Issue Summary

When using the Legacy editor, using at-mentions, date picker or macro picker on a long page will cause the picker window to be displayed at the very bottom of the page.

The picker window offset seems to be proportional to how far down the scrollbar has navigated along the page, which means:

• there is no offset at the top of the page
• the offset is worsened at the very bottom of the page

Steps to Reproduce

1. Create a new page using the Legacy editor
2. Add a date picker or at-mention in the first line of the page (works well)
3. Add multiple line breaks until a scroll bar appears
4. Scroll to the last line and add a date picker or at-mention
5. Scroll further down and notice the window appears at the very bottom of the page (undesired behavior)

Expected Results

The picker windows are displayed at the expected location and aligned with the cursor:

Actual Results

The picker windows are displayed at the bottom of the page, sometimes below the end of the page's body:

Workaround

The available workarounds are:

1. Copy a date, user or group from the top of the page (or another page) and paste it at the desired location
2. Scroll to the very bottom of the page (cursor needs to be placed at the page's footer) and find the picker window