major refactoring

- completely remove preview_list and all references
  - instead use preview.rs to grab struct from hashmap at runtime
  - this allows for file previews to be implemented easier and more seamlessly
- add JoshutoPageState struct for scrolling
  - previously cursor would stick at position 6 and won't move until reaching the top or bottom of dirlisting
  - now they stick to the current page and only move when they hit the threshold provided in settings

14 files changed, 255 insertions, 249 deletions

diff --git a/src/joshuto.rs b/src/joshuto.rs
index 2e44735..17ae3e2 100644
--- a/src/joshuto.rs
+++ b/src/joshuto.rs
@@ -13,6 +13,7 @@ pub mod config;
 mod command;
 mod history;
 mod input;
+mod preview;
 mod sort;
 mod structs;
 mod ui;
@@ -27,7 +28,6 @@ pub struct JoshutoTab {
     pub curr_path: path::PathBuf,
     pub parent_list: Option<structs::JoshutoDirList>,
     pub curr_list: Option<structs::JoshutoDirList>,
-    pub preview_list: Option<structs::JoshutoDirList>,
 }
 
 impl JoshutoTab {
@@ -38,7 +38,7 @@ impl JoshutoTab {
         history.populate_to_root(&curr_path, sort_type);
 
         /* load up directories */
-        let curr_view: Option<structs::JoshutoDirList> =
+        let curr_list: Option<structs::JoshutoDirList> =
             match history.pop_or_create(&curr_path, sort_type) {
                 Ok(s) => { Some(s) },
                 Err(e) => {
@@ -47,7 +47,7 @@ impl JoshutoTab {
                 },
             };
 
-        let parent_view: Option<structs::JoshutoDirList> =
+        let parent_list: Option<structs::JoshutoDirList> =
             match curr_path.parent() {
                 Some(parent) => {
                     match history.pop_or_create(&parent, sort_type) {
@@ -61,33 +61,11 @@ impl JoshutoTab {
                 None => { None },
             };
 
-        let preview_view: Option<structs::JoshutoDirList>;
-        if let Some(s) = curr_view.as_ref() {
-            match s.get_curr_entry() {
-                Some(dirent) => {
-                    if dirent.path.is_dir() {
-                        preview_view = match history.pop_or_create(&dirent.path, sort_type) {
-                            Ok(s) => Some(s),
-                            Err(_) => None,
-                        };
-                    } else {
-                        preview_view = None;
-                    }
-                },
-                None => {
-                    preview_view = None;
-                }
-            }
-        } else {
-            preview_view = None
-        }
-
         JoshutoTab {
                 curr_path,
                 history,
-                curr_list: curr_view,
-                parent_list: parent_view,
-                preview_list: preview_view,
+                curr_list,
+                parent_list,
             }
     }
 }
@@ -158,18 +136,6 @@ impl<'a> JoshutoContext<'a> {
         if gone {
             self.tabs[self.tab_index].parent_list = None;
         }
-
-        let mut gone = false;
-        if let Some(s) = self.tabs[self.tab_index].preview_list.as_mut() {
-            if !s.path.exists() {
-                gone = true;
-            } else if s.need_update() {
-                s.update(&self.config_t.sort_type);
-            }
-        }
-        if gone {
-            self.tabs[self.tab_index].preview_list = None;
-        }
     }
 }
 
@@ -223,7 +189,7 @@ pub fn resize_handler(context: &mut JoshutoContext)
 {
     context.views.redraw_views();
     ncurses::refresh();
-    ui::refresh(&context);
+    ui::refresh(context);
     ui::redraw_tab_view(&context.views.tab_win, &context);
     ncurses::doupdate();
 }
@@ -234,12 +200,13 @@ pub fn run(mut config_t: config::JoshutoConfig,
     theme_t: config::JoshutoTheme)
 {
     ui::init_ncurses(&theme_t);
-
     ncurses::doupdate();
 
     let mut context = JoshutoContext::new(&mut config_t, &mimetype_t, &theme_t);
-
     command::NewTab::new_tab(&mut context);
+    preview::preview_file(&mut context);
+    ui::refresh(&mut context);
+    ncurses::doupdate();
 
