show a toast if the slideshow ended + implement moving backwards

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

@@ -52,8 +52,10 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
     private var mRotationDegrees = 0f
     private var mLastHandledOrientation = 0
     private var mPrevHashcode = 0
+
     private var mSlideshowHandler = Handler()
     private var mSlideshowInterval = SLIDESHOW_DEFAULT_INTERVAL
+    private var mSlideshowMoveBackwards = false
 
     companion object {
         var screenWidth = 0
@@ -261,6 +263,7 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
     private fun startSlideshow() {
         hideSystemUI()
         mSlideshowInterval = config.slideshowInterval
+        mSlideshowMoveBackwards = config.slideshowMoveBackwards
         mIsSlideshowActive = true
         scheduleSwipe()
         window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
@@ -280,7 +283,12 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
         if (mIsSlideshowActive) {
             mSlideshowHandler.postDelayed({
                 if (mIsSlideshowActive && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1 && !isDestroyed) {
-                    view_pager.currentItem = ++view_pager.currentItem
+                    val before = view_pager.currentItem
+                    view_pager.currentItem = if (mSlideshowMoveBackwards) --view_pager.currentItem else ++view_pager.currentItem
+                    if (before == view_pager.currentItem) {
+                        stopSlideshow()
+                        toast(R.string.slideshow_ended)
+                    }
                 }
             }, mSlideshowInterval * 1000L)
         }

app/src/main/res/values-cs/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Zobrazit skryté média</string>

app/src/main/res/values-de/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Versteckte Ordner zeigen</string>

app/src/main/res/values-es/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Mostrar carpetas ocultas</string>

app/src/main/res/values-fr/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Afficher les dossiers cachés</string>

app/src/main/res/values-hu/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Show hidden media</string>

app/src/main/res/values-it/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Mostra cartelle nascoste</string>

app/src/main/res/values-ja/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">非表示フォルダーを表示</string>

app/src/main/res/values-pl/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Pokazuj ukryte foldery</string>

app/src/main/res/values-pt-rBR/strings.xml

@@ -87,6 +87,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Mostrar pastas ocultas</string>

app/src/main/res/values-pt/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Mostrar pastas ocultas</string>

app/src/main/res/values-ru/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Показать скрытые папки</string>

app/src/main/res/values-sk/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Náhodné poradie</string>
     <string name="use_fade">Používať miznúce animácie</string>
     <string name="move_backwards">Ísť opačným smerom</string>
+    <string name="slideshow_ended">Prezentácia skončila</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Zobraziť skryté médiá</string>

app/src/main/res/values-sv/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Visa dolda mappar</string>

app/src/main/res/values-tr/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Gizli klasörleri göster</string>

app/src/main/res/values-zh-rCN/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">显示所有</string>

app/src/main/res/values-zh-rTW/strings.xml

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">秀出隱藏資料夾</string>

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

@@ -86,6 +86,7 @@
     <string name="random_order">Random order</string>
     <string name="use_fade">Use fade animations</string>
     <string name="move_backwards">Move backwards</string>
+    <string name="slideshow_ended">The slideshow ended</string>
 
     <!-- Settings -->
     <string name="show_hidden_media">Show hidden media</string>