This expands input events to represent sub-pixel mouse positions, devices responsible for generating events, and raw
device-oriented events. The X11 back end is refactored to make full use of the new expressiveness. Other backends have
had new functionality minimally stubbed out, save for the macos backend which already supports sub-pixel mouse
positions.
Previously, if a `Window` was `Drop`ped while open, the window would
remain open until the user pressed the x button. This fixes the
behaviour so that the window is closed when dropped if it has not
already been closed.
This can happen when window is destroyed/created during a call to user
callback as this causes WindowDelegate method to be called.
Instead if the user callback is `None` store the event in
`pending_events`.
* Remove NSTitledWindowMask for windows with no decorations. This
makes sure that they do not have a title bar.
* Transparency is not be taken into account as we could have a window
with a titlebar or without that is transparent.
Making applications track modifier keys results in unnecessary work for
consumers, it's error prone, and it turns out to have unavoidable bugs.
For example, alt-tabbing with x11 results in the alt modifier state
getting stuck.
To resolve these problems, this patch adds a Mods value to the keyboard
input event.
Based on this patch: d287fa96e3
WaitEventsIterator implements waiting by first calling XPeekEvent which
will block until at least 1 event is queued, and then it delegates to
PollEventsIterator to actually handle the new event. PollEventsIterator
was previously picky about which events it would process. Events of
other types would get stuck at the head of the X event queue, and
PollEventsIterator would return None. This initiated a busy loop in the
WaitEventsIterator because it would XPeekEvent, see that something is
there, and then PollEventsIterator would return None, and the process
would repeat.
This is resolved by using XNextEvent in the PollEventsIterator instead
of XCheckTypedEvent. Any event in the queue will be popped. Even if
winit isn't interested in the event, this means XPeekEvent will block
again to wait for another event instead of the previous behavior.
