web clipboard handling

.cargo/config.toml

@@ -0,0 +1,6 @@
+[alias]
+run-wasm = ["run", "--release", "--package", "run-wasm", "--"]
+
+# Using unstable APIs is required for writing to clipboard
+[target.wasm32-unknown-unknown]
+rustflags = ["--cfg=web_sys_unstable_apis"]

Cargo.toml

@@ -22,7 +22,10 @@ default_fonts = ["egui/default_fonts"]
 serde = ["egui/serde"]
 
 [dependencies]
-bevy = { version = "0.10", default-features = false, features = ["bevy_render", "bevy_asset"] }
+bevy = { version = "0.10", default-features = false, features = [
+    "bevy_render",
+    "bevy_asset",
+] }
 egui = { version = "0.21.0", default-features = false, features = ["bytemuck"] }
 webbrowser = { version = "0.8.2", optional = true }
 
@@ -39,3 +42,24 @@ bevy = { version = "0.10", default-features = false, features = [
     "bevy_pbr",
     "bevy_core_pipeline",
 ] }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+winit = "0.28"
+web-sys = { version = "0.3.63", features = [
+    "Clipboard",
+    "ClipboardEvent",
+    "DataTransfer",
+    'Document',
+    'EventTarget',
+    "Window",
+    "Navigator",
+] }
+js-sys = "0.3.63"
+wasm-bindgen = "0.2.84"
+wasm-bindgen-futures = "0.4.36"
+console_log = "1.0.0"
+log = "0.4"
+crossbeam-channel = "0.5.8"
+
+[workspace]
+members = ["run-wasm"]

examples/ui.rs

@@ -25,7 +25,13 @@ fn main() {
         .insert_resource(ClearColor(Color::rgb(0.0, 0.0, 0.0)))
         .insert_resource(Msaa::Sample4)
         .init_resource::<UiState>()
-        .add_plugins(DefaultPlugins)
+        .add_plugins(DefaultPlugins.set(WindowPlugin {
+            primary_window: Some(Window {
+                prevent_default_event_handling: false,
+                ..default()
+            }),
+            ..default()
+        }))
         .add_plugin(EguiPlugin)
         .add_startup_system(configure_visuals_system)
         .add_startup_system(configure_ui_state_system)

run-wasm/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "run-wasm"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+cargo-run-wasm = "0.2.0"

run-wasm/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    cargo_run_wasm::run_wasm_with_css("body { margin: 0px; }");
+}

src/lib.rs

@@ -58,7 +58,13 @@ pub mod systems;
 /// Egui render node.
 pub mod egui_node;
 
+/// Clipboard management for web
+#[cfg(all(feature = "manage_clipboard", target_arch = "wasm32"))]
+pub mod web_clipboard;
+
 pub use egui;
+#[cfg(all(feature = "manage_clipboard", target_arch = "wasm32"))]
+use web_clipboard::{WebEventCopy, WebEventCut, WebEventPaste};
 
 use crate::{
     egui_node::{EguiPipeline, EGUI_SHADER_HANDLE},
@@ -146,8 +152,15 @@ pub struct EguiInput(pub egui::RawInput);
 pub struct EguiClipboard {
     #[cfg(not(target_arch = "wasm32"))]
     clipboard: ThreadLocal<Option<RefCell<Clipboard>>>,
+    /// for copy events.
+    #[cfg(target_arch = "wasm32")]
+    pub web_copy: web_clipboard::WebChannel<WebEventCopy>,
+    /// for copy events.
+    #[cfg(target_arch = "wasm32")]
+    pub web_cut: web_clipboard::WebChannel<WebEventCut>,
+    /// for paste events, only supporting strings.
     #[cfg(target_arch = "wasm32")]
-    clipboard: String,
+    pub web_paste: web_clipboard::WebChannel<WebEventPaste>,
 }
 
 #[cfg(feature = "manage_clipboard")]
@@ -159,12 +172,20 @@ impl EguiClipboard {
 
     /// Gets clipboard contents. Returns [`None`] if clipboard provider is unavailable or returns an error.
     #[must_use]
-    pub fn get_contents(&self) -> Option<String> {
+    #[cfg(not(target_arch = "wasm32"))]
+    pub fn get_contents(&mut self) -> Option<String> {
+        self.get_contents_impl()
+    }
+
+    /// Gets clipboard contents. Returns [`None`] if clipboard provider is unavailable or returns an error.
+    #[must_use]
+    #[cfg(target_arch = "wasm32")]
+    pub fn get_contents(&mut self) -> Option<String> {
         self.get_contents_impl()
     }
 
     #[cfg(not(target_arch = "wasm32"))]
-    fn set_contents_impl(&self, contents: &str) {
+    fn set_contents_impl(&mut self, contents: &str) {
         if let Some(mut clipboard) = self.get() {
             if let Err(err) = clipboard.set_text(contents.to_owned()) {
                 log::error!("Failed to set clipboard contents: {:?}", err);
@@ -174,11 +195,11 @@ impl EguiClipboard {
 
     #[cfg(target_arch = "wasm32")]
     fn set_contents_impl(&mut self, contents: &str) {
-        self.clipboard = contents.to_owned();
+        web_clipboard::clipboard_copy(contents.to_owned());
     }
 
