View containers in activity bar are still visible if there is no view inside

[vbfox]

• VSCode Version: 1.23.0

Steps to Reproduce:

1. Add a new item to viewContainers/activitybar in an extension
2. Hide all the views of this container conditionally (In the Ionide F# case the "project" view only make sense if a "project" or "solution" file is found)
3. Notice that the icon is still visible but empty

It also seem that the container icon is always visible even when the extension isn't loaded (no F# file in workspace). With 10+ extensions installed if each add an icon the activity bar will be cluttered pretty fast (While it's not needed, few workspace activate all my extensions).

Note: I found a few issue about the configurability (#48704 & #48706) but none about the fact that empty views look buggy.

Ping @Krzysztof-Cieslak

[sandy081]

@vbfox View container will be not shown only when no views are registered to it. If there are some views registered in the view container and the views are hidden either by user or by extension (conditional visibility), then view container is shown. It is mainly because if user has hidden all the views then he/she can hide the view container using the context menu in the activity bar.

I see conditional visibility has nothing to do with the user and user might see an empty view container. Will think about it and any suggestions are welcome.

It also seem that the container icon is always visible even when the extension isn't loaded

View containers and views are descriptive contributions (package.json) and hence does not need activation.

[vbfox]

My suggestion would be to by default hide them when there is no displayable view inside (Counting user-hidden views as displayable as a gesture exists to show them, but not views hidden via when).

Alternatively it can be done by extensions themselves if #48704 is done but it's a little less practical if multiple extensions wants to share a container.

In the current state I fear that the activity bar will slowly creep with as much icons as languages I have installed, with only one or two of them containing something when a user open a workspace.

[sandy081]

To verify:

• Register a view container in activity bar using viewsContainers extension point. For example:

"contributes": {
	"viewsContainers": {
		"activitybar": [
                        {
			    "id": "test",
			    "title": "Test",
			     "icon": "resources/test.svg"
		        }
                  ]
	}
}

• Add views to the above registered view container with when context . For example:

"contributes": {
	"views": {
		"test": [
			{
				"id": "myview",
				"name": "My View",
                "when": "somecontext"
			}
		]
	}
}

• You can implement the view by referring to documentation and [samples] (https://github.com/Microsoft/vscode-extension-samples/tree/master/tree-view-sample). Refer to jsonOutline example that uses when property.

Verify that the view container is not visible when

• No views are registered to the container
• All views are hidden because of their when condition

Otherwise, view container is shown even if user hides the views.

[aeschli]

Verified with the tree-view-sample