make mousewheel scroll instead of change selection

src/ui/mod.rs

@@ -86,8 +86,8 @@ fn handle_events(page: UiPage, ui_state: &UiState) -> io::Result<Option<UiEvent>
             }
             Event::Mouse(mouse) => {
                 return Ok(match mouse.kind {
-                    MouseEventKind::ScrollUp => Some(UiEvent::Up(1, false)),
+                    MouseEventKind::ScrollUp => Some(UiEvent::Scroll(-1)),
-                    MouseEventKind::ScrollDown => Some(UiEvent::Down(1, false)),
+                    MouseEventKind::ScrollDown => Some(UiEvent::Scroll(1)),
                     MouseEventKind::Down(MouseButton::Left) => {
                         find_hit_row(mouse.row, ui_state).map(UiEvent::Enter)
                     }

src/ui/state.rs

@@ -259,6 +259,12 @@ impl<'a> UiState<'a> {
                 }
                 (true, state)
             }
+            (mut state, UiEvent::Scroll(step)) => {
+                if let Some(table_state) = state.table_state_mut() {
+                    table_state.scroll(step);
+                }
+                (true, state)
+            }
             (mut state, UiEvent::SelectAt(selected)) => {
                 if let Some(table_state) = state.table_state_mut() {
                     table_state.select(selected);
@@ -333,6 +339,7 @@ pub enum UiEvent {
     Back,
     Up(usize, bool),
     Down(usize, bool),
+    Scroll(isize),
     Errors,
     Select,
     #[allow(dead_code)]

src/ui/table.rs

@@ -100,6 +100,13 @@ impl ScrollbarTableState {
         after
     }
 
+    pub fn scroll(&mut self, step: isize) {
+        *self.table.offset_mut() = self.table.offset().saturating_add_signed(step);
+        let selected = self.selected().saturating_add_signed(step).min(self.count - 1);
+        self.table.select(Some(selected));
+        self.scrollbar = self.scrollbar.position(selected);
+    }
+
     pub fn select(&mut self, selected: usize) {
         self.table.select(Some(selected));
         self.scrollbar = self.scrollbar.position(selected);