     #[cfg(not(target_arch = "wasm32"))]
-    fn get_contents_impl(&self) -> Option<String> {
+    fn get_contents_impl(&mut self) -> Option<String> {
         if let Some(mut clipboard) = self.get() {
             match clipboard.get_text() {
                 Ok(contents) => return Some(contents),
@@ -190,8 +211,8 @@ impl EguiClipboard {
 
     #[cfg(target_arch = "wasm32")]
     #[allow(clippy::unnecessary_wraps)]
-    fn get_contents_impl(&self) -> Option<String> {
-        Some(self.clipboard.clone())
+    fn get_contents_impl(&mut self) -> Option<String> {
+        self.web_paste.try_read_clipboard_event().map(|e| e.0)
     }
 
     #[cfg(not(target_arch = "wasm32"))]
@@ -533,6 +554,8 @@ impl Plugin for EguiPlugin {
         world.init_resource::<EguiUserTextures>();
         world.init_resource::<EguiMousePosition>();
 
+        #[cfg(all(feature = "manage_clipboard", target_arch = "wasm32"))]
+        app.add_startup_system(web_clipboard::startup_setup_web_events);
         app.add_startup_systems(
             (
                 setup_new_windows_system,

src/systems.rs

@@ -54,7 +54,7 @@ impl<'w, 's> InputEvents<'w, 's> {
 #[derive(SystemParam)]
 pub struct InputResources<'w, 's> {
     #[cfg(feature = "manage_clipboard")]
-    pub egui_clipboard: Res<'w, crate::EguiClipboard>,
+    pub egui_clipboard: ResMut<'w, crate::EguiClipboard>,
     pub keyboard_input: Res<'w, Input<KeyCode>>,
     #[system_param(ignore)]
     _marker: PhantomData<&'s ()>,
@@ -72,12 +72,32 @@ pub struct ContextSystemParams<'w, 's> {
 /// Processes Bevy input and feeds it to Egui.
 pub fn process_input_system(
     mut input_events: InputEvents,
-    input_resources: InputResources,
+    mut input_resources: InputResources,
     mut context_params: ContextSystemParams,
     egui_settings: Res<EguiSettings>,
     mut egui_mouse_position: ResMut<EguiMousePosition>,
     time: Res<Time>,
+    mut is_mac: Local<bool>,
 ) {
+    use std::sync::Once;
+    static START: Once = Once::new();
+
+    START.call_once(|| {
+        // run initialization here
+        *is_mac = cfg!(target_os = "macos");
+        #[cfg(target_arch = "wasm32")]
+        {
+            let window = web_sys::window().expect("window");
+
+            let nav = window.navigator();
+            let user_agent = nav.user_agent();
+            if let Ok(user_agent) = user_agent {
+                log::debug!("{:?}", user_agent);
+                *is_mac = user_agent.contains("Macintosh;");
+            }
+        }
+    });
+
     // This is a workaround for Windows. For some reason, `WindowFocused` event isn't fired
     // when a window is created.
     if let Some(event) = input_events.ev_window_created.iter().last() {
@@ -101,12 +121,8 @@ pub fn process_input_system(
     let win = input_resources.keyboard_input.pressed(KeyCode::LWin)
         || input_resources.keyboard_input.pressed(KeyCode::RWin);
 
-    let mac_cmd = if cfg!(target_os = "macos") {
-        win
-    } else {
-        false
-    };
-    let command = if cfg!(target_os = "macos") { win } else { ctrl };
+    let mac_cmd = if *is_mac { win } else { false };
+    let command = if *is_mac { win } else { ctrl };
 
     let modifiers = egui::Modifiers {
         alt,
@@ -250,20 +266,47 @@ pub fn process_input_system(
                 // We also check that it's an `ButtonState::Pressed` event, as we don't want to
                 // copy, cut or paste on the key release.
                 #[cfg(feature = "manage_clipboard")]
-                if command && pressed {
-                    match key {
-                        egui::Key::C => {
+                {
+                    #[cfg(not(target_arch = "wasm32"))]
+                    if command && pressed {
+                        match key {
+                            egui::Key::C => {
+                                focused_input.events.push(egui::Event::Copy);
+                            }
+                            egui::Key::X => {
+                                focused_input.events.push(egui::Event::Cut);
+                            }
+                            egui::Key::V => {
+                                if let Some(contents) =
+                                    input_resources.egui_clipboard.get_contents()
+                                {
+                                    focused_input.events.push(egui::Event::Text(contents))
+                                }
+                            }
+                            _ => {}
+                        }
+                    }
+                    #[cfg(target_arch = "wasm32")]
+                    {
+                        if input_resources
+                            .egui_clipboard
+                            .web_copy
+                            .try_read_clipboard_event()
+                            .is_some()
+                        {
                             focused_input.events.push(egui::Event::Copy);
                         }
-                        egui::Key::X => {
+                        if input_resources
+                            .egui_clipboard
+                            .web_cut
+                            .try_read_clipboard_event()
+                            .is_some()
+                        {
                             focused_input.events.push(egui::Event::Cut);
                         }
-                        egui::Key::V => {
-                            if let Some(contents) = input_resources.egui_clipboard.get_contents() {
-                                focused_input.events.push(egui::Event::Text(contents))
-                            }
+                        if let Some(contents) = input_resources.egui_clipboard.get_contents() {
+                            focused_input.events.push(egui::Event::Text(contents));
                         }
-                        _ => {}
                     }
                 }
             }