web: Download the file on save dialog

web/Cargo.toml

@@ -72,7 +72,8 @@ features = [
     "ChannelMergerNode", "ChannelSplitterNode", "ClipboardEvent", "DataTransfer", "Element", "Event",
     "EventTarget", "GainNode", "Headers", "HtmlCanvasElement", "HtmlDocument", "HtmlElement", "HtmlFormElement",
     "HtmlInputElement", "HtmlTextAreaElement", "KeyboardEvent", "Location", "PointerEvent",
-    "Request", "RequestInit", "Response", "Storage", "WheelEvent", "Window", "ReadableStream", "RequestCredentials"
+    "Request", "RequestInit", "Response", "Storage", "WheelEvent", "Window", "ReadableStream", "RequestCredentials",
+    "Url",
 ]
 
 [package.metadata.cargo-machete]

web/src/ui.rs

@@ -8,11 +8,15 @@ use ruffle_core::backend::ui::{
 };
 use ruffle_web_common::JsResult;
 use std::borrow::Cow;
+use std::sync::{Mutex, MutexGuard};
 use url::Url;
 use wasm_bindgen::JsCast;
-use web_sys::{HtmlCanvasElement, HtmlDocument, HtmlTextAreaElement};
+use web_sys::{
+    Blob, HtmlCanvasElement, HtmlDocument, HtmlElement, HtmlTextAreaElement, Url as JsUrl,
+};
 
 use chrono::{DateTime, Utc};
+use js_sys::Uint8Array;
 
 #[allow(dead_code)]
 #[derive(Debug)]
@@ -116,6 +120,91 @@ impl FileDialogResult for WebFileDialogResult {
     fn refresh(&mut self) {}
 }
 
+pub struct WebDownloadFileData {
+    file_name: String,
+    contents: Vec<u8>,
+    downloaded: bool,
+}
+
+pub struct WebDownloadFileDialogResult {
+    data: Mutex<WebDownloadFileData>,
+}
+
+impl WebDownloadFileDialogResult {
+    fn new(file_name: String) -> WebDownloadFileDialogResult {
+        Self {
+            data: Mutex::new(WebDownloadFileData {
+                file_name,
+                contents: Vec::new(),
+                downloaded: false,
+            }),
+        }
+    }
+
+    fn data(&self) -> MutexGuard<'_, WebDownloadFileData> {
+        self.data.lock().expect("non-poisoned data")
+    }
+
+    fn download(mut data: MutexGuard<WebDownloadFileData>) -> Option<()> {
+        let array = Uint8Array::from(&data.contents[..]);
+        let blob = Blob::new_with_u8_array_sequence(&array).ok()?;
+        let window = web_sys::window()?;
+        let document = window.document()?;
+        let a = document.create_element("a").ok()?;
+
+        let url = JsUrl::create_object_url_with_blob(&blob).ok()?;
+        a.set_attribute("href", &url).ok()?;
+        a.set_attribute("download", &data.file_name).ok()?;
+        a.dyn_into::<HtmlElement>().ok()?.click();
+        data.downloaded = true;
+        Some(())
+    }
+}
+
+impl FileDialogResult for WebDownloadFileDialogResult {
+    fn is_cancelled(&self) -> bool {
+        self.data().downloaded
+    }
+
+    fn creation_time(&self) -> Option<DateTime<Utc>> {
+        None
+    }
+
+    fn modification_time(&self) -> Option<DateTime<Utc>> {
+        None
+    }
+
+    fn file_name(&self) -> Option<String> {
+        Some(self.data().file_name.clone())
+    }
+
+    fn size(&self) -> Option<u64> {
+        Some(self.data().contents.len() as u64)
+    }
+
+    fn file_type(&self) -> Option<String> {
+        None
+    }
+
+    fn creator(&self) -> Option<String> {
+        None
+    }
+
+    fn contents(&self) -> &[u8] {
+        tracing::warn!("Reading downloaded file not implemented");
+        &[]
+    }
+
+    fn write(&self, to_write: &[u8]) {
+        let mut data = self.data();
+        data.contents = to_write.to_vec();
+
+        Self::download(data);
+    }
+
+    fn refresh(&mut self) {}
+}
+
 /// An implementation of `UiBackend` utilizing `web_sys` bindings to input APIs.
 pub struct WebUiBackend {
     js_player: JavascriptPlayer,
@@ -312,30 +401,13 @@ impl UiBackend for WebUiBackend {
 
     fn display_file_save_dialog(
         &mut self,
-        _file_name: String,
+        file_name: String,
         _title: String,
     ) -> Option<DialogResultFuture> {
-        None
-        /* Temporary disabled while #14949 is being fixed
-
-        // Prevent opening multiple dialogs at the same time
-        if self.dialog_open {
-            return None;
-        }
-        self.dialog_open = true;
-
-        // Create the dialog future
         Some(Box::pin(async move {
-            // Select the location to save the file to
-            let dialog = AsyncFileDialog::new()
-                .set_title(&title)
-                .set_file_name(&file_name);
-
-            let result: Result<Box<dyn FileDialogResult>, DialogLoaderError> = Ok(Box::new(
-                WebFileDialogResult::new(dialog.save_file().await).await,
-            ));
+            let result: Result<Box<dyn FileDialogResult>, DialogLoaderError> =
+                Ok(Box::new(WebDownloadFileDialogResult::new(file_name)));
             result
         }))
-        */
     }
 }