fix tree window while moving up down

1 files changed, 6 insertions, 6 deletions

diff --git a/src/preview.rs b/src/preview.rs
index da56708..e0554ba 100644
--- a/src/preview.rs
+++ b/src/preview.rs
@@ -644,19 +644,19 @@ impl Directory {
     /// is selected and the size of the window used to display.
     pub fn calculate_tree_window(&self, height: usize) -> (usize, usize, usize) {
         let length = self.content.len();
-        let mut top = if self.selected_index < height {
+        let mut top = if self.selected_index < height - 1 {
             0
         } else {
-            self.selected_index
+            self.selected_index - 1
         };
-        let mut bottom = if self.selected_index < height {
-            height
+        let mut bottom = if self.selected_index < height - 1 {
+            height - 1
         } else {
-            self.selected_index + height
+            self.selected_index + height - 1
         };
 
         let padding = std::cmp::max(10, height / 2);
-        if self.selected_index > height {
+        if self.selected_index >= height - 1 {
             top -= padding;
             bottom += padding;
         }