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use super::drag_n_drop::DragNDropState;
use super::keyboard::{convert_key_press_event, convert_key_release_event, key_mods};
use super::*;
use crate::wrappers::connection_poller::{ConnectionPoller, PollStatus};
use crate::wrappers::xkbcommon::XkbcommonState;
use crate::{
Event, MouseButton, MouseEvent, PhyPoint, PhySize, ScrollDelta, WindowEvent, WindowHandler,
WindowInfo,
};
use std::error::Error;
use std::rc::Rc;
use std::time::{Duration, Instant};
use x11rb::connection::Connection;
use x11rb::protocol::Event as XEvent;
pub(crate) struct EventLoop {
handler: Box<dyn WindowHandler>,
window: WindowInner,
parent_handle: Option<ParentHandle>,
new_physical_size: Option<PhySize>,
frame_interval: Duration,
event_loop_running: bool,
drag_n_drop: DragNDropState,
xkb_state: Option<XkbcommonState>,
}
impl EventLoop {
pub fn new(
window: WindowInner, handler: impl WindowHandler + 'static,
parent_handle: Option<ParentHandle>, xkb_state: Option<XkbcommonState>,
) -> Self {
Self {
window,
handler: Box::new(handler),
parent_handle,
frame_interval: Duration::from_millis(15),
event_loop_running: false,
new_physical_size: None,
drag_n_drop: DragNDropState::NoCurrentSession,
xkb_state,
}
}
#[inline]
fn drain_xcb_events(&mut self) -> Result<(), Box<dyn Error>> {
// the X server has a tendency to send spurious/extraneous configure notify events when a
// window is resized, and we need to batch those together and just send one resize event
// when they've all been coalesced.
self.new_physical_size = None;
while let Some(event) = self.window.xcb_connection.conn.poll_for_event()? {
self.handle_xcb_event(event);
}
if let Some(size) = self.new_physical_size.take() {
self.window.window_info =
WindowInfo::from_physical_size(size, self.window.window_info.scale());
let window_info = self.window.window_info;
self.handle_event(Event::Window(WindowEvent::Resized(window_info)));
}
Ok(())
}
// Event loop
pub fn run(&mut self) -> Result<(), Box<dyn Error>> {
let connection = Rc::clone(&self.window.xcb_connection);
let mut poller = ConnectionPoller::new(&connection.conn)?;
let mut last_frame = Instant::now();
self.event_loop_running = true;
while self.event_loop_running {
// We'll try to keep a consistent frame pace. If the last frame couldn't be processed in
// the expected frame time, this will throttle down to prevent multiple frames from
// being queued up. The conditional here is needed because event handling and frame
// drawing is interleaved. The `poll()` function below will wait until the next frame
// can be drawn, or until the window receives an event. We thus need to manually check
// if it's already time to draw a new frame.
let next_frame = last_frame + self.frame_interval;
if Instant::now() >= next_frame {
self.handler.on_frame(&mut crate::Window::new(Window { inner: &self.window }));
last_frame = Instant::max(next_frame, Instant::now() - self.frame_interval);
}
// Check for any events in the internal buffers
// before going to sleep:
self.drain_xcb_events()?;
// FIXME: handle errors
if let PollStatus::ReadAvailable = poller.wait(next_frame).unwrap() {
self.drain_xcb_events()?;
}
// Check if the parents's handle was dropped (such as when the host
// requested the window to close)
if let Some(parent_handle) = &self.parent_handle {
if parent_handle.parent_did_drop() {
self.handle_must_close();
self.window.close_requested.set(false);
}
}
// Check if the user has requested the window to close
if self.window.close_requested.get() {
self.handle_must_close();
self.window.close_requested.set(false);
}
}
poller.delete()?;
Ok(())
}
fn handle_xcb_event(&mut self, event: XEvent) {
// For all the keyboard and mouse events, you can fetch
// `x`, `y`, `detail`, and `state`.
// - `x` and `y` are the position inside the window where the cursor currently is
// when the event happened.
// - `detail` will tell you which keycode was pressed/released (for keyboard events)
// or which mouse button was pressed/released (for mouse events).
// For mouse events, here's what the value means (at least on my current mouse):
// 1 = left mouse button
// 2 = middle mouse button (scroll wheel)
// 3 = right mouse button
// 4 = scroll wheel up
// 5 = scroll wheel down
// 8 = lower side button ("back" button)
// 9 = upper side button ("forward" button)
// Note that you *will* get a "button released" event for even the scroll wheel
// events, which you can probably ignore.
// - `state` will tell you the state of the main three mouse buttons and some of
// the keyboard modifier keys at the time of the event.
