t/951: DomConverter should actively prevent unwanted scrolling on focus

[oleq]

Suggested merge commit message (convention)

Fix: DomConverter should actively prevent unwanted scrolling on focus. Closes ckeditor/ckeditor5#4068. Closes ckeditor/ckeditor5#3903.

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Additional information

Requires ckeditor/ckeditor5-utils#156.

[Reinmar]

A more complete solution would be to look for all elements up in the tree (starting from the editable) which have scrollTop or something indicating that they are scrollable. But I guess that fixing the editable and viewport is OK for now.

[Reinmar]

R- for a different reason, though. AFAIU this issue concerns Blink and Webkit. So:

• the issue and solution (env check) should not be about Webkit only,
• perhaps we could target the solution to all browsers in order to avoid code branching?

I'm not 100% sure that the latter is a good idea, but it's something worth checking. The Webkit thing should be resolved though.

[oskarwrobel]

This PR also closes https://github.com/ckeditor/ckeditor5-engine/issues/707.

[oleq]

@Reinmar

AFAIU this issue concerns Blink and Webkit

the issue and solution (env check) should not be about Webkit only,

I'm a little bit confused what you meant by this.

[Reinmar]

That this is not only about Webkit. This is about Webkit and Blink. Right? So why is there if ( webkit ) in the code?

[oleq]

Ah... so you're referring to ckeditor/ckeditor5-utils#156 (comment), right?

[Reinmar]

Yep. But it's not only about the code but also communication (issue, PR title, changelog, etc.).

[oleq]

I made the fix generic for all web browsers in 7431a14. Checked Firefox and Edge, and nothing looks wrong so I guess we may go with it this way.

[Reinmar]

It seems that it also fixed https://github.com/ckeditor/ckeditor5-engine/issues/706! :)

[Reinmar]

Would be green light but I miss a manual test. It's something that you need to test manually. OTOH... it's also an issue which we see quite well when using the editor. So, ok – I'm merging :)