Implemented sort order for DAV documents

app/src/main/kotlin/at/bitfire/davdroid/db/WebDavDocument.kt

@@ -32,6 +32,7 @@ import java.time.Instant
         Index("parentId")
     ]
 )
+// If any column name is modified, also change it in [DavDocumentsProvider$queryChildDocuments]
 data class WebDavDocument(
 
     @PrimaryKey(autoGenerate = true)

app/src/main/kotlin/at/bitfire/davdroid/db/WebDavDocumentDao.kt

@@ -24,6 +24,9 @@ interface WebDavDocumentDao {
     @Query("SELECT * FROM webdav_document WHERE parentId=:parentId")
     fun getChildren(parentId: Long): List<WebDavDocument>
 
+    @Query("SELECT * FROM webdav_document WHERE parentId=:parentId ORDER BY :orderBy")
+    fun getChildrenOrdered(parentId: Long, orderBy: String): List<WebDavDocument>
+
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     fun insertOrReplace(document: WebDavDocument): Long
 

app/src/main/kotlin/at/bitfire/davdroid/webdav/DavDocumentsProvider.kt

@@ -287,7 +287,21 @@ class DavDocumentsProvider(
             runningQueryChildren.remove(parentId)
 
         // Regardless of whether the worker is done, return the children we already have
-        for (child in documentDao.getChildren(parentId)) {
+        val children = if (sortOrder == null) {
+            documentDao.getChildren(parentId)
+        } else {
+            documentDao.getChildrenOrdered(
+                parentId,
+                // Convert the cursor's column name into Room's
+                sortOrder
+                    .replace(Document.COLUMN_DOCUMENT_ID, "id")
+                    .replace(Document.COLUMN_DISPLAY_NAME, "displayName")
+                    .replace(Document.COLUMN_MIME_TYPE, "mimeType")
+                    .replace(Document.COLUMN_SIZE, "size")
+                    .replace(Document.COLUMN_LAST_MODIFIED, "lastModified")
+            )
+        }
+        for (child in children) {
             val bundle = child.toBundle(parent)
             result.addRow(bundle)
         }