[wp-trac] [WordPress Trac] #44431: Post editor toolbar: inconsistent and bugged sticky behaviour, and; incorrect paragraph styles menu positioning on scroll

[WordPress Trac]

#44431: Post editor toolbar: inconsistent and bugged sticky behaviour, and;
incorrect paragraph styles menu positioning on scroll
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 Reporter:  startsat60                      |      Owner:  (none)
     Type:  defect (bug)                    |     Status:  new
 Priority:  normal                          |  Milestone:  Awaiting Review
Component:  Administration                  |    Version:  4.9.6
 Severity:  normal                          |   Keywords:  has-screenshots
  Focuses:  ui, javascript, administration  |
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 The MCE editor toolbar exhibits inconsistent and incorrect sticky
 behaviour on scroll. There are three patterns I've observed:

 ''**1)** If you wait for more than a few seconds before scrolling, the
 editor toolbar will not stick, and you'll need to scroll up to make any
 changes on medium-long posts.''

 ''**2)** If you scroll within approximately 1 sec of the toolbar
 appearing, it will stick to the top of the window, and will never unstick,
 causing it to cover the Title field, preventing it from being edited, and
 also when scrolling down past the main content textarea, it will remain
 stuck and will overlap subsequent fields as well.''

 ''**3)** In the "goldilocks zone" between the above time periods, it's
 possible to have the toolbar stick when scrolling, then unstick, and it
 will remain in the location where it became unstuck, usually in the middle
 of the main content textarea.''

 **Initial page load**
 [[Image(etNrM5q)]]

 ----

 Along a similar vein, the paragraph style menu positioning is also
 incorrectly implemented. It appears that the logic to determine its
 position is:

 ''**1)** Take the Y page offset for the paragraph style menu button''

 ''**2)** Apply this offset to the fixed menu as its top style property''

 This is only legitimate when the user does not scroll. As soon as the user
 scrolls, whether the toolbar sticks or not, the page offset of the menu
 button applied as the top offset of the menu will cause the menu to appear
 entirely disconnected from the button.

 If the toolbar is not stuck, then the menu will always at least still be
 visible, because it's not possible to click the menu button once it has
 been scrolled out of view, and its page offset will be small enough that
 the menu will still appear within the window.

 However, if the toolbar is not initially visible before scrolling, or if
 it sticks on scroll, then the menu will be placed outside of the viewable
 window, making it inaccessible.

 ----

 We have the following active plugins that interact with the post add/edit
 form: TinyMCE Advanced v4.7.11, Advanced Custom Fields Pro v5.5.10, and
 Gravity Forms v2.1.3.9. Deactivating any/all of these plugins had no
 discernible impact on the above behaviour.

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Ticket URL: <https://core.trac.wordpress.org/ticket/44431>
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