Add exclusive fullscreen mode (#925)

* Add exclusive fullscreen mode

* Add `WindowExtMacOS::set_fullscreen_presentation_options`

* Capture display for exclusive fullscreen on macOS

* Fix applying video mode on macOS after a fullscreen cycle

* Fix compilation on iOS

* Set monitor appropriately for fullscreen on macOS

* Fix exclusive to borderless fullscreen transitions on macOS

* Fix borderless to exclusive fullscreen transition on macOS

* Sort video modes on Windows

* Fix fullscreen issues on Windows

* Fix video mode changes during exclusive fullscreen on Windows

* Add video mode sorting for macOS and iOS

* Fix monitor `ns_screen` returning `None` after video mode change

* Fix "multithreaded" example on macOS

* Restore video mode upon closing an exclusive fullscreen window

* Fix "multithreaded" example closing multiple windows at once

* Fix compilation on Linux

* Update FEATURES.md

* Don't care about logical monitor groups on X11

* Add exclusive fullscreen for X11

* Update FEATURES.md

* Fix transitions between exclusive and borderless fullscreen on X11

* Update CHANGELOG.md

* Document that Wayland doesn't support exclusive fullscreen

* Replace core-graphics display mode bindings on macOS

* Use `panic!()` instead of `unreachable!()` in "fullscreen" example

* Fix fullscreen "always on top" flag on Windows

* Track current monitor for fullscreen in "multithreaded" example

* Fix exclusive fullscreen sometimes not positioning window properly

* Format

* More formatting and fix CI issues

* Fix formatting

* Fix changelog formatting

src/platform_impl/linux/mod.rs

@@ -13,8 +13,8 @@ use crate::{
     event::Event,
     event_loop::{ControlFlow, EventLoopClosed, EventLoopWindowTarget as RootELW},
     icon::Icon,
-    monitor::{MonitorHandle as RootMonitorHandle, VideoMode},
-    window::{CursorIcon, WindowAttributes},
+    monitor::{MonitorHandle as RootMonitorHandle, VideoMode as RootVideoMode},
+    window::{CursorIcon, Fullscreen, WindowAttributes},
 };
 
 mod dlopen;
@@ -92,7 +92,7 @@ impl DeviceId {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub enum MonitorHandle {
     X(x11::MonitorHandle),
     Wayland(wayland::MonitorHandle),
@@ -140,7 +140,7 @@ impl MonitorHandle {
     }
 
     #[inline]
-    pub fn video_modes(&self) -> Box<dyn Iterator<Item = VideoMode>> {
+    pub fn video_modes(&self) -> Box<dyn Iterator<Item = RootVideoMode>> {
         match self {
             MonitorHandle::X(m) => Box::new(m.video_modes()),
             MonitorHandle::Wayland(m) => Box::new(m.video_modes()),
@@ -148,6 +148,46 @@ impl MonitorHandle {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum VideoMode {
+    X(x11::VideoMode),
+    Wayland(wayland::VideoMode),
+}
+
+impl VideoMode {
+    #[inline]
+    pub fn size(&self) -> PhysicalSize {
+        match self {
+            &VideoMode::X(ref m) => m.size(),
+            &VideoMode::Wayland(ref m) => m.size(),
+        }
+    }
+
+    #[inline]
+    pub fn bit_depth(&self) -> u16 {
+        match self {
+            &VideoMode::X(ref m) => m.bit_depth(),
+            &VideoMode::Wayland(ref m) => m.bit_depth(),
+        }
+    }
+
+    #[inline]
+    pub fn refresh_rate(&self) -> u16 {
+        match self {
+            &VideoMode::X(ref m) => m.refresh_rate(),
+            &VideoMode::Wayland(ref m) => m.refresh_rate(),
+        }
+    }
+
+    #[inline]
+    pub fn monitor(&self) -> RootMonitorHandle {
+        match self {
+            &VideoMode::X(ref m) => m.monitor(),
+            &VideoMode::Wayland(ref m) => m.monitor(),
+        }
+    }
+}
+
 impl Window {
     #[inline]
     pub fn new<T>(
@@ -310,17 +350,15 @@ impl Window {
     }
 
     #[inline]
-    pub fn fullscreen(&self) -> Option<RootMonitorHandle> {
+    pub fn fullscreen(&self) -> Option<Fullscreen> {
         match self {
             &Window::X(ref w) => w.fullscreen(),
-            &Window::Wayland(ref w) => w.fullscreen().map(|monitor_id| RootMonitorHandle {
-                inner: MonitorHandle::Wayland(monitor_id),
-            }),
+            &Window::Wayland(ref w) => w.fullscreen(),
         }
     }
 
