Fix: video frames to layers working using folder dialog request (#3513) (#3718)

apps/photocraft-web/src/web.rs

@@ -382,6 +382,8 @@ fn services(inbox: Inbox) -> Services {
                 };
                 reply.send(answer);
             }),
+            // Browser folder handles cannot be represented as filesystem paths for engine commands.
+            FileDialogRequest::Folder { .. } => reply.send(None),
             // No save dialog on the web: the suggested name becomes the download name.
             FileDialogRequest::Save { suggested } => {
                 let name = std::path::Path::new(&suggested).file_name().map_or_else(|| suggested.clone(), |n| n.to_string_lossy().to_string());

apps/photocraft/src/services.rs

@@ -115,6 +115,13 @@ fn show_file_dialog(request: FileDialogRequest, parent: Option<&eframe::Frame>,
                 Box::pin(async move { picked.await.map(|file| FileDialogAnswer::Paths(vec![path_of(&file)])) })
             }
         }
+        FileDialogRequest::Folder { initial_dir } => {
+            if let Some(dir) = initial_dir {
+                dialog = dialog.set_directory(dir);
+            }
+            let picked = dialog.pick_folder();
+            Box::pin(async move { picked.await.map(|folder| FileDialogAnswer::FolderTo(path_of(&folder))) })
+        }
         FileDialogRequest::Save { suggested } => {
             for (name, exts) in save_filters(&suggested) {
                 dialog = dialog.add_filter(name, &exts);

crates/ui-egui/src/file_dialog.rs

@@ -21,12 +21,14 @@ use serde_json::{Value, json};
 use crate::PhotocraftApp;
 use crate::file_open::display_name;
 
-/// What a file dialog asks the user for.
+/// What a file or folder dialog asks the user for.
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum FileDialogRequest {
     /// Files to read: several for File › Open, one for a command that reads a file (Place,
     /// scripts, notes, presets). Starts in `initial_dir` (the last-used folder, UI-217-3).
     Open { multiple: bool, initial_dir: Option<String>, extensions: Option<Vec<String>> },
+    /// Which folder to read from. Starts in `initial_dir` when available.
+    Folder { initial_dir: Option<String> },
     /// Where to write, starting from `suggested` (a file name, or the document's own path).
     Save { suggested: String },
 }
@@ -42,6 +44,8 @@ pub enum FileDialogAnswer {
     ContentsMany(Vec<(String, Vec<u8>)>),
     /// The path to save to (desktop), or the download's name (web).
     SaveTo(String),
+    /// The selected folder's path (desktop).
+    FolderTo(String),
     /// No dialog could be shown (on Linux: no desktop portal and no zenity, #3354); the message
     /// says what to install. Reported as an error rather than taken for Cancel.
     Unavailable(String),
@@ -88,7 +92,7 @@ impl PhotocraftApp {
     }
 
     /// Show a file dialog; `then` continues with the user's choice on a later frame (see the
-    /// module docs). Returns at once with `{"fileDialog": "open" | "save"}`; `Err` without a
+    /// module docs). Returns at once with `{"fileDialog": "open" | "folder" | "save"}`; `Err` without a
     /// dialog service ("cancelled", as before there were async dialogs) or while one is open.
     pub(crate) fn ask_file(
         &mut self,
@@ -103,6 +107,7 @@ impl PhotocraftApp {
         }
         let kind = match request {
             FileDialogRequest::Open { .. } => "open",
+            FileDialogRequest::Folder { .. } => "folder",
             FileDialogRequest::Save { .. } => "save",
         };
         let then: Then = Box::new(move |app, answer| match answer {
@@ -114,6 +119,16 @@ impl PhotocraftApp {
         Ok(json!({ "fileDialog": kind }))
     }
 
