Mouse button 1 (left) is activated.
Mouse button 2 (middle) is activated.
Mouse button 3 (right) is activated.
Mouse button 4 (scroll up) is activated.
Mouse button 5 (scroll down) is activated.
Control key is activated.
Forward mask indicates the event has been forward from ibus.
Handled mask indicates the event has been handled by ibus.
Hyper key is activated.
It is an alias of IBUS_FORWARD_MASK.
Cap Lock is locked.
Meta key is activated.
Modifier 1 (Usually Alt_L (0x40), Alt_R (0x6c), Meta_L (0xcd)) activated.
Modifier 2 (Usually Num_Lock (0x4d)) activated.
Modifier 3 activated.
Modifier 4 (Usually Super_L (0xce), Hyper_L (0xcf)) activated.
Modifier 5 (ISO_Level3_Shift (0x5c), Mode_switch (0xcb)) activated.
Modifier mask for the all the masks above.
Key is released.
Shift is activated.
Super (Usually Win) key is activated.
Handles key modifier such as control, shift and alt and release event. Note that nits 15 - 25 are currently unused, while bit 29 is used internally.