     #[inline]
-    pub fn set_fullscreen(&self, monitor: Option<RootMonitorHandle>) {
+    pub fn set_fullscreen(&self, monitor: Option<Fullscreen>) {
         match self {
             &Window::X(ref w) => w.set_fullscreen(monitor),
             &Window::Wayland(ref w) => w.set_fullscreen(monitor),

src/platform_impl/linux/wayland/event_loop.rs

@@ -16,8 +16,11 @@ use crate::{
     dpi::{PhysicalPosition, PhysicalSize},
     event::ModifiersState,
     event_loop::{ControlFlow, EventLoopClosed, EventLoopWindowTarget as RootELW},
-    monitor::VideoMode,
-    platform_impl::platform::sticky_exit_callback,
+    monitor::{MonitorHandle as RootMonitorHandle, VideoMode as RootVideoMode},
+    platform_impl::platform::{
+        sticky_exit_callback, MonitorHandle as PlatformMonitorHandle,
+        VideoMode as PlatformVideoMode,
+    },
 };
 
 use super::{window::WindowStore, DeviceId, WindowId};
@@ -603,17 +606,67 @@ impl<T> Drop for SeatData<T> {
  * Monitor stuff
  */
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct VideoMode {
+    pub(crate) size: (u32, u32),
+    pub(crate) bit_depth: u16,
+    pub(crate) refresh_rate: u16,
+    pub(crate) monitor: MonitorHandle,
+}
+
+impl VideoMode {
+    #[inline]
+    pub fn size(&self) -> PhysicalSize {
+        self.size.into()
+    }
+
+    #[inline]
+    pub fn bit_depth(&self) -> u16 {
+        self.bit_depth
+    }
+
+    #[inline]
+    pub fn refresh_rate(&self) -> u16 {
+        self.refresh_rate
+    }
+
+    #[inline]
+    pub fn monitor(&self) -> RootMonitorHandle {
+        RootMonitorHandle {
+            inner: PlatformMonitorHandle::Wayland(self.monitor.clone()),
+        }
+    }
+}
+
+#[derive(Clone)]
 pub struct MonitorHandle {
     pub(crate) proxy: wl_output::WlOutput,
     pub(crate) mgr: OutputMgr,
 }
 
-impl Clone for MonitorHandle {
-    fn clone(&self) -> MonitorHandle {
-        MonitorHandle {
-            proxy: self.proxy.clone(),
-            mgr: self.mgr.clone(),
-        }
+impl PartialEq for MonitorHandle {
+    fn eq(&self, other: &Self) -> bool {
+        self.native_identifier() == other.native_identifier()
+    }
+}
+
+impl Eq for MonitorHandle {}
+
+impl PartialOrd for MonitorHandle {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(&other))
+    }
+}
+
+impl Ord for MonitorHandle {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.native_identifier().cmp(&other.native_identifier())
+    }
+}
+
+impl std::hash::Hash for MonitorHandle {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.native_identifier().hash(state);
     }
 }
 
@@ -680,15 +733,20 @@ impl MonitorHandle {
     }
 
     #[inline]
-    pub fn video_modes(&self) -> impl Iterator<Item = VideoMode> {
+    pub fn video_modes(&self) -> impl Iterator<Item = RootVideoMode> {
+        let monitor = self.clone();
+
         self.mgr
             .with_info(&self.proxy, |_, info| info.modes.clone())
             .unwrap_or(vec![])
             .into_iter()
-            .map(|x| VideoMode {
-                size: (x.dimensions.0 as u32, x.dimensions.1 as u32),
-                refresh_rate: (x.refresh_rate as f32 / 1000.0).round() as u16,
-                bit_depth: 32,
+            .map(move |x| RootVideoMode {
+                video_mode: PlatformVideoMode::Wayland(VideoMode {
+                    size: (x.dimensions.0 as u32, x.dimensions.1 as u32),
+                    refresh_rate: (x.refresh_rate as f32 / 1000.0).round() as u16,
+                    bit_depth: 32,
+                    monitor: monitor.clone(),
+                }),
             })
     }
 }

src/platform_impl/linux/wayland/mod.rs

@@ -3,7 +3,8 @@
 
 pub use self::{
     event_loop::{
-        EventLoop, EventLoopProxy, EventLoopWindowTarget, MonitorHandle, WindowEventsSink,
+        EventLoop, EventLoopProxy, EventLoopWindowTarget, MonitorHandle, VideoMode,
+        WindowEventsSink,
     },
     window::Window,
 };

src/platform_impl/linux/wayland/window.rs

@@ -8,10 +8,11 @@ use crate::{
     error::{ExternalError, NotSupportedError, OsError as RootOsError},
     monitor::MonitorHandle as RootMonitorHandle,
     platform_impl::{
+        platform::wayland::event_loop::{available_monitors, primary_monitor},
         MonitorHandle as PlatformMonitorHandle,
         PlatformSpecificWindowBuilderAttributes as PlAttributes,
     },
-    window::{CursorIcon, WindowAttributes},
+    window::{CursorIcon, Fullscreen, WindowAttributes},
 };
 
 use smithay_client_toolkit::{
@@ -25,7 +26,6 @@ use smithay_client_toolkit::{
 };
 
 use super::{make_wid, EventLoopWindowTarget, MonitorHandle, WindowId};
-use crate::platform_impl::platform::wayland::event_loop::{available_monitors, primary_monitor};
 
 pub struct Window {
     surface: wl_surface::WlSurface,
@@ -108,13 +108,19 @@ impl Window {
         }
 
