Widgets: Keyboard events prevention while focused

[Marek Lewandowski]

Widgets: Keyboard events prevention while focused

since: 4.3beta (didn't check earlier) until major

Occurs in all browsers.

1. open any image2 pluigin sample (i.e. plugins/image2/samples/image2.html)
2. click on image (in order to focus it, blue outline should appear)
3. press alt+f10

Expected result:
Toolbar should be focused.

Current result:
Focus stays at image widget.

Additional info:

1. issue does not occurs within content editable.
2. it also prevents lots of browser hotkeys, like chromium alt+d (address bar highlight).
3. here's line which may be modified in order to solve the problem: ​https://github.com/ckeditor/ckeditor-dev/blob/major/plugins/widget/plugin.js#L2332

simple idea would be to add || ( CKEDITOR.ALT & keyCode ) But there still end user may experience some issue, with other browser hotkeys, i.e.

• in most browsers pressing (just) F6 will cycle focus between browsers top ui elements, like address bar, page content, bookmarks, extensions icons.
• F5 should reload page
• F12 should open browser inspector

Suggestion:
We may also add handling for tab key, for jumping to next element

[Piotrek Koszuliński]

Hmm... seems that widget's keystroke blocker is too greedy. Perhaps it will be enough to exclude ALT keystrokes, just like we exluded CTRL ones.

[Marek Lewandowski]

Created branch t/10911 at dev. I've added handling for ALT + x hotkeys. At the end I didn't enabled single function key presses, because we decided that it is not that big deal for our end users.

[Frederico Caldeira Knabben]

This is a good "one step" improvement.

[Marek Lewandowski]

Merged with ​git:3c40e20dd2 to major.