XGrabKeyboard on the same display as XRecord breaks event delivery.
XRecord captures events globally without any grab needed.
Also: use XPending() before select() to check Xlib internal buffer,
and add XFlush before XRecordProcessReplies after select().
- XRecordRange is 32 bytes: core_requests(0), core_replies(2),
ext_requests(4), ext_replies(10), delivered_events(16),
device_events(18), errors(20), client_started(24), client_died(28)
- XRecordClientSpec is XID = unsigned long (8 bytes), not int (4 bytes)
- Use XRecordAllClients=3 instead of XRecordCurrentClients=1
XGrabKeyboard returns success but never delivers events to a windowless
client on modern X11. XRecord is the standard way to capture keyboard
events globally — used by xdotool, xbindkeys, and input methods.
Architecture:
- XRecord: captures all keyboard events (no grab needed)
- XGrabKeyboard: still used to block original events from reaching apps
- XTest: injects modified events
Dynamically loads libXtst.so.6 for XRecord functions.
Events flow: XRecord callback → thread-safe queue → daemon event loop.
CRITICAL BUG: XEvent was { _type, _pad[24], data } (data at offset 28)
but in X11 it's a union where ALL variants start at offset 0. This meant
event.data.key.state/keycode read from completely wrong offsets — every
keystroke produced garbage characters.
Fixed by replacing XEvent with a raw [u8; 192] byte buffer and using
event_type() and key() accessor methods that cast from offset 0.
Also fixed same bug in x11_inject.rs.
XPending returned 0 even with active keyboard grab. Using select() on
the X11 connection file descriptor with 100ms timeout to reliably detect
when the X server sends events. Also adds XSelectInput on root window
and XConnectionNumber for the fd.
Without XSelectInput, XGrabKeyboard grabs the keyboard but the X server
never sends KeyPress/KeyRelease events to our connection. Also flushes
after grab to ensure it takes effect.
- Use XPending() to check for events before XNextEvent (non-blocking)
- Add is_grabbed() and has_pending_events() public methods
- Auto re-grab keyboard when grab is silently lost (tray, WM focus)
- Fixes AppImage daemon receiving zero keystroke events
