material_layout_keylines_screen_edge_margin"
-                    app:srcCompat="@drawable/ic_arrow_back_24dp"
+                    app:srcCompat="@drawable/ic_skip_previous_24dp"
                     app:tint="?attr/colorOnPrimary" />
 
                 <LinearLayout
                     android:id="@+id/reader_seekbar"
-                    android:layout_width="match_parent"
+                    android:layout_width="0dp"
                     android:layout_height="match_parent"
-                    android:background="@drawable/reader_seekbar_background"
-                    android:paddingStart="10dp"
-                    android:paddingEnd="10dp">
+                    android:layout_weight="1"
+                    android:background="@drawable/reader_seekbar_button"
+                    android:paddingStart="8dp"
+                    android:paddingEnd="8dp">
 
                     <TextView
                         android:id="@+id/left_page_text"
@@ -128,18 +126,15 @@
 
                 </LinearLayout>
 
-                <!-- android:background="?selectableItemBackgroundBorderless"-->
                 <ImageButton
                     android:id="@+id/right_chapter"
-                    android:layout_width="40dp"
-                    android:layout_height="40dp"
-                    android:layout_gravity="center"
+                    android:layout_width="48dp"
+                    android:layout_height="48dp"
                     android:layout_marginStart="8dp"
-                    android:layout_marginEnd="50dp"
-                    android:background="@drawable/reader_seekbar_background"
+                    android:background="@drawable/reader_seekbar_button"
                     android:contentDescription="@string/action_next_chapter"
                     android:padding="@dimen/material_layout_keylines_screen_edge_margin"
-                    app:srcCompat="@drawable/ic_arrow_forward_24dp"
+                    app:srcCompat="@drawable/ic_skip_next_24dp"
                     app:tint="?attr/colorOnPrimary" />
 
             </LinearLayout>