     let wait_duration: time::Duration = time::Duration::from_millis(100);
 
diff --git a/src/joshuto/command/change_directory.rs b/src/joshuto/command/change_directory.rs
index 14bd192..ec3be8e 100644
--- a/src/joshuto/command/change_directory.rs
+++ b/src/joshuto/command/change_directory.rs
@@ -62,28 +62,11 @@ impl command::Runnable for ChangeDirectory {
 
             let curr_list = curr_tab.curr_list.take();
             curr_tab.history.put_back(curr_list);
-
-            let preview_list = curr_tab.preview_list.take();
-            curr_tab.history.put_back(preview_list);
         }
 
         curr_tab.curr_list = match curr_tab.history.pop_or_create(&curr_tab.curr_path,
                     &context.config_t.sort_type) {
             Ok(s) => {
-                if let Some(dirent) = s.get_curr_entry() {
-                    if dirent.path.is_dir() {
-                        curr_tab.preview_list = match curr_tab.history.pop_or_create(
-                                    &dirent.path, &context.config_t.sort_type) {
-                            Ok(s) => {
-                                Some(s)
-                            },
-                            Err(e) => {
-                                eprintln!("{}", e);
-                                None
-                            },
-                        };
-                    }
-                }
                 Some(s)
             },
             Err(e) => {
@@ -102,12 +85,10 @@ impl command::Runnable for ChangeDirectory {
             };
         }
 
-        ui::redraw_view(&context.theme_t, &context.views.left_win,
-                curr_tab.parent_list.as_ref());
-        ui::redraw_view_detailed(&context.theme_t, &context.views.mid_win,
-                curr_tab.curr_list.as_ref());
-        ui::redraw_view(&context.theme_t, &context.views.right_win,
-                curr_tab.preview_list.as_ref());
+        ui::redraw_view(&context.config_t, &context.theme_t,
+                &context.views.left_win, curr_tab.parent_list.as_mut());
+        ui::redraw_view_detailed(&context.config_t, &context.theme_t,
+                &context.views.mid_win, curr_tab.curr_list.as_mut());
 
         ui::redraw_status(&context.theme_t, &context.views,
                 curr_tab.curr_list.as_ref(),
diff --git a/src/joshuto/command/cursor_move.rs b/src/joshuto/command/cursor_move.rs
index f8496ee..775ac28 100644
--- a/src/joshuto/command/cursor_move.rs
+++ b/src/joshuto/command/cursor_move.rs
@@ -6,8 +6,8 @@ use std::fmt;
 
 use joshuto;
 use joshuto::ui;
-
 use joshuto::command;
+use joshuto::preview;
 
 #[derive(Clone, Debug)]
 pub struct CursorMove {
@@ -25,62 +25,42 @@ impl CursorMove {
 
     pub fn cursor_move(new_index: i32, context: &mut joshuto::JoshutoContext)
     {
-        let curr_tab = &mut context.tabs[context.tab_index];
-
-        if let Some(ref mut curr_list) = curr_tab.curr_list {
-            let curr_index = curr_list.index;
-            let dir_len = curr_list.contents.len() as i32;
+        {
+            let curr_tab = &mut context.tabs[context.tab_index];
 
-            let mut new_index = new_index;
-            if new_index <= 0 {
-                new_index = 0;
-                if curr_index <= 0 {
-                    return;
-                }
-            } else if new_index >= dir_len {
-                new_index = dir_len - 1;
-                if curr_index == dir_len - 1 {
-                    return;
+            if let Some(ref mut curr_list) = curr_tab.curr_list {
+                let curr_index = curr_list.index;
+                let dir_len = curr_list.contents.len() as i32;
+
+                let mut new_index = new_index;
+                if new_index <= 0 {
+                    new_index = 0;
+                    if curr_index <= 0 {
+                        return;
+                    }
+                } else if new_index >= dir_len {
+                    new_index = dir_len - 1;
+                    if curr_index == dir_len - 1 {
+                        return;
+                    }
                 }
-            }
 
