1482188 - Migrate customizableui toolbar bindings to Custom Elements

Status: RESOLVED DUPLICATE of bug 1473311

(Firefox :: Toolbars and Customization, task)

Description

[Brian Grinstead [:bgrins]]

From https://bgrins.github.io/xbl-analysis/tree/#customizableui-toolbar, we've got:

customizableui-toolbar
Used features: property (3), method (1), constructor (1)
Selectors: toolbar[customizable="true"] (content/browser.css)

    customizableui-toolbar-menubar-autohide
    Used features: field (2), handler (4), method (3), constructor (1), destructor (1)
    Selectors: #toolbar-menubar[autohide="true"] (content/browser.css)

    customizableui-toolbar-drag
    Used features: field (1), constructor (1)
    Selectors: #toolbar-menubar:not([autohide="true"]), #TabsToolbar (linux/browser.css), #nav-bar (linux/browser.css)

There's a bit of trickiness around the selectors these apply to, but just eyeballing it, I think we could set up a Custom Element on something like `<toolbar is="customizable-toolbar">` as an alternative to `[customizable="true"]`, folding the 'drag' variation into the main element and conditionally apply that behavior based on ID / platform. And then have `<toolbar is="customizable-toolbar-menubar-autohide">` as an alternative to `#toolbar-menubar[autohide="true"`, or something like that.

One thing we'll have to confirm is that the "customizable" and "autohide" attributes don't change at runtime (causing the XBL binding to change), since we can't change which Custom Element applies at runtime.
  
Source is here: https://searchfox.org/mozilla-central/source/browser/components/customizableui/content/toolbar.xml.

Comment 1

[Brian Grinstead [:bgrins]]

Just realized these bindings are already covered by JS changes proposed in Bug 1473311.