shorten some model variable names

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

@@ -330,7 +330,7 @@ class DirectoryAdapter(val activity: SimpleActivity, val dirs: MutableList<Direc
                 photo_cnt.text = directory.mediaCnt.toString()
                 dir_pin.visibility = if (isPinned) View.VISIBLE else View.GONE
                 toggleItemSelection(this, markedItems.contains(pos), pos)
-                activity.loadImage(directory.thumbnail, dir_thumbnail)
+                activity.loadImage(directory.tmb, dir_thumbnail)
 
                 setOnClickListener { viewClicked(multiSelector, directory, pos) }
                 setOnLongClickListener {

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

@@ -235,7 +235,7 @@ class MediaAdapter(val activity: SimpleActivity, var media: MutableList<Medium>,
     class ViewHolder(val view: View, val itemClick: (Medium) -> (Unit)) : SwappingHolder(view, MultiSelector()) {
         fun bindView(activity: SimpleActivity, multiSelectorCallback: ModalMultiSelectorCallback, multiSelector: MultiSelector, medium: Medium, pos: Int): View {
             itemView.apply {
-                play_outline.visibility = if (medium.isVideo) View.VISIBLE else View.GONE
+                play_outline.visibility = if (medium.video) View.VISIBLE else View.GONE
                 photo_name.beVisibleIf(displayFilenames)
                 photo_name.text = medium.name
                 toggleItemSelection(this, markedItems.contains(pos), pos)

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

@@ -24,7 +24,7 @@ class MyPagerAdapter(val activity: ViewPagerActivity, fm: FragmentManager, val m
         bundle.putSerializable(MEDIUM, medium)
         val fragment: ViewPagerFragment
 
-        if (medium.isVideo) {
+        if (medium.video) {
             fragment = VideoFragment()
         } else {
             fragment = PhotoFragment()

app/src/main/kotlin/com/simplemobiletools/gallery/helpers/Constants.kt

@@ -18,7 +18,7 @@ val DIR_COLUMN_CNT = "dir_column_cnt"
 val MEDIA_COLUMN_CNT = "media_column_cnt"
 val SHOW_ALL = "show_all"   // display images and videos from all folders together
 val SHOW_MEDIA = "show_media"
-val SAVE_FOLDER_PREFIX = "folder_"
+val SAVE_FOLDER_PREFIX = "folder2_"
 val HIDE_FOLDER_TOOLTIP_SHOWN = "hide_folder_tooltip_shown"
 val EXCLUDED_FOLDERS = "excluded_folders"
 val INCLUDED_FOLDERS = "included_folders"
@@ -31,7 +31,7 @@ val GET_IMAGE_INTENT = "get_image_intent"
 val GET_VIDEO_INTENT = "get_video_intent"
 val GET_ANY_INTENT = "get_any_intent"
 val SET_WALLPAPER_INTENT = "set_wallpaper_intent"
-val DIRECTORIES = "directories"
+val DIRECTORIES = "directories2"
 
 val REQUEST_EDIT_IMAGE = 1
 val REQUEST_SET_WALLPAPER = 2

app/src/main/kotlin/com/simplemobiletools/gallery/models/Directory.kt

@@ -6,10 +6,10 @@ import com.simplemobiletools.commons.helpers.SORT_BY_SIZE
 import com.simplemobiletools.commons.helpers.SORT_DESCENDING
 import java.io.Serializable
 
-data class Directory(val path: String, val thumbnail: String, val name: String, var mediaCnt: Int, val date_modified: Long, val date_taken: Long,
+data class Directory(val path: String, val tmb: String, val name: String, var mediaCnt: Int, val modified: Long, val taken: Long,
                      var size: Long) : Serializable, Comparable<Directory> {
     companion object {
-        private val serialVersionUID = -6553345863575455L
+        private val serialVersionUID = -6553345863555455L
         var sorting: Int = 0
     }
 
@@ -29,16 +29,16 @@ data class Directory(val path: String, val thumbnail: String, val name: String,
             else
                 -1
         } else if (sorting and SORT_BY_DATE_MODIFIED != 0) {
-            result = if (date_modified == other.date_modified)
+            result = if (modified == other.modified)
                 0
-            else if (date_modified > other.date_modified)
+            else if (modified > other.modified)
                 1
             else
                 -1
         } else {
-            result = if (date_taken == other.date_taken)
+            result = if (taken == other.taken)
                 0
-            else if (date_taken > other.date_taken)
+            else if (taken > other.taken)
                 1
             else
                 -1

app/src/main/kotlin/com/simplemobiletools/gallery/models/Medium.kt

@@ -10,9 +10,9 @@ import com.simplemobiletools.commons.helpers.SORT_DESCENDING
 import java.io.File
 import java.io.Serializable
 
-data class Medium(val name: String, var path: String, val isVideo: Boolean, val date_modified: Long, val date_taken: Long, val size: Long) : Serializable, Comparable<Medium> {
+data class Medium(val name: String, var path: String, val video: Boolean, val modified: Long, val taken: Long, val size: Long) : Serializable, Comparable<Medium> {
     companion object {
-        private val serialVersionUID = -6553149466975455L
+        private val serialVersionUID = -6553149366975455L
         var sorting: Int = 0
     }
 
@@ -20,7 +20,7 @@ data class Medium(val name: String, var path: String, val isVideo: Boolean, val
 
     fun isGif() = path.isGif()
 
-    fun isImage() = !isGif() && !isVideo
+    fun isImage() = !isGif() && !video
 
     fun getMimeType() = File(path).getMimeType()
 
@@ -36,16 +36,16 @@ data class Medium(val name: String, var path: String, val isVideo: Boolean, val
             else
                 -1
         } else if (sorting and SORT_BY_DATE_MODIFIED != 0) {
-            res = if (date_modified == other.date_modified)
+            res = if (modified == other.modified)
                 0
-            else if (date_modified > other.date_modified)
+            else if (modified > other.modified)
                 1
             else
                 -1
         } else {
-            res = if (date_taken == other.date_taken)
+            res = if (taken == other.taken)
                 0
-            else if (date_taken > other.date_taken)
+            else if (taken > other.taken)
                 1
             else
                 -1