Handle regular expressions in global search

[CaptainDaVinci]

Fixes #5349

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• Change in CHANGELOG.md described
• Tests created for changes
• Manually tested changed features in running JabRef
• Screenshots added in PR description (for bigger UI changes)
• Ensured that the git commit message is a good one
• Check documentation status (Issue created for outdated help page at help.jabref.org?)

[CaptainDaVinci]

Is this approach good towards fixing the issue?

[Siedlerchr]

Yes, this is a good start. It would be really cool if you could use the validation icon stuff like it's done in the entry editor or in the shared database dialog or in the preferences.

[CaptainDaVinci]

The current commit checks for valid regex before setting the active search state, in case of invalid regex a message is shows next to the search bar.

[tobiasdiez]

Thanks for your contribution. The code looks good. It would be nice if you could implement Christoph's suggestion before we merge.

[tobiasdiez]

Please use LOGGER.debug because this error is kind of expected.

[tobiasdiez]

Suggested change

	currentResults.setText(Localization.lang("Invalid Regex"));
	currentResults.setText(Localization.lang("Invalid regular expression"));

[tobiasdiez]

As @Siedlerchr suggests, it would be nice if you could report the invalid regex to the user directly in the text box. We use the following validation framework for this: https://github.com/sialcasa/mvvmFX/wiki/Validation (the other places where this library is used might give you a good idea how to implement it - sounds more scarier than it actually is)

[CaptainDaVinci]

The UI is a bit off, I am not sure how to align it and provide a margin.

[Siedlerchr]

Thanks for the update. The validator icon is always a bit difficult.
You can try to style it with css. You can try with ScenicView to identify the property : https://github.com/JonathanGiles/scenic-view

[Siedlerchr]

Is this ready now or do you want to check if you can tweak the CSS a bit?

[CaptainDaVinci]

I haven't tried tweaking the CSS, yet. I'll try making that change today.

[CaptainDaVinci]

I tried making a change in gui/Base.css

 .mainToolbar > .container > .search-field > .label {
     -fx-end-margin: 1em;
 }

But it didn't change anything. Any pointers on what might be wrong?
From ScenicView, the parent of .search-field does not have a style class, would that matter?

[tobiasdiez]

What are you trying to do exactly?

[CaptainDaVinci]

I'm trying to add a margin to the error-icon which appears when an invalid regular expression is entered, the icon is of styleClass label.

[tobiasdiez]

Ok, it's always a bit tricky with the css identifiers. First, I would add something like -fx-background-color: blue; -fx-text-fill: green; which makes it more evident that the css does apply to the correct element. Then you can play around with the css identifier, maybe .search-field .label works (it should apply to every label contained in the searchfield. Finally, according to https://docs.oracle.com/javase/8/javafx/api/javafx/scene/doc-files/cssref.html#region, the additional space should be added with -fx-padding: 1em 2em 1em 2em; (or whatever numbers are fittting). In JavaFX, there is no real margin tag as in HTML, so you have to use paddings. Hope that works.

[CaptainDaVinci]

Added a right padding to the error icon. But on hovering over the icon, the tool-tip of search field is shown instead of the error message.

[Siedlerchr]

I think the problem with the tooltip is not that big. You have the message at the right side. So I guess this is not that important