-            let dir_list = curr_tab.preview_list.take();
-            if let Some(s) = dir_list {
-                curr_tab.history.insert(s);
+                curr_list.index = new_index;
             }
 
-            curr_list.index = new_index;
-        }
-
-        if let Some(ref curr_list) = curr_tab.curr_list {
-            let curr_index = curr_list.index as usize;
-            let new_path = &curr_list.contents[curr_index].path;
-
-            ui::display_contents(&context.theme_t, &context.views.mid_win, curr_list);
-            ncurses::wnoutrefresh(context.views.mid_win.win);
-
-            if new_path.is_dir() {
-                match curr_tab.history.pop_or_create(new_path.as_path(),
-                        &context.config_t.sort_type) {
-                    Ok(s) => {
-                        curr_tab.preview_list = Some(s);
-                        ui::redraw_view(&context.theme_t, &context.views.right_win,
-                                curr_tab.preview_list.as_ref());
-                    },
-                    Err(e) => ui::wprint_err(&context.views.right_win, e.to_string().as_str()),
-                }
-            } else {
-                ncurses::werase(context.views.right_win.win);
-                ncurses::wnoutrefresh(context.views.right_win.win);
+            if let Some(ref mut curr_list) = curr_tab.curr_list {
+                ui::display_contents(&context.config_t, &context.theme_t, &context.views.mid_win, curr_list);
             }
-
             ui::redraw_status(&context.theme_t, &context.views,
                     curr_tab.curr_list.as_ref(),
                     &curr_tab.curr_path,
                     &context.username, &context.hostname);
 
-            ncurses::doupdate();
+            ncurses::wnoutrefresh(context.views.mid_win.win);
         }
+
+        preview::preview_file(context);
+        ncurses::doupdate();
     }
 }
 
diff --git a/src/joshuto/command/file_operation.rs b/src/joshuto/command/file_operation.rs
index d6b3ef8..27477df 100644
--- a/src/joshuto/command/file_operation.rs
+++ b/src/joshuto/command/file_operation.rs
@@ -215,7 +215,6 @@ impl PasteFiles {
             }
             0
         });
-
         (rx, child)
     }
 }
@@ -239,18 +238,20 @@ impl std::fmt::Debug for PasteFiles {
 impl command::Runnable for PasteFiles {
     fn execute(&self, context: &mut joshuto::JoshutoContext)
     {
-        let file_operation = fileop.lock().unwrap();
+        {
+            let file_operation = fileop.lock().unwrap();
 
-        let curr_tab = &context.tabs[context.tab_index];
-        let cprocess = match *file_operation {
-                FileOp::Copy => self.copy(&curr_tab.curr_path),
-                FileOp::Cut => self.cut(&curr_tab.curr_path),
-            };
-        context.threads.push(cprocess);
+            let curr_tab = &context.tabs[context.tab_index];
+            let cprocess = match *file_operation {
+                    FileOp::Copy => self.copy(&curr_tab.curr_path),
+                    FileOp::Cut => self.cut(&curr_tab.curr_path),
+                };
+            context.threads.push(cprocess);
+        }
 
         ncurses::timeout(0);
 
-        ui::refresh(&context);
+        ui::refresh(context);
 
         ncurses::doupdate();
     }
@@ -304,13 +305,11 @@ impl command::Runnable for DeleteFiles {
 
             ui::wprint_msg(&context.views.bot_win, "Deleted files");
 
