next_xevent don't block anymore!

Now the next_xevent (from the safex11) will not block forever. So we
can listen the socket without doing some thread stuff.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/safe_x11/event.rs b/src/safe_x11/event.rs
new file mode 100644
index 0000000..2519bad
--- /dev/null
+++ b/src/safe_x11/event.rs
@@ -0,0 +1,33 @@
+use x11::xlib::{
+    XConnectionNumber,
+    Display,
+    XEvent,
+};
+
+use std::mem::uninitialized;
+
+use libc::c_int;
+
+#[link(name = "safex11")]
+extern {
+    /// Get an XEvent if there're one on the queue or wait a little before continue.
+    fn select_next_event(display: *mut Display, x11_fd: c_int, ev: *mut XEvent) -> c_int;
+}
+
+/// Get the file descriptor for the XServer
+pub fn x11_fd(display: *mut Display) -> c_int {
+    unsafe { XConnectionNumber(display) }
+}
+
+/// Get the next event from the xserver. This call will not block forever
+/// (like XNextEvent), instead it will wait for a certain time (1 second
+/// for now, but it can change) so we're not blocking the socket interface
+/// on the main thread.
+pub fn next_xevent(display: *mut Display, fd: c_int) -> XEvent {
+    unsafe {
+        let mut last_event: XEvent = uninitialized();
+        let retval = select_next_event(display, fd, &mut last_event) as i32;
+        last_event
+    }
+}
+