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// Take a look at the license at the top of the repository in the LICENSE file.
use crate::{prelude::*, SpinButton};
use glib::{
signal::{connect_raw, SignalHandlerId},
translate::*,
};
use libc::{c_double, c_int};
use std::{boxed::Box as Box_, mem::transmute};
impl SpinButton {
/// Emitted to convert the users input into a double value.
///
/// The signal handler is expected to use [`EditableExt::text()`][crate::prelude::EditableExt::text()]
/// to retrieve the text of the spinbutton and set @new_value to the
/// new value.
///
/// The default conversion uses g_strtod().
///
/// # Returns
///
/// [`true`] for a successful conversion, [`false`] if the input
/// was not handled, and `GTK_INPUT_ERROR` if the conversion failed.
///
/// ## `new_value`
/// return location for the new value
pub fn connect_input<F>(&self, f: F) -> SignalHandlerId
where
F: Fn(&Self) -> Option<Result<f64, ()>> + 'static,
{
unsafe {
let f: Box_<F> = Box_::new(f);
connect_raw(
self.as_ptr() as *mut _,
b"input\0".as_ptr() as *mut _,
Some(transmute(input_trampoline::<F> as usize)),
Box_::into_raw(f),
)
}
}
}
unsafe extern "C" fn input_trampoline<F: Fn(&SpinButton) -> Option<Result<f64, ()>> + 'static>(
this: *mut ffi::GtkSpinButton,
new_value: *mut c_double,
f: &F,
) -> c_int {
match f(SpinButton::from_glib_borrow(this).unsafe_cast_ref()) {
Some(Ok(v)) => {
*new_value = v;
glib::ffi::GTRUE
}
Some(Err(_)) => ffi::GTK_INPUT_ERROR,
None => glib::ffi::GFALSE,
}
}