         // Check for fullscreen requirements
-        if let Some(RootMonitorHandle {
-            inner: PlatformMonitorHandle::Wayland(ref monitor_id),
-        }) = attributes.fullscreen
-        {
-            frame.set_fullscreen(Some(&monitor_id.proxy));
-        } else if attributes.maximized {
-            frame.set_maximized();
+        match attributes.fullscreen {
+            Some(Fullscreen::Exclusive(_)) => {
+                panic!("Wayland doesn't support exclusive fullscreen")
+            }
+            Some(Fullscreen::Borderless(RootMonitorHandle {
+                inner: PlatformMonitorHandle::Wayland(ref monitor_id),
+            })) => frame.set_fullscreen(Some(&monitor_id.proxy)),
+            Some(Fullscreen::Borderless(_)) => unreachable!(),
+            None => {
+                if attributes.maximized {
+                    frame.set_maximized();
+                }
+            }
         }
 
         frame.set_resizable(attributes.resizable);
@@ -252,25 +258,31 @@ impl Window {
         }
     }
 
-    pub fn fullscreen(&self) -> Option<MonitorHandle> {
+    pub fn fullscreen(&self) -> Option<Fullscreen> {
         if *(self.fullscreen.lock().unwrap()) {
-            Some(self.current_monitor())
+            Some(Fullscreen::Borderless(RootMonitorHandle {
+                inner: PlatformMonitorHandle::Wayland(self.current_monitor()),
+            }))
         } else {
             None
         }
     }
 
-    pub fn set_fullscreen(&self, monitor: Option<RootMonitorHandle>) {
-        if let Some(RootMonitorHandle {
-            inner: PlatformMonitorHandle::Wayland(ref monitor_id),
-        }) = monitor
-        {
-            self.frame
-                .lock()
-                .unwrap()
-                .set_fullscreen(Some(&monitor_id.proxy));
-        } else {
-            self.frame.lock().unwrap().unset_fullscreen();
+    pub fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        match fullscreen {
+            Some(Fullscreen::Exclusive(_)) => {
+                panic!("Wayland doesn't support exclusive fullscreen")
+            }
+            Some(Fullscreen::Borderless(RootMonitorHandle {
+                inner: PlatformMonitorHandle::Wayland(ref monitor_id),
+            })) => {
+                self.frame
+                    .lock()
+                    .unwrap()
+                    .set_fullscreen(Some(&monitor_id.proxy));
+            }
+            Some(Fullscreen::Borderless(_)) => unreachable!(),
+            None => self.frame.lock().unwrap().unset_fullscreen(),
         }
     }
 

src/platform_impl/linux/x11/mod.rs

@@ -11,7 +11,7 @@ mod window;
 mod xdisplay;
 
 pub use self::{
-    monitor::MonitorHandle,
+    monitor::{MonitorHandle, VideoMode},
     window::UnownedWindow,
     xdisplay::{XConnection, XError, XNotSupported},
 };

src/platform_impl/linux/x11/monitor.rs

@@ -4,47 +4,66 @@ use parking_lot::Mutex;
 
 use super::{
     ffi::{
-        RRCrtcChangeNotifyMask, RROutputPropertyNotifyMask, RRScreenChangeNotifyMask, True, Window,
-        XRRScreenResources,
+        RRCrtc, RRCrtcChangeNotifyMask, RRMode, RROutputPropertyNotifyMask,
+        RRScreenChangeNotifyMask, True, Window, XRRCrtcInfo, XRRScreenResources,
     },
     util, XConnection, XError,
 };
 use crate::{
     dpi::{PhysicalPosition, PhysicalSize},
-    monitor::VideoMode,
+    monitor::{MonitorHandle as RootMonitorHandle, VideoMode as RootVideoMode},
+    platform_impl::{MonitorHandle as PlatformMonitorHandle, VideoMode as PlatformVideoMode},
 };
 
