1529280 - (overflow-debugging) [meta] Overflow Debugging

Status: NEW

(DevTools :: Inspector, enhancement, P3)

Description

[Patrick Brosset <:pbro>]

This is the [meta] bug used to track the "Overflow Debugging" feature implementation in the inspector.

At a high-level, this feature consists of the following tasks:

• New [scroll] badge: Add an inspector-badge next to elements that do have a scrollable overflow area.
• Make sure that the badge appears/disappears dynamically upon CSS changes.
• Make scrollbars pickable: When using the element picker, clicking on a scrollbar should select the element that the scrollbar belongs to. It should, however, still be possible to scroll through the page or nested scrollable elements while the picker mode is engaged.
• Fix all scrollbars introduced by DevTools: DevTools unfortunately introduces some unwanted scrollbars of its own. In particular, when using the flexbox or grid highlighters. These should be fixed first.
• Reveal overflowing elements on [scroll] badge click: Make the inspector badge clickable. When done, filter the markup-view to only the container and its descendants that cause the overflow.