Comment 0 for bug 1311699

MirEvent::action is currently effectively an opaque value, as Mir headers do not specify its meaning.

So event.h must either define counterparts to the android AMOTION_EVENT_ACTION_* values below or split up the action and pointer index into separate variables.

"""
/* Bit shift for the action bits holding the pointer index as
 * defined by AMOTION_EVENT_ACTION_POINTER_INDEX_MASK.
 */
#define AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT 8

enum {
    /* Bit mask of the parts of the action code that are the action itself.
     */
    AMOTION_EVENT_ACTION_MASK = 0xff,

    /* Bits in the action code that represent a pointer index, used with
     * AMOTION_EVENT_ACTION_POINTER_DOWN and AMOTION_EVENT_ACTION_POINTER_UP. Shifting
     * down by AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT provides the actual pointer
     * index where the data for the pointer going up or down can be found.
     */
    AMOTION_EVENT_ACTION_POINTER_INDEX_MASK = 0xff00,
"""

Right now in the "Qt compositor" code I had to resort to locally defining those values, which is a hack:

""
// from android-input AMOTION_EVENT_ACTION_*, hidden inside mir bowels
// mir headers should define them
const int QtEventFeeder::MirEventActionMask = 0xff;
const int QtEventFeeder::MirEventActionPointerIndexMask = 0xff00;
const int QtEventFeeder::MirEventActionPointerIndexShift = 8;
""