Defining Draggable Regions in Web Content (for custom title bars)

[diekus]

Hola CSSWG! Diego from Edge here, looking to get your feedback and ideas on standardizing the prefixed CSS property -webkit-app-region. The reason for this is that while defining custom title bars we need a way for the developer to mark regions and content as draggable/not-draggable.

The values we want to leverage to enable marking content draggable are:

• -webkit-app-region: drag
• -webkit-app-region: no-drag

Here's a link to the explainer of Window Controls Overlay that addresses this challenge.

If the developer included a textbox in the title bar for example, this area should be marked as not draggable, since it receives input and is generally not poised for be dragged from while moving the window.

[dbaron]

Duplicate of #7017 (which is newer, but has more discussion)?