egui/egui_web/src/backend.rs

372 lines
12 KiB
Rust

use crate::{glow_wrapping::WrappedGlowPainter, *};
use egui::TexturesDelta;
pub use egui::{pos2, Color32};
// ----------------------------------------------------------------------------
/// Data gathered between frames.
#[derive(Default)]
pub struct WebInput {
/// Required because we don't get a position on touched
pub latest_touch_pos: Option<egui::Pos2>,
/// Required to maintain a stable touch position for multi-touch gestures.
pub latest_touch_pos_id: Option<egui::TouchId>,
pub raw: egui::RawInput,
}
impl WebInput {
pub fn new_frame(&mut self, canvas_size: egui::Vec2) -> egui::RawInput {
egui::RawInput {
screen_rect: Some(egui::Rect::from_min_size(Default::default(), canvas_size)),
pixels_per_point: Some(native_pixels_per_point()), // We ALWAYS use the native pixels-per-point
time: Some(now_sec()),
..self.raw.take()
}
}
}
// ----------------------------------------------------------------------------
use std::sync::atomic::Ordering::SeqCst;
pub struct NeedRepaint(std::sync::atomic::AtomicBool);
impl Default for NeedRepaint {
fn default() -> Self {
Self(true.into())
}
}
impl NeedRepaint {
pub fn fetch_and_clear(&self) -> bool {
self.0.swap(false, SeqCst)
}
pub fn set_true(&self) {
self.0.store(true, SeqCst);
}
}
// ----------------------------------------------------------------------------
fn web_location() -> epi::Location {
let location = web_sys::window().unwrap().location();
let hash = percent_decode(&location.hash().unwrap_or_default());
let query = location
.search()
.unwrap_or_default()
.strip_prefix('?')
.map(percent_decode)
.unwrap_or_default();
let query_map = parse_query_map(&query)
.iter()
.map(|(k, v)| (k.to_string(), v.to_string()))
.collect();
epi::Location {
url: percent_decode(&location.href().unwrap_or_default()),
protocol: percent_decode(&location.protocol().unwrap_or_default()),
host: percent_decode(&location.host().unwrap_or_default()),
hostname: percent_decode(&location.hostname().unwrap_or_default()),
port: percent_decode(&location.port().unwrap_or_default()),
hash,
query,
query_map,
origin: percent_decode(&location.origin().unwrap_or_default()),
}
}
fn parse_query_map(query: &str) -> BTreeMap<&str, &str> {
query
.split('&')
.filter_map(|pair| {
if pair.is_empty() {
None
} else {
Some(if let Some((key, value)) = pair.split_once('=') {
(key, value)
} else {
(pair, "")
})
}
})
.collect()
}
#[test]
fn test_parse_query() {
assert_eq!(parse_query_map(""), BTreeMap::default());
assert_eq!(parse_query_map("foo"), BTreeMap::from_iter([("foo", "")]));
assert_eq!(
parse_query_map("foo=bar"),
BTreeMap::from_iter([("foo", "bar")])
);
assert_eq!(
parse_query_map("foo=bar&baz=42"),
BTreeMap::from_iter([("foo", "bar"), ("baz", "42")])
);
assert_eq!(
parse_query_map("foo&baz=42"),
BTreeMap::from_iter([("foo", ""), ("baz", "42")])
);
assert_eq!(
parse_query_map("foo&baz&&"),
BTreeMap::from_iter([("foo", ""), ("baz", "")])
);
}
// ----------------------------------------------------------------------------
pub struct AppRunner {
pub(crate) frame: epi::Frame,
egui_ctx: egui::Context,
painter: WrappedGlowPainter,
pub(crate) input: WebInput,
app: Box<dyn epi::App>,
pub(crate) needs_repaint: std::sync::Arc<NeedRepaint>,
storage: LocalStorage,
last_save_time: f64,
screen_reader: crate::screen_reader::ScreenReader,
pub(crate) text_cursor_pos: Option<egui::Pos2>,
pub(crate) mutable_text_under_cursor: bool,
textures_delta: TexturesDelta,
}
impl AppRunner {
pub fn new(canvas_id: &str, app_creator: epi::AppCreator) -> Result<Self, JsValue> {
let painter = WrappedGlowPainter::new(canvas_id).map_err(JsValue::from)?;
let prefer_dark_mode = crate::prefer_dark_mode();
let frame = epi::Frame::new(epi::backend::FrameData {
info: epi::IntegrationInfo {
name: "egui_web",
web_info: Some(epi::WebInfo {
location: web_location(),
}),
prefer_dark_mode,
cpu_usage: None,
native_pixels_per_point: Some(native_pixels_per_point()),
},
output: Default::default(),
});
let needs_repaint: std::sync::Arc<NeedRepaint> = Default::default();
let egui_ctx = egui::Context::with_repaint_callback({
let needs_repaint = needs_repaint.clone();
move || {
needs_repaint.0.store(true, SeqCst);
}
});
load_memory(&egui_ctx);
if prefer_dark_mode == Some(true) {
egui_ctx.set_visuals(egui::Visuals::dark());
} else {
egui_ctx.set_visuals(egui::Visuals::light());
}
let storage = LocalStorage::default();
let app = app_creator(&epi::CreationContext {
egui_ctx: egui_ctx.clone(),
integration_info: frame.info(),
storage: Some(&storage),
gl: painter.painter.gl().clone(),
});
let mut runner = Self {
frame,
egui_ctx,
painter,
input: Default::default(),
app,
needs_repaint,
storage,
last_save_time: now_sec(),
screen_reader: Default::default(),
text_cursor_pos: None,
mutable_text_under_cursor: false,
textures_delta: Default::default(),
};
runner.input.raw.max_texture_side = Some(runner.painter.max_texture_side());
Ok(runner)
}
pub fn egui_ctx(&self) -> &egui::Context {
&self.egui_ctx
}
pub fn auto_save(&mut self) {
let now = now_sec();
let time_since_last_save = now - self.last_save_time;
if time_since_last_save > self.app.auto_save_interval().as_secs_f64() {
if self.app.persist_egui_memory() {
save_memory(&self.egui_ctx);
}
self.app.save(&mut self.storage);
self.last_save_time = now;
}
}
pub fn canvas_id(&self) -> &str {
self.painter.canvas_id()
}
pub fn warm_up(&mut self) -> Result<(), JsValue> {
if self.app.warm_up_enabled() {
let saved_memory: egui::Memory = self.egui_ctx.memory().clone();
self.egui_ctx.memory().set_everything_is_visible(true);
self.logic()?;
*self.egui_ctx.memory() = saved_memory; // We don't want to remember that windows were huge.
