[Android] Improve media loading

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Thu Jun 20 18:14:26 2019 +0200| [a2853bb92129facc9471456244ed002fbc3a81fd] | committer: Geoffrey Métais

Improve media loading

> https://code.videolan.org/videolan/vlc-android/commit/a2853bb92129facc9471456244ed002fbc3a81fd
---

 .../vlc/providers/medialibrary/MedialibraryProvider.kt     | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/vlc-android/src/org/videolan/vlc/providers/medialibrary/MedialibraryProvider.kt b/vlc-android/src/org/videolan/vlc/providers/medialibrary/MedialibraryProvider.kt
index 4fa6a0af5..512b9ef59 100644
--- a/vlc-android/src/org/videolan/vlc/providers/medialibrary/MedialibraryProvider.kt
+++ b/vlc-android/src/org/videolan/vlc/providers/medialibrary/MedialibraryProvider.kt
@@ -38,8 +38,9 @@ import org.videolan.vlc.viewmodels.SortableModel
 
 abstract class MedialibraryProvider<T : MediaLibraryItem>(val context: Context, val scope: SortableModel) : HeaderProvider() {
     protected val medialibrary = Medialibrary.getInstance()
+    private lateinit var dataSource : DataSource<Int, T>
     val loading = MutableLiveData<Boolean>().apply { value = false }
-
+    @Volatile private var isRefreshing = false
 
     protected open val sortKey : String = this.javaClass.simpleName
     var sort = Medialibrary.SORT_DEFAULT
@@ -87,10 +88,12 @@ abstract class MedialibraryProvider<T : MediaLibraryItem>(val context: Context,
     }
 
     fun refresh(): Boolean {
+        if (isRefreshing || !medialibrary.isStarted) return false
         headers.clear()
-        if (pagedList.value?.dataSource?.isInvalid == false) {
+        if (!dataSource.isInvalid) {
             loading.postValue(true)
-            pagedList.value?.dataSource?.invalidate()
+            isRefreshing = true
+            dataSource.invalidate()
         }
         return true
     }
@@ -113,8 +116,6 @@ abstract class MedialibraryProvider<T : MediaLibraryItem>(val context: Context,
         }
     }
 
-
-
     inner class MLDataSource : PositionalDataSource<T>() {
 
         @ExperimentalCoroutinesApi
@@ -130,6 +131,7 @@ abstract class MedialibraryProvider<T : MediaLibraryItem>(val context: Context,
                         false
                     }
                 }
+                isRefreshing = false
                 loading.postValue(false)
             }
         }
@@ -140,6 +142,6 @@ abstract class MedialibraryProvider<T : MediaLibraryItem>(val context: Context,
     }
 
     inner class MLDatasourceFactory : DataSource.Factory<Int, T>() {
-        override fun create() = MLDataSource()
+        override fun create() = MLDataSource().also { dataSource = it }
     }
 }
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