-// Used to test XRandR < 1.5 code path. This should always be committed as false.
-const FORCE_RANDR_COMPAT: bool = false;
-// Also used for testing. This should always be committed as false.
+// Used for testing. This should always be committed as false.
 const DISABLE_MONITOR_LIST_CACHING: bool = false;
 
 lazy_static! {
-    static ref XRANDR_VERSION: Mutex<Option<(c_int, c_int)>> = Mutex::default();
     static ref MONITORS: Mutex<Option<Vec<MonitorHandle>>> = Mutex::default();
 }
 
-fn version_is_at_least(major: c_int, minor: c_int) -> bool {
-    if let Some((avail_major, avail_minor)) = *XRANDR_VERSION.lock() {
-        if avail_major == major {
-            avail_minor >= minor
-        } else {
-            avail_major > major
-        }
-    } else {
-        unreachable!();
-    }
-}
-
 pub fn invalidate_cached_monitor_list() -> Option<Vec<MonitorHandle>> {
     // We update this lazily.
     (*MONITORS.lock()).take()
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct VideoMode {
+    pub(crate) size: (u32, u32),
+    pub(crate) bit_depth: u16,
+    pub(crate) refresh_rate: u16,
+    pub(crate) native_mode: RRMode,
+    pub(crate) monitor: Option<MonitorHandle>,
+}
+
+impl VideoMode {
+    #[inline]
+    pub fn size(&self) -> PhysicalSize {
+        self.size.into()
+    }
+
+    #[inline]
+    pub fn bit_depth(&self) -> u16 {
+        self.bit_depth
+    }
+
+    #[inline]
+    pub fn refresh_rate(&self) -> u16 {
+        self.refresh_rate
+    }
+
+    #[inline]
+    pub fn monitor(&self) -> RootMonitorHandle {
+        RootMonitorHandle {
+            inner: PlatformMonitorHandle::X(self.monitor.clone().unwrap()),
+        }
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct MonitorHandle {
     /// The actual id
-    id: u32,
+    pub(crate) id: RRCrtc,
     /// The name of the monitor
     pub(crate) name: String,
     /// The size of the monitor
@@ -61,16 +80,43 @@ pub struct MonitorHandle {
     video_modes: Vec<VideoMode>,
 }
 
+impl PartialEq for MonitorHandle {
+    fn eq(&self, other: &Self) -> bool {
+        self.id == other.id
+    }
+}
+
+impl Eq for MonitorHandle {}
+
+impl PartialOrd for MonitorHandle {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(&other))
+    }
+}
+
+impl Ord for MonitorHandle {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.id.cmp(&other.id)
+    }
+}
+
+impl std::hash::Hash for MonitorHandle {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.id.hash(state);
+    }
+}
+
 impl MonitorHandle {
-    fn from_repr(
+    fn new(
         xconn: &XConnection,
         resources: *mut XRRScreenResources,
-        id: u32,
-        repr: util::MonitorRepr,
+        id: RRCrtc,
+        crtc: *mut XRRCrtcInfo,
         primary: bool,
     ) -> Option<Self> {
-        let (name, hidpi_factor, video_modes) = unsafe { xconn.get_output_info(resources, &repr)? };
-        let (dimensions, position) = unsafe { (repr.size(), repr.position()) };
+        let (name, hidpi_factor, video_modes) = unsafe { xconn.get_output_info(resources, crtc)? };
+        let dimensions = unsafe { ((*crtc).width as u32, (*crtc).height as u32) };
+        let position = unsafe { ((*crtc).x as i32, (*crtc).y as i32) };
         let rect = util::AaRect::new(position, dimensions);
         Some(MonitorHandle {
             id,
@@ -107,8 +153,14 @@ impl MonitorHandle {
     }
 
     #[inline]
-    pub fn video_modes(&self) -> impl Iterator<Item = VideoMode> {
-        self.video_modes.clone().into_iter()
+    pub fn video_modes(&self) -> impl Iterator<Item = RootVideoMode> {
+        let monitor = self.clone();
+        self.video_modes.clone().into_iter().map(move |mut x| {
+            x.monitor = Some(monitor.clone());
+            RootVideoMode {
+                video_mode: PlatformVideoMode::X(x),
+            }
+        })
     }
 }
 
@@ -139,8 +191,12 @@ impl XConnection {
 
     fn query_monitor_list(&self) -> Vec<MonitorHandle> {
         unsafe {
+            let mut major = 0;
+            let mut minor = 0;
+            (self.xrandr.XRRQueryVersion)(self.display, &mut major, &mut minor);
+
             let root = (self.xlib.XDefaultRootWindow)(self.display);
-            let resources = if version_is_at_least(1, 3) {
+            let resources = if (major == 1 && minor >= 3) || major > 1 {
                 (self.xrandr.XRRGetScreenResourcesCurrent)(self.display, root)
             } else {
                 // WARNING: this function is supposedly very slow, on the order of hundreds of ms.
@@ -155,48 +211,19 @@ impl XConnection {
             let mut available;
             let mut has_primary = false;
 