-            let curr_tab = &context.tabs[context.tab_index];
-            ui::redraw_view(&context.theme_t, &context.views.left_win,
-                    curr_tab.parent_list.as_ref());
-            ui::redraw_view_detailed(&context.theme_t, &context.views.mid_win,
-                    curr_tab.curr_list.as_ref());
-            ui::redraw_view(&context.theme_t, &context.views.right_win,
-                    curr_tab.preview_list.as_ref());
+            let curr_tab = &mut context.tabs[context.tab_index];
+            ui::redraw_view(&context.config_t, &context.theme_t,
+                    &context.views.left_win, curr_tab.parent_list.as_mut());
+            ui::redraw_view_detailed(&context.config_t, &context.theme_t,
+                    &context.views.mid_win, curr_tab.curr_list.as_mut());
         } else {
             let curr_tab = &context.tabs[context.tab_index];
             ui::redraw_status(&context.theme_t, &context.views,
@@ -373,7 +372,7 @@ impl RenameFile {
                 match fs::rename(&path, &new_path) {
                     Ok(_) => {
                         context.reload_dirlists();
-                        ui::refresh(&context);
+                        ui::refresh(context);
                     },
                     Err(e) => {
                         ui::wprint_err(&context.views.bot_win, e.to_string().as_str());
diff --git a/src/joshuto/command/new_directory.rs b/src/joshuto/command/new_directory.rs
index 0cdd407..c3beacf 100644
--- a/src/joshuto/command/new_directory.rs
+++ b/src/joshuto/command/new_directory.rs
@@ -49,8 +49,7 @@ impl command::Runnable for NewDirectory {
 
             match std::fs::create_dir_all(&path) {
                 Ok(_) => {
-                    context.reload_dirlists();
-                    ui::refresh(&context);
+                    command::ReloadDirList::reload(context);
                 },
                 Err(e) => {
                     ui::wprint_err(&context.views.bot_win, e.to_string().as_str());
diff --git a/src/joshuto/command/open_file.rs b/src/joshuto/command/open_file.rs
index 27b5cf5..dd05756 100644
--- a/src/joshuto/command/open_file.rs
+++ b/src/joshuto/command/open_file.rs
@@ -11,7 +11,7 @@ use joshuto;
 use joshuto::command;
 use joshuto::input;
 use joshuto::config::mimetype;
-use joshuto::structs;
+use joshuto::preview;
 use joshuto::ui;
 use joshuto::unix;
 use joshuto::window;
@@ -56,6 +56,8 @@ impl OpenFile {
 
         } else if paths[0].is_dir() {
             Self::into_directory(&paths[0], context);
+            preview::preview_file(context);
+            ncurses::doupdate();
         }
     }
 
@@ -72,16 +74,21 @@ impl OpenFile {
         }
 
         {
-            let dir_list = curr_tab.parent_list.take();
-            curr_tab.history.put_back(dir_list);
+            let parent_list = curr_tab.parent_list.take();
+            curr_tab.history.put_back(parent_list);
 
             let curr_list = curr_tab.curr_list.take();
             curr_tab.parent_list = curr_list;
-
-            let preview_list = curr_tab.preview_list.take();
-            curr_tab.curr_list = preview_list;
         }
 
+        curr_tab.curr_list = match curr_tab.history.pop_or_create(&path, &context.config_t.sort_type) {
+                Ok(s) => Some(s),
+                Err(e) => {
+                    ui::wprint_err(&context.views.left_win, e.to_string().as_str());
+                    None
+                },
+            };
+
         /* update curr_path */
         match path.strip_prefix(curr_tab.curr_path.as_path()) {
             Ok(s) => curr_tab.curr_path.push(s),
@@ -91,40 +98,15 @@ impl OpenFile {
             }
         }
 
-        if let Some(s) = curr_tab.curr_list.as_ref() {
-            if s.contents.len() > 0 {
-                let dirent: &structs::JoshutoDirEntry = &s.contents[s.index as usize];
-                let new_path: path::PathBuf = dirent.path.clone();
-
-                if new_path.is_dir() {
-                    curr_tab.preview_list = match curr_tab.history.pop_or_create(
-                                new_path.as_path(), &context.config_t.sort_type) {
-                        Ok(s) => { Some(s) },
-                        Err(e) => {
-                            ui::wprint_err(&context.views.right_win,
-                                    e.to_string().as_str());
-                            None
-                        },
-                    };
-                } else {
-                    ncurses::werase(context.views.right_win.win);
-                }
-            }
-        }
-
-        ui::redraw_view(&context.theme_t, &context.views.left_win,
-                curr_tab.parent_list.as_ref());
-        ui::redraw_view_detailed(&context.theme_t, &context.views.mid_win,
-                curr_tab.curr_list.as_ref());
-        ui::redraw_view(&context.theme_t, &context.views.right_win,
-                curr_tab.preview_list.as_ref());
+        ui::redraw_view(&context.config_t, &context.theme_t,
+                &context.views.left_win, curr_tab.parent_list.as_mut());
+        ui::redraw_view_detailed(&context.config_t, &context.theme_t,
+                &context.views.mid_win, curr_tab.curr_list.as_mut());
 
