Bug 1348: Fix X11 XI Multitouch

I got access to a touchscreen laptop w/ Debian 9, hence I could fix and test the implementation.

X11 DisplayDriver.java:
- Store and pass through xi_opcode of XI extension, queried at initialization stage

X11Window.c Fixes:
- Initialize JavaWindow's xiTouchCoords[].id w/ -1, as required to track the pointer

- Pass through xi_opcode as stored in X11 DisplayDriver

X11Display.c Fixes:
- sendTouchScreenEvent: Throw RuntimeException if 0 > actionId (Internal Error: based on xiTouchCoords[].id tracking)

- DispatchMessages's windowPointer determination:
-- Query potenial XI Event first: IF XI Event, must use XIDeviceEvent's event Window
-- Only IF not an XI Event, we can use evt.xany.window as the event window

- DispatchMessages's XI Event Handling:
-- Always break deviceid search loop if id found, preserving index and time spend

Works on my Debian 9 device, tested w/ com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NEWT:
- One pointer (finger) press, drag and release (click)
- PinchToZoomGesture works
- DoubleTabScrollGesture works

+++

Potential Issues:

JavaWindow's xiTouchCoords[].id accuracy is crucial to pointer tracking
during XI_TouchBegin -> XI_TouchUpdate -> XI_TouchEnd.

In the normal course of action:
- XI_TouchBegin sets the id, assuming it is yet set
- XI_TouchUpdate assumes it is set
- XI_TouchEnd clears the id, assuming it is set

This field in the JavaWindow array only gets reset to -1 once at native window
creation. We may need to figure out when to reset this field to -1.

If the XI_TouchEnd events would get lost for whatever reason,
the above tracking state would be broken.

0 files changed, 0 insertions, 0 deletions