Implement Refresh on DocumentProvider

"When interacting with DocumentUI or the built-in Android System Internal Files Manager app and performing Create, Rename, and Delete operations, DocumentsUI will not automatically refresh the changes.
Previously, users had to manually pull down from the top to refresh the changes. This commit aims to fix this issue by automatically notifying the system that changes have occurred and triggering a requery."

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/DocumentProvider.kt

@@ -9,8 +9,10 @@
 package org.dolphinemu.dolphinemu.features
 
 import android.annotation.TargetApi
+import android.content.Context
 import android.database.Cursor
 import android.database.MatrixCursor
+import android.net.Uri
 import android.os.Build
 import android.os.CancellationSignal
 import android.os.ParcelFileDescriptor
@@ -93,6 +95,8 @@ class DocumentProvider : DocumentsProvider() {
                 appendDocument(file, result)
             }
         }
+        result.setNotificationUri(context!!.contentResolver, DocumentsContract.buildChildDocumentsUri(
+                "${context!!.packageName}.user", parentDocumentId))
         return result
     }
 
@@ -121,6 +125,7 @@ class DocumentProvider : DocumentsProvider() {
         } else {
             file.createNewFile()
         }
+        refreshDocument(parentDocumentId)
         return pathToDocumentId(file)
     }
 
@@ -128,7 +133,9 @@ class DocumentProvider : DocumentsProvider() {
         rootDirectory ?: return
 
         val file = documentIdToPath(documentId)
+        val fileParent = file.parentFile
         file.deleteRecursively()
+        refreshDocument(pathToDocumentId(fileParent!!))
     }
 
     override fun renameDocument(documentId: String, displayName: String): String? {
@@ -137,9 +144,19 @@ class DocumentProvider : DocumentsProvider() {
         val file = documentIdToPath(documentId)
         val dest = findFileNameForNewFile(File(file.parentFile, displayName))
         file.renameTo(dest)
+        refreshDocument(pathToDocumentId(file.parentFile!!))
         return pathToDocumentId(dest)
     }
 
+    private fun refreshDocument(parentDocumentId: String) {
+        val parentUri: Uri =
+                DocumentsContract.buildChildDocumentsUri(
+                        "${context!!.packageName}.user",
+                        parentDocumentId
+                )
+        context!!.contentResolver.notifyChange(parentUri, null)
+    }
+
     override fun isChildDocument(parentDocumentId: String, documentId: String): Boolean
         = documentId.startsWith(parentDocumentId)