Macro notification_plugin

macro_rules! notification_plugin {
    (|$arg:ident| $body:block) => { ... };
    ($name:expr, |$arg:ident| $body:block) => { ... };
}

Defines a new notification callback.

This macro has two variants: If passed just a callback function, that function is registered as a callback for all hook events. If passed a null-terminated hook name and a callback function, that function will be registered as a callback for that specific hook event. The callback function itself will in either case recive an argument of type *mut notify_entry.

For example:

use tmux_plugin::notification_plugin;
use std::ffi::{CStr, CString};

// Enforce that window names are lower case.
notification_plugin!(b"window-renamed\0", |notify_entry| {
    let window = unsafe { (*notify_entry).window };
    let window_name = unsafe { CStr::from_ptr((*window).name) };
    let lowercase_name = window_name
        .to_string_lossy()
        .into_owned()
        .to_lowercase();
    let c_string = CString::new(lowercase_name)
        .expect("Does not contain null bytes, as the source was a valid C str");
    unsafe {
        // Free the old name, and duplicate the new name so
        // that tmux can later free it safely.
        libc::free((*window).name as *mut _);
        (*window).name = libc::strdup(c_string.as_ptr())
    }
});