add

crates/eframe/src/web/events.rs

@@ -9,12 +9,26 @@ pub(crate) fn paint_and_schedule(runner_ref: &WebRunner) -> Result<(), JsValue>
     // Only paint and schedule if there has been no panic
     if let Some(mut runner_lock) = runner_ref.try_lock() {
         paint_if_needed(&mut runner_lock);
+        drop_files(&mut runner_lock);
         drop(runner_lock);
         runner_ref.request_animation_frame()?;
     }
     Ok(())
 }
 
+fn drop_files(runner: &mut AppRunner) {
+    if !runner.input.raw.dropped_files.is_empty() {
+        for mut dropped_file in runner.input.raw.dropped_files.drain(..) {
+            if let Some(stream_url) = dropped_file.stream_url {
+                if *dropped_file.need_drop_url {
+                    let _ = web_sys::Url::revoke_object_url(&stream_url);
+                    dropped_file.need_drop_url = false.into();
+                }
+            }
+        }
+    }
+}
+
 fn paint_if_needed(runner: &mut AppRunner) {
     if runner.needs_repaint.needs_repaint() {
         if runner.has_outstanding_paint_data() {

crates/eframe/src/web/mod.rs

@@ -249,11 +249,11 @@ pub fn percent_decode(s: &str) -> String {
 
 /// Load the data from a dropped file.
 pub async fn get_data(
-    dropped_file: &egui::DroppedFile,
-    drop_file: bool,
+    dropped_file: &mut egui::DroppedFile,
 ) -> Result<std::sync::Arc<[u8]>, String> {
     use wasm_bindgen_futures::JsFuture;
 
+    dropped_file.need_drop_url = false.into();
     let url = dropped_file.stream_url.clone().ok_or("No stream URL")?;
 
     let window = web_sys::window().ok_or("No Window object")?;
@@ -282,9 +282,7 @@ pub async fn get_data(
     let bytes = js_sys::Uint8Array::new(&array_buffer).to_vec();
     log::debug!("Loaded {} bytes", bytes.len());
 
-    if drop_file {
-        let _ = web_sys::Url::revoke_object_url(&url);
-    }
+    dropped_file.need_drop_url = true.into();
 
     Ok(std::sync::Arc::from(bytes.into_boxed_slice()))
 }

crates/egui/src/data/input.rs

@@ -1,5 +1,7 @@
 //! The input needed by egui.
 
+use std::sync::Arc;
+
 use epaint::ColorImage;
 
 use crate::{emath::*, Key, ViewportId, ViewportIdMap};
@@ -335,6 +337,9 @@ pub struct DroppedFile {
     /// Set by the `eframe` web backend.
     pub last_modified: Option<std::time::SystemTime>,
 
+    /// drop the url
+    pub need_drop_url: Arc<bool>,
+
     /// Set by the `eframe` web backend.
     pub stream_url: Option<String>,
 }

crates/egui_demo_app/src/wrap_app.rs

@@ -499,9 +499,9 @@ impl WrapApp {
                         if file.stream_url.is_some()
                             && ui.button("Read file (output in console)").clicked()
                         {
-                            let one_file = file.clone();
+                            let mut one_file = file.clone();
                             let func = async move {
-                                let res = eframe::web::get_data(&one_file, true);
+                                let res = eframe::web::get_data(&mut one_file);
                                 match res.await {
                                     Ok(data) => {
                                         log::info!("Read {} bytes", data.len());
@@ -513,7 +513,6 @@ impl WrapApp {
                                 }
                             };
                             wasm_bindgen_futures::spawn_local(func);
-                            file.stream_url = None;
                         }
                     }
                 });