fix(plugins): respect cwd and start filepicker at filesystem root (#3161)

* allow padding cwd to plugins

* improve strider performance and fix alias cwd issue

* style(fmt): rustfmt

3 files changed, 39 insertions, 21 deletions

diff --git a/default-plugins/fixture-plugin-for-tests/src/main.rs b/default-plugins/fixture-plugin-for-tests/src/main.rs
index fe740f74..0da45a2f 100644
--- a/default-plugins/fixture-plugin-for-tests/src/main.rs
+++ b/default-plugins/fixture-plugin-for-tests/src/main.rs
@@ -1,5 +1,6 @@
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeMap;
+use std::io::prelude::*;
 use zellij_tile::prelude::*;
 
 // This is a fixture plugin used only for tests in Zellij
@@ -300,6 +301,10 @@ impl ZellijPlugin for State {
                         LayoutInfo::BuiltIn("compact".to_owned()),
                     );
                 },
+                Key::Ctrl('8') => {
+                    let mut file = std::fs::File::create("/host/hi-from-plugin.txt").unwrap();
+                    file.write_all(b"Hi there!").unwrap();
+                },
                 _ => {},
             },
             Event::CustomMessage(message, payload) => {
diff --git a/default-plugins/strider/src/main.rs b/default-plugins/strider/src/main.rs
index 2e06240a..1ad2e70c 100644
--- a/default-plugins/strider/src/main.rs
+++ b/default-plugins/strider/src/main.rs
@@ -43,6 +43,9 @@ impl ZellijPlugin for State {
                 Key::Down | Key::Char('j') => {
                     let currently_selected = self.selected();
                     let next = self.selected().saturating_add(1);
+                    if next >= self.files.len() {
+                        refresh_directory(self);
+                    }
                     *self.selected_mut() = min(self.files.len().saturating_sub(1), next);
                     if currently_selected != self.selected() {
                         should_render = true;
@@ -76,6 +79,9 @@ impl ZellijPlugin for State {
                 Mouse::ScrollDown(_) => {
                     let currently_selected = self.selected();
                     let next = self.selected().saturating_add(1);
+                    if next >= self.files.len() {
+                        refresh_directory(self);
+                    }
                     *self.selected_mut() = min(self.files.len().saturating_sub(1), next);
                     if currently_selected != self.selected() {
                         should_render = true;
@@ -121,6 +127,7 @@ impl ZellijPlugin for State {
     }
 
     fn render(&mut self, rows: usize, cols: usize) {
+        self.current_rows = Some(rows);
         for i in 0..rows {
             if self.selected() < self.scroll() {
                 *self.scroll_mut() = self.selected();
diff --git a/default-plugins/strider/src/state.rs b/default-plugins/strider/src/state.rs
index be4ede4b..230e92ea 100644
--- a/default-plugins/strider/src/state.rs
+++ b/default-plugins/strider/src/state.rs
@@ -19,6 +19,7 @@ pub struct State {
     pub loading: bool,
     pub loading_animation_offset: u8,
     pub should_open_floating: bool,
+    pub current_rows: Option<usize>,
 }
 
 impl State {
@@ -40,7 +41,7 @@ impl State {
     pub fn traverse_dir_or_open_file(&mut self) {
         if let Some(f) = self.files.get(self.selected()) {
             match f.clone() {
-                FsEntry::Dir(p, _) => {
+                FsEntry::Dir(p) => {
                     self.path = p;
                     refresh_directory(self);
                 },
@@ -55,14 +56,14 @@ impl State {
 
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone)]
 pub enum FsEntry {
-    Dir(PathBuf, usize),
+    Dir(PathBuf),
     File(PathBuf, u64),
 }
 
 impl FsEntry {
     pub fn name(&self) -> String {
         let path = match self {
-            FsEntry::Dir(p, _) => p,
+            FsEntry::Dir(p) => p,
             FsEntry::File(p, _) => p,
         };
         path.file_name().unwrap().to_string_lossy().into_owned()
@@ -70,7 +71,7 @@ impl FsEntry {
 
     pub fn as_line(&self, width: usize) -> String {
         let info = match self {
-            FsEntry::Dir(_, s) => s.to_string(),
+            FsEntry::Dir(_s) => "".to_owned(),
             FsEntry::File(_, s) => pb::convert(*s as f64),
         };
         let space = width.saturating_sub(info.len());
@@ -89,22 +90,27 @@ impl FsEntry {
 }
 
 pub(crate) fn refresh_directory(state: &mut State) {
-    state.files = read_dir(Path::new(ROOT).join(&state.path))
-        .unwrap()
-        .filter_map(|res| {
-            res.and_then(|d| {
-                if d.metadata()?.is_dir() {
-                    let children = read_dir(d.path())?.count();
-                    Ok(FsEntry::Dir(d.path(), children))
-                } else {
-                    let size = d.metadata()?.len();
-                    Ok(FsEntry::File(d.path(), size))
-                }
-            })
-            .ok()
-            .filter(|d| !d.is_hidden_file() || !state.hide_hidden_files)
-        })
-        .collect();
-
+    // TODO: might be good to do this asynchronously with a worker
+    let mut max_lines = (state.current_rows.unwrap_or(50) + state.scroll()) * 2; // 100 is arbitrary for performance reasons
+    let mut files = vec![];
+    for entry in read_dir(Path::new(ROOT).join(&state.path)).unwrap() {
+        if let Ok(entry) = entry {
+            if max_lines == 0 {
+                break;
+            }
+            let entry_metadata = entry.metadata().unwrap();
+            let entry = if entry_metadata.is_dir() {
+                FsEntry::Dir(entry.path())
+            } else {
+                let size = entry_metadata.len();
+                FsEntry::File(entry.path(), size)
+            };
+            if !entry.is_hidden_file() || !state.hide_hidden_files {
+                max_lines = max_lines.saturating_sub(1);
+                files.push(entry);
+            }
+        }
+    }
+    state.files = files;
     state.files.sort_unstable();
 }