         ui::redraw_status(&context.theme_t, &context.views,
                 curr_tab.curr_list.as_ref(),
                 &curr_tab.curr_path,
                 &context.username, &context.hostname);
-
-        ncurses::doupdate();
     }
 }
 
diff --git a/src/joshuto/command/parent_directory.rs b/src/joshuto/command/parent_directory.rs
index c11eac7..912394f 100644
--- a/src/joshuto/command/parent_directory.rs
+++ b/src/joshuto/command/parent_directory.rs
@@ -6,8 +6,9 @@ use std;
 use std::fmt;
 
 use joshuto;
-use joshuto::ui;
 use joshuto::command;
+use joshuto::preview;
+use joshuto::ui;
 
 #[derive(Clone, Debug)]
 pub struct ParentDirectory;
@@ -15,35 +16,19 @@ pub struct ParentDirectory;
 impl ParentDirectory {
     pub fn new() -> Self { ParentDirectory }
     pub fn command() -> &'static str { "parent_directory" }
-}
-
-impl command::JoshutoCommand for ParentDirectory {}
 
-impl std::fmt::Display for ParentDirectory {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result
+    pub fn parent_directory(context: &mut joshuto::JoshutoContext) -> bool
     {
-        f.write_str(Self::command())
-    }
-}
-
-impl command::Runnable for ParentDirectory {
-    fn execute(&self, context: &mut joshuto::JoshutoContext)
-    {
-
         let curr_tab = &mut context.tabs[context.tab_index];
-
         if curr_tab.curr_path.pop() == false {
-            return;
+            return false;
         }
 
         match std::env::set_current_dir(&curr_tab.curr_path) {
             Ok(_) => {
                 {
-                    let dir_list = curr_tab.preview_list.take();
-                    curr_tab.history.put_back(dir_list);
-
                     let curr_list = curr_tab.curr_list.take();
-                    curr_tab.preview_list = curr_list;
+                    curr_tab.history.put_back(curr_list);
 
                     let parent_list = curr_tab.parent_list.take();
                     curr_tab.curr_list = parent_list;
@@ -65,22 +50,41 @@ impl command::Runnable for ParentDirectory {
                     },
                 }
 
-                ui::redraw_view(&context.theme_t, &context.views.left_win,
-                        curr_tab.parent_list.as_ref());
-                ui::redraw_view_detailed(&context.theme_t, &context.views.mid_win,
-                        curr_tab.curr_list.as_ref());
-                ui::redraw_view(&context.theme_t, &context.views.right_win,
-                        curr_tab.preview_list.as_ref());
+                ui::redraw_view(&context.config_t, &context.theme_t,
+                        &context.views.left_win, curr_tab.parent_list.as_mut());
+                ui::redraw_view_detailed(&context.config_t, &context.theme_t,
+                        &context.views.mid_win, curr_tab.curr_list.as_mut());
 
                 ui::redraw_status(&context.theme_t, &context.views,
                         curr_tab.curr_list.as_ref(),
                         &curr_tab.curr_path,
                         &context.username, &context.hostname);
+                return true;
             },
             Err(e) => {
                 ui::wprint_err(&context.views.bot_win, e.to_string().as_str());
+                return false;
             },
         };
-        ncurses::doupdate();
+
+    }
+}
+
+impl command::JoshutoCommand for ParentDirectory {}
+
+impl std::fmt::Display for ParentDirectory {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result
+    {
+        f.write_str(Self::command())
+    }
+}
+
+impl command::Runnable for ParentDirectory {
+    fn execute(&self, context: &mut joshuto::JoshutoContext)
+    {
+        if Self::parent_directory(context) {
+            preview::preview_file(context);
+            ncurses::doupdate();
+        }
     }
 }
diff --git a/src/joshuto/command/reload_dir.rs b/src/joshuto/command/reload_dir.rs
index c262359..e597e79 100644
--- a/src/joshuto/command/reload_dir.rs
+++ b/src/joshuto/command/reload_dir.rs
@@ -19,8 +19,7 @@ impl ReloadDirList {
     pub fn reload(context: &mut joshuto::JoshutoContext)
     {
         context.reload_dirlists();
-        ui::refresh(&context);
-        ncurses::doupdate();
+        ui::refresh(context);
     }
 }
 
