Originally, we used List<Object>, but this caused compilation issues with
setListData(). Perhaps getListData() should return List<Object> while
setListData() takes List<?>?
G
On Jan 22, 2011, at 6:16 PM, calathus wrote:
> hi,
> I found my BXML to Java translator had an issue due to some "strange" usage
> of anonymous type in wtk.
>
> in pivot wtk classes, there are a few classes using anonymous type('?'), for
> example, in ListButton, getListData defined to return List<?>.
> List<?> getListData()
>
> This make following code compile error.
> getListData().add(new ListItem())
>
> In order to pass compiler, we need to use cast.
>
> ((List<Object>)getListData()).add(new ListItem())
> or
> ((List<ListItem>)getListData()).add(new ListItem())
> ...
> since add method is frequently used, this cast is quite verbose.
> if we declare variable, we may need to use only one cast, but often these
> codes are generated by a program, it is much simpler to use above approach.
>
> The only advantage of using anonymous type is that it allows to cast to
> another parametrized list type(e.g, List<ListItem>)) while if we use
> List<Object> as return type this is not possible, but how often such a cast
> is used??
>
> there are similar cases in wtk classes:
>
> grep -R "<?>" * | grep -v .svn | grep private | grep wtk | grep "List<"
> wtk/src/org/apache/pivot/wtk/TreeView.java: private List<?> branchData;
> wtk/src/org/apache/pivot/wtk/TreeView.java: private List<?> treeData =
> null;
> wtk/src/org/apache/pivot/wtk/TableView.java: private List<?> tableData =
> null;
> wtk/src/org/apache/pivot/wtk/ListView.java: private List<?> listData =
> null;
> wtk/src/org/apache/pivot/wtk/SuggestionPopup.java: private List<?>
> suggestionData;
> wtk/src/org/apache/pivot/wtk/ListButton.java: private List<?> listData;
> wtk/src/org/apache/pivot/wtk/Spinner.java: private List<?> spinnerData =
> null;
>
> Have you considered this kind of issue?
>
> --
> Cheers,
> calathus
>
>
>
