changed FullscreenEvent to be On, Off, Toggle instead of a simple bool

src/backends/window_event.rs

@@ -265,18 +265,31 @@ impl<Window> ConfigureEvent<Window> {
     }
 }
 
+#[derive(Debug)]
+pub enum FullscreenState {
+    On,
+    Off,
+    Toggle,
+}
+
+impl From<bool> for FullscreenState {
+    fn from(value: bool) -> Self {
+        match value {
+            true => Self::On,
+            false => Self::Off,
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct FullscreenEvent<Window> {
-    window: Window,
-    new_fullscreen: bool,
+    pub window: Window,
+    pub state: FullscreenState,
 }
 
 impl<Window> FullscreenEvent<Window> {
-    pub fn new(window: Window, new_fullscreen: bool) -> Self {
-        Self {
-            window,
-            new_fullscreen,
-        }
+    pub fn new(window: Window, state: FullscreenState) -> Self {
+        Self { window, state }
     }
 }
 

src/backends/xlib/mod.rs

@@ -1,5 +1,5 @@
 use log::{error, warn};
-use std::{ffi::CString, rc::Rc};
+use std::{ffi::CString, mem::MaybeUninit, rc::Rc};
 
 use thiserror::Error;
 
@@ -17,9 +17,9 @@ use self::keysym::{
 use super::{
     keycodes::VirtualKeyCode,
     window_event::{
-        ButtonEvent, ConfigureEvent, DestroyEvent, EnterEvent, KeyEvent,
-        KeyOrMouseBind, KeyState, MapEvent, ModifierState, MotionEvent, Point,
-        UnmapEvent, WindowEvent,
+        ButtonEvent, ConfigureEvent, DestroyEvent, EnterEvent, FullscreenEvent,
+        FullscreenState, KeyEvent, KeyOrMouseBind, KeyState, MapEvent,
+        ModifierState, MotionEvent, Point, UnmapEvent, WindowEvent,
     },
     WindowServerBackend,
 };
@@ -285,6 +285,53 @@ impl XLib {
                     ))
                 })
             }
+            xlib::PropertyNotify => {
+                let ev = unsafe { &event.property };
+
+                (ev.atom == self.atoms.net_wm_window_type)
+                    .then(|| {
+                        (self.get_atom_property(
+                            ev.window,
+                            self.atoms.net_wm_state,
+                        ) == Some(self.atoms.net_wm_state_fullscreen))
+                        .then(|| {
+                            XLibWindowEvent::FullscreenEvent(
+                                FullscreenEvent::new(
+                                    ev.window,
+                                    FullscreenState::On,
+                                ),
+                            )
+                        })
+                    })
+                    .flatten()
+            }
+            xlib::ClientMessage => {
+                let ev = unsafe { &event.client_message };
+
+                (ev.message_type == self.atoms.net_wm_state)
+                    .then(|| {
+                        let data = ev.data.as_longs();
+                        (data[1] as u64 == self.atoms.net_wm_state_fullscreen
+                            || data[2] as u64
+                                == self.atoms.net_wm_state_fullscreen)
+                            .then(|| {
+                                XLibWindowEvent::FullscreenEvent(
+                                    FullscreenEvent::new(
+                                        ev.window,
+                                        match data[0] /* as u64 */ {
+                                            0 => FullscreenState::Off,
+                                            1 => FullscreenState::On,
+                                            2 => FullscreenState::Toggle,
+                                            _ => {
+                                                unreachable!()
+                                            }
+                                        },
+                                    ),
+                                )
+                            })
+                    })
+                    .flatten()
+            }
             _ => None,
         }
     }
@@ -308,6 +355,37 @@ impl XLib {
         }
     }
 
+    fn get_atom_property(
+        &self,
+        window: xlib::Window,
+        atom: xlib::Atom,
+    ) -> Option<xlib::Atom> {
+        let mut di = 0;
+        let mut dl0 = 0;
+        let mut dl1 = 0;
+        let mut da = 0;
+
+        let mut atom_out = MaybeUninit::<xlib::Atom>::zeroed();
+
+        unsafe {
+            (xlib::XGetWindowProperty(
+                self.dpy(),
+                window,
+                atom,
+                0,
+                std::mem::size_of::<xlib::Atom>() as i64,
+                0,
+                xlib::XA_ATOM,
+                &mut da,
+                &mut di,
+                &mut dl0,
+                &mut dl1,
+                atom_out.as_mut_ptr() as *mut _,
+            ) != 0)
+                .then(|| atom_out.assume_init())
+        }
+    }
+
     fn check_for_protocol(
         &self,
         window: xlib::Window,

src/state.rs

@@ -8,9 +8,9 @@ use crate::{
     backends::{
         keycodes::{MouseButton, VirtualKeyCode},
         window_event::{
-            ButtonEvent, ConfigureEvent, KeyBind, KeyEvent, KeyState, MapEvent,
-            ModifierKey, ModifierState, MotionEvent, MouseBind, Point,
-            WindowEvent,
+            ButtonEvent, ConfigureEvent, FullscreenEvent, KeyBind, KeyEvent,
+            KeyState, MapEvent, ModifierKey, ModifierState, MotionEvent,
+            MouseBind, Point, WindowEvent,
         },
         xlib::XLib,
         WindowServerBackend,
@@ -464,6 +464,12 @@ where
                     //     None => self.xlib.configure_window(event),
                     // }
                 }
+                WindowEvent::FullscreenEvent(FullscreenEvent {
+                    window,
+                    state,
+                }) => {
+                    info!("FullscreenEvent for window {}: {:?}", window, state);
+                }
 
                 // i dont think i actually have to handle destroy notify events.
                 // every window should be unmapped regardless