Almost kinda functional description box

src/app/models.rs

@@ -0,0 +1,107 @@
+use tui::widgets::TableState;
+
+pub trait Scrollable {
+  fn scroll_down(&mut self);
+  fn scroll_up(&mut self);
+}
+
+pub struct StatefulTable<T> {
+  pub state: TableState,
+  pub items: Vec<T>,
+}
+
+impl<T> Default for StatefulTable<T> {
+  fn default() -> StatefulTable<T> {
+    StatefulTable {
+      state: TableState::default(),
+      items: Vec::new(),
+    }
+  }
+}
+
+impl<T> StatefulTable<T> {
+  pub fn set_items(&mut self, items: Vec<T>) {
+    let items_len = items.len();
+    self.items = items;
+    if !self.items.is_empty() {
+      let selected_row = self.state.selected().map_or(0, |i| {
+        if i > 0 && i < items_len {
+          i
+        } else if i >= items_len {
+          items_len - 1
+        } else {
+          0
+        }
+      });
+      self.state.select(Some(selected_row));
+    }
+  }
+
+  pub fn current_selection(&self) -> &T {
+    &self.items[self.state.selected().unwrap_or(0)]
+  }
+}
+
+impl<T> Scrollable for StatefulTable<T> {
+  fn scroll_down(&mut self) {
+    let selected_row = match self.state.selected() {
+      Some(i) => {
+        if i >= self.items.len() - 1 {
+          0
+        } else {
+          i + 1
+        }
+      }
+      None => 0,
+    };
+
+    self.state.select(Some(selected_row));
+  }
+
+  fn scroll_up(&mut self) {
+    let selected_row = match self.state.selected() {
+      Some(i) => {
+        if i == 0 {
+          self.items.len() - 1
+        } else {
+          i - 1
+        }
+      }
+      None => 0,
+    };
+
+    self.state.select(Some(selected_row));
+  }
+}
+
+#[derive(Default)]
+pub struct ScrollableText {
+  pub items: Vec<String>,
+  pub offset: u16,
+}
+
+impl ScrollableText {
+  pub fn with_string(item: String) -> ScrollableText {
+    let items: Vec<&str> = item.split('\n').collect();
+    let items: Vec<String> = items.iter().map(|it| it.to_string()).collect();
+    ScrollableText { items, offset: 0 }
+  }
+
+  pub fn get_text(&self) -> String {
+    self.items.join("\n")
+  }
+}
+
+impl Scrollable for ScrollableText {
+  fn scroll_down(&mut self) {
+    if self.offset < self.items.len() as u16 {
+      self.offset += 1;
+    }
+  }
+
+  fn scroll_up(&mut self) {
+    if self.offset > 0 {
+      self.offset -= 1;
+    }
+  }
+}