Accessibility: Close popover when ESC is pressed

Always good to have a few external links:

https://bitsofco.de/accessible-modal-dialog/#6allowtheesckeytoclosethedi...
https://simplyaccessible.com/article/closing-modals/
https://medium.com/@matuzo/writing-javascript-with-accessibility-in-mind...

I'm all for adding accessibility, however this feature further deviates from the native Bootstrap plugin (more so than it already has).

To keep BC, I would say this would also need a setting that could be disabled if such functionality is not desired, for whatever reason.

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1. +++ b/js/popover.js
   @@ -60,6 +60,15 @@ var Drupal = Drupal || {};
   +          .keyup(function (event) {
   

   This should be .on('keyup.bs.popover', function (e) { instead.

2. +++ b/js/popover.js
   @@ -60,6 +60,15 @@ var Drupal = Drupal || {};
   +            // Close popup when ESC is pressed.
   

   Comment should be above the method/anonymous function invocation with a space before it as well (in between chain).

3. +++ b/js/popover.js
   @@ -60,6 +60,15 @@ var Drupal = Drupal || {};
   +            if (event.which === 27) {
   +              if($currentPopover) {
   

   Also, there's no need for two if code blocks here, just use one with &&.

bump...

bump... again...

1. +++ b/js/popover.js
   @@ -65,6 +66,16 @@ var Drupal = Drupal || {};
   +          .keyup(function (event) {
   

   Again, this should be .on('keyup.bs.popover', function (e) {.

   That being said, it really shouldn't be bound at all unless the setting is enabled.

2. +++ b/js/popover.js
   @@ -65,6 +66,16 @@ var Drupal = Drupal || {};
   +            if ($.fn.popover.Constructor.DEFAULTS.closeOnEscape
   

   This shouldn't be using the global setting. Individual popups may have this option manually configured. This should retrieve the option from $currentPopover itself.

Ok. I've gone through the existing code and the above patches.

The more I looked at it, the more I realized it made very little difference to have an additional setting just for escape.

Furthermore, the existing popover_trigger_autoclose setting doesn't really make a lot of sense, name wise; so I've renamed it popover_auto_close and combined all the existing functionalty with the new functionality as a single setting.

The description of the new setting explains in great detail when an automatic close will happen.

I've also gone ahead and created a change record for this issue.

While browsing anonymously, I get "Uncaught Error: Syntax error, unrecognized expression: unsupported pseudo: focusable". From a quick internet search, it appears as though this pseudo selector is only available if jQuery UI is loaded.

Hopefully I'll figure out a nice fix today. If I do, I'll create a separate issue with a patch and link back to this one.

I added a new issue with a patch to address the issue I brought up in #19. https://www.drupal.org/project/bootstrap/issues/3013236#comment-12853020