[Android] Fix prefetched navigation

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Thu Feb  7 12:30:15 2019 +0100| [03e21f0cda317cde380db9264f9765240d7c2b57] | committer: Geoffrey Métais

Fix prefetched navigation

> https://code.videolan.org/videolan/vlc-android/commit/03e21f0cda317cde380db9264f9765240d7c2b57
---

 vlc-android/src/org/videolan/vlc/providers/BrowserProvider.kt | 4 ++++
 vlc-android/src/org/videolan/vlc/providers/NetworkProvider.kt | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/vlc-android/src/org/videolan/vlc/providers/BrowserProvider.kt b/vlc-android/src/org/videolan/vlc/providers/BrowserProvider.kt
index cb296197f..e4002ad23 100644
--- a/vlc-android/src/org/videolan/vlc/providers/BrowserProvider.kt
+++ b/vlc-android/src/org/videolan/vlc/providers/BrowserProvider.kt
@@ -258,6 +258,10 @@ abstract class BrowserProvider(val context: Context, val dataset: LiveDataset<Me
         loading.value = false
     }
 
+    protected fun getList(url: String) =  prefetchLists[url]
+
+    protected fun removeList(url: String) =  prefetchLists.remove(url)
+
     fun saveList(media: MediaWrapper) = foldersContentMap[media]?.let { if (!it.isEmpty()) prefetchLists[media.location] = it }
 
     fun isFolderEmpty(mw: MediaWrapper) = foldersContentMap[mw]?.isEmpty() ?: true
diff --git a/vlc-android/src/org/videolan/vlc/providers/NetworkProvider.kt b/vlc-android/src/org/videolan/vlc/providers/NetworkProvider.kt
index 0456ebfb8..9046b5d12 100644
--- a/vlc-android/src/org/videolan/vlc/providers/NetworkProvider.kt
+++ b/vlc-android/src/org/videolan/vlc/providers/NetworkProvider.kt
@@ -49,13 +49,20 @@ class NetworkProvider(context: Context, dataset: LiveDataset<MediaLibraryItem>,
     override fun fetch() {}
 
     override fun refresh(): Boolean {
+        val list by lazy(LazyThreadSafetyMode.NONE) { getList(url!!) }
         return if (url == null) {
             dataset.value = mutableListOf<MediaLibraryItem>().apply {
                 getFavoritesList(favorites?.value)?.let { addAll(it) }
             }
             launch { browseRoot() }
             true
+        } else if (list !== null) {
+            dataset.value = list as MutableList<MediaLibraryItem>
+            removeList(url)
+            parseSubDirectories()
+            true
         } else super.refresh()
+
     }
 
     override fun parseSubDirectories() {