+    /// Ask the user to choose a folder, starting in the folder of the most recent file when known.
+    /// `then` receives the selected path when the dialog is answered.
+    pub(crate) fn ask_folder(&mut self, then: impl FnOnce(&mut Self, String) -> Result<Value, String> + 'static) -> Result<Value, String> {
+        let initial_dir = last_used_dir(&self.ui.recent_files);
+        self.ask_file(FileDialogRequest::Folder { initial_dir }, move |app, answer| match answer {
+            FileDialogAnswer::FolderTo(path) => then(app, path),
+            _ => Err(UNEXPECTED.into()),
+        })
+    }
+
     /// Ask where to save: `then` gets the chosen path, with a lowercase extension when
     /// Preferences ▸ File Handling › Lowercase Extension is on (its default).
     ///
@@ -193,6 +208,7 @@ impl PhotocraftApp {
                 }
                 FileDialogAnswer::Contents(name, bytes) => app.open_contents(vec![(name, bytes)]),
                 FileDialogAnswer::ContentsMany(files) => app.open_contents(files),
+                FileDialogAnswer::FolderTo(_) => return Err(UNEXPECTED.into()),
                 FileDialogAnswer::SaveTo(_) | FileDialogAnswer::Unavailable(_) => return Err(UNEXPECTED.into()),
             }
             Ok(Value::Null)
@@ -290,6 +306,7 @@ fn read_picked(answer: FileDialogAnswer) -> Result<(String, Vec<u8>), String> {
             let bytes = photocraft_format::read_file(std::path::Path::new(&path)).map_err(|e| format!("{}: {e}", display_name(&path)))?;
             Ok((path, bytes))
         }
+        FileDialogAnswer::FolderTo(_) => Err(UNEXPECTED.into()),
         FileDialogAnswer::SaveTo(_) | FileDialogAnswer::Unavailable(_) => Err(UNEXPECTED.into()),
     }
 }

crates/ui-egui/src/file_dialog/tests.rs

@@ -175,6 +175,30 @@ fn open_starts_in_the_last_used_folder() {
     );
 }
 
+#[test]
+fn ask_folder_uses_the_async_dialog_and_returns_the_selected_path() {
+    let (mut app, open, _) = app();
+    let ctx = egui::Context::default();
+    app.ui.recent_files = vec!["/pics/cat.psd".into()];
+    let selected = Rc::new(RefCell::new(None));
+    let result = selected.clone();
+
+    assert_eq!(
+        app.ask_folder(move |_, path| {
+            *result.borrow_mut() = Some(path);
+            Ok(Value::Null)
+        })
+        .unwrap(),
+        json!({"fileDialog": "folder"})
+    );
+    app.poll_file_dialog(&ctx, None);
+    assert!(matches!(open.borrow().as_slice(), [(FileDialogRequest::Folder { initial_dir: Some(dir) }, _)] if dir == "/pics"));
+
+    answer(&open, Some(FileDialogAnswer::FolderTo("/pics/frames".into())));
+    app.poll_file_dialog(&ctx, None);
+    assert_eq!(selected.borrow().as_deref(), Some("/pics/frames"));
+}
+
 #[test]
 fn filtered_picker_requests_only_the_given_extensions() {
     let (mut app, open, _) = app();

crates/ui-egui/src/menus.rs

@@ -292,6 +292,9 @@ pub(crate) fn invoke_unguarded(app: &mut PhotocraftApp, ctx: &egui::Context, id:
                 app.open_dialog_file()
             }
         }
+        "file.import.videoFramesToLayers" if params.get("path").and_then(Value::as_str).is_none() => {
+            app.ask_folder(|app, path| app.run("file.import.videoFramesToLayers", json!({"path": path})).map_err(|e| e.to_string()))
+        }
         "file.save" => {
             // Writes back only to a layered file; a flat one goes through Save As.
             let tga_bits = crate::targa_options_ui::bits_param(&params, id)?;

crates/ui-egui/tests/export_as_scaling.rs

@@ -24,6 +24,7 @@ fn harness() -> Option<(Harness, Writes)> {
                     file_dialog: Some(Box::new(|request, _parent, reply| {
                         reply.send(match request {
                             FileDialogRequest::Save { suggested } => Some(FileDialogAnswer::SaveTo(suggested)),
+                            FileDialogRequest::Folder { .. } => None,
                             FileDialogRequest::Open { .. } => None,
                         })
                     })),