[
Date Prev][
Date Next][
Thread Prev][
Thread Next][
Date Index][
Thread Index]
[
List Home]
|
Re: [cross-project-issues-dev] Information about the "Generifing JFace viewers" project
|
Right all API in JavaFX is generified - and yes you simply have to take
the most basic type you have but like outlined already by Lars' one
often is able to find a base type (e.g. think about a File-Tree-Viewer
where the base class is always a File-Instance).
What worries me more how to deal with Object[] in the viewers which you
made generic but I'm uncertain this is legal from an API point of view
because some dumb man could have written code like this:
> public class TestMe {
> public interface B<E> {
> public E[] test();
> }
>
> public static class C implements B<String> {
> @Override
> public String[] test() {
> return new String[1];
> }
> }
>
> public static void main(String[] args) {
> B t = new C();
> Object[] v = t.test();
> v[0] = new Object();
> }
> }
which would break at the very moment someone adds generics
> public class TestMe {
> public interface B<E> {
> public E[] test();
> }
>
> public static class C implements B<String> {
> @Override
> public String[] test() {
> return new String[1];
> }
> }
>
> public static void main(String[] args) {
> B t = new C();
> Object[] v = t.test();
> v[0] = new Object(); // BAM BAM BAM ArrayStoreException!!!!!
> }
> }
It is highly unlikely that someone did something like that with
JFace-Viewers but the really bad thing is that no compiler can ever
catch this problem.
Tom
On 30.07.14 13:03, Erdal Karaca wrote:
> I am no JavaFX expert, but it has Views (for example, TreeView) whose
> "Items" are aware of a root generic type: for example,
> TreeView#setRoot(TreeItem<T>)...
> If the viewer input has no base class for all of its elements, then the
> API user would have to use Object again.
> I wonder how the JavaFX devs/community solved this issue...
>
>
>
> 2014-07-30 12:44 GMT+02:00 Lars Vogel <lars.vogel@xxxxxxxxx
> <mailto:lars.vogel@xxxxxxxxx>>:
>
> - Some stuff just doesn't make sense to be generified because it
> often contains various kinds of objects, e.g. (tree) viewers. See
> also _http://dev.eclipse.org/mhonarc/lists/platform-ui-dev/msg05459.html_.
>
> We need to investigate that, for example in the e4 tools project
> our tree is based on MApplicationElement hence for us it would make
> sense to have a generified TreeViewer.
>
>
> 2014-07-30 11:42 GMT+02:00 Daniel Megert <daniel_megert@xxxxxxxxxx
> <mailto:daniel_megert@xxxxxxxxxx>>:
>
> Just for the records, here are some constraints that I required
> in order to agree to continue that work:
>
> - Some stuff just doesn't make sense to be generified because it
> often contains various kinds of objects, e.g. (tree) viewers.
> See also
> _http://dev.eclipse.org/mhonarc/lists/platform-ui-dev/msg05459.html_.
>
> - If generified types cannot be plugged together unless
> everything is again just Object or Class, it's not worth to
> generify those types.
> - The generified code must be in a shape so that clients can
> start to fix their code by invoking Refactor > Infer Generic
> Type Arguments... This needs to be validate on existing Platform
> UI code.
>
> Dani
>
>
>
> From: Lars Vogel <lars.vogel@xxxxxxxxx
> <mailto:lars.vogel@xxxxxxxxx>>
> To: cross-project-issues-dev@xxxxxxxxxxx
> <mailto:cross-project-issues-dev@xxxxxxxxxxx>, Jeanderson
> Candido <jeandersonbc@xxxxxxxxx
> <mailto:jeandersonbc@xxxxxxxxx>>, Hendrik Still
> <Gamma32@xxxxxxxxx <mailto:Gamma32@xxxxxxxxx>>
> Date: 30.07.2014 11:23
> Subject: [cross-project-issues-dev] Information about the
> "Generifing JFace viewers" project
> Sent by: cross-project-issues-dev-bounces@xxxxxxxxxxx
> <mailto:cross-project-issues-dev-bounces@xxxxxxxxxxx>
> ------------------------------------------------------------------------
>
>
>
> Hi,
>
> as some of you probably remember, the platform.ui team started a
> GSoC project last year to generify the JFace viewer framework.
> We (platform.ui team together with John Arthone and Dani Megert)
> decided that it is worth to finish this project and started a
> new GSoC project.
>
> Jeanderson Barros Candido (cc) is working on this project with
> Hendrik Still (cc) (GSoC student from last year) and me as mentor.
>
> I personally think the work looks already very good and plan to
> integrated it soon into the master. We are trying to learn from
> the experience from last year, therefore:
>
> - We plan to integrate it as a whole, not piece wise so people
> can fix warning messages created by this change
> - We reworking the JFace snippets and tests at the same time to
> have a first proof-point
> - We plan to use it for platform views to validate that it works
>
>
> Of course generifying an existing API, will result in certain
> limitations and some suggested a complete rewrite of the JFace
> viewer framework but this is currently not the scope of this
> project.
>
> The implementation is currently done at
> Github: _https://github.com/jeandersonbc/eclipse.platform.ui_and
> we do our planning
> in _https://github.com/jeandersonbc/gsoc14-eclipse-planning_.
>
> If someone wants to test the new implementation and provide
> feedback, please let us know.
>
> Best regards, Lars_______________________________________________
> cross-project-issues-dev mailing list
> cross-project-issues-dev@xxxxxxxxxxx
> <mailto:cross-project-issues-dev@xxxxxxxxxxx>
> To change your delivery options, retrieve your password, or
> unsubscribe from this list, visit
> https://dev.eclipse.org/mailman/listinfo/cross-project-issues-dev
>
> _______________________________________________
> cross-project-issues-dev mailing list
> cross-project-issues-dev@xxxxxxxxxxx
> <mailto:cross-project-issues-dev@xxxxxxxxxxx>
> To change your delivery options, retrieve your password, or
> unsubscribe from this list, visit
> https://dev.eclipse.org/mailman/listinfo/cross-project-issues-dev
>
>
>
> _______________________________________________
> cross-project-issues-dev mailing list
> cross-project-issues-dev@xxxxxxxxxxx
> <mailto:cross-project-issues-dev@xxxxxxxxxxx>
> To change your delivery options, retrieve your password, or
> unsubscribe from this list, visit
> https://dev.eclipse.org/mailman/listinfo/cross-project-issues-dev
>
>
>
>
> _______________________________________________
> cross-project-issues-dev mailing list
> cross-project-issues-dev@xxxxxxxxxxx
> To change your delivery options, retrieve your password, or unsubscribe from this list, visit
> https://dev.eclipse.org/mailman/listinfo/cross-project-issues-dev
>
