Added fast scroll to message list

app/src/main/java/eu/faircode/email/FixedRecyclerView.java

@@ -75,5 +75,4 @@ public class FixedRecyclerView extends RecyclerView {
             return false;
         }
     }
-
 }

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -446,6 +446,14 @@ public class FragmentMessages extends FragmentBase {
 
         rvMessage.setAdapter(adapter);
 
+        rvMessage.addOnScrollListener(new RecyclerView.OnScrollListener() {
+            @Override
+            public void onScrolled(@NonNull RecyclerView rv, int dx, int dy) {
+                int pos = (rv.getChildCount() == 0 ? 0 : rv.getChildAt(0).getTop());
+                swipeRefresh.setEnabled(pull && pos >= 0);
+            }
+        });
+
         seekBar.setOnTouchListener(new View.OnTouchListener() {
             @Override
             public boolean onTouch(View v, MotionEvent event) {

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

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_pressed="true">
+        <shape android:shape="rectangle">
+            <solid android:color="?android:attr/colorAccent" />
+        </shape>
+    </item>
+    <item>
+        <shape android:shape="rectangle">
+            <solid android:color="?android:attr/colorPrimary" />
+        </shape>
+    </item>
+</selector>

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

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="?colorSeparator" />
+</shape>

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

@@ -150,7 +150,14 @@
                 android:clipToPadding="false"
                 android:paddingBottom="90dp"
                 android:scrollbarStyle="outsideOverlay"
+                android:scrollbarThumbVertical="@drawable/fast_scroll_thumb"
+                android:scrollbarTrackVertical="@drawable/fast_scroll_track"
                 android:scrollbars="vertical"
+                app:fastScrollEnabled="true"
+                app:fastScrollHorizontalThumbDrawable="@drawable/fast_scroll_thumb"
+                app:fastScrollHorizontalTrackDrawable="@drawable/fast_scroll_track"
+                app:fastScrollVerticalThumbDrawable="@drawable/fast_scroll_thumb"
+                app:fastScrollVerticalTrackDrawable="@drawable/fast_scroll_track"
                 app:layout_constraintBottom_toTopOf="@+id/bottom_navigation"
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintStart_toStartOf="parent"