winit/src/platform/linux/x11/monitor.rs
2018-05-27 08:49:35 -04:00

270 lines
8.5 KiB
Rust

use std::os::raw::*;
use std::sync::Arc;
use parking_lot::Mutex;
use super::ffi::{
RRCrtcChangeNotifyMask,
RROutputPropertyNotifyMask,
RRScreenChangeNotifyMask,
True,
Window,
XRRScreenResources,
};
use super::{util, XConnection, XError};
// 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<MonitorId>>> = 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<MonitorId>> {
// We update this lazily.
(*MONITORS.lock()).take()
}
#[derive(Debug, Clone)]
pub struct MonitorId {
/// The actual id
id: u32,
/// The name of the monitor
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: f32,
/// Used to determine which windows are on this monitor
pub(crate) rect: util::Rect,
}
impl MonitorId {
fn from_repr(
xconn: &Arc<XConnection>,
resources: *mut XRRScreenResources,
id: u32,
repr: util::MonitorRepr,
primary: bool,
) -> 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::Rect::new(position, dimensions);
MonitorId {
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) -> (u32, u32) {
self.dimensions
}
pub fn get_position(&self) -> (i32, i32) {
self.position
}
#[inline]
pub fn get_hidpi_factor(&self) -> f32 {
self.hidpi_factor
}
}
pub fn get_monitor_for_window(
xconn: &Arc<XConnection>,
window_rect: Option<util::Rect>,
) -> MonitorId {
let monitors = get_available_monitors(xconn);
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(xconn: &Arc<XConnection>) -> Vec<MonitorId> {
unsafe {
let root = (xconn.xlib.XDefaultRootWindow)(xconn.display);
// WARNING: this function is supposedly very slow, on the order of hundreds of ms.
// Upon failure, `resources` will be null.
let resources = (xconn.xrandr.XRRGetScreenResources)(xconn.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 xconn.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 = xconn.xrandr_1_5.as_ref().unwrap();
let mut monitor_count = 0;
let monitors = (xrandr_1_5.XRRGetMonitors)(xconn.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;
available.push(MonitorId::from_repr(
xconn,
resources,
monitor_index as u32,
monitor.into(),
is_primary,
));
}
(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 = (xconn.xrandr.XRRGetOutputPrimary)(xconn.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 = (xconn.xrandr.XRRGetCrtcInfo)(xconn.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;
available.push(MonitorId::from_repr(
xconn,
resources,
crtc_id as u32,
crtc,
is_primary,
));
}
(xconn.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;
}
}
(xconn.xrandr.XRRFreeScreenResources)(resources);
available
}
}
pub fn get_available_monitors(xconn: &Arc<XConnection>) -> Vec<MonitorId> {
let mut monitors_lock = MONITORS.lock();
(*monitors_lock)
.as_ref()
.cloned()
.or_else(|| {
let monitors = Some(query_monitor_list(xconn));
if !DISABLE_MONITOR_LIST_CACHING {
(*monitors_lock) = monitors.clone();
}
monitors
})
.unwrap()
}
#[inline]
pub fn get_primary_monitor(xconn: &Arc<XConnection>) -> MonitorId {
get_available_monitors(xconn)
.into_iter()
.find(|monitor| monitor.primary)
.expect("[winit] Failed to find any monitors using XRandR.")
}
pub fn select_input(xconn: &Arc<XConnection>, 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 {
(xconn.xrandr.XRRQueryVersion)(
xconn.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 {
(xconn.xrandr.XRRQueryExtension)(
xconn.display,
&mut event_offset,
&mut error_offset,
)
};
if status != True {
xconn.check_errors()?;
unreachable!("[winit] `XRRQueryExtension` failed but no error was received.");
}
let mask = RRCrtcChangeNotifyMask
| RROutputPropertyNotifyMask
| RRScreenChangeNotifyMask;
unsafe { (xconn.xrandr.XRRSelectInput)(xconn.display, root, mask) };
Ok(event_offset)
}