From df1d1dddc6759fcfdff8494f7350c4ecd3934670 Mon Sep 17 00:00:00 2001
From: Marco De Araujo <marco.araujo.junior@gmail.com>
Date: Fri, 9 Jan 2026 11:56:35 -0400
Subject: [PATCH] Scrollbar initial values

---
 src/ui/app.rs                     | 30 ++++++++++++++++++++----------
 src/ui/components/monitor_list.rs |  4 ++--
 src/ui/dashboard/model.rs         |  7 +++++--
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/src/ui/app.rs b/src/ui/app.rs
index 76dead9..4d2dbca 100644
--- a/src/ui/app.rs
+++ b/src/ui/app.rs
@@ -116,13 +116,19 @@ impl App {
     fn render(&mut self) {
         let _ = self.terminal.draw(|frame| {
             let area = frame.area();
+
+            const HEADER_HEIGHT: u16 = 3;
+            const FOOTER_HEIGHT: u16 = 3;
+
+            let max_content_height = area.height.saturating_sub(HEADER_HEIGHT + FOOTER_HEIGHT);
+
             let chunks = Layout::default()
                 .direction(Direction::Vertical)
                 .margin(1)
                 .constraints([
-                    Constraint::Length(3),
-                    Constraint::Min(1),
-                    Constraint::Length(3),
+                    Constraint::Length(HEADER_HEIGHT),
+                    Constraint::Length(max_content_height.max(1)),
+                    Constraint::Length(FOOTER_HEIGHT),
                 ])
                 .split(area);
 
@@ -177,7 +183,13 @@ impl App {
             .begin_symbol(Some("↑"))
             .end_symbol(Some("↓"));
 
-        frame.render_stateful_widget(scrollbar, area[1], &mut state.scroll_state);
+        frame.render_stateful_widget(
+            scrollbar,
+            area[1],
+            &mut state
+                .scroll_state
+                .viewport_content_length(area[0].height as usize),
+        );
     }
 
     fn handle_events(&mut self) -> io::Result<()> {
@@ -191,12 +203,10 @@ impl App {
 
                 match key.code {
                     KeyCode::Char('q') | KeyCode::Esc => self.should_quit = true,
-                    KeyCode::Up | KeyCode::Char('k') => {
-                        self.state.scroll_state.prev();
-                    }
-                    KeyCode::Down | KeyCode::Char('j') => {
-                        self.state.scroll_state.next();
-                    }
+                    KeyCode::Up | KeyCode::Char('k') => self.state.scroll_state.prev(),
+                    KeyCode::Down | KeyCode::Char('j') => self.state.scroll_state.next(),
+                    KeyCode::Home => self.state.scroll_state.first(),
+                    KeyCode::End => self.state.scroll_state.last(),
                     _ => {}
                 }
             }
diff --git a/src/ui/components/monitor_list.rs b/src/ui/components/monitor_list.rs
index 31dd468..0fc4256 100644
--- a/src/ui/components/monitor_list.rs
+++ b/src/ui/components/monitor_list.rs
@@ -3,7 +3,7 @@ use std::cmp::min;
 use crate::i18n::t;
 use crate::ui::dashboard::{
     MonitorStatus, MonitorViewState,
-    model::{DashboardViewState, GroupViewState},
+    model::{DashboardViewState, GroupViewState, BORDER_LINES_VIEW},
 };
 use ratatui::{
     Frame,
@@ -21,7 +21,7 @@ pub fn render_monitor_list(main_frame: &mut Frame, area: Rect, state: &Dashboard
         .groups
         .iter()
         .map(|g| {
-            let height_neeed = 3 + g.monitors.len();
+            let height_neeed = BORDER_LINES_VIEW + g.monitors.len();
             Constraint::Length(height_neeed as u16)
         })
         .collect();
diff --git a/src/ui/dashboard/model.rs b/src/ui/dashboard/model.rs
index c408c54..a375ed9 100644
--- a/src/ui/dashboard/model.rs
+++ b/src/ui/dashboard/model.rs
@@ -4,7 +4,7 @@ use crate::i18n::t;
 use ratatui::widgets::ScrollbarState;
 use rayon::prelude::*;
 
-const BORDER_LINES_VIEW: usize = 3;
+pub const BORDER_LINES_VIEW: usize = 3;
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum MonitorStatus {
@@ -37,6 +37,7 @@ pub struct DashboardViewState {
     pub error_message: Option<String>,
     pub auto_refresh_interval: u32,
     pub scroll_state: ScrollbarState,
+    content_length: usize,
 }
 
 impl DashboardViewState {
@@ -49,6 +50,7 @@ impl DashboardViewState {
             error_message: None,
             auto_refresh_interval: 300,
             scroll_state: ScrollbarState::new(0),
+            content_length: 0,
         }
     }
 
@@ -75,6 +77,7 @@ impl DashboardViewState {
             error_message: None,
             auto_refresh_interval: data.auto_refresh_interval.max(30),
             scroll_state: ScrollbarState::new(content_length.saturating_sub(1)),
+            content_length,
         }
     }
 
@@ -83,7 +86,7 @@ impl DashboardViewState {
     }
 
     pub fn show_vertical_scrollbar(&self, height: u16) -> bool {
-        height < self.get_all_monitors().len() as u16
+        height < self.content_length as u16
     }
 }