-            if self.xrandr_1_5.is_some() && version_is_at_least(1, 5) && !FORCE_RANDR_COMPAT {
-                // We're in XRandR >= 1.5, enumerate monitors. This supports things like MST and
-                // videowalls.
-                let xrandr_1_5 = self.xrandr_1_5.as_ref().unwrap();
-                let mut monitor_count = 0;
-                let monitors =
-                    (xrandr_1_5.XRRGetMonitors)(self.display, root, 1, &mut monitor_count);
-                assert!(monitor_count >= 0);
-                available = Vec::with_capacity(monitor_count as usize);
-                for monitor_index in 0..monitor_count {
-                    let monitor = monitors.offset(monitor_index as isize);
-                    let is_primary = (*monitor).primary != 0;
+            let primary = (self.xrandr.XRRGetOutputPrimary)(self.display, root);
+            available = Vec::with_capacity((*resources).ncrtc as usize);
+            for crtc_index in 0..(*resources).ncrtc {
+                let crtc_id = *((*resources).crtcs.offset(crtc_index as isize));
+                let crtc = (self.xrandr.XRRGetCrtcInfo)(self.display, resources, crtc_id);
+                let is_active = (*crtc).width > 0 && (*crtc).height > 0 && (*crtc).noutput > 0;
+                if is_active {
+                    let is_primary = *(*crtc).outputs.offset(0) == primary;
                     has_primary |= is_primary;
-                    MonitorHandle::from_repr(
-                        self,
-                        resources,
-                        monitor_index as u32,
-                        monitor.into(),
-                        is_primary,
-                    )
-                    .map(|monitor_id| available.push(monitor_id));
-                }
-                (xrandr_1_5.XRRFreeMonitors)(monitors);
-            } else {
-                // We're in XRandR < 1.5, enumerate CRTCs. Everything will work except MST and
-                // videowall setups will also show monitors that aren't in the logical groups the user
-                // cares about.
-                let primary = (self.xrandr.XRRGetOutputPrimary)(self.display, root);
-                available = Vec::with_capacity((*resources).ncrtc as usize);
-                for crtc_index in 0..(*resources).ncrtc {
-                    let crtc_id = *((*resources).crtcs.offset(crtc_index as isize));
-                    let crtc = (self.xrandr.XRRGetCrtcInfo)(self.display, resources, crtc_id);
-                    let is_active = (*crtc).width > 0 && (*crtc).height > 0 && (*crtc).noutput > 0;
-                    if is_active {
-                        let crtc = util::MonitorRepr::from(crtc);
-                        let is_primary = crtc.get_output() == primary;
-                        has_primary |= is_primary;
-                        MonitorHandle::from_repr(self, resources, crtc_id as u32, crtc, is_primary)
-                            .map(|monitor_id| available.push(monitor_id));
-                    }
-                    (self.xrandr.XRRFreeCrtcInfo)(crtc);
+                    MonitorHandle::new(self, resources, crtc_id, crtc, is_primary)
+                        .map(|monitor_id| available.push(monitor_id));
                 }
+                (self.xrandr.XRRFreeCrtcInfo)(crtc);
             }
 
             // If no monitors were detected as being primary, we just pick one ourselves!
@@ -236,19 +263,15 @@ impl XConnection {
     }
 
     pub fn select_xrandr_input(&self, root: Window) -> Result<c_int, XError> {
-        {
-            let mut version_lock = XRANDR_VERSION.lock();
-            if version_lock.is_none() {
-                let mut major = 0;
-                let mut minor = 0;
-                let has_extension =
-                    unsafe { (self.xrandr.XRRQueryVersion)(self.display, &mut major, &mut minor) };
-                if has_extension != True {
-                    panic!("[winit] XRandR extension not available.");
-                }
-                *version_lock = Some((major, minor));
-            }
-        }
+        let has_xrandr = unsafe {
+            let mut major = 0;
+            let mut minor = 0;
+            (self.xrandr.XRRQueryVersion)(self.display, &mut major, &mut minor)
+        };
+        assert!(
+            has_xrandr == True,
+            "[winit] XRandR extension not available."
+        );
 
         let mut event_offset = 0;
         let mut error_offset = 0;

src/platform_impl/linux/x11/util/randr.rs

@@ -1,7 +1,10 @@
 use std::{env, slice, str::FromStr};
 
-use super::*;
-use crate::{dpi::validate_hidpi_factor, monitor::VideoMode};
+use super::{
+    ffi::{CurrentTime, RRCrtc, RRMode, Success, XRRCrtcInfo, XRRScreenResources},
+    *,
+};
+use crate::{dpi::validate_hidpi_factor, platform_impl::platform::x11::VideoMode};
 
 pub fn calc_dpi_factor(
     (width_px, height_px): (u32, u32),
@@ -34,47 +37,6 @@ pub fn calc_dpi_factor(
     dpi_factor
 }
 
