fix text input on wasm (#394)

* add text input to ui example

* it works now (but this is a weird hack)

* much less hacky way of doing this

* handle backspace and other special keys gracefully

* update edit text string to make more clear you can edit it

* fix: support no ascii characters too

---------

Co-authored-by: Sébastien Crozet <sebcrozet@dimforge.com>

Author: ValorZard

examples/ui.rs

@@ -22,6 +22,7 @@ async fn main() {
 
     // UI state
     let mut rotation_speed = 0.014;
+    let mut text = String::from("Edit text here!");
     let mut opacity = 1.0;
     let mut cube_color = [1.0, 0.0, 0.0];
 
@@ -54,6 +55,9 @@ async fn main() {
                     ui.label("Opacity:");
                     ui.add(egui::Slider::new(&mut opacity, 0.0..=1.0));
 
+                    // Text Input
+                    ui.add(egui::TextEdit::singleline(&mut text));
+
                     // Color picker
                     ui.label("Cube Color:");
 

src/window/wgpu_canvas.rs

@@ -611,6 +611,16 @@ impl WgpuCanvas {
                         Action::Press,
                         Modifiers::empty(),
                     ));
+                    // Emit a Char event for single-character (printable) keys so
+                    // egui text fields receive text input. Skip when a command
+                    // modifier is held so shortcuts (e.g. Ctrl+A) don't insert text,
+                    // mirroring the native path which relies on winit's `text` field.
+                    let key_string = event.key();
+                    if !event.ctrl_key() && !event.meta_key() && key_string.chars().count() == 1 {
+                        if let Some(ch) = key_string.chars().next() {
+                            pending.borrow_mut().push(WindowEvent::Char(ch));
+                        }
+                    }
                 });
                 let _ = web_window
                     .add_event_listener_with_callback("keydown", closure.as_ref().unchecked_ref());