add the fast scroll to directory view too

app/src/main/kotlin/com/simplemobiletools/gallery/activities/MainActivity.kt

@@ -64,7 +64,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
         mIsThirdPartyIntent = mIsPickImageIntent || mIsPickVideoIntent || mIsGetImageContentIntent || mIsGetVideoContentIntent ||
                 mIsGetAnyContentIntent || mIsSetWallpaperIntent
 
-        directories_holder.setOnRefreshListener({ getDirectories() })
+        directories_refresh_layout.setOnRefreshListener({ getDirectories() })
         mDirs = ArrayList<Directory>()
         mStoredAnimateGifs = config.animateGifs
         storeStoragePaths()
@@ -107,7 +107,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
         super.onPause()
         mCurrAsyncTask?.shouldStop = true
         storeDirectories()
-        directories_holder.isRefreshing = false
+        directories_refresh_layout.isRefreshing = false
         mIsGettingDirs = false
         mStoredAnimateGifs = config.animateGifs
     }
@@ -152,7 +152,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
         val token = object : TypeToken<List<Directory>>() {}.type
         val dirs = Gson().fromJson<ArrayList<Directory>>(config.directories, token) ?: ArrayList<Directory>(1)
         if (dirs.size == 0) {
-            directories_holder.isRefreshing = true
+            directories_refresh_layout.isRefreshing = true
         } else {
             gotDirectories(dirs)
         }
@@ -324,7 +324,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
     }
 
     fun gotDirectories(dirs: ArrayList<Directory>) {
-        directories_holder.isRefreshing = false
+        directories_refresh_layout.isRefreshing = false
         mIsGettingDirs = false
 
         if (dirs.hashCode() == mDirs.hashCode())
@@ -347,6 +347,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
         }
 
         directories_grid.adapter = adapter
+        directories_fastscroller.setViews(directories_grid, directories_refresh_layout)
     }
 
     override fun refreshItems() {

app/src/main/kotlin/com/simplemobiletools/gallery/views/FastScroller.kt

@@ -54,7 +54,7 @@ class FastScroller : LinearLayout {
     }
 
     private fun updateHandlePosition() {
-        if (handle.isSelected)
+        if (handle.isSelected || recyclerView == null)
             return
 
         val verticalScrollOffset = recyclerView!!.computeVerticalScrollOffset()

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

@@ -2,16 +2,31 @@
 <android.support.v4.widget.SwipeRefreshLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/directories_refresh_layout"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <RelativeLayout
         android:id="@+id/directories_holder"
         android:layout_width="match_parent"
-    android:layout_height="match_parent">
+        android:layout_height="wrap_content">
 
         <com.simplemobiletools.gallery.views.MyScalableRecyclerView
             android:id="@+id/directories_grid"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-        android:scrollbars="vertical"
+            android:scrollbars="none"
             app:layoutManager="android.support.v7.widget.GridLayoutManager"
             app:spanCount="@integer/directory_columns"/>
 
+        <com.simplemobiletools.gallery.views.FastScroller
+            android:id="@+id/directories_fastscroller"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:layout_alignParentEnd="true"
+            android:layout_alignParentRight="true"
+            android:paddingLeft="@dimen/normal_margin"
+            android:paddingStart="@dimen/normal_margin"/>
+
+    </RelativeLayout>
 </android.support.v4.widget.SwipeRefreshLayout>

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

@@ -25,7 +25,8 @@
             android:layout_height="match_parent"
             android:layout_alignParentEnd="true"
             android:layout_alignParentRight="true"
-            android:paddingLeft="@dimen/normal_margin"/>
+            android:paddingLeft="@dimen/normal_margin"
+            android:paddingStart="@dimen/normal_margin"/>
 
     </RelativeLayout>
 </android.support.v4.widget.SwipeRefreshLayout>

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

@@ -8,6 +8,7 @@
         android:id="@+id/fastscroller_handle"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:alpha="0"
         android:background="@drawable/fastscroller_handle"/>
 
 </merge>