// Take a look at the license at the top of the repository in the LICENSE file.

use crate::{prelude::*, X11Display};
#[cfg(feature = "xlib")]
#[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
use glib::signal::{connect_raw, SignalHandlerId};
#[cfg(all(feature = "v4_4", feature = "egl"))]
#[cfg_attr(docsrs, doc(cfg(all(feature = "v4_4", feature = "egl"))))]
use khronos_egl as egl;
#[cfg(feature = "xlib")]
#[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
use std::{boxed::Box as Box_, mem::transmute};
#[cfg(feature = "xlib")]
#[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
use x11::xlib;

#[cfg(not(feature = "xlib"))]
use crate::{XCursor, XWindow};
use glib::{translate::*, IntoGStr};
#[cfg(feature = "xlib")]
#[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
use x11::xlib::{Cursor as XCursor, Window as XWindow};

impl X11Display {
    /// Retrieves the EGL display connection object for the given GDK display.
    ///
    /// This function returns `NULL` if GDK is using GLX.
    ///
    /// # Returns
    ///
    /// the EGL display object
    #[cfg(all(feature = "v4_4", feature = "egl"))]
    #[cfg_attr(docsrs, doc(cfg(all(feature = "v4_4", feature = "egl"))))]
    #[doc(alias = "gdk_x11_display_get_egl_display")]
    #[doc(alias = "get_egl_display")]
    pub fn egl_display(&self) -> Option<egl::Display> {
        unsafe {
            let ptr = ffi::gdk_x11_display_get_egl_display(self.to_glib_none().0);
            if ptr.is_null() {
                None
            } else {
                Some(egl::Display::from_ptr(ptr))
            }
        }
    }

    /// Returns the X cursor belonging to a [`gdk::Cursor`][crate::gdk::Cursor], potentially
    /// creating the cursor.
    ///
    /// Be aware that the returned cursor may not be unique to @cursor.
    /// It may for example be shared with its fallback cursor. On old
    /// X servers that don't support the XCursor extension, all cursors
    /// may even fall back to a few default cursors.
    /// ## `cursor`
    /// a [`gdk::Cursor`][crate::gdk::Cursor]
    ///
    /// # Returns
    ///
    /// an Xlib Cursor.
    #[doc(alias = "gdk_x11_display_get_xcursor")]
    #[doc(alias = "get_xcursor")]
    pub fn xcursor(&self, cursor: &gdk::Cursor) -> XCursor {
        unsafe { ffi::gdk_x11_display_get_xcursor(self.to_glib_none().0, cursor.to_glib_none().0) }
    }

    /// Returns the root X window used by [`gdk::Display`][crate::gdk::Display].
    ///
    /// # Returns
    ///
    /// an X Window
    #[doc(alias = "gdk_x11_display_get_xrootwindow")]
    #[doc(alias = "get_xrootwindow")]
    pub fn xrootwindow(&self) -> XWindow {
        unsafe { ffi::gdk_x11_display_get_xrootwindow(self.to_glib_none().0) }
    }

    /// Returns the X display of a [`gdk::Display`][crate::gdk::Display].
    ///
    /// # Returns
    ///
    /// an X display
    #[cfg(feature = "xlib")]
    #[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
    #[doc(alias = "gdk_x11_display_get_xdisplay")]
    #[doc(alias = "get_xdisplay")]
    pub unsafe fn xdisplay(&self) -> *mut xlib::Display {
        ffi::gdk_x11_display_get_xdisplay(self.to_glib_none().0) as *mut xlib::Display
    }

    /// Returns the X Screen used by [`gdk::Display`][crate::gdk::Display].
    ///
    /// # Returns
    ///
    /// an X Screen
    #[cfg(feature = "xlib")]
    #[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
    #[doc(alias = "gdk_x11_display_get_xscreen")]
    #[doc(alias = "get_xscreen")]
    pub unsafe fn xscreen(&self) -> *mut xlib::Screen {
        ffi::gdk_x11_display_get_xscreen(self.to_glib_none().0) as *mut xlib::Screen
    }

    /// The ::xevent signal is a low level signal that is emitted
    /// whenever an XEvent has been received.
    ///
    /// When handlers to this signal return [`true`], no other handlers will be
    /// invoked. In particular, the default handler for this function is
    /// GDK's own event handling mechanism, so by returning [`true`] for an event
    /// that GDK expects to translate, you may break GDK and/or GTK+ in
    /// interesting ways. You have been warned.
    ///
    /// If you want this signal handler to queue a [`gdk::Event`][crate::gdk::Event], you can use
    /// gdk_display_put_event().
    ///
    /// If you are interested in X GenericEvents, bear in mind that
    /// XGetEventData() has been already called on the event, and
    /// XFreeEventData() will be called afterwards.
    /// ## `xevent`
    /// a pointer to the XEvent to process
    ///
    /// # Returns
    ///
    /// [`true`] to stop other handlers from being invoked for the event.
    ///   [`false`] to propagate the event further.
    #[cfg(feature = "xlib")]
    #[cfg_attr(docsrs, doc(cfg(feature = "xlib")))]
    #[doc(alias = "xevent")]
    pub unsafe fn connect_xevent<F: Fn(&Self, *mut xlib::XEvent) -> glib::Propagation + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn xevent_trampoline<
            F: Fn(&X11Display, *mut xlib::XEvent) -> glib::Propagation + 'static,
        >(
            this: *mut ffi::GdkX11Display,
            xevent: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this), xevent as *mut xlib::XEvent).into_glib()
        }
        let f: Box_<F> = Box_::new(f);
        connect_raw(
            self.as_ptr() as *mut _,
            b"xevent\0".as_ptr() as *const _,
            Some(transmute::<_, unsafe extern "C" fn()>(
                xevent_trampoline::<F> as *const (),
            )),
            Box_::into_raw(f),
        )
    }

    /// Sets the program class.
    ///
    /// The X11 backend uses the program class to set the class name part
    /// of the `WM_CLASS` property on toplevel windows; see the ICCCM.
    /// ## `display`
    /// a [`gdk::Display`][crate::gdk::Display]
    /// ## `program_class`
    /// a string
    #[doc(alias = "gdk_x11_display_set_program_class")]
    pub fn set_program_class(&self, program_class: impl IntoGStr) {
        assert_initialized_main_thread!();
        unsafe {
            program_class.run_with_gstr(|program_class| {
                ffi::gdk_x11_display_set_program_class(
                    self.upcast_ref::<gdk::Display>().to_glib_none().0,
                    program_class.as_ptr(),
                );
            });
        }
    }
}