Add 'selection' option to render whitespace

[RMacfarlane]

#1477

Since whitespace is rendered as part of the line content and not on the selection layer, and since render line already responds to selection changes in some cases, the change I made is to view line rendering. Now, if the setting is on, any selections that are on the line are part of the line data for rendering. When applying whitespace, it checks the selections to see if the whitespace character is part of that range or not.

[alexdima]

🎉 Nice work! You've done all the right changes, there are 3 things I would change:

• stay away from undefined (personal preference)
• don't use Range because that contains line numbers and create a new class that only contains the data the render line code needs
• remove the inner loop in the render whitespace (the one where using .some(...))

[RMacfarlane]

Thanks for the great feedback! 👍 I’ve added a LineRange class, updated to using null, and eliminated the inner loop of checking selections.

[alexdima]

👍 Really nice! I just found one little bug! Please merge once you cover that!

[alexdima]

Here the check should be charIndex >= currentSelection.endOffset. Reverse-engineered steps to observe a bug:

• have some text * (<space>, *, <space>).
• create 3 multiple cursors before the first space, before the * and before the second space.
• press shift+right
• the whitespace is not painted in the second <space> due to this check.

This case could serve as a good unit test.

Actual:

Expected:

[RMacfarlane]

Nice catch! I added a test for this

[alexdima]

nitpick: small style inconsistency, use here currentSelection && ... instead of !!currentSelection && ...

[RMacfarlane]

removing the !! causes a typescript error since isInWhitespace should be a boolean, so will leave as is

[rebornix]

Found a tiny bug with multi cursor, looks like related to how the selection boundaries are validated

    vscode.languages.registerDocumentLinkProvider('*', {
        provideDocumentLinks: (document: vscode.TextDocument) => {
            return [{
                range: new vscode.Range(0, 0, 0, 2),
                target: vscode.Uri.parse('command:extension.uidialog')
            }];
        }
    })

Indentations are all whitespaces. Put a cursor before v of vscode and another cursor before p of provideDocumentLinks. Then shift+arrow-down then shift+arrow-right

when the end of the first cursor meets the beginning of the second cursor, the last whitespace is not rendered.

[rebornix]

It's already merged. I'll create a new issue.

[RMacfarlane]

@rebornix Nice find! Seems to be an existing problem unrelated to this change