diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
index a40b70ed4..1f9225c5e 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
@@ -234,7 +234,7 @@ public class MediaActivity extends SimpleActivity
             }
         }
 
-        Medium.mSorting = mConfig.getSorting();
+        Medium.Companion.setSorting(mConfig.getSorting());
         Collections.sort(media);
         Utils.Companion.scanFiles(getApplicationContext(), invalidFiles);
 
diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
index 14fcc8e59..2288c163d 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
@@ -380,7 +380,7 @@ public class ViewPagerActivity extends SimpleActivity
             }
         }
 
-        Medium.mSorting = mConfig.getSorting();
+        Medium.Companion.setSorting(mConfig.getSorting());
         Collections.sort(media);
         int j = 0;
         for (Medium medium : media) {
diff --git a/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java b/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java
deleted file mode 100644
index 4522efc2a..000000000
--- a/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java
+++ /dev/null
@@ -1,82 +0,0 @@
-package com.simplemobiletools.gallery.models;
-
-import com.simplemobiletools.gallery.Constants;
-
-import java.io.Serializable;
-
-public class Medium implements Serializable, Comparable {
-    private static final long serialVersionUID = -6543139465975455L;
-    private final String mName;
-    private final boolean mIsVideo;
-    private final long mTimestamp;
-    private final long mSize;
-    public static int mSorting;
-    private String mPath;
-
-    public Medium(String name, String path, boolean isVideo, long timestamp, long size) {
-        mName = name;
-        mPath = path;
-        mIsVideo = isVideo;
-        mTimestamp = timestamp;
-        mSize = size;
-    }
-
-    public String getName() {
-        return mName;
-    }
-
-    public void setPath(String path) {
-        mPath = path;
-    }
-
-    public String getPath() {
-        return mPath;
-    }
-
-    public boolean getIsVideo() {
-        return mIsVideo;
-    }
-
-    public long getTimestamp() {
-        return mTimestamp;
-    }
-
-    public long getSize() {
-        return mSize;
-    }
-
-    public boolean isGif() {
-        return getPath().toLowerCase().endsWith(".gif");
-    }
-
-    public boolean isImage() {
-        return !isGif() && !getIsVideo();
-    }
-
-    @Override
-    public int compareTo(Object object) {
-        final Medium medium = (Medium) object;
-        int res;
-        if ((mSorting & Constants.SORT_BY_NAME) != 0) {
-            res = mPath.compareTo(medium.getPath());
-        } else if ((mSorting & Constants.SORT_BY_DATE) != 0) {
-            res = (mTimestamp > medium.getTimestamp()) ? 1 : -1;
-        } else {
-            res = (mSize > medium.getSize()) ? 1 : -1;
-        }
-
-        if ((mSorting & Constants.SORT_DESCENDING) != 0) {
-            res *= -1;
-        }
-        return res;
-    }
-
-    @Override
-    public String toString() {
-        return "Medium {" +
-                "isVideo=" + getIsVideo() +
-                ", timestamp=" + getTimestamp() +
-                ", size=" + getSize() +
-                ", path=" + getPath() + "}";
-    }
-}
diff --git a/app/src/main/kotlin/com/simplemobiletools/gallery/asynctasks/GetDirectoriesAsynctask.kt b/app/src/main/kotlin/com/simplemobiletools/gallery/asynctasks/GetDirectoriesAsynctask.kt
index 24f96112a..054489353 100644
--- a/app/src/main/kotlin/com/simplemobiletools/gallery/asynctasks/GetDirectoriesAsynctask.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/gallery/asynctasks/GetDirectoriesAsynctask.kt
@@ -79,7 +79,7 @@ class GetDirectoriesAsynctask(val context: Context, val isPickVideo: Boolean, va
 
         val dirs = ArrayList(directories.values)
         filterDirectories(dirs)
-        Directory.mSorting = mConfig.directorySorting
+        Directory.sorting = mConfig.directorySorting
         Collections.sort<Directory>(dirs)
 
         context.scanFiles(invalidFiles) {}
diff --git a/app/src/main/java/com/simplemobiletools/gallery/models/Directory.kt b/app/src/main/kotlin/com/simplemobiletools/gallery/models/Directory.kt
similarity index 64%
rename from app/src/main/java/com/simplemobiletools/gallery/models/Directory.kt
rename to app/src/main/kotlin/com/simplemobiletools/gallery/models/Directory.kt
index 258bde275..dede382c9 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/models/Directory.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/gallery/models/Directory.kt
@@ -9,25 +9,23 @@ class Directory(val path: String, val thumbnail: String, val name: String, var m
 
     override fun compareTo(other: Directory): Int {
         var res: Int
-        if (mSorting and Constants.SORT_BY_NAME != 0) {
+        if (sorting and Constants.SORT_BY_NAME != 0) {
             res = path.compareTo(other.path)
-        } else if (mSorting and Constants.SORT_BY_DATE != 0) {
+        } else if (sorting and Constants.SORT_BY_DATE != 0) {
             res = if (timestamp > other.timestamp) 1 else -1
         } else {
             res = if (size > other.size) 1 else -1
         }
 
-        if (mSorting and Constants.SORT_DESCENDING != 0) {
+        if (sorting and Constants.SORT_DESCENDING != 0) {
             res *= -1
         }
         return res
     }
 
-    override fun toString(): String {
-        return "Directory {path=$path, thumbnail=$thumbnail, name=$name, timestamp=$timestamp, mediaCnt=$mediaCnt}"
-    }
+    override fun toString() = "Directory {path=$path, thumbnail=$thumbnail, name=$name, mediaCnt=$mediaCnt, timestamp=$timestamp, size $size}"
 
     companion object {
-        var mSorting: Int = 0
+        var sorting: Int = 0
     }
 }
diff --git a/app/src/main/kotlin/com/simplemobiletools/gallery/models/Medium.kt b/app/src/main/kotlin/com/simplemobiletools/gallery/models/Medium.kt
new file mode 100644
index 000000000..d7ef3b110
--- /dev/null
+++ b/app/src/main/kotlin/com/simplemobiletools/gallery/models/Medium.kt
@@ -0,0 +1,36 @@
+package com.simplemobiletools.gallery.models
+
+import com.simplemobiletools.gallery.Constants
+
+import java.io.Serializable
+
+class Medium(val name: String, var path: String, val isVideo: Boolean, val timestamp: Long, val size: Long) : Serializable, Comparable<Medium> {
+    val isGif: Boolean
+        get() = path.toLowerCase().endsWith(".gif")
+
+    val isImage: Boolean
+        get() = !isGif && !isVideo
+
+    override fun compareTo(other: Medium): Int {
+        var res: Int
+        if (sorting and Constants.SORT_BY_NAME != 0) {
+            res = path.compareTo(other.path)
+        } else if (sorting and Constants.SORT_BY_DATE != 0) {
+            res = if (timestamp > other.timestamp) 1 else -1
+        } else {
+            res = if (size > other.size) 1 else -1
+        }
+
+        if (sorting and Constants.SORT_DESCENDING != 0) {
+            res *= -1
+        }
+        return res
+    }
+
+    override fun toString() = "Medium {name=$name, path=$path, isVideo=$isVideo, timestamp=$timestamp, size=$size}"
+
+    companion object {
+        private val serialVersionUID = -6543139465975455L
+        var sorting: Int = 0
+    }
+}