tree e83911b7b5f51ff16b712c3661a2ef1d15cf7933
parent f85dae83dfec0108f76429981f4acb07ba64210d
author Sergei Tachenov <sergei.tachenov@jetbrains.com> 1691408362 +0300
committer Maxim Kartashev <maxim.kartashev@jetbrains.com> 1692692363 +0400

JBR-5824 Ensure popup menus are on the correct screen

This is a very old bug, JDK-6415065.

What happens here is that when the position
of a popup menu is calculated, it can expand
above or below, depending on the position
of the parent menu, the item being expanded
and the size of the submenu and screen resolution.

If the menu decides to expand above,
the position calculation in JMenu.getPopupMenuOrigin
may yield a coordinate above the current screen.
Later, JPopupMenu.adjustPopupLocationToFitScreen
tries to fit the entire menu into the screen.
However, it has no idea which screen is correct,
as all it has is an (x, y) location. If that
location is invalid, it may correct it by
fitting it into the screen. However, if it is
valid, but located on an incorrect screen,
then the whole logic goes awry and the menu
is fitted into the wrong screen.

Fix by pre-adjusting the Y location to fit
into the correct screen in JMenu.getPopupMenuOrigin,
where the correct screen is still known.
The resulting location may still not be final,
as the menu's height needs to be taken into
account as well, but that's exactly what
JPopupMenu.adjustPopupLocationToFitScreen does.
Since the coordinate is on the correct screen now,
it fits the menu into the same screen, which
guarantees it'll be the correct one.