couple changes related to toggling fullscreen

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

@@ -98,6 +98,11 @@ open class PhotoVideoActivity : SimpleActivity(), ViewPagerFragment.FragmentList
         } finally {
             cursor?.close()
         }
+
+        window.decorView.setOnSystemUiVisibilityChangeListener { visibility ->
+            val isFullscreen = visibility and View.SYSTEM_UI_FLAG_FULLSCREEN != 0
+            mFragment.fullscreenToggled(isFullscreen)
+        }
     }
 
     override fun onResume() {
@@ -157,13 +162,4 @@ open class PhotoVideoActivity : SimpleActivity(), ViewPagerFragment.FragmentList
             showSystemUI()
         }
     }
-
-    override fun systemUiVisibilityChanged(visibility: Int) {
-        if (visibility and View.SYSTEM_UI_FLAG_FULLSCREEN == 0) {
-            mIsFullScreen = false
-            showSystemUI()
-        } else {
-            mIsFullScreen = true
-        }
-    }
 }

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

@@ -112,6 +112,14 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
 
         if (config.hideSystemUI)
             fragmentClicked()
+
+        window.decorView.setOnSystemUiVisibilityChangeListener { visibility ->
+            mIsFullScreen = visibility and View.SYSTEM_UI_FLAG_FULLSCREEN != 0
+            view_pager.adapter?.let {
+                (it as MyPagerAdapter).toggleFullscreen(mIsFullScreen)
+                checkSystemUI()
+            }
+        }
     }
 
     override fun onDestroy() {
@@ -445,6 +453,10 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
 
     override fun fragmentClicked() {
         mIsFullScreen = !mIsFullScreen
+        checkSystemUI()
+    }
+
+    private fun checkSystemUI() {
         if (mIsFullScreen) {
             hideSystemUI()
         } else {
@@ -452,15 +464,6 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
         }
     }
 
-    override fun systemUiVisibilityChanged(visibility: Int) {
-        if (visibility and View.SYSTEM_UI_FLAG_FULLSCREEN == 0) {
-            mIsFullScreen = false
-            showSystemUI()
-        } else {
-            mIsFullScreen = true
-        }
-    }
-
     private fun updateActionbarTitle() {
         runOnUiThread {
             if (mPos < mMedia.size) {

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

@@ -5,7 +5,6 @@ import android.support.v4.app.Fragment
 import android.support.v4.app.FragmentManager
 import android.support.v4.app.FragmentStatePagerAdapter
 import android.support.v4.view.PagerAdapter
-import android.util.SparseArray
 import android.view.ViewGroup
 import com.simplemobiletools.gallery.activities.ViewPagerActivity
 import com.simplemobiletools.gallery.fragments.PhotoFragment
@@ -15,7 +14,7 @@ import com.simplemobiletools.gallery.helpers.MEDIUM
 import com.simplemobiletools.gallery.models.Medium
 
 class MyPagerAdapter(val activity: ViewPagerActivity, fm: FragmentManager, val media: MutableList<Medium>) : FragmentStatePagerAdapter(fm) {
-    private val mFragments = SparseArray<ViewPagerFragment>()
+    private val mFragments = HashMap<Int, ViewPagerFragment>()
     override fun getCount() = media.size
 
     override fun getItem(position: Int): Fragment {
@@ -49,4 +48,10 @@ class MyPagerAdapter(val activity: ViewPagerActivity, fm: FragmentManager, val m
     }
 
     fun getCurrentFragment(position: Int) = mFragments.get(position)
+
+    fun toggleFullscreen(isFullscreen: Boolean) {
+        for ((pos, fragment) in mFragments) {
+            fragment.fullscreenToggled(isFullscreen)
+        }
+    }
 }

app/src/main/kotlin/com/simplemobiletools/gallery/fragments/PhotoFragment.kt

@@ -42,7 +42,6 @@ class PhotoFragment : ViewPagerFragment() {
     lateinit var view: ViewGroup
     private var isFragmentVisible = false
     private var wasInit = false
-    private var RATIO_THRESHOLD = 0.1
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         view = inflater.inflate(R.layout.pager_photo_item, container, false) as ViewGroup
@@ -100,9 +99,6 @@ class PhotoFragment : ViewPagerFragment() {
         }
         loadImage()
 
-        activity.window.decorView.setOnSystemUiVisibilityChangeListener { visibility ->
-            listener?.systemUiVisibilityChanged(visibility)
-        }
         wasInit = true
 
         return view
@@ -256,4 +252,8 @@ class PhotoFragment : ViewPagerFragment() {
     private fun photoClicked() {
         listener?.fragmentClicked()
     }
+
+    override fun fullscreenToggled(isFullscreen: Boolean) {
+
+    }
 }

app/src/main/kotlin/com/simplemobiletools/gallery/fragments/VideoFragment.kt

@@ -60,12 +60,6 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
         }
 
         mIsFullscreen = activity.window.decorView.systemUiVisibility and View.SYSTEM_UI_FLAG_FULLSCREEN == View.SYSTEM_UI_FLAG_FULLSCREEN
-
-        activity.window.decorView.setOnSystemUiVisibilityChangeListener { visibility ->
-            mIsFullscreen = visibility and View.SYSTEM_UI_FLAG_FULLSCREEN != 0
-            checkFullscreen()
-            listener?.systemUiVisibilityChanged(visibility)
-        }
         checkFullscreen()
 
         return mView
@@ -114,8 +108,6 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
     }
 
     private fun toggleFullscreen() {
-        mIsFullscreen = !mIsFullscreen
-        checkFullscreen()
         listener?.fragmentClicked()
     }
 
@@ -372,4 +364,9 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
 
         mIsDragged = false
     }
+
+    override fun fullscreenToggled(isFullscreen: Boolean) {
+        mIsFullscreen = isFullscreen
+        checkFullscreen()
+    }
 }

app/src/main/kotlin/com/simplemobiletools/gallery/fragments/ViewPagerFragment.kt

@@ -5,9 +5,9 @@ import android.support.v4.app.Fragment
 abstract class ViewPagerFragment : Fragment() {
     var listener: FragmentListener? = null
 
+    abstract fun fullscreenToggled(isFullscreen: Boolean)
+
     interface FragmentListener {
         fun fragmentClicked()
-
-        fun systemUiVisibilityChanged(visibility: Int)
     }
 }