Remove the error list zone widget

[isidorn]

I would like to remove the error zone widget due to the following reasons:

1. All of this functionality should live in the error list in the panel
2. Looks bad
3. I have a feeling that people are not using this, though for this assumption to be verified I would need @seanmcbreen to check some usage numbers

One of the rare features that the zone widget has and that is missing in the error list is captured here #13285

So once we have that and if the usage numbers are not high I propose to remove the error list zone widget. If we decide not to remove it then I volonter to make it look better.
@jrieken does not have a strong feeling against removing it

Opinions welcome @egamma @chrisdias @sandy081

Picture for reference

[jrieken]

No strong feelings, but things to think of

• we need to keep/maintain it for the standalone editor - to keep diagnostics accessible and because there is no alternative feature
• compared to the error list it allows for easier diagnostics navigation scoped to the current file or when using in editor-full-screen-mode

[egamma]

I fully agree that the error list zone looks totally ugly for the 'abc' language service.

This is how the error zone widget looks normally:

Support for navigating from one error to next inside the editor using the keyboard without having the Problems panel open is a must have feature for an editor. This is for both keyboard accessibility and productivity. I use F8 all the time, since I mostly work without the Problems panel open.

What can be discussed is whether the error message should be shown in the status bar as it is commonly done or inside the a zone widget. Using a zone widget is consistent with our approach to use 'peek' for in contextual information and this is my preference.

We must remove the quick fixes at the bottom. Now that we have a light bulb they are redundant.

[jrieken]

We must remove the quick fixes at the bottom. Now that we have a light bulb they are redundant.

That I removed with #13287. For mighty abc language the ugliness comes from it always producing a multiline error - which we must render properly using a mono-space font.

[sandy081]

Removing the error widget is not a good suggestion and I think it is removing useful functionality from the editor. I do not think Problems view is a replacement to Error widget. It is not easy to get the error description from problems view for a given error at given line. It will be more difficult if there are more errors on a single line.

Instead, I think it will be useful to show error widgets for all errors in the editor when asked.

[isidorn]

Closing as this will not happen