QFileDialog: document the consequences of being "widgetless"

After 37ca2224eca671200a2710f57f970d2993e62aa5 it's an exposed
behavior change that the widgets and related paraphernalia don't exist.

Task-number: QTBUG-34100
Change-Id: Ie0ebcb8c5c5668b6c12c5447f25bfbfd893dec6c
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 383e3ab3f4..22d467661e 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -184,6 +184,13 @@ Q_WIDGETS_EXPORT _qt_filedialog_save_file_url_hook qt_filedialog_save_file_url_h
   The \l{dialogs/standarddialogs}{Standard Dialogs} example shows
   how to use QFileDialog as well as other built-in Qt dialogs.
 
+  By default, a platform-native file dialog will be used if the platform has
+  one. In that case, the widgets which would otherwise be used to construct the
+  dialog will not be instantiated, so related accessors such as layout() and
+  itemDelegate() will return null. You can set the \l DontUseNativeDialog option to
+  ensure that the widget-based implementation will be used instead of the
+  native dialog.
+
   \sa QDir, QFileInfo, QFile, QColorDialog, QFontDialog, {Standard Dialogs Example},
       {Application Example}
 */
@@ -243,7 +250,8 @@ Q_WIDGETS_EXPORT _qt_filedialog_save_file_url_hook qt_filedialog_save_file_url_h
 
     \value DontUseNativeDialog Don't use the native file dialog. By
     default, the native file dialog is used unless you use a subclass
-    of QFileDialog that contains the Q_OBJECT macro.
+    of QFileDialog that contains the Q_OBJECT macro, or the platform
+    does not have a native dialog of the type that you require.
 
     \value ReadOnly Indicates that the model is readonly.