Implement table scroll down/up

src/event.rs

@@ -89,6 +89,8 @@ pub enum UserEvent {
     GoToRight,
     PageDown,
     PageUp,
+    ScrollDown,
+    ScrollUp,
     Confirm,
     Close,
     QuickFilter,
@@ -130,6 +132,8 @@ impl UserEventMapper {
             (KeyEvent::new(KeyCode::Right, KeyModifiers::NONE), UserEvent::Right),
             (KeyEvent::new(KeyCode::Char('h'), KeyModifiers::NONE), UserEvent::Left),
             (KeyEvent::new(KeyCode::Left, KeyModifiers::NONE), UserEvent::Left),
+            (KeyEvent::new(KeyCode::Char('e'), KeyModifiers::CONTROL), UserEvent::ScrollDown),
+            (KeyEvent::new(KeyCode::Char('y'), KeyModifiers::CONTROL), UserEvent::ScrollUp),
             (KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE), UserEvent::Confirm),
             (KeyEvent::new(KeyCode::Backspace, KeyModifiers::NONE), UserEvent::Close),
             (KeyEvent::new(KeyCode::Char('h'), KeyModifiers::CONTROL), UserEvent::Close),

src/view/table.rs

@@ -207,6 +207,14 @@ impl TableView {
                     self.table_state.select_prev_col();
                     self.table_state.update_table_state();
                 }
+                UserEvent::ScrollDown => {
+                    self.table_state.scroll_down();
+                    self.table_state.update_table_state();
+                }
+                UserEvent::ScrollUp => {
+                    self.table_state.scroll_up();
+                    self.table_state.update_table_state();
+                }
                 UserEvent::QuickFilter => {
                     self.start_filtering();
                 }
@@ -314,6 +322,8 @@ fn build_helps(
         BuildHelpsItem::new(UserEvent::GoToBottom, "Select last row"),
         BuildHelpsItem::new(UserEvent::GoToLeft, "Select first column"),
         BuildHelpsItem::new(UserEvent::GoToRight, "Select last column"),
+        BuildHelpsItem::new(UserEvent::ScrollDown, "Scroll down"),
+        BuildHelpsItem::new(UserEvent::ScrollUp, "Scroll up"),
         BuildHelpsItem::new(UserEvent::Confirm, "Open selected item"),
         BuildHelpsItem::new(UserEvent::QuickFilter, "Filter items"),
         BuildHelpsItem::new(UserEvent::Expand, "Expand selected attribute"),
@@ -337,6 +347,8 @@ fn build_helps(
         BuildHelpsItem::new(UserEvent::GoToBottom, "Select last row"),
         BuildHelpsItem::new(UserEvent::GoToLeft, "Select first column"),
         BuildHelpsItem::new(UserEvent::GoToRight, "Select last column"),
+        BuildHelpsItem::new(UserEvent::ScrollDown, "Scroll down"),
+        BuildHelpsItem::new(UserEvent::ScrollUp, "Scroll up"),
         BuildHelpsItem::new(UserEvent::Confirm, "Open selected item"),
         BuildHelpsItem::new(UserEvent::Reset, "Clear filter"),
         BuildHelpsItem::new(UserEvent::Expand, "Expand selected attribute"),
@@ -384,6 +396,7 @@ fn build_short_helps(
         BuildShortHelpsItem::group(vec![UserEvent::Down, UserEvent::Up], "Select row", 6),
         BuildShortHelpsItem::group(vec![UserEvent::Left, UserEvent::Right], "Select col", 7),
         BuildShortHelpsItem::group(vec![UserEvent::GoToTop, UserEvent::GoToBottom], "Top/Bottom", 11),
+        BuildShortHelpsItem::group(vec![UserEvent::ScrollDown, UserEvent::ScrollUp], "Scroll", 12),
         BuildShortHelpsItem::single(UserEvent::Confirm, "Open", 2),
         BuildShortHelpsItem::single(UserEvent::QuickFilter, "Filter", 5),
         BuildShortHelpsItem::single(UserEvent::Expand, "Expand", 4),
@@ -400,6 +413,7 @@ fn build_short_helps(
         BuildShortHelpsItem::group(vec![UserEvent::Down, UserEvent::Up], "Select row", 6),
         BuildShortHelpsItem::group(vec![UserEvent::Left, UserEvent::Right], "Select col", 7),
         BuildShortHelpsItem::group(vec![UserEvent::GoToTop, UserEvent::GoToBottom], "Top/Bottom", 11),
+        BuildShortHelpsItem::group(vec![UserEvent::ScrollDown, UserEvent::ScrollUp], "Scroll", 12),
         BuildShortHelpsItem::single(UserEvent::Confirm, "Open", 2),
         BuildShortHelpsItem::single(UserEvent::Reset, "Clear filter", 5),
         BuildShortHelpsItem::single(UserEvent::Expand, "Expand", 4),

src/widget/table.rs

@@ -220,6 +220,30 @@ impl TableState {
         self.offset_col = self.total_cols - count;
     }
 
+    pub fn scroll_down(&mut self) {
+        if self.total_rows == 0 {
+            return;
+        }
+        if self.offset_row + self.height < self.total_rows {
+            self.offset_row += 1;
+            if self.selected_row < self.offset_row {
+                self.selected_row = self.offset_row;
+            }
+        }
+    }
+
+    pub fn scroll_up(&mut self) {
+        if self.total_rows == 0 {
+            return;
+        }
+        if self.offset_row > 0 {
+            self.offset_row -= 1;
+            if self.selected_row - self.offset_row >= self.height {
+                self.selected_row = self.offset_row + self.height - 1;
+            }
+        }
+    }
+
     pub fn select_index(&mut self, index: usize, offset_index: usize) {
         if index >= self.total_rows {
             return;