feat: implement Linux global hotkey support using X11 and XDG portal backends with integrated media controls.

internal/xhotkey/hotkey_linux_x11.go

@@ -0,0 +1,80 @@
+//go:build linux && cgo
+
+package hotkey
+
+/*
+#cgo LDFLAGS: -lX11
+
+#include <stdint.h>
+
+int displayTest();
+int waitHotkey(uintptr_t hkhandle, unsigned int mod, int key);
+*/
+import "C"
+import (
+	"context"
+	"errors"
+	"fmt"
+	"runtime"
+	"runtime/cgo"
+)
+
+func (hk *Hotkey) registerX11() error {
+	if C.displayTest() != 0 {
+		return fmt.Errorf("X11 display not available (is DISPLAY set?)")
+	}
+	hk.mu.Lock()
+	if hk.registered {
+		hk.mu.Unlock()
+		return errors.New("hotkey already registered.")
+	}
+	hk.backend = linuxHKX11
+	hk.registered = true
+	hk.ctx, hk.cancel = context.WithCancel(context.Background())
+	hk.canceled = make(chan struct{})
+	hk.mu.Unlock()
+
+	go hk.handleX11()
+	return nil
+}
+
+func (hk *Hotkey) handleX11() {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	var mod Modifier
+	for _, m := range hk.mods {
+		mod = mod | m
+	}
+	h := cgo.NewHandle(hk)
+	defer h.Delete()
+
+	for {
+		_ = C.waitHotkey(C.uintptr_t(h), C.uint(mod), C.int(hk.key))
+		close(hk.canceled)
+		return
+	}
+}
+
+//export checkCancel
+func checkCancel(h uintptr) C.int {
+	hk := cgo.Handle(h).Value().(*Hotkey)
+	select {
+	case <-hk.ctx.Done():
+		return 1
+	default:
+		return 0
+	}
+}
+
+//export hotkeyDown
+func hotkeyDown(h uintptr) {
+	hk := cgo.Handle(h).Value().(*Hotkey)
+	hk.keydownIn <- Event{}
+}
+
+//export hotkeyUp
+func hotkeyUp(h uintptr) {
+	hk := cgo.Handle(h).Value().(*Hotkey)
+	hk.keyupIn <- Event{}
+}