more fine grain error handling for previewing directories

2 files changed, 44 insertions, 10 deletions

diff --git a/src/preview/preview_default.rs b/src/preview/preview_default.rs
index bb5ea64..9f2fb66 100644
--- a/src/preview/preview_default.rs
+++ b/src/preview/preview_default.rs
@@ -4,17 +4,37 @@ use crate::context::AppContext;
 use crate::fs::JoshutoMetadata;
 use crate::preview::{preview_dir, preview_file};
 
+#[derive(Debug, Clone)]
+pub enum PreviewState {
+    Loading,
+    Error { message: String },
+}
+
+impl PreviewState {
+    pub fn is_loading(&self) -> bool {
+        match *self {
+            Self::Loading => true,
+            _ => false,
+        }
+    }
+}
+
 pub fn load_preview_path(context: &mut AppContext, p: path::PathBuf, metadata: JoshutoMetadata) {
     let preview_options = context.config_ref().preview_options_ref();
-
     if metadata.is_dir() {
-        let need_to_load = context
-            .tab_context_ref()
-            .curr_tab_ref()
-            .history_ref()
+        let tab = context.tab_context_ref().curr_tab_ref();
+        // only load if there doesn't already exist a loading thread and
+        // there isn't an entry in history
+        let need_to_load = tab
+            .history_metadata_ref()
             .get(p.as_path())
-            .map(|e| e.need_update())
-            .unwrap_or(true);
+            .map(|m| m.is_loading())
+            .unwrap_or(true)
+            && tab
+                .history_ref()
+                .get(p.as_path())
+                .map(|e| e.need_update())
+                .unwrap_or(true);
 
         if need_to_load {
             preview_dir::Background::load_preview(context, p);
diff --git a/src/preview/preview_dir.rs b/src/preview/preview_dir.rs
index cf592a9..ab0931b 100644
--- a/src/preview/preview_dir.rs
+++ b/src/preview/preview_dir.rs
@@ -4,6 +4,7 @@ use std::thread;
 use crate::context::AppContext;
 use crate::event::AppEvent;
 use crate::fs::JoshutoDirList;
+use crate::preview::preview_default::PreviewState;
 
 pub struct Background {}
 
@@ -16,11 +17,24 @@ impl Background {
             .curr_tab_ref()
             .option_ref()
             .clone();
+        let tab_id = context.tab_context_ref().curr_tab_id();
+
+        // add to loading state
+        context
+            .tab_context_mut()
+            .curr_tab_mut()
+            .history_metadata_mut()
+            .insert(p.clone(), PreviewState::Loading);
 
         thread::spawn(move || {
-            if let Ok(dirlist) = JoshutoDirList::from_path(p, &options, &tab_options) {
-                let _ = event_tx.send(AppEvent::PreviewDir(Ok(Box::new(dirlist))));
-            }
+            let path_clone = p.clone();
+            let dir_res = JoshutoDirList::from_path(p, &options, &tab_options);
+            let res = AppEvent::PreviewDir {
+                id: tab_id,
+                path: path_clone,
+                res: Box::new(dir_res),
+            };
+            let _ = event_tx.send(res);
         })
     }
 }