implement passable #[command]

src/device/browse.rs

@@ -1,6 +1,17 @@
 use crate::*;
 
-def_command!(FileBrowserCommand: |sampler: Sampler|{
+impl App {
+    /// Return reference to content browser if open.
+    ///
+    /// ```
+    /// assert_eq!(tek::App::default().browser(), None);
+    /// ```
+    pub fn browser (&self) -> Option<&Browse> {
+        if let Dialog::Browse(_, ref b) = self.dialog { Some(b) } else { None }
+    }
+}
+
+def_command!(FileBrowserCommand: |_browse: Browse|{
     //("begin"   []            Some(Self::Begin))
     //("cancel"  []            Some(Self::Cancel))
     //("confirm" []            Some(Self::Confirm))
@@ -539,3 +550,20 @@ def_command!(CropCommand: |pool: Pool| {
         Ok(None)
     }
 });
+
+pub fn scan (dir: &PathBuf) -> Usually<(Vec<OsString>, Vec<OsString>)> {
+    let (mut subdirs, mut files) = std::fs::read_dir(dir)?
+        .fold((vec!["..".into()], vec![]), |(mut subdirs, mut files), entry|{
+            let entry = entry.expect("failed to read drectory entry");
+            let meta = entry.metadata().expect("failed to read entry metadata");
+            if meta.is_file() {
+                files.push(entry.file_name());
+            } else if meta.is_dir() {
+                subdirs.push(entry.file_name());
+            }
+            (subdirs, files)
+        });
+    subdirs.sort();
+    files.sort();
+    Ok((subdirs, files))
+}