// http://rtbo.github.io/rust-xcb/src/xcb/ffi/xproto.rs.html#445
match event {
////
// window
////
XEvent::ClientMessage(event) => {
if event.format != 32 {
return;
}
if event.data.as_data32()[0] == self.window.xcb_connection.atoms.WM_DELETE_WINDOW {
self.handle_close_requested();
return;
}
////
// drag n drop
////
if event.type_ == self.window.xcb_connection.atoms.XdndEnter {
if let Err(_e) = self.drag_n_drop.handle_enter_event(
&self.window,
&mut *self.handler,
&event,
) {
// TODO: log warning
}
} else if event.type_ == self.window.xcb_connection.atoms.XdndPosition {
if let Err(_e) = self.drag_n_drop.handle_position_event(
&self.window,
&mut *self.handler,
&event,
) {
// TODO: log warning
}
} else if event.type_ == self.window.xcb_connection.atoms.XdndDrop {
if let Err(_e) =
self.drag_n_drop.handle_drop_event(&self.window, &mut *self.handler, &event)
{
// TODO: log warning
}
} else if event.type_ == self.window.xcb_connection.atoms.XdndLeave {
self.drag_n_drop.handle_leave_event(&self.window, &mut *self.handler, &event);
}
}
XEvent::SelectionNotify(event) => {
if event.property == self.window.xcb_connection.atoms.XdndSelection {
if let Err(_e) = self.drag_n_drop.handle_selection_notify_event(
&self.window,
&mut *self.handler,
&event,
) {
// TODO: Log warning
}
}
}
XEvent::ConfigureNotify(event) => {
let new_physical_size = PhySize::new(event.width as u32, event.height as u32);
if self.new_physical_size.is_some()
|| new_physical_size != self.window.window_info.physical_size()
{
self.new_physical_size = Some(new_physical_size);
}
}
////
// mouse
////
XEvent::MotionNotify(event) => {
let physical_pos = PhyPoint::new(event.event_x as i32, event.event_y as i32);
let logical_pos = physical_pos.to_logical(&self.window.window_info);
self.handle_event(Event::Mouse(MouseEvent::CursorMoved {
position: logical_pos,
modifiers: key_mods(event.state),
}));
}
XEvent::EnterNotify(event) => {
self.handle_event(Event::Mouse(MouseEvent::CursorEntered));
// since no `MOTION_NOTIFY` event is generated when `ENTER_NOTIFY` is generated,
// we generate a CursorMoved as well, so the mouse position from here isn't lost
let physical_pos = PhyPoint::new(event.event_x as i32, event.event_y as i32);
let logical_pos = physical_pos.to_logical(&self.window.window_info);
self.handle_event(Event::Mouse(MouseEvent::CursorMoved {
position: logical_pos,
modifiers: key_mods(event.state),
}));
}
XEvent::LeaveNotify(_) => {
self.handle_event(Event::Mouse(MouseEvent::CursorLeft));
}
XEvent::ButtonPress(event) => match event.detail {
4..=7 => {
self.handle_event(Event::Mouse(MouseEvent::WheelScrolled {
delta: match event.detail {
4 => ScrollDelta::Lines { x: 0.0, y: 1.0 },
5 => ScrollDelta::Lines { x: 0.0, y: -1.0 },
6 => ScrollDelta::Lines { x: -1.0, y: 0.0 },
7 => ScrollDelta::Lines { x: 1.0, y: 0.0 },
_ => unreachable!(),
},
modifiers: key_mods(event.state),
}));
}
detail => {
let button_id = mouse_id(detail);
self.handle_event(Event::Mouse(MouseEvent::ButtonPressed {
button: button_id,
modifiers: key_mods(event.state),
}));
}
},
XEvent::ButtonRelease(event) if !(4..=7).contains(&event.detail) => {
let button_id = mouse_id(event.detail);
self.handle_event(Event::Mouse(MouseEvent::ButtonReleased {
button: button_id,
modifiers: key_mods(event.state),
}));
}
////
// keys
////
XEvent::KeyPress(event) => {
let ev = Event::Keyboard(convert_key_press_event(&event, &mut self.xkb_state));
self.handle_event(ev);
}
XEvent::KeyRelease(event) => {
let ev = Event::Keyboard(convert_key_release_event(&event, &mut self.xkb_state));
self.handle_event(ev);
}
XEvent::FocusIn(_) => {
self.window.is_focused.set(true);
self.handle_event(Event::Window(WindowEvent::Focused));
}
XEvent::FocusOut(_) => {
self.window.is_focused.set(false);
self.handle_event(Event::Window(WindowEvent::Unfocused));
}
_ => {}
}
}
fn handle_event(&mut self, event: Event) {
self.handler.on_event(&mut crate::Window::new(Window { inner: &self.window }), event);
}
fn handle_close_requested(&mut self) {
// FIXME: handler should decide whether window stays open or not
self.handle_must_close();
}
fn handle_must_close(&mut self) {
self.handle_event(Event::Window(WindowEvent::WillClose));
self.event_loop_running = false;
}
}
fn mouse_id(id: u8) -> MouseButton {
match id {
1 => MouseButton::Left,
2 => MouseButton::Middle,
3 => MouseButton::Right,
8 => MouseButton::Back,
9 => MouseButton::Forward,
id => MouseButton::Other(id),
}
}