// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// DO NOT EDIT

use crate::{Initable, MemoryMonitorWarningLevel};
use glib::{
    prelude::*,
    signal::{connect_raw, SignalHandlerId},
    translate::*,
};
use std::boxed::Box as Box_;

glib::wrapper! {
    /// `GMemoryMonitor` will monitor system memory and suggest to the application
    /// when to free memory so as to leave more room for other applications.
    /// It is implemented on Linux using the
    /// [Low Memory Monitor](https://gitlab.freedesktop.org/hadess/low-memory-monitor/)
    /// ([API documentation](https://hadess.pages.freedesktop.org/low-memory-monitor/)).
    ///
    /// There is also an implementation for use inside Flatpak sandboxes.
    ///
    /// Possible actions to take when the signal is received are:
    ///
    ///  - Free caches
    ///  - Save files that haven’t been looked at in a while to disk, ready to be reopened when needed
    ///  - Run a garbage collection cycle
    ///  - Try and compress fragmented allocations
    ///  - Exit on idle if the process has no reason to stay around
    ///  - Call [`malloc_trim(3)`](man:malloc_trim(3)) to return cached heap pages to
    ///    the kernel (if supported by your libc)
    ///
    /// Note that some actions may not always improve system performance, and so
    /// should be profiled for your application. `malloc_trim()`, for example, may
    /// make future heap allocations slower (due to releasing cached heap pages back
    /// to the kernel).
    ///
    /// See [type@Gio.MemoryMonitorWarningLevel] for details on the various warning
    /// levels.
    ///
    /// **⚠️ The following code is in c ⚠️**
    ///
    /// ```c
    /// static void
    /// warning_cb (GMemoryMonitor *m, GMemoryMonitorWarningLevel level)
    /// {
    ///   g_debug ("Warning level: %d", level);
    ///   if (warning_level > G_MEMORY_MONITOR_WARNING_LEVEL_LOW)
    ///     drop_caches ();
    /// }
    ///
    /// static GMemoryMonitor *
    /// monitor_low_memory (void)
    /// {
    ///   GMemoryMonitor *m;
    ///   m = g_memory_monitor_dup_default ();
    ///   g_signal_connect (G_OBJECT (m), "low-memory-warning",
    ///                     G_CALLBACK (warning_cb), NULL);
    ///   return m;
    /// }
    /// ```
    ///
    /// Don’t forget to disconnect the [`low-memory-warning`][struct@crate::MemoryMonitor#low-memory-warning]
    /// signal, and unref the `GMemoryMonitor` itself when exiting.
    ///
    /// ## Signals
    ///
    ///
    /// #### `low-memory-warning`
    ///  Emitted when the system is running low on free memory. The signal
    /// handler should then take the appropriate action depending on the
    /// warning level. See the #GMemoryMonitorWarningLevel documentation for
    /// details.
    ///
    ///
    ///
    /// # Implements
    ///
    /// [`MemoryMonitorExt`][trait@crate::prelude::MemoryMonitorExt], [`InitableExt`][trait@crate::prelude::InitableExt]
    #[doc(alias = "GMemoryMonitor")]
    pub struct MemoryMonitor(Interface<ffi::GMemoryMonitor, ffi::GMemoryMonitorInterface>) @requires Initable;

    match fn {
        type_ => || ffi::g_memory_monitor_get_type(),
    }
}

impl MemoryMonitor {
    pub const NONE: Option<&'static MemoryMonitor> = None;

    /// Gets a reference to the default #GMemoryMonitor for the system.
    ///
    /// # Returns
    ///
    /// a new reference to the default #GMemoryMonitor
    #[doc(alias = "g_memory_monitor_dup_default")]
    pub fn dup_default() -> MemoryMonitor {
        unsafe { from_glib_full(ffi::g_memory_monitor_dup_default()) }
    }
}

mod sealed {
    pub trait Sealed {}
    impl<T: super::IsA<super::MemoryMonitor>> Sealed for T {}
}

/// Trait containing all [`struct@MemoryMonitor`] methods.
///
/// # Implementors
///
/// [`MemoryMonitor`][struct@crate::MemoryMonitor]
pub trait MemoryMonitorExt: IsA<MemoryMonitor> + sealed::Sealed + 'static {
    /// Emitted when the system is running low on free memory. The signal
    /// handler should then take the appropriate action depending on the
    /// warning level. See the #GMemoryMonitorWarningLevel documentation for
    /// details.
    /// ## `level`
    /// the #GMemoryMonitorWarningLevel warning level
    #[cfg(feature = "v2_64")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v2_64")))]
    #[doc(alias = "low-memory-warning")]
    fn connect_low_memory_warning<F: Fn(&Self, MemoryMonitorWarningLevel) + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn low_memory_warning_trampoline<
            P: IsA<MemoryMonitor>,
            F: Fn(&P, MemoryMonitorWarningLevel) + 'static,
        >(
            this: *mut ffi::GMemoryMonitor,
            level: ffi::GMemoryMonitorWarningLevel,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(
                MemoryMonitor::from_glib_borrow(this).unsafe_cast_ref(),
                from_glib(level),
            )
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"low-memory-warning\0".as_ptr() as *const _,
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    low_memory_warning_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }
}

impl<O: IsA<MemoryMonitor>> MemoryMonitorExt for O {}