The old dispatch mechanism has been left in place and continues to
be used by default for now. To enable native input dispatch,
edit the ENABLE_NATIVE_DISPATCH constant in WindowManagerPolicy.
Includes part of the new input event NDK API. Some details TBD.
To wire up input dispatch, as the ViewRoot adds a window to the
window session it receives an InputChannel object as an output
argument. The InputChannel encapsulates the file descriptors for a
shared memory region and two pipe end-points. The ViewRoot then
provides the InputChannel to the InputQueue. Behind the
scenes, InputQueue simply attaches handlers to the native PollLoop object
that underlies the MessageQueue. This way MessageQueue doesn't need
to know anything about input dispatch per-se, it just exposes (in native
code) a PollLoop that other components can use to monitor file descriptor
state changes.
There can be zero or more targets for any given input event. Each
input target is specified by its input channel and some parameters
including flags, an X/Y coordinate offset, and the dispatch timeout.
An input target can request either synchronous dispatch (for foreground apps)
or asynchronous dispatch (fire-and-forget for wallpapers and "outside"
targets). Currently, finding the appropriate input targets for an event
requires a call back into the WindowManagerServer from native code.
In the future this will be refactored to avoid most of these callbacks
except as required to handle pending focus transitions.
End-to-end event dispatch mostly works!
To do: event injection, rate limiting, ANRs, testing, optimization, etc.
Change-Id: I8c36b2b9e0a2d27392040ecda0f51b636456de25
The major things going on here:
- The MotionEvent API is now extended to included "pointer ID" information, for
applications to keep track of individual fingers as they move up and down.
PointerLocation has been updated to take advantage of this.
- The input system now has logic to generate MotionEvents with the new ID
information, synthesizing an identifier as new points are down and trying to
keep pointer ids consistent across events by looking at the distance between
the last and next set of pointers.
- We now support the new multitouch driver protocol, and will use that instead
of the old one if it is available. We do NOT use any finger id information
coming from the driver, but always synthesize pointer ids in user space.
(This is simply because we don't yet have a driver reporting this information
from which to base an implementation on.)
- Increase maximum number of fingers to 10. This code has only been used
with a driver that reports up to 2, so no idea how more will actually work.
- Oh and the input system can now detect and report physical DPAD devices.
This will be used to avoid unnecessarily listening to data from sensors
that function as event devices.
Signed-off-by: Mike Lockwood <lockwood@android.com>
The kernel can now publish a property describing the layout of virtual
hardware buttons on the touchscreen. These outside of the display
area (outside of the absolute x and y controller range the driver
reports), and when the user presses on them a key event will be
generated rather than a touch event.
This also includes a number of tweaks to the absolute controller
processing to make things work better on the new screens. For
example, we now reject down events outside of the display area.
Still left to be done is the ability to cancel a key down event,
so the user can slide up from the virtual keys to the touch screen
without causing a virtual key to execute.
