Add support for page up and page down

src/command_bar.rs

@@ -342,6 +342,14 @@ impl CommandBar {
                 self.update_command_list();
                 self.history_index = None;
             }
+            KeyCode::PageUp if key.modifiers == KeyModifiers::CONTROL => {
+                self.text_view.lock().await.scroll_to_start();
+            }
+            KeyCode::PageUp => self.text_view.lock().await.page_up(),
+            KeyCode::PageDown if key.modifiers == KeyModifiers::CONTROL => {
+                self.text_view.lock().await.scroll_to_end();
+            }
+            KeyCode::PageDown => self.text_view.lock().await.page_down(),
             KeyCode::Backspace => {
                 if self.command_line.chars().count() == 1 {
                     self.show_hint();

src/text.rs

@@ -160,6 +160,47 @@ impl TextView {
         }
     }
 
+    pub fn page_up(&mut self) {
+        if self.max_main_axis() > 0 {
+            self.auto_scroll = false;
+        }
+
+        let page_height = self.frame_height - 5;
+
+        if self.scroll.0 < page_height {
+            self.scroll.0 = 0;
+        } else {
+            self.scroll.0 -= page_height;
+        }
+    }
+
+    pub fn page_down(&mut self) {
+        let max_main_axis = self.max_main_axis();
+        let page_height = self.frame_height - 5;
+
+        self.scroll.0 += page_height;
+        self.scroll.0 = self.scroll.0.clamp(0, max_main_axis);
+
+        if self.scroll.0 == max_main_axis {
+            self.auto_scroll = true;
+        }
+    }
+
+    pub fn scroll_to_start(&mut self) {
+        if self.max_main_axis() > 0 {
+            self.auto_scroll = false;
+        }
+
+        self.scroll.0 = 0;
+    }
+
+    pub fn scroll_to_end(&mut self) {
+        let max_main_axis = self.max_main_axis();
+
+        self.scroll.0 = max_main_axis;
+        self.auto_scroll = true;
+    }
+
     pub fn left_scroll(&mut self) {
         if self.scroll.1 < 3 {
             self.scroll.1 = 0;