DO NOT MERGE: Don't create DocumentInfo instances in background.

Cursor access is not threadsafe resulting in operations on incorrect files.

Bug: 30082168
Change-Id: Ib36d5b7acdee9463b6ebd2553172e5ecb4d70857

packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java

@@ -753,21 +753,17 @@ public class DirectoryFragment extends Fragment
     private void openDocuments(final Selection selected) {
         Metrics.logUserAction(getContext(), Metrics.USER_ACTION_OPEN);
 
-        new GetDocumentsTask() {
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            @Override
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
-            void onDocumentsReady(List<DocumentInfo> docs) {
         // TODO: Implement support in Files activity for opening multiple docs.
         BaseActivity.get(DirectoryFragment.this).onDocumentsPicked(docs);
     }
-        }.execute(selected);
-    }
 
     private void shareDocuments(final Selection selected) {
         Metrics.logUserAction(getContext(), Metrics.USER_ACTION_SHARE);
 
-        new GetDocumentsTask() {
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            @Override
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
-            void onDocumentsReady(List<DocumentInfo> docs) {
         Intent intent;
 
         // Filter out directories and virtual files - those can't be shared.
@@ -809,8 +805,6 @@ public class DirectoryFragment extends Fragment
         intent = Intent.createChooser(intent, getActivity().getText(R.string.share_via));
         startActivity(intent);
     }
-        }.execute(selected);
-    }
 
     private String generateDeleteMessage(final List<DocumentInfo> docs) {
         String message;
@@ -855,9 +849,9 @@ public class DirectoryFragment extends Fragment
         assert(!selected.isEmpty());
 
         final DocumentInfo srcParent = getDisplayState().stack.peek();
-        new GetDocumentsTask() {
+
-            @Override
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            void onDocumentsReady(final List<DocumentInfo> docs) {
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
 
         TextView message =
                 (TextView) mInflater.inflate(R.layout.dialog_delete_confirmation, null);
@@ -878,6 +872,7 @@ public class DirectoryFragment extends Fragment
             .setPositiveButton(
                  android.R.string.yes,
                  new DialogInterface.OnClickListener() {
+                    @Override
                     public void onClick(DialogInterface dialog, int id) {
                         // Finish selection mode first which clears selection so we
                         // don't end up trying to deselect deleted documents.
@@ -900,8 +895,6 @@ public class DirectoryFragment extends Fragment
             .setNegativeButton(android.R.string.no, null)
             .show();
     }
-        }.execute(selected);
-    }
 
     private void transferDocuments(final Selection selected, final @OpType int mode) {
         if(mode == FileOperationService.OPERATION_COPY) {
@@ -934,9 +927,8 @@ public class DirectoryFragment extends Fragment
                 ? R.string.menu_move : R.string.menu_copy;
         intent.putExtra(DocumentsContract.EXTRA_PROMPT, getResources().getString(drawerTitleId));
 
-        new GetDocumentsTask() {
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            @Override
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
-            void onDocumentsReady(List<DocumentInfo> docs) {
         // TODO: Can this move to Fragment bundle state?
         getDisplayState().selectedDocumentsForCopy = docs;
 
@@ -952,9 +944,6 @@ public class DirectoryFragment extends Fragment
         startActivityForResult(intent, REQUEST_COPY_DESTINATION);
     }
 
-        }.execute(selected);
-    }
-
     private static boolean hasDirectory(List<DocumentInfo> docs) {
         for (DocumentInfo info : docs) {
             if (Document.MIME_TYPE_DIR.equals(info.mimeType)) {
@@ -971,13 +960,10 @@ public class DirectoryFragment extends Fragment
         // Rename option is only available in menu when 1 document selected
         assert(selected.size() == 1);
 
-        new GetDocumentsTask() {
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            @Override
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
-            void onDocumentsReady(List<DocumentInfo> docs) {
         RenameDocumentFragment.show(getFragmentManager(), docs.get(0));
     }
-        }.execute(selected);
-    }
 
     @Override
     public void initDocumentHolder(DocumentHolder holder) {
@@ -1135,11 +1121,11 @@ public class DirectoryFragment extends Fragment
         }
     }
 
-    void copySelectionToClipboard(Selection selection) {
+    void copySelectionToClipboard(Selection selected) {
-        assert(!selection.isEmpty());
+        assert(!selected.isEmpty());
-        new GetDocumentsTask() {
+
-            @Override
+        // Model must be accessed in UI thread, since underlying cursor is not threadsafe.
-            void onDocumentsReady(List<DocumentInfo> docs) {
+        List<DocumentInfo> docs = mModel.getDocuments(selected);
         mClipper.clipDocuments(docs);
         Activity activity = getActivity();
         Snackbars.makeSnackbar(activity,
@@ -1147,8 +1133,6 @@ public class DirectoryFragment extends Fragment
                         R.plurals.clipboard_files_clipped, docs.size(), docs.size()),
                 Snackbar.LENGTH_SHORT).show();
     }
-        }.execute(selection);
-    }
 
     public void pasteFromClipboard() {
         Metrics.logUserAction(getContext(), Metrics.USER_ACTION_PASTE_CLIPBOARD);
@@ -1456,25 +1440,6 @@ public class DirectoryFragment extends Fragment
             mShadowView.draw(canvas);
         }
     }
-    /**
-     * Abstract task providing support for loading documents *off*
-     * the main thread. And if it isn't obvious, creating a list
-     * of documents (especially large lists) can be pretty expensive.
-     */
-    private abstract class GetDocumentsTask
-            extends AsyncTask<Selection, Void, List<DocumentInfo>> {
-        @Override
-        protected final List<DocumentInfo> doInBackground(Selection... selected) {
-            return mModel.getDocuments(selected[0]);
-        }
-
-        @Override
-        protected final void onPostExecute(List<DocumentInfo> docs) {
-            onDocumentsReady(docs);
-        }
-
-        abstract void onDocumentsReady(List<DocumentInfo> docs);
-    }
 
     @Override
     public boolean isSelected(String modelId) {