This request makes the created popup take an explicit grab. An explicit
grab will be dismissed when the user dismisses the popup, or when the
client destroys the xdg_popup. This can be done by the user clicking
outside the surface, using the keyboard, or even locking the screen
through closing the lid or a timeout.
If the compositor denies the grab, the popup will be immediately
dismissed.
This request must be used in response to some sort of user action like a
button press, key press, or touch down event. The serial number of the
event should be passed as 'serial'.
The parent of a grabbing popup must either be an xdg_toplevel surface or
another xdg_popup with an explicit grab. If the parent is another
xdg_popup it means that the popups are nested, with this popup now being
the topmost popup.
Nested popups must be destroyed in the reverse order they were created
in, e.g. the only popup you are allowed to destroy at all times is the
topmost one.
When compositors choose to dismiss a popup, they may dismiss every
nested grabbing popup as well. When a compositor dismisses popups, it
will follow the same dismissing order as required from the client.
The parent of a grabbing popup must either be another xdg_popup with an
active explicit grab, or an xdg_popup or xdg_toplevel, if there are no
explicit grabs already taken.
If the topmost grabbing popup is destroyed, the grab will be returned to
the parent of the popup, if that parent previously had an explicit grab.
If the parent is a grabbing popup which has already been dismissed, this
popup will be immediately dismissed. If the parent is a popup that did
not take an explicit grab, an error will be raised.
During a popup grab, the client owning the grab will receive pointer
and touch events for all their surfaces as normal (similar to an
"owner-events" grab in X11 parlance), while the top most grabbing popup
will always have keyboard focus.
make the popup take an explicit grab
This request makes the created popup take an explicit grab. An explicit grab will be dismissed when the user dismisses the popup, or when the client destroys the xdg_popup. This can be done by the user clicking outside the surface, using the keyboard, or even locking the screen through closing the lid or a timeout.
If the compositor denies the grab, the popup will be immediately dismissed.
This request must be used in response to some sort of user action like a button press, key press, or touch down event. The serial number of the event should be passed as 'serial'.
The parent of a grabbing popup must either be an xdg_toplevel surface or another xdg_popup with an explicit grab. If the parent is another xdg_popup it means that the popups are nested, with this popup now being the topmost popup.
Nested popups must be destroyed in the reverse order they were created in, e.g. the only popup you are allowed to destroy at all times is the topmost one.
When compositors choose to dismiss a popup, they may dismiss every nested grabbing popup as well. When a compositor dismisses popups, it will follow the same dismissing order as required from the client.
The parent of a grabbing popup must either be another xdg_popup with an active explicit grab, or an xdg_popup or xdg_toplevel, if there are no explicit grabs already taken.
If the topmost grabbing popup is destroyed, the grab will be returned to the parent of the popup, if that parent previously had an explicit grab.
If the parent is a grabbing popup which has already been dismissed, this popup will be immediately dismissed. If the parent is a popup that did not take an explicit grab, an error will be raised.
During a popup grab, the client owning the grab will receive pointer and touch events for all their surfaces as normal (similar to an "owner-events" grab in X11 parlance), while the top most grabbing popup will always have keyboard focus.