Previously it was possible for a window to register as a parentless
blocking modal then add itself to a stealable parent's modal chain,
bypassing a mode misbehavior check in create_window()
Also relaxes reciprocity for blockers with the same parent. This
scenario is usually created by simultaneous MessageBoxes. It's not
an ideal UX to cascade these, but there's no need to crash over it.
and the CaptureInput mode. They are a source of unneeded complexity
in WindowServer and have proven prone to regressions, so this patch
replaces them with a simple input preemption scheme using Popups.
Popup windows now have ergonomics similar to menus: When open,
a popup preempts all mouse and key events for the entire window
stack; however, they are fragile and will close after WindowServer
swallows the first event outside them. This is similar to how combo
box windows and popups work in the classic Windows DE and has the
added benefit of letting the user click anywhere to dismiss a popup
without having to worry about unwanted interactions with other
widgets.
Previously Menus set themselves as active input solely to make
sure CaptureInput modals would close, but this is a functional
half-truth. Menus don't actually use the active input role; they
preempt normal Windows during event handling instead.
Now the active input window is notified on preemption and Menus
can remain outside the active input concept. This lets us make
more granular choices about modal behavior. For now, the only
thing clients care about is menu preemption on popup.
Fixes windows which close on changes to active input closing
on their own context menus.
This was too restrictive and there are already UI elements that rely
on this behavior. Now Blocking modals will preempt interaction with
all windows in their modal chain except those descending from them.
Fixes crashing in FilePicker when permission is denied.
Previously, Windows only understood blocking modality: Windows were
either modal, i.e., in a blocking state, or not. Windows could also
be set as Accessories or ToolWindows, attributes which technically
applied modes to their parents but were implemented ad hoc. This patch
redefines these modal effects as WindowModes and sets up some helpers.
This will let us simplify a lot of modal logic in the upcoming patches
and make it easier to build new modal effects in the future.
Windows can now set 1 of 5 modes before reification:
-Modeless: No modal effect; begins a new modal chain
-Passive: Window joins its modal chain but has no effect
-RenderAbove: Window renders above its parent
-CaptureInput: Window captures the active input role from its parent
-Blocking: Window blocks all interaction with its modal chain
States like fullscreen and tiling are dynamic and don't alter behavior
in modal chains, so they aren't included.
