made export remember where the last save location was

src/exporter.rs

@@ -133,8 +133,11 @@ fn collect_scene_data(layout: &DungeonLayout, settings: &UiSettings) -> SceneDat
 // Open a dialog to select an export destination.
 pub fn select_export_target(settings: &UiSettings) -> Result<ExportTarget, String> {
     if settings.export_format == ExportFormat::Folder {
-        let folder = FileDialog::new()
+        let mut dialog = FileDialog::new().set_title("Export composite masks folder");
-            .set_title("Export composite masks folder")
+        if let Some(ref last_path) = settings.last_export_path {
+            dialog = dialog.set_directory(last_path);
+        }
+        let folder = dialog
             .pick_folder()
             .ok_or_else(|| "Export canceled".to_string())?;
         return Ok(ExportTarget::Folder(folder));
@@ -149,6 +152,10 @@ pub fn select_export_target(settings: &UiSettings) -> Result<ExportTarget, Strin
         .set_file_name(&default_name)
         .add_filter(settings.export_format.label(), &[ext]);
 
+    if let Some(ref last_path) = settings.last_export_path {
+        dialog = dialog.set_directory(last_path);
+    }
+
     let mut path = dialog
         .save_file()
         .ok_or_else(|| "Export canceled".to_string())?;

src/main.rs

@@ -174,6 +174,19 @@ impl eframe::App for DungeonApp {
                     return;
                 }
             };
+
+            // Update the last export path in settings to remember the directory.
+            match &target {
+                exporter::ExportTarget::File(path) => {
+                    if let Some(parent) = path.parent() {
+                        self.settings.last_export_path = Some(parent.to_string_lossy().to_string());
+                    }
+                }
+                exporter::ExportTarget::Folder(path) => {
+                    self.settings.last_export_path = Some(path.to_string_lossy().to_string());
+                }
+            }
+
             let layout = self.layout.clone();
             let settings = self.settings.clone();
             let (tx, rx) = mpsc::channel();

src/ui.rs

@@ -131,6 +131,7 @@ pub struct UiSettings {
     pub export_height: u32,
     pub allow_export_aspect_change: bool,
     pub export_show_grid: bool,
+    pub last_export_path: Option<String>,
     pub add_tool: AddTool,
     pub add_text_value: String,
     pub min_start_marker_size: usize,
@@ -184,6 +185,7 @@ impl Default for UiSettings {
             export_height: 1080,
             allow_export_aspect_change: false,
             export_show_grid: true,
+            last_export_path: None,
             add_tool: AddTool::None,
             add_text_value: "Text".to_string(),
             min_start_marker_size: 1,