Improve drop-down menu for replaceable class

[Francesco Casella]

Please consider the attached test package. Enable replaceable support, load it, open the model S1 and double-click on m

• m.RM has a default type TestReplaceableComments.RM1. This is not visible, so it seems that something's missing here. We should display the default type in grey as we do for the default values of parameters, see e.g. the value of p in the same window.
• the entries of the drop-down menu contain the Modelica code "redeclare model RM = XXX". Maybe it would be better to skip the "redeclare model RM = " part, and rather show the class names and their comments, which normally contain useful information to identify what the class is good for
• the last item of the redeclarable classes is "TestReplaceableComments.M.RM". As far as I understand, according to ​Section 5.3.2 of the specification, this shouldn't be there, because composite name lookup inside non-package classes should be restricted to encapsulated elements.

Last, but not least, if you now open S2 and double click on m, you should actually see that RM has already been redeclared to RM2, the same way p was changed to 5.

[Adrian Pop]

Partially fixed via:
​https://github.com/OpenModelica/OpenModelica/pull/6777
default choice is now populated.

[Francesco Casella]

Looks good, when I open the parameter window of m in S2 I see the redeclared class.

[Andrea Bartolini]

Regarding S2, it seems to work on Ubuntu 18.04 (when I open the parameter window of m in S2 I see the redeclared class).

Regarding S1, all the issues listed above are still present.

[Adrian Pop]

Should be fixed via:

​https://github.com/OpenModelica/OpenModelica/pull/6827

[Francesco Casella]

@adrpo, this is much improved, but we still have a problem: you can't distinguish the case where there is no redeclare from the other ones. When you double-click on m in S1, you see Replaceable model 1 as if there was actually a redeclare statement, which is in fact not there; what you are seeing is the original element which has not been redeclared. That should be displayed in grey, as with default parameter values if you don't change them.

Along the same line, when you click on the drop-down menu, there should also be an empty entry, and if you click on it, no redeclare should be applied.

Minor comment: I would probably remove the quotation marks and just put the text of the comment alongside the class name. It is easy to distinguish them because they are separated by the first space in each menu entry.

[Adrian Pop]

As I wrote in the PR: "not sure how to make greyed display value in a comobox but I greyed it out in the list". I guess @adeas31 can probably help us with this.

[Francesco Casella]

Replying to adrpo:

As I wrote in the PR: "not sure how to make greyed display value in a comobox but I greyed it out in the list". I guess @adeas31 can probably help us with this.

OK. In fact, I saw the blank line in the drop-down list, but that's not appropriate; a blank line should be provided instead if one wants to remove the redeclare and get back to the default behaviour.

EDIT: of course I meant the greyed-out line, sorry

[Adrian Pop]

Is not the blank line, the item is grey in the list. I talked with @adeas31 who gave me some pointers. I will try that and see how it goes.

[Adrian Pop]

This PR fixes some of the issues:

​https://github.com/OpenModelica/OpenModelica/pull/6836

but greying out the default doesn't work yet, I asked @adeas31 for help with this one.

[Adrian Pop]

Grey stuff is now not only in our hair :)

​https://github.com/OpenModelica/OpenModelica/pull/6838

[Francesco Casella]

I tested this in the 1.17.0 nightly and it looks very good. I understand 1.16.0-dev.beta4 is basically the same, so I'm closing this ticket. I'll test the beta tomorrow anyway.