[FF] It's not possible to DnD inline widget inside nested editable

[Piotrek Koszuliński]

1. Open ​http://ckeditor.dev/plugins/widget/dev/nestedwidgets.html
2. Try dragging one of the placeholders.
3. The drop caret is invisible inside nested editable. It is visible only when dragging over the outer editable.

It seemed to work fine on major some time ago.

[Piotrek Koszuliński]

It seemed to work fine on major some time ago.

Thus, it needs to be bisected.

[Olek Nowodziński]

​git:8c1b9a6b0ac3d is the first bad commit.

[Piotrek Koszuliński]

Interesting :)

[Olek Nowodziński]

But truth to tell, it's all about ​this line.

A comment related to this change: ​https://dev.ckeditor.com/ticket/12172#comment:10

[Olek Nowodziński]

First attempt:

• ​branch:t/13141
• Focus widget/editor on draghandler's mousedown, so before dragstart. It looks like FF got issues when messing with focus on dragstart thus unable to drop into nested editable.

[Olek Nowodziński]

Finally it tuned out that the best solution is to leave this ticket and wait for Firefox team to act. The solution (hack) in comment:8 breaks undo (an additional step with focused widget). Other possible regressions are also hard to predict and the code gets tricky. It's a sad trade–off between undo and DnD.

It's quite possible that a more general and bulletproof approach to DnD+focus would do the job, but it requires time and resources. Together with Reinmar, we made a decision to put this ticket aside (at least in 4.5).

[Piotrek Koszuliński]

Two more things:

• ​branch:t/13141 contains a patch that one could use if they more cared about DnD in nested editables on Firefox than about the regressions that it introduces.
• We find support for DnD in nested editables less important than those regressions, because they affect every scenario. That's why we chose to not act.