add colored background to the currently selected directory thumbnail

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

@@ -227,8 +227,8 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
     }
 
     private fun checkIfColorChanged() {
-        if (directories_grid.adapter != null && getRecyclerAdapter().foregroundColor != config.primaryColor) {
-            getRecyclerAdapter().updatePrimaryColor(config.primaryColor)
+        if (directories_grid.adapter != null && getRecyclerAdapter().primaryColor != config.primaryColor) {
+            getRecyclerAdapter().primaryColor = config.primaryColor
             directories_vertical_fastscroller.updateHandleColor()
             directories_horizontal_fastscroller.updateHandleColor()
         }

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/DirectoryAdapter.kt

@@ -1,5 +1,6 @@
 package com.simplemobiletools.gallery.adapters
 
+import android.graphics.PorterDuff
 import android.support.v7.view.ActionMode
 import android.support.v7.widget.RecyclerView
 import android.util.SparseArray
@@ -33,19 +34,19 @@ class DirectoryAdapter(val activity: SimpleActivity, var dirs: MutableList<Direc
     var actMode: ActionMode? = null
     var itemViews = SparseArray<View>()
     val selectedPositions = HashSet<Int>()
-    var foregroundColor = config.primaryColor
+    var primaryColor = config.primaryColor
     var pinnedFolders = config.pinnedFolders
     var scrollVertically = !config.scrollHorizontally
 
     fun toggleItemSelection(select: Boolean, pos: Int) {
-        if (itemViews[pos] != null)
-            itemViews[pos].dir_check.beVisibleIf(select)
-
-        if (select)
+        if (select) {
+            itemViews[pos].dir_check.background.setColorFilter(primaryColor, PorterDuff.Mode.SRC_IN)
             selectedPositions.add(pos)
-        else
+        } else
             selectedPositions.remove(pos)
 
+        itemViews[pos]?.dir_check?.beVisibleIf(select)
+
         if (selectedPositions.isEmpty()) {
             actMode?.finish()
             return
@@ -59,14 +60,6 @@ class DirectoryAdapter(val activity: SimpleActivity, var dirs: MutableList<Direc
         actMode?.invalidate()
     }
 
-    fun updatePrimaryColor(color: Int) {
-        foregroundColor = color
-        (0..itemViews.size() - 1).mapNotNull { itemViews[it] }
-                .forEach {
-
-                }
-    }
-
     val adapterListener = object : MyAdapterListener {
         override fun toggleItemSelectionAdapter(select: Boolean, position: Int) {
             toggleItemSelection(select, position)
@@ -411,6 +404,8 @@ class DirectoryAdapter(val activity: SimpleActivity, var dirs: MutableList<Direc
 
                 setOnClickListener { viewClicked(directory) }
                 setOnLongClickListener { if (isPickIntent) viewClicked(directory) else viewLongClicked(); true }
+
+
             }
             return itemView
         }

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

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="oval">
+
+    <solid
+        android:color="@color/color_primary"/>
+
+</shape>

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

@@ -13,12 +13,14 @@
 
     <ImageView
         android:id="@+id/dir_check"
-        android:layout_width="@dimen/pin_size"
-        android:layout_height="@dimen/pin_size"
+        android:layout_width="@dimen/selection_check_size"
+        android:layout_height="@dimen/selection_check_size"
         android:layout_alignParentEnd="true"
         android:layout_alignParentRight="true"
         android:layout_alignParentTop="true"
         android:layout_margin="@dimen/small_margin"
+        android:background="@drawable/circle_background"
+        android:padding="@dimen/tiny_margin"
         android:src="@drawable/ic_check"/>
 
     <ImageView

app/src/main/res/values-sw600dp/dimens.xml

@@ -2,6 +2,7 @@
     <dimen name="dir_tmb_size">150dp</dimen>
     <dimen name="medium_tmb_size">120dp</dimen>
     <dimen name="pin_size">30dp</dimen>
+    <dimen name="selection_check_size">38dp</dimen>
     <dimen name="play_outline_size">60dp</dimen>
     <dimen name="play_outline_size_big">230dp</dimen>
     <dimen name="timer_padding">32dp</dimen>

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

@@ -3,6 +3,7 @@
     <dimen name="dir_tmb_size">150dp</dimen>
     <dimen name="medium_tmb_size">100dp</dimen>
     <dimen name="pin_size">20dp</dimen>
+    <dimen name="selection_check_size">26dp</dimen>
     <dimen name="play_outline_size">40dp</dimen>
     <dimen name="play_outline_size_big">150dp</dimen>
     <dimen name="timer_padding">24dp</dimen>