Event Loop 2.0 API and Windows implementation (#638)

* Rename EventsLoop and associated types to EventLoop * Rename WindowEvent::Refresh to WindowEvent::Redraw * Remove second thread from win32 backend * Update run_forever to hijack thread * Replace windows Mutex with parking_lot Mutex * Implement new ControlFlow and associated events * Add StartCause::Init support, timer example * Add ability to send custom user events * Fully invert windows control flow so win32 calls into winit's callback * Add request_redraw * Rename platform to platform_impl * Rename os to platform, add Ext trait postfixes * Add platform::desktop module with EventLoopExt::run_return * Re-organize into module structure * Improve documentation * Small changes to examples * Improve docs for run and run_return * Change instances of "events_loop" to "event_loop" * Rename MonitorId to MonitorHandle * Add CHANGELOG entry * Improve WaitUntil timer precision * When SendEvent is called during event closure, buffer events * Fix resize lag when waiting in some situations * Update send test and errors that broke some examples/APIs * Improve clarity/fix typos in docs * Fix unreachable panic after setting ControlFlow to Poll during some RedrawRequested events. * Fix crash when running in release mode * Remove crossbeam dependency and make drop events work again * Remove serde implementations from ControlFlow * Fix 1.24.1 build * Fix freeze when setting decorations * Replace &EventLoop in callback with &EventLoopWindowTarget * Document and implement Debug for EventLoopWindowTarget * Fix some deadlocks that could occur when changing window state * Fix thread executor not executing closure when called from non-loop thread * Fix buffered events not getting dispatched * Fix crash with runner refcell not getting dropped * Address review feedback * Fix CHANGELOG typo * Catch panics in user callback
2019-02-05 10:30:33 -05:00 · 2019-02-05 10:30:33 -05:00 · 9602716ed2
commit 9602716ed2
parent 7be1d16263
92 changed files with 3467 additions and 1260 deletions
--- a/src/platform_impl/linux/x11/monitor.rs
+++ b/src/platform_impl/linux/x11/monitor.rs
@ -0,0 +1,269 @@
+use std::os::raw::*;
+
+use parking_lot::Mutex;
+
+use {PhysicalPosition, PhysicalSize};
+use super::{util, XConnection, XError};
+use super::ffi::{
+    RRCrtcChangeNotifyMask,
+    RROutputPropertyNotifyMask,
+    RRScreenChangeNotifyMask,
+    True,
+    Window,
+    XRRScreenResources,
+};
+
+// 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.
+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)]
+pub struct MonitorHandle {
+    /// The actual id
+    id: u32,
+    /// The name of the monitor
+    pub(crate) name: String,
+    /// The size of the monitor
+    dimensions: (u32, u32),
+    /// The position of the monitor in the X screen
+    position: (i32, i32),
+    /// If the monitor is the primary one
+    primary: bool,
+    /// The DPI scale factor
+    pub(crate) hidpi_factor: f64,
+    /// Used to determine which windows are on this monitor
+    pub(crate) rect: util::AaRect,
+}
+
+impl MonitorHandle {
+    fn from_repr(
+        xconn: &XConnection,
+        resources: *mut XRRScreenResources,
+        id: u32,
+        repr: util::MonitorRepr,
+        primary: bool,
+    ) -> Option<Self> {
+        let (name, hidpi_factor) = unsafe { xconn.get_output_info(resources, &repr)? };
+        let (dimensions, position) = unsafe { (repr.get_dimensions(), repr.get_position()) };
+        let rect = util::AaRect::new(position, dimensions);
+        Some(MonitorHandle {
+            id,
+            name,
+            hidpi_factor,
+            dimensions,
+            position,
+            primary,
+            rect,
+        })
+    }
+
+    pub fn get_name(&self) -> Option<String> {
+        Some(self.name.clone())
+    }
+
+    #[inline]
+    pub fn get_native_identifier(&self) -> u32 {
+        self.id as u32
+    }
+
+    pub fn get_dimensions(&self) -> PhysicalSize {
+        self.dimensions.into()
+    }
+
+    pub fn get_position(&self) -> PhysicalPosition {
+        self.position.into()
+    }
+
+    #[inline]
+    pub fn get_hidpi_factor(&self) -> f64 {
+        self.hidpi_factor
+    }
+}
+
+impl XConnection {
+    pub fn get_monitor_for_window(&self, window_rect: Option<util::AaRect>) -> MonitorHandle {
+        let monitors = self.get_available_monitors();
+        let default = monitors
+            .get(0)
+            .expect("[winit] Failed to find any monitors using XRandR.");
+
+        let window_rect = match window_rect {
+            Some(rect) => rect,
+            None => return default.to_owned(),
+        };
+
+        let mut largest_overlap = 0;
+        let mut matched_monitor = default;
+        for monitor in &monitors {
+            let overlapping_area = window_rect.get_overlapping_area(&monitor.rect);
+            if overlapping_area > largest_overlap {
+                largest_overlap = overlapping_area;
+                matched_monitor = &monitor;
+            }
+        }
+
+        matched_monitor.to_owned()
+    }
+
+    fn query_monitor_list(&self) -> Vec<MonitorHandle> {
+        unsafe {
+            let root = (self.xlib.XDefaultRootWindow)(self.display);
+            // WARNING: this function is supposedly very slow, on the order of hundreds of ms.
+            // Upon failure, `resources` will be null.
+            let resources = (self.xrandr.XRRGetScreenResources)(self.display, root);
+            if resources.is_null() {
+                panic!("[winit] `XRRGetScreenResources` returned NULL. That should only happen if the root window doesn't exist.");
+            }
+
+            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;
+                    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);
+                }
+            }
+
+            // If no monitors were detected as being primary, we just pick one ourselves!
+            if !has_primary {
+                if let Some(ref mut fallback) = available.first_mut() {
+                    // Setting this here will come in handy if we ever add an `is_primary` method.
+                    fallback.primary = true;
+                }
+            }
+
+            (self.xrandr.XRRFreeScreenResources)(resources);
+            available
+        }
+    }
+
+    pub fn get_available_monitors(&self) -> Vec<MonitorHandle> {
+        let mut monitors_lock = MONITORS.lock();
+        (*monitors_lock)
+            .as_ref()
+            .cloned()
+            .or_else(|| {
+                let monitors = Some(self.query_monitor_list());
+                if !DISABLE_MONITOR_LIST_CACHING {
+                    (*monitors_lock) = monitors.clone();
+                }
+                monitors
+            })
+            .unwrap()
+    }
+
+    #[inline]
+    pub fn get_primary_monitor(&self) -> MonitorHandle {
+        self.get_available_monitors()
+            .into_iter()
+            .find(|monitor| monitor.primary)
+            .expect("[winit] Failed to find any monitors using XRandR.")
+    }
+
+    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 mut event_offset = 0;
+        let mut error_offset = 0;
+        let status = unsafe {
+            (self.xrandr.XRRQueryExtension)(
+                self.display,
+                &mut event_offset,
+                &mut error_offset,
+            )
+        };
+
+        if status != True {
+            self.check_errors()?;
+            unreachable!("[winit] `XRRQueryExtension` failed but no error was received.");
+        }
+
+        let mask = RRCrtcChangeNotifyMask
+            | RROutputPropertyNotifyMask
+            | RRScreenChangeNotifyMask;
+        unsafe { (self.xrandr.XRRSelectInput)(self.display, root, mask) };
+
+        Ok(event_offset)
+    }
+}