@@ -37,5 +36,6 @@ impl command::Runnable for ReloadDirList {
     fn execute(&self, context: &mut joshuto::JoshutoContext)
     {
         Self::reload(context);
+        ncurses::doupdate();
     }
 }
diff --git a/src/joshuto/command/show_hidden.rs b/src/joshuto/command/show_hidden.rs
index 853c7b7..47944ea 100644
--- a/src/joshuto/command/show_hidden.rs
+++ b/src/joshuto/command/show_hidden.rs
@@ -38,17 +38,13 @@ impl command::Runnable for ToggleHiddenFiles {
                     s.update(&context.config_t.sort_type);
                 }
 
-                if let Some(s) = tab.preview_list.as_mut() {
-                    s.update(&context.config_t.sort_type);
-                }
-
                 if let Some(s) = tab.parent_list.as_mut() {
                     s.update(&context.config_t.sort_type);
                 }
             }
         }
 
-        ui::refresh(&context);
+        ui::refresh(context);
 
         ncurses::doupdate();
     }
diff --git a/src/joshuto/command/tab_switch.rs b/src/joshuto/command/tab_switch.rs
index 4c38fa0..577ea34 100644
--- a/src/joshuto/command/tab_switch.rs
+++ b/src/joshuto/command/tab_switch.rs
@@ -21,7 +21,7 @@ impl TabSwitch {
     pub fn tab_switch(new_index: i32, context: &mut joshuto::JoshutoContext)
     {
         context.tab_index = new_index as usize;
-        ui::refresh(&context);
+        ui::refresh(context);
         ui::redraw_tab_view(&context.views.tab_win, &context);
 
         ncurses::doupdate();
diff --git a/src/joshuto/history.rs b/src/joshuto/history.rs
index 58445ef..dbf2f68 100644
--- a/src/joshuto/history.rs
+++ b/src/joshuto/history.rs
@@ -4,6 +4,7 @@ use std::path;
 
 use joshuto::structs;
 use joshuto::sort;
+use std::collections::hash_map::Entry;
 
 pub struct DirHistory {
     map: HashMap<path::PathBuf, structs::JoshutoDirList>,
@@ -67,6 +68,34 @@ impl DirHistory {
         }
     }
 
+    pub fn get_mut_or_create(&mut self, path: &path::Path,
+       sort_type: &sort::SortType)
+            -> Option<&mut structs::JoshutoDirList>
+    {
+        let pathbuf = path.to_path_buf();
+
+        {
+            let entry = self.map.entry(pathbuf.clone());
+            match entry {
+                Entry::Occupied(mut entry) => {
+                    {
+                        let dir_entry = entry.get_mut();
+                        if dir_entry.need_update() {
+                            dir_entry.update(sort_type);
+                        }
+                    }
+                },
+                Entry::Vacant(entry) => {
+                    if let Ok(s) = structs::JoshutoDirList::new(path.clone().to_path_buf(), &sort_type) {
+                        entry.insert(s);
+                    }
+                },
+            };
+        }
+
+        self.map.get_mut(&pathbuf)
+    }
+
     pub fn put_back(&mut self, dirlist: Option<structs::JoshutoDirList>)
     {
         if let Some(s) = dirlist {
diff --git a/src/joshuto/preview.rs b/src/joshuto/preview.rs
new file mode 100644
index 0000000..5136949
--- /dev/null
+++ b/src/joshuto/preview.rs
@@ -0,0 +1,27 @@
+extern crate ncurses;
+
+use joshuto;
+use joshuto::ui;
+
+pub fn preview_file(context: &mut joshuto::JoshutoContext)
+{
+    let curr_tab = &mut context.tabs[context.tab_index];
+
+    if let Some(ref curr_list) = curr_tab.curr_list {
+        if let Some(entry) = curr_list.get_curr_entry() {
+            if entry.path.is_dir() {
+                if let Some(dirlist) = curr_tab.history.get_mut_or_create(&entry.path, &context.config_t.sort_type) {
+                    ui::display_contents(&context.config_t, &context.theme_t, &context.views.right_win, dirlist);
+                } else {
+                    ncurses::werase(context.views.right_win.win);
+                    ncurses::waddstr(context.views.right_win.win, "Can't find direntry");
+                    ncurses::wnoutrefresh(context.views.right_win.win);
+                }
+            } else {
+                ncurses::werase(context.views.right_win.win);
+                ncurses::waddstr(context.views.right_win.win, "Not a directory");
+                ncurses::wnoutrefresh(context.views.right_win.win);
+            }
+        }
+    }
+}
diff --git a/src/joshuto/structs.rs b/src/joshuto/structs.rs
index b2da9ca..7cbbcad 100644
--- a/src/joshuto/structs.rs
+++ b/src/joshuto/structs.rs
@@ -6,7 +6,7 @@ use std::time;
 
