Use async file picker API

src/filepicker.rs

@@ -0,0 +1,54 @@
+use std::{
+    path::PathBuf,
+    sync::{Arc, Weak},
+};
+
+use winit::window::Window;
+
+pub struct FilePicker {
+    window: Option<Weak<Window>>,
+}
+
+impl FilePicker {
+    pub fn new() -> Self {
+        Self { window: None }
+    }
+
+    pub fn set_window(&mut self, window: &Arc<Window>) {
+        self.window = Some(Arc::downgrade(window));
+    }
+
+    pub fn new_dialog(&self) -> FileDialogBuilder {
+        let mut dialog = rfd::AsyncFileDialog::new();
+        if let Some(window) = self.window.as_ref().and_then(|w| w.upgrade()) {
+            dialog = dialog.set_parent(&window);
+        }
+        FileDialogBuilder { dialog }
+    }
+}
+
+pub struct FileDialogBuilder {
+    dialog: rfd::AsyncFileDialog,
+}
+
+impl FileDialogBuilder {
+    pub fn add_filter(self, name: impl Into<String>, extensions: &[impl ToString]) -> Self {
+        Self {
+            dialog: self.dialog.add_filter(name, extensions),
+        }
+    }
+
+    pub fn set_file_name(self, file_name: impl Into<String>) -> Self {
+        Self {
+            dialog: self.dialog.set_file_name(file_name),
+        }
+    }
+
+    pub fn pick_file(self) -> Option<PathBuf> {
+        pollster::block_on(self.dialog.pick_file()).map(Into::into)
+    }
+
+    pub fn save_file(self) -> Option<PathBuf> {
+        pollster::block_on(self.dialog.save_file()).map(Into::into)
+    }
+}