Eclipse new folding feature does not work when use show only selected element feature

[totomomo18]

When you put one the show only selected element feature
(A great killer underrated feature of Eclipse that is somewhat hidden and should put in the front)
in order to focus working on method only in a class
all the folding little icons disappear from the editor and you can not do any folding on the focus method
not until you disable the show only selected menu to the editor
once you see all the methods in the class the folding icons appear again in the editor

[danthe1st]

More context on that (to whoever wants to know why this happens):
From what I have seen, folding is generally disabled when the "Only show selected Java element" option is used.
This is because https://github.com/eclipse-jdt/eclipse.jdt.ui/blob/master/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java#L1879 is called only if EDITOR_SHOW_SEGMENTS is disabled (EDITOR_SHOW_SEGMENTS is the preference for "Only show selected Java element").

Because of this, enableProjection() won't be called and folding is not active.

If the code is changed to enable folding with that option, the folding isn't made available when selecting an element because enableProjection() is only called initially.
When overriding setVisibleRegion(int, int) and calling prepareDelayedProjection(), it can result in too much code being displayed (going further than the selected element).

In general, jface seems to disable projections when the visible region changes and I don't think I wouldn't feel comfortable changing something about that because I have no idea about that topic.

This is not specific to custom folding regions but it seems to be the case with Java folding in general. I don't know what exactly causes this though.

[danthe1st]

So to sum up, it seems like jface/ProjectionViewer currently (probably) doesn't support allow projections/folding with visible regions from what I can see. I guess this might be something that would need to be done in Eclipse Platform.
If one forces projections to be enabled (by manually calling enableProjection()), it seems to show too much text in the visible region.

[totomomo18]

So what does it mean ? will you keep this issue open to be fixed in the future ? I don't see this issue assign to anyone or be flagged as a bug or a feature request. Am I suppose to add this issue to another Eclipse repo like eclipse.jdt becouse you said the problem is with the Eclipse Platform project ? . I really think this should be fixed I want to use folding with the show selected element turned on. The show selected element is such a killer feature in Eclipse which no other Ide have no Intellij or Vscode which keeps me in Eclipse. You should not hide this killer feature and even promote it. If you can only fix the folding feature that will make it even better

[danthe1st]

So what does it mean ? will you keep this issue open to be fixed in the future ?

I am not a committer. I just commented what I saw about this.

I don't see this issue assign to anyone or be flagged as a bug or a feature request.

I guess nobody really took a look at it until now. I don't think this is a bug as there is actual logic disabling folding in these scenarios.

Am I suppose to add this issue to another Eclipse repo like eclipse.jdt becouse you said the problem is with the Eclipse Platform project ?

If you can reproduce it with only Eclipse platform (without JDT, e.g. with a custom editor), I guess you could probably probably write a feature request asking for ProjectionViewer to support folding with visible regions.

I really think this should be fixed I want to use folding with the show selected element turned on.

This (as are the other Eclipse projects) is an Open Source project. If you (or someone you know) has the capabilities to fix it, feel free to create a pull request. In general, people might fix it if they care enough about the issue but nobody is forced to work on it. People have limited time I guess.
Some companies let their employers contribute the features they need/want. Some volunteers contribute whatever they want to have/think is interesting to do. Some people might implement what they think the Eclipse IDE needs.

If you can only fix the folding feature that will make it even better

To be honest, I personally don't consider this a bug but a feature that is not implemented (or two features that just cannot be used together). It is explicitly disabled in JDT-UI and Eclipse Platform's ProjectionViewer seems to generally disable projections (folding) when setVisibleRegion is called.

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But again, I am just an outside contributor who implemented some of the new folding features and saw your issue. I am not a committer.

[totomomo18]

Thank you so much for your replay and your help. I am kind of new on asking for a feature or reporting a bug on Github and on a Open Source project. You say no one is obligated to work on it since it is a feature not a bug so could you just leave this issue open as a feature request so that maybe someone may look at it and maybe try to fix it ? No one is going see this issue if it is closed. Is there anything else I can do or somewhere else to complain to push Eclipse foundation to add this feature ?

