show proper error for download category

app/src/main/java/awais/instagrabber/activities/DirectorySelectActivity.java

@@ -81,6 +81,10 @@ public class DirectorySelectActivity extends BaseLanguageActivity {
             showErrorDialog(getString(R.string.select_a_folder));
             return;
         }
+        if (!"com.android.externalstorage.documents".equals(data.getData().getAuthority())) {
+            showErrorDialog(getString(R.string.dir_select_no_download_folder));
+            return;
+        }
         AppExecutors.INSTANCE.getMainThread().execute(() -> {
             try {
                 viewModel.setupSelectedDir(data);

app/src/main/java/awais/instagrabber/fragments/settings/DownloadsPreferencesFragment.java

@@ -102,7 +102,9 @@ public class DownloadsPreferencesFragment extends BasePreferencesFragment {
                     final ConfirmDialogFragment dialogFragment = ConfirmDialogFragment.newInstance(
                             123,
                             R.string.error,
-                            "Please report this error to the developers:\n\n" + sw.toString(),
+                            "com.android.externalstorage.documents".equals(data.getData().getAuthority())
+                                ? "Please report this error to the developers:\n\n" + sw.toString()
+                                : getString(R.string.dir_select_no_download_folder),
                             R.string.ok,
                             0,
                             0

app/src/main/java/awais/instagrabber/utils/DownloadUtils.java

@@ -68,7 +68,7 @@ public final class DownloadUtils {
         if (TextUtils.isEmpty(barinstaDirUri)) {
             throw new ReselectDocumentTreeException("folder path is null or empty");
         }
-        if (!barinstaDirUri.startsWith("content")) {
+        if (!barinstaDirUri.startsWith("content://com.android.externalstorage.documents")) {
             // reselect the folder in selector view
             throw new ReselectDocumentTreeException(Uri.parse(barinstaDirUri));
         }

app/src/main/res/values/strings.xml

@@ -512,6 +512,7 @@
     <string name="dir_select_folder_not_exist">The previously selected folder does not exist now:</string>
     <string name="dir_select_message2">Re-select the directory or select a new directory by clicking the button below.</string>
     <string name="select_a_folder">No folder selected!</string>
+    <string name="dir_select_no_download_folder">Please choose a directory from your storage, not a category on the sidebar.</string>
     <string name="dir_select_success_message">Success! Please wait. Starting app…</string>
     <string name="barinsta_folder">Barinsta folder</string>
     <string name="top">Top</string>