 use joshuto::sort;
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct JoshutoMetadata {
     pub len: u64,
     pub modified: time::SystemTime,
@@ -31,7 +31,7 @@ impl JoshutoMetadata {
     }
 }
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct JoshutoDirEntry {
     pub file_name: ffi::OsString,
     pub file_name_as_string: String,
@@ -65,6 +65,57 @@ impl JoshutoDirEntry {
 
 }
 
+#[derive(Clone, Debug)]
+pub struct JoshutoPageState {
+    pub start: usize,
+    pub end: usize,
+}
+
+impl JoshutoPageState {
+    pub fn new() -> Self
+    {
+        JoshutoPageState {
+            start: 0,
+            end: 0,
+        }
+    }
+
+    pub fn update(&mut self, index: i32, win_rows: i32, vec_len: usize, offset: usize)
+    {
+        if self.start + offset < index as usize && self.end > index as usize + offset {
+            return;
+        }
+        self.end = self.start + win_rows as usize;
+
+        if win_rows as usize >= vec_len {
+            self.start = 0;
+            self.end = vec_len;
+        } else if index as i32 - self.start as i32 <= offset as i32 {
+            self.start = if index as usize <= offset {
+                    0
+                } else {
+                    index as usize - offset
+                };
+            self.end = if self.start + win_rows as usize >= vec_len {
+                    vec_len
+                } else {
+                    self.start + win_rows as usize
+                };
+        } else if self.end as i32 <= offset as i32 + index {
+            self.end = if index as usize + offset >= vec_len {
+                    vec_len
+                } else {
+                    index as usize + offset
+                };
+            self.start = if self.end < win_rows as usize {
+                    0
+                } else {
+                    self.end - win_rows as usize
+                };
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct JoshutoDirList {
     pub index: i32,
@@ -72,7 +123,8 @@ pub struct JoshutoDirList {
     pub update_needed: bool,
     pub metadata: JoshutoMetadata,
     pub contents: Vec<JoshutoDirEntry>,
-    pub selected: usize
+    pub selected: usize,
+    pub pagestate: JoshutoPageState,
 }
 
 impl JoshutoDirList {
@@ -89,6 +141,7 @@ impl JoshutoDirList {
 
         let metadata = fs::metadata(&path)?;
         let metadata = JoshutoMetadata::from(&metadata)?;
+        let pagestate = JoshutoPageState::new();
 
         Ok(JoshutoDirList {
             index,
@@ -97,6 +150,7 @@ impl JoshutoDirList {
             metadata,
             contents,
             selected: 0,
+            pagestate,
         })
     }
 
diff --git a/src/joshuto/ui.rs b/src/joshuto/ui.rs
index 52957bb..1a39d0a 100644
--- a/src/joshuto/ui.rs
+++ b/src/joshuto/ui.rs
@@ -157,7 +157,9 @@ fn wprint_file_mode(win: ncurses::WINDOW, file: &structs::JoshutoDirEntry)
 
     let mode = file.metadata.permissions.mode();
 
