Accessory windows are windows that, when activated, will activate
their parent and bring all other accessory windows of that parent
to the front of the window stack. Accessory windows can only be
active input windows. The accessory window's parent is always the
active window regardless of whether it is also the active input
window.
In order to route input correctly, input is now sent to the active
input window, which can be any accessory window or their parent,
or any regular window.
During app teardown, the Application object may be destroyed before
something else, and so having Application::the() return a reference was
obscuring the truth about its lifetime.
This patch makes the API more honest by returning a pointer. While
this makes call sites look a bit more sketchy, do note that the global
Application pointer only becomes null during app teardown.
A GUI::Widget can now set an optional content margin (4x0 by default.)
Pixels in the content margin will be ignored for hit testing purposes.
Use this to allow frame-like widgets (like GUI::Frame!) to ignore any
mouse events in the frame area, and instead let those go to parent.
This allows GUI::Splitter to react "sooner" to mouse events that were
previously swallowed by the child widgets instead of ending up in the
splitter. The net effect is that 2 more pixels on each side of a
splitter handle are now interactive and usable for splitting! :^)
Previously the focused widget would only get cleared on replacement or
on destruction (being a WeakPtr and all.) This could lead to window
dispatching events to a focused widget after it had been removed from
the window's widget tree.
The same issue existed for the hovered widget, etc. So this patch
makes sure that we eagerly clear the various widget pointers in Window
immediately when they are removed from the window's widget tree.
This patch adds a magenta rectangle around the currently inspected
widget. This allows you to browse an app's widget tree somewhat
visually using the Inspector. :^)
This allows windows/widgets to learn when something is being dragged
over them. They can then repaint themselves somehow to indicate that
they are willing to accept a drop.
Currently this is piggybacking somewhat on the mouse event mechanism
in WindowServer. I'm not sure that's the best design but it seemed
easier to do it this way right now.