self.egui_ctx.clear_animations();
}
Ok(())
}
/// Returns `true` if egui requests a repaint.
///
/// Call [`Self::paint`] later to paint
pub fn logic(&mut self) -> Result<(bool, Vec<egui::ClippedPrimitive>), JsValue> {
let frame_start = now_sec();
resize_canvas_to_screen_size(self.canvas_id(), self.app.max_size_points());
let canvas_size = canvas_size_in_points(self.canvas_id());
let raw_input = self.input.new_frame(canvas_size);
let full_output = self.egui_ctx.run(raw_input, |egui_ctx| {
self.app.update(egui_ctx, &self.frame);
});
let egui::FullOutput {
platform_output,
needs_repaint,
textures_delta,
shapes,
} = full_output;
self.handle_platform_output(platform_output);
self.textures_delta.append(textures_delta);
let clipped_primitives = self.egui_ctx.tessellate(shapes);
{
let app_output = self.frame.take_app_output();
let epi::backend::AppOutput {
quit: _, // Can't quit a web page
window_size: _, // Can't resize a web page
window_title: _, // TODO: change title of window
decorated: _, // Can't toggle decorations
drag_window: _, // Can't be dragged
} = app_output;
}
self.frame.lock().info.cpu_usage = Some((now_sec() - frame_start) as f32);
Ok((needs_repaint, clipped_primitives))
}
/// Paint the results of the last call to [`Self::logic`].
pub fn paint(&mut self, clipped_primitives: &[egui::ClippedPrimitive]) -> Result<(), JsValue> {
let textures_delta = std::mem::take(&mut self.textures_delta);
self.painter.clear(self.app.clear_color());
self.painter.paint_and_update_textures(
clipped_primitives,
self.egui_ctx.pixels_per_point(),
&textures_delta,
)?;
Ok(())
}
fn handle_platform_output(&mut self, platform_output: egui::PlatformOutput) {
if self.egui_ctx.options().screen_reader {
self.screen_reader
.speak(&platform_output.events_description());
}
let egui::PlatformOutput {
cursor_icon,
open_url,
copied_text,
events: _, // already handled
mutable_text_under_cursor,
text_cursor_pos,
} = platform_output;
set_cursor_icon(cursor_icon);
if let Some(open) = open_url {
crate::open_url(&open.url, open.new_tab);
}
#[cfg(web_sys_unstable_apis)]
if !copied_text.is_empty() {
set_clipboard_text(&copied_text);
}
#[cfg(not(web_sys_unstable_apis))]
let _ = copied_text;
self.mutable_text_under_cursor = mutable_text_under_cursor;
if self.text_cursor_pos != text_cursor_pos {
text_agent::move_text_cursor(text_cursor_pos, self.canvas_id());
self.text_cursor_pos = text_cursor_pos;
}
}
}
/// Install event listeners to register different input events
/// and start running the given app.
pub fn start(canvas_id: &str, app_creator: epi::AppCreator) -> Result<AppRunnerRef, JsValue> {
let mut runner = AppRunner::new(canvas_id, app_creator)?;
runner.warm_up()?;
start_runner(runner)
}
/// Install event listeners to register different input events
/// and starts running the given `AppRunner`.
fn start_runner(app_runner: AppRunner) -> Result<AppRunnerRef, JsValue> {
let runner_container = AppRunnerContainer {
runner: Arc::new(Mutex::new(app_runner)),
panicked: Arc::new(AtomicBool::new(false)),
};
install_canvas_events(&runner_container)?;
install_document_events(&runner_container)?;
text_agent::install_text_agent(&runner_container)?;
repaint_every_ms(&runner_container, 1000)?; // just in case. TODO: make it a parameter
paint_and_schedule(&runner_container.runner, runner_container.panicked.clone())?;
// Disable all event handlers on panic
std::panic::set_hook(Box::new({
let previous_hook = std::panic::take_hook();
let panicked = runner_container.panicked;
move |panic_info| {
tracing::info_span!("egui_panic_handler").in_scope(|| {
tracing::trace!("setting panicked flag");
panicked.store(true, SeqCst);
tracing::info!("egui disabled all event handlers due to panic");
});
// Propagate panic info to the previously registered panic hook
previous_hook(panic_info);
}
}));
Ok(runner_container.runner)
}