Implement File > Open menu item

gpui/src/platform/mod.rs

@@ -41,6 +41,7 @@ pub trait App {
         options: WindowOptions,
         executor: Rc<executor::Foreground>,
     ) -> Result<Box<dyn Window>>;
+    fn prompt_for_paths(&self, options: PathPromptOptions) -> Option<Vec<PathBuf>>;
     fn fonts(&self) -> Arc<dyn FontSystem>;
     fn quit(&self);
 }
@@ -66,6 +67,12 @@ pub struct WindowOptions<'a> {
     pub title: Option<&'a str>,
 }
 
+pub struct PathPromptOptions {
+    pub files: bool,
+    pub directories: bool,
+    pub multiple: bool,
+}
+
 pub trait FontSystem: Send + Sync {
     fn load_family(&self, name: &str) -> anyhow::Result<Vec<FontId>>;
     fn select_font(