-pub enum MonitorRepr {
-    Monitor(*mut ffi::XRRMonitorInfo),
-    Crtc(*mut ffi::XRRCrtcInfo),
-}
-
-impl MonitorRepr {
-    pub unsafe fn get_output(&self) -> ffi::RROutput {
-        match *self {
-            // Same member names, but different locations within the struct...
-            MonitorRepr::Monitor(monitor) => *((*monitor).outputs.offset(0)),
-            MonitorRepr::Crtc(crtc) => *((*crtc).outputs.offset(0)),
-        }
-    }
-
-    pub unsafe fn size(&self) -> (u32, u32) {
-        match *self {
-            MonitorRepr::Monitor(monitor) => ((*monitor).width as u32, (*monitor).height as u32),
-            MonitorRepr::Crtc(crtc) => ((*crtc).width as u32, (*crtc).height as u32),
-        }
-    }
-
-    pub unsafe fn position(&self) -> (i32, i32) {
-        match *self {
-            MonitorRepr::Monitor(monitor) => ((*monitor).x as i32, (*monitor).y as i32),
-            MonitorRepr::Crtc(crtc) => ((*crtc).x as i32, (*crtc).y as i32),
-        }
-    }
-}
-
-impl From<*mut ffi::XRRMonitorInfo> for MonitorRepr {
-    fn from(monitor: *mut ffi::XRRMonitorInfo) -> Self {
-        MonitorRepr::Monitor(monitor)
-    }
-}
-
-impl From<*mut ffi::XRRCrtcInfo> for MonitorRepr {
-    fn from(crtc: *mut ffi::XRRCrtcInfo) -> Self {
-        MonitorRepr::Crtc(crtc)
-    }
-}
-
 impl XConnection {
     // Retrieve DPI from Xft.dpi property
     pub unsafe fn get_xft_dpi(&self) -> Option<f64> {
@@ -96,11 +58,11 @@ impl XConnection {
     }
     pub unsafe fn get_output_info(
         &self,
-        resources: *mut ffi::XRRScreenResources,
-        repr: &MonitorRepr,
+        resources: *mut XRRScreenResources,
+        crtc: *mut XRRCrtcInfo,
     ) -> Option<(String, f64, Vec<VideoMode>)> {
         let output_info =
-            (self.xrandr.XRRGetOutputInfo)(self.display, resources, repr.get_output());
+            (self.xrandr.XRRGetOutputInfo)(self.display, resources, *(*crtc).outputs.offset(0));
         if output_info.is_null() {
             // When calling `XRRGetOutputInfo` on a virtual monitor (versus a physical display)
             // it's possible for it to return null.
@@ -132,6 +94,10 @@ impl XConnection {
                     size: (x.width, x.height),
                     refresh_rate: (refresh_rate as f32 / 1000.0).round() as u16,
                     bit_depth: bit_depth as u16,
+                    native_mode: x.id,
+                    // This is populated in `MonitorHandle::video_modes` as the
+                    // video mode is returned to the user
+                    monitor: None,
                 }
             });
 
@@ -144,7 +110,7 @@ impl XConnection {
             dpi / 96.
         } else {
             calc_dpi_factor(
-                repr.size(),
+                ((*crtc).width as u32, (*crtc).height as u32),
                 (
                     (*output_info).mm_width as u64,
                     (*output_info).mm_height as u64,
@@ -155,4 +121,61 @@ impl XConnection {
         (self.xrandr.XRRFreeOutputInfo)(output_info);
         Some((name, hidpi_factor, modes.collect()))
     }
+    pub fn set_crtc_config(&self, crtc_id: RRCrtc, mode_id: RRMode) -> Result<(), ()> {
+        unsafe {
+            let mut major = 0;
+            let mut minor = 0;
+            (self.xrandr.XRRQueryVersion)(self.display, &mut major, &mut minor);
+
+            let root = (self.xlib.XDefaultRootWindow)(self.display);
+            let resources = if (major == 1 && minor >= 3) || major > 1 {
+                (self.xrandr.XRRGetScreenResourcesCurrent)(self.display, root)
+            } else {
+                (self.xrandr.XRRGetScreenResources)(self.display, root)
+            };
+
+            let crtc = (self.xrandr.XRRGetCrtcInfo)(self.display, resources, crtc_id);
+            let status = (self.xrandr.XRRSetCrtcConfig)(
+                self.display,
+                resources,
+                crtc_id,
+                CurrentTime,
+                (*crtc).x,
+                (*crtc).y,
+                mode_id,
+                (*crtc).rotation,
+                (*crtc).outputs.offset(0),
+                1,
+            );
+
+            (self.xrandr.XRRFreeCrtcInfo)(crtc);
+            (self.xrandr.XRRFreeScreenResources)(resources);
+
+            if status == Success as i32 {
+                Ok(())
+            } else {
+                Err(())
+            }
+        }
+    }
+    pub fn get_crtc_mode(&self, crtc_id: RRCrtc) -> RRMode {
+        unsafe {
+            let mut major = 0;
+            let mut minor = 0;
+            (self.xrandr.XRRQueryVersion)(self.display, &mut major, &mut minor);
+
+            let root = (self.xlib.XDefaultRootWindow)(self.display);
+            let resources = if (major == 1 && minor >= 3) || major > 1 {
+                (self.xrandr.XRRGetScreenResourcesCurrent)(self.display, root)
+            } else {
+                (self.xrandr.XRRGetScreenResources)(self.display, root)
+            };
+
+            let crtc = (self.xrandr.XRRGetCrtcInfo)(self.display, resources, crtc_id);
+            let mode = (*crtc).mode;
+            (self.xrandr.XRRFreeCrtcInfo)(crtc);
+            (self.xrandr.XRRFreeScreenResources)(resources);
+            mode
+        }
+    }
 }