+    ncurses::wattron(win, ncurses::COLOR_PAIR(6));
     ncurses::waddstr(win, unix::stringify_mode(mode).as_str());
+    ncurses::wattroff(win, ncurses::COLOR_PAIR(6));
 }
 
 pub fn wprint_file_info(win: ncurses::WINDOW, file: &structs::JoshutoDirEntry)
@@ -237,20 +239,18 @@ pub fn wprint_direntry(win: &window::JoshutoPanel,
     wprint_file_name(win, file, coord);
 }
 
-pub fn refresh(context: &joshuto::JoshutoContext)
+pub fn refresh(context: &mut joshuto::JoshutoContext)
 {
     if context.tabs.len() == 0 {
         return;
     }
 
-    let curr_tab = &context.tabs[context.tab_index];
+    let curr_tab = &mut context.tabs[context.tab_index];
 
-    redraw_view(&context.theme_t, &context.views.left_win,
-            curr_tab.parent_list.as_ref());
-    redraw_view_detailed(&context.theme_t, &context.views.mid_win,
-            curr_tab.curr_list.as_ref());
-    redraw_view(&context.theme_t, &context.views.right_win,
-            curr_tab.preview_list.as_ref());
+    redraw_view(&context.config_t, &context.theme_t,
+            &context.views.left_win, curr_tab.parent_list.as_mut());
+    redraw_view_detailed(&context.config_t, &context.theme_t,
+            &context.views.mid_win, curr_tab.curr_list.as_mut());
 
     redraw_status(&context.theme_t, &context.views,
             curr_tab.curr_list.as_ref(),
@@ -258,11 +258,11 @@ pub fn refresh(context: &joshuto::JoshutoContext)
             &context.username, &context.hostname);
 }
 
-pub fn redraw_view(theme_t: &config::JoshutoTheme, win: &window::JoshutoPanel,
-        view: Option<&structs::JoshutoDirList>)
+pub fn redraw_view(config_t: &config::JoshutoConfig, theme_t: &config::JoshutoTheme, win: &window::JoshutoPanel,
+        mut view: Option<&mut structs::JoshutoDirList>)
 {
-    if let Some(s) = view {
-        display_contents(theme_t, win, s);
+    if let Some(s) = view.as_mut() {
+        display_contents(config_t, theme_t, win, s);
         ncurses::wnoutrefresh(win.win);
     } else {
         ncurses::werase(win.win);
@@ -270,11 +270,11 @@ pub fn redraw_view(theme_t: &config::JoshutoTheme, win: &window::JoshutoPanel,
     ncurses::wnoutrefresh(win.win);
 }
 
-pub fn redraw_view_detailed(theme_t: &config::JoshutoTheme, win: &window::JoshutoPanel,
-        view: Option<&structs::JoshutoDirList>)
+pub fn redraw_view_detailed(config_t: &config::JoshutoConfig, theme_t: &config::JoshutoTheme, win: &window::JoshutoPanel,
+        mut view: Option<&mut structs::JoshutoDirList>)
 {
-    if let Some(s) = view {
-        display_contents(theme_t, win, s);
+    if let Some(ref mut s) = view {
+        display_contents(config_t, theme_t, win, s);
         ncurses::wnoutrefresh(win.win);
     } else {
         ncurses::werase(win.win);
@@ -333,44 +333,32 @@ pub fn draw_loading_bar(theme_t: &config::JoshutoTheme,
             theme_t.selection.colorpair);
 }
 
-pub fn display_contents(theme_t: &config::JoshutoTheme,
-        win: &window::JoshutoPanel,
-        entry: &structs::JoshutoDirList) {
-    use std::os::unix::fs::PermissionsExt;
-
-    ncurses::werase(win.win);
-    if win.cols <= 6 {
-        return;
-    }
-
-    let index = entry.index as usize;
-    let dir_contents = &entry.contents;
-    let vec_len = dir_contents.len();
+pub fn display_contents(config_t: &config::Joshut