Warning when invoking explorer.newFile (fix #100604)

[bpasero]

This PR fixes #100604

[isidorn]

@bpasero I would prefer if we use a precondition to disable the command completely in that case.
What do you think?

[bpasero]

@isidorn ah ok, my understanding was that the user explicitly binds this command to a certain key? In that case, when condition would not help? Check the screenshot from original issue.

[isidorn]

@bpasero I think it would help even in that case. when case would help, a preconditoin would not.
precondition I think applies for the keybinding
if the when is false even if there is a keybinding it would not trigger it

[bpasero]

@isidorn I think it is the other way around. The when condition is lost once the user defines the keybinding, by default it will not have any when condition.

Do you already have a context key for the explorer being available or not?

[isidorn]

Try this WorkbenchStateContext.notEqualsTo('workspace')
Code pointer how I use it for example

vscode/src/vs/workbench/contrib/files/browser/explorerViewlet.ts

Line 288 in d88f099

when: ContextKeyExpr.and(WorkbenchStateContext.notEqualsTo('workspace'), RemoteNameContext.notEqualsTo(''), IsWebContext.toNegated()),

[bpasero]

@isidorn actually you already do this here:

vscode/src/vs/workbench/contrib/files/browser/fileActions.contribution.ts

Lines 224 to 225 in c1031ce

	appendToCommandPalette(NEW_FILE_COMMAND_ID, { value: NEW_FILE_LABEL, original: 'New File' }, category, WorkspaceFolderCountContext.notEqualsTo('0'));
	appendToCommandPalette(NEW_FOLDER_COMMAND_ID, { value: NEW_FOLDER_LABEL, original: 'New Folder' }, category, WorkspaceFolderCountContext.notEqualsTo('0'));

via WorkspaceFolderCountContext.notEqualsTo('0')

Problem is that you cannot do this on the level of commands:

vscode/src/vs/workbench/contrib/files/browser/fileActions.ts

Lines 926 to 938 in 744f2ab

	CommandsRegistry.registerCommand({
	id: NEW_FILE_COMMAND_ID,
	handler: async (accessor) => {
	await openExplorerAndCreate(accessor, false);
	}
	});
	CommandsRegistry.registerCommand({
	id: NEW_FOLDER_COMMAND_ID,
	handler: async (accessor) => {
	await openExplorerAndCreate(accessor, true);
	}
	});

Once you register a command, it needs to be executable always.

An alternative is to simply return early from the command if the explorer is not visible instead of showing this warning...

[isidorn]

Then it seems like there is nothing smarter to do here.
Your approach improves the error message, so let's go with that -> approved.