[danthe1st]

You say no one is obligated to work on it since it is a feature not a bug

Even for bugs, nobody is forced to fix them. But for new features, there is often less interest in implementing them (after all, people can't implement all the features they'd maybe want).

could you just leave this issue open as a feature request

I would also recommend leaving it open. But I don't have the authority to close issues anyway ;)

[totomomo18]

I thought you close the issue since you are the one that responded to my issue :) so who close the issue and why ?
Can I repost this issue in the next eclipse version if they wont fix it ? is that allowed ?
I don't want to be banned . how do I get in touch with a committer
edit: Now that I check it again it seem to be an open issue not closed how can I add a label of enhancement to it ?

[danthe1st]

None of what I say is authoritative.

Can I repost this issue in the next eclipse version if they wont fix it ?

I don't think that's wanted. I'd just keep this one open. If there's interest from other people, that might help but I don't know. One thing that might work for finding people interested in doing that is (1) make sure you know where the issue originates from (I just told you what it looks like from a semi-quick analysis), (2) make sure it's reported there and (3) maybe you can get someone with the appropriate permissions (I don't have these permissions and I don't know the exact guidelines on that if they exist) to attach a "help wanted" (or similar) label to it.

How do I get in touch with a committer

There might be one taking a look at it at some point.
If necessary, I guess you could ping also ping one or ask on the corresponding mailing list. But note that different projects (e.g. JDT, Eclipse Platform, SWT, etc.) have different committers. The Eclipse Foundation has publicly available lists of committers for different projects.

But I think the more important point (if you want this implemented) is convincing someone that this is more important (for them) than other things they work on (like fixing bugs, implementing "multi-release" projects, implementing things necessary for JDK 25 or whatever). This person doesn't need to be a committer but a committer would eventually be needed to review and merge the changes (this would need to be a committer in the project that is modified - but once you have implemented these changes, finding a committer willing to review it is probably easier).

---

One option you could try is see what is actually possible in terms of folding and visible regions in Eclipse Platform (with a custom editor and without JDT) and if that seems insufficient create an issue for that in Eclipse Platform (and adding context on why this is needed).

[totomomo18]

I do not understand what is exactly the Eclipse platform that you want me to create an issue in it ? where is it ? is it a repo on github different from this eclipse.jdt.ui github repo or is it somewhere else like another site ? what if I post this problem on the eclipse reddit channel could that help ?
Anyways thank you for your help so much

[danthe1st]

The Eclipse IDE project is split into many project. For example, there's SWT which is the UI framework, eclipse.platform which contains some general framework and runtime stuff (I think) that are common for all Eclipse bundles, eclipse.platform.ui which contains UI-related parts of the Eclipse IDE that are essentially the base of all Eclipse packages (eclipse.platform.ui contains ProjectionViewer so that's where I think the issue probably originates from).
On the JDT side, the most important projects (in my opinion) are JDT-Core which contains the Eclipse Java Compiler and non-UI parts of the Java tooling and JDT-UI (this repository) which contains the UI parts of the Java tooling (for example Java folding).

There are also many other projects like CDT (for C/C++ development) and PDT (for PHP development).

[danthe1st]

I have created this issue in eclipse.platform.ui. I don't have any expectations of this being implemented if nobody considers this important enough.

Please note the following:

Other contributors may consider this suggestion, or not, at their own convenience. The most efficient way to get it fixed is that I implement it myself and contribute it back as a good quality patch to the project.

[totomomo18]

Again Thank you very much for your help

[danthe1st]

@totomomo18 I tried to write a (prototypical) implementation in eclipse-platform/eclipse.platform.ui#3074 which seems to work for me but I am unsure whether this is ok that way. I am not sure whether there is a reasonable option for you to test it though (you'd need to set up a development environment (Eclipse installation + workspace?) where you could build both Eclipse Platform and JDT-UI).