export now uses separate thread to avoid application locking up

src/exporter.rs

@@ -19,6 +19,11 @@ const LOCKED_DOOR: (u8, u8, u8, u8) = (80, 200, 120, 255);
 const ARCHWAY: (u8, u8, u8, u8) = (70, 130, 220, 255);
 const WHITE: (u8, u8, u8, u8) = (255, 255, 255, 255);
 
+pub enum ExportTarget {
+    File(PathBuf),
+    Folder(PathBuf),
+}
+
 #[derive(Debug, Clone, Copy)]
 enum DoorStyle {
     Solid,
@@ -111,17 +116,13 @@ fn collect_scene_data(layout: &DungeonLayout, settings: &UiSettings) -> SceneDat
     scene
 }
 
-pub fn export_with_dialog(
-    layout: &DungeonLayout,
-    settings: &UiSettings,
-) -> Result<PathBuf, String> {
+pub fn select_export_target(settings: &UiSettings) -> Result<ExportTarget, String> {
     if settings.export_format == ExportFormat::Folder {
         let folder = FileDialog::new()
             .set_title("Export composite masks folder")
             .pick_folder()
             .ok_or_else(|| "Export canceled".to_string())?;
-        export_composite_masks(layout, settings, &folder)?;
-        return Ok(folder);
+        return Ok(ExportTarget::Folder(folder));
     }
 
     let ext = settings.export_format.extension();
@@ -141,6 +142,20 @@ pub fn export_with_dialog(
         path.set_extension(ext);
     }
 
+    Ok(ExportTarget::File(path))
+}
+
+pub fn export_to_target(
+    layout: &DungeonLayout,
+    settings: &UiSettings,
+    target: ExportTarget,
+) -> Result<PathBuf, String> {
+    match target {
+        ExportTarget::Folder(folder) => {
+            export_composite_masks(layout, settings, &folder)?;
+            Ok(folder)
+        }
+        ExportTarget::File(path) => {
             match settings.export_format {
                 ExportFormat::Svg => {
                     let svg = build_svg(layout, settings);
@@ -160,8 +175,9 @@ pub fn export_with_dialog(
                 }
                 ExportFormat::Folder => unreachable!(),
             }
-
             Ok(path)
+        }
+    }
 }
 
 fn render_pixmap(layout: &DungeonLayout, settings: &UiSettings) -> Result<Pixmap, String> {

src/main.rs

@@ -5,6 +5,8 @@ mod settings;
 mod ui;
 
 use std::collections::HashSet;
+use std::sync::mpsc;
+use std::thread;
 
 use eframe::egui;
 use egui::{Color32, Stroke};
@@ -25,6 +27,7 @@ struct DungeonApp {
     settings: UiSettings,
     layout: DungeonLayout,
     drag_state: Option<DragState>,
+    export_rx: Option<mpsc::Receiver<Result<std::path::PathBuf, String>>>,
 }
 
 impl Default for DungeonApp {
@@ -48,6 +51,7 @@ impl Default for DungeonApp {
             settings,
             layout,
             drag_state: None,
+            export_rx: None,
         }
     }
 }
@@ -62,7 +66,7 @@ impl Drop for DungeonApp {
 
 impl eframe::App for DungeonApp {
     fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        let panel_result = draw_side_panel(ctx, &mut self.settings);
+        let panel_result = draw_side_panel(ctx, &mut self.settings, self.export_rx.is_some());
 
         if self.settings.min_room_size > self.settings.max_room_size {
             self.settings.max_room_size = self.settings.min_room_size;
@@ -77,9 +81,37 @@ impl eframe::App for DungeonApp {
         if panel_result.reset_clicked || panel_result.settings_changed {
             self.regenerate_layout();
         }
-        if panel_result.export_clicked {
-            if let Err(err) = exporter::export_with_dialog(&self.layout, &self.settings) {
+        if panel_result.export_clicked && self.export_rx.is_none() {
+            let target = match exporter::select_export_target(&self.settings) {
+                Ok(target) => target,
+                Err(err) => {
                     eprintln!("{err}");
+                    return;
+                }
+            };
+            let layout = self.layout.clone();
+            let settings = self.settings.clone();
+            let (tx, rx) = mpsc::channel();
+            thread::spawn(move || {
+                let result = exporter::export_to_target(&layout, &settings, target);
+                let _ = tx.send(result);
+            });
+            self.export_rx = Some(rx);
+        }
+
+        if let Some(rx) = &self.export_rx {
+            match rx.try_recv() {
+                Ok(Ok(_)) => {
+                    self.export_rx = None;
+                }
+                Ok(Err(err)) => {
+                    eprintln!("{err}");
+                    self.export_rx = None;
+                }
+                Err(mpsc::TryRecvError::Empty) => {}
+                Err(mpsc::TryRecvError::Disconnected) => {
+                    self.export_rx = None;
+                }
             }
         }
 

src/ui.rs

@@ -152,7 +152,11 @@ pub struct SidePanelResult {
     pub export_clicked: bool,
 }
 
-pub fn draw_side_panel(ctx: &egui::Context, settings: &mut UiSettings) -> SidePanelResult {
+pub fn draw_side_panel(
+    ctx: &egui::Context,
+    settings: &mut UiSettings,
+    export_in_progress: bool,
+) -> SidePanelResult {
     let mut result = SidePanelResult::default();
 
     egui::SidePanel::left("options_panel")
@@ -175,7 +179,7 @@ pub fn draw_side_panel(ctx: &egui::Context, settings: &mut UiSettings) -> SidePa
             ui.separator();
 
             match settings.active_tab {
-                Tab::Generate => draw_generate_tab(ui, settings, &mut result),
+                Tab::Generate => draw_generate_tab(ui, settings, &mut result, export_in_progress),
                 Tab::Layout => draw_layout_tab(ui, settings, &mut result),
             }
         });
@@ -183,7 +187,12 @@ pub fn draw_side_panel(ctx: &egui::Context, settings: &mut UiSettings) -> SidePa
     result
 }
 
-fn draw_generate_tab(ui: &mut egui::Ui, settings: &mut UiSettings, result: &mut SidePanelResult) {
+fn draw_generate_tab(
+    ui: &mut egui::Ui,
+    settings: &mut UiSettings,
+    result: &mut SidePanelResult,
+    export_in_progress: bool,
+) {
     ui.label(RichText::new("Grid Settings").strong());
     ui.add_space(8.0);
 
@@ -339,6 +348,11 @@ fn draw_generate_tab(ui: &mut egui::Ui, settings: &mut UiSettings, result: &mut
     if ui.button("Export Image").clicked() {
         result.export_clicked = true;
     }
+
+    if export_in_progress {
+        ui.add_space(6.0);
+        ui.add(egui::ProgressBar::new(0.0).animate(true));
+    }
 }
 
 fn draw_layout_tab(ui: &mut egui::Ui, settings: &mut UiSettings, result: &mut SidePanelResult) {