src/platform_impl/linux/x11/window.rs

@@ -16,12 +16,13 @@ use parking_lot::Mutex;
 use crate::{
     dpi::{LogicalPosition, LogicalSize},
     error::{ExternalError, NotSupportedError, OsError as RootOsError},
-    monitor::MonitorHandle as RootMonitorHandle,
+    monitor::{MonitorHandle as RootMonitorHandle, VideoMode as RootVideoMode},
     platform_impl::{
         x11::{ime::ImeContextCreationError, MonitorHandle as X11MonitorHandle},
         MonitorHandle as PlatformMonitorHandle, OsError, PlatformSpecificWindowBuilderAttributes,
+        VideoMode as PlatformVideoMode,
     },
-    window::{CursorIcon, Icon, WindowAttributes},
+    window::{CursorIcon, Fullscreen, Icon, WindowAttributes},
 };
 
 use super::{ffi, util, EventLoopWindowTarget, ImeSender, WindowId, XConnection, XError};
@@ -46,9 +47,11 @@ pub struct SharedState {
     pub guessed_dpi: Option<f64>,
     pub last_monitor: Option<X11MonitorHandle>,
     pub dpi_adjusted: Option<(f64, f64)>,
-    pub fullscreen: Option<RootMonitorHandle>,
-    // Used to restore position after exiting fullscreen.
+    pub fullscreen: Option<Fullscreen>,
+    // Used to restore position after exiting fullscreen
     pub restore_position: Option<(i32, i32)>,
+    // Used to restore video mode after exiting fullscreen
+    pub desktop_video_mode: Option<(ffi::RRCrtc, ffi::RRMode)>,
     pub frame_extents: Option<util::FrameExtentsHeuristic>,
     pub min_inner_size: Option<LogicalSize>,
     pub max_inner_size: Option<LogicalSize>,
@@ -408,6 +411,7 @@ impl UnownedWindow {
             if window_attrs.fullscreen.is_some() {
                 window
                     .set_fullscreen_inner(window_attrs.fullscreen.clone())
+                    .unwrap()
                     .queue();
             }
             if window_attrs.always_on_top {
@@ -564,41 +568,122 @@ impl UnownedWindow {
         self.set_netwm(fullscreen.into(), (fullscreen_atom as c_long, 0, 0, 0))
     }
 
-    fn set_fullscreen_inner(&self, monitor: Option<RootMonitorHandle>) -> util::Flusher<'_> {
-        match monitor {
+    fn set_fullscreen_inner(&self, fullscreen: Option<Fullscreen>) -> Option<util::Flusher<'_>> {
+        let mut shared_state_lock = self.shared_state.lock();
+        let old_fullscreen = shared_state_lock.fullscreen.clone();
+        if old_fullscreen == fullscreen {
+            return None;
+        }
+        shared_state_lock.fullscreen = fullscreen.clone();
+
+        match (&old_fullscreen, &fullscreen) {
+            // Store the desktop video mode before entering exclusive
+            // fullscreen, so we can restore it upon exit, as XRandR does not
+            // provide a mechanism to set this per app-session or restore this
+            // to the desktop video mode as macOS and Windows do
+            (
+                &None,
+                &Some(Fullscreen::Exclusive(RootVideoMode {
+                    video_mode: PlatformVideoMode::X(ref video_mode),
+                })),
+            )
+            | (
+                &Some(Fullscreen::Borderless(_)),
+                &Some(Fullscreen::Exclusive(RootVideoMode {
+                    video_mode: PlatformVideoMode::X(ref video_mode),
+                })),
+            ) => {
+                let monitor = video_mode.monitor.as_ref().unwrap();
+                shared_state_lock.desktop_video_mode =
+                    Some((monitor.id, self.xconn.get_crtc_mode(monitor.id)));
+            }
+            // Restore desktop video mode upon exiting exclusive fullscreen
+            (&Some(Fullscreen::Exclusive(_)), &None)
+            | (&Some(Fullscreen::Exclusive(_)), &Some(Fullscreen::Borderless(_))) => {
+                let (monitor_id, mode_id) = shared_state_lock.desktop_video_mode.take().unwrap();
+                self.xconn
+                    .set_crtc_config(monitor_id, mode_id)
+                    .expect("failed to restore desktop video mode");
+            }
+            _ => (),
+        }
+
+        drop(shared_state_lock);
+
+        match fullscreen {
             None => {
                 let flusher = self.set_fullscreen_hint(false);
-                if let Some(position) = self.shared_state.lock().restore_position.take() {
+                let mut shared_state_lock = self.shared_state.lock();
+                if let Some(position) = shared_state_lock.restore_position.take() {
                     self.set_position_inner(position.0, position.1).queue();
                 }
-                flusher
+                Some(flusher)
             }
-            Some(RootMonitorHandle {
-                inner: PlatformMonitorHandle::X(monitor),
-            }) => {
+            Some(fullscreen) => {
+                let (video_mode, monitor) = match fullscreen {
+                    Fullscreen::Exclusive(RootVideoMode {
+                        video_mode: PlatformVideoMode::X(ref video_mode),
+                    }) => (Some(video_mode), video_mode.monitor.as_ref().unwrap()),
+                    Fullscreen::Borderless(RootMonitorHandle {
+                        inner: PlatformMonitorHandle::X(ref monitor),
+                    }) => (None, monitor),
+                    _ => unreachable!(),
+                };
+
+                if let Some(video_mode) = video_mode {
+                    // FIXME: this is actually not correct if we're setting the
+                    // video mode to a resolution higher than the current
+                    // desktop resolution, because XRandR does not automatically
+                    // reposition the monitors to the right and below this
+                    // monitor.
+                    //
+                    // What ends up happening is we will get the fullscreen
+                    // window showing up on those monitors as well, because
+                    // their virtual position now overlaps with the monitor that
+                    // we just made larger..
+                    //
+                    // It'd be quite a bit of work to handle this correctly (and
+                    // nobody else seems to bother doing this correctly either),
+                    // so we're just leaving this broken. Fixing this would
+                    // involve storing all CRTCs upon entering fullscreen,
+                    // restoring them upon exit, and after entering fullscreen,
+                    // repositioning displays to the right and below this
+                    // display. I think there would still be edge cases that are
+                    // difficult or impossible to handle correctly, e.g. what if
+                    // a new monitor was plugged in while in fullscreen?
+                    //
+                    // I think we might just want to disallow setting the video
+                    // mode higher than the current desktop video mode (I'm sure
+                    // this will make someone unhappy, but it's very unusual for
+                    // games to want to do this anyway).
+                    self.xconn
+                        .set_crtc_config(monitor.id, video_mode.native_mode)
+                        .expect("failed to set video mode");
+                }
+
                 let window_position = self.outer_position_physical();
                 self.shared_state.lock().restore_position = Some(window_position);
                 let monitor_origin: (i32, i32) = monitor.position().into();
                 self.set_position_inner(monitor_origin.0, monitor_origin.1)
                     .queue();
-                self.set_fullscreen_hint(true)
+                Some(self.set_fullscreen_hint(true))
             }
-            _ => unreachable!(),
         }
     }
 
     #[inline]
-    pub fn fullscreen(&self) -> Option<RootMonitorHandle> {
+    pub fn fullscreen(&self) -> Option<Fullscreen> {
         self.shared_state.lock().fullscreen.clone()
     }
 
     #[inline]
-    pub fn set_fullscreen(&self, monitor: Option<RootMonitorHandle>) {
-        self.shared_state.lock().fullscreen = monitor.clone();
-        self.set_fullscreen_inner(monitor)
-            .flush()
-            .expect("Failed to change window fullscreen state");
-        self.invalidate_cached_frame_extents();
+    pub fn set_fullscreen(&self, fullscreen: Option<Fullscreen>) {
+        if let Some(flusher) = self.set_fullscreen_inner(fullscreen) {
+            flusher
+                .flush()
+                .expect("Failed to change window fullscreen state");
+            self.invalidate_cached_frame_extents();
+        }
     }
 
     fn get_rect(&self) -> util::AaRect {