feat: Historical navigation within one characteristic (#11)

Author: dmtrKovalenko

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
   "cSpell.words": [
-    "Blendr"
+    "Blendr",
+    "Keydown"
   ]
 }

src/route.rs

@@ -6,7 +6,10 @@ use crate::{
 use btleplug::api::Peripheral;
 use std::{
     ops::{Deref, DerefMut},
-    sync::{atomic::AtomicU16, Arc, RwLock},
+    sync::{
+        atomic::{AtomicIsize, AtomicU16},
+        Arc, RwLock,
+    },
     time::Duration,
 };
 use tokio::time::{self, timeout};
@@ -19,6 +22,46 @@ pub struct CharacteristicValue {
     pub data: Vec<u8>,
 }
 
+/// Atomic implementation for optional index
+#[derive(Debug)]
+pub struct AtomicOptionalIndex(AtomicIsize);
+
+impl Default for AtomicOptionalIndex {
+    fn default() -> Self {
+        Self(AtomicIsize::new(-1))
+    }
+}
+
+impl AtomicOptionalIndex {
+    pub fn read(&self) -> Option<usize> {
+        let value = self.0.load(std::sync::atomic::Ordering::SeqCst);
+
+        if value < 0 {
+            None
+        } else {
+            Some(value as usize)
+        }
+    }
+
+    pub fn write(&self, value: usize) {
+        let new_value: isize = if let Ok(new_value) = value.try_into() {
+            new_value
+        } else {
+            tracing::error!(
+                "Failed to convert atomic optional index. Falling back to the isize max"
+            );
+
+            isize::MAX
+        };
+
+        self.0.store(new_value, std::sync::atomic::Ordering::SeqCst)
+    }
+
+    pub fn annulate(&self) {
+        self.0.store(-1, std::sync::atomic::Ordering::SeqCst)
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum Route {
     PeripheralList,
@@ -27,10 +70,14 @@ pub enum Route {
         peripheral: HandledPeripheral,
         retry: Arc<AtomicU16>,
     },
+    // todo pull out into separate struct with default impl
     CharacteristicView {
         peripheral: ConnectedPeripheral,
         characteristic: ConnectedCharacteristic,
-        value: Arc<RwLock<Option<CharacteristicValue>>>,
+        /// If index is negative should show the latest mode,
+        /// can't use option here cause it will require additional mutex lock around while we can use simple atomic here
+        historical_view_index: Arc<AtomicOptionalIndex>,
+        history: Arc<RwLock<Vec<CharacteristicValue>>>,
     },
 }
 
@@ -74,15 +121,16 @@ impl Route {
                 Route::CharacteristicView {
                     peripheral,
                     characteristic,
-                    value,
+                    history,
+                    ..
                 },
             ) => loop {
                 let ble_peripheral = &peripheral.peripheral.ble_peripheral;
                 if let Ok(data) = ble_peripheral
                     .read(&characteristic.ble_characteristic)
                     .await
                 {
-                    value.write().unwrap().replace(CharacteristicValue {
+                    history.write().unwrap().push(CharacteristicValue {
                         time: chrono::Local::now(),
                         data,
                     });

src/tui/connection_view.rs

@@ -1,9 +1,12 @@
 use crate::{
-    bluetooth::display_properties,
-    route::Route,
+    bluetooth::ConnectedCharacteristic,
+    route::{CharacteristicValue, Route},
     tui::{
-        ui::{block, BlendrBlock},
-        AppRoute,
+        ui::{
+            block::{self, Title},
+            BlendrBlock,
+        },
+        AppRoute, HandleKeydownResult,
     },
     Ctx,
 };
@@ -52,6 +55,54 @@ fn try_parse_numeric_value<T: ByteOrder>(
     })
 }
 
+fn render_title_with_navigation_controls(
+    area: &tui::layout::Rect,
+    char: &ConnectedCharacteristic,
+    historical_view_index: Option<usize>,
+    history: &[CharacteristicValue],
+) -> Title<'static> {
+    const PREVIOUS_BUTTON: &str = " [<- Previous]  ";
+    const PREVIOUS_BUTTON_DENSE: &str = " [<-]  ";
+    const NEXT_BUTTON: &str = "  [Next ->] ";
+    const NEXT_BUTTON_DENSE: &str = "  [->] ";
+
+    let mut spans = vec![];
+    let available_width = area.width - 2; // 2 chars for borders on the left and right
+    let base_title = format!(
+        "Characteristic {} / Service {}",
+        char.char_name(),
+        char.service_name()
+    );
+
+    let previous_button_style = if history.len() < 2 || historical_view_index == Some(0) {
+        Style::default().fg(Color::DarkGray)
+    } else {
+        Style::default()
+    };
+
+    let next_button_style = if history.len() < 2 || historical_view_index.is_none() {
+        Style::default().fg(Color::DarkGray)
+    } else {
+        Style::default()
+    };
+
+    let not_enough_space = (available_width as i32).saturating_sub(
+        PREVIOUS_BUTTON.len() as i32 + NEXT_BUTTON.len() as i32 + base_title.len() as i32,
+    ) < 0;
+
+    if not_enough_space {
+        spans.push(Span::styled(PREVIOUS_BUTTON_DENSE, previous_button_style));
+        spans.push(Span::raw(format!("Char. {}", char.char_name())));
+        spans.push(Span::styled(NEXT_BUTTON_DENSE, next_button_style));
+    } else {
+        spans.push(Span::styled(PREVIOUS_BUTTON, previous_button_style));
+        spans.push(Span::raw(base_title));
+        spans.push(Span::styled(NEXT_BUTTON, next_button_style));
+    }
+
+    Title::new(spans)
+}
+
 impl AppRoute for ConnectionView {
     fn new(ctx: std::sync::Arc<crate::Ctx>) -> Self
     where
@@ -67,21 +118,63 @@ impl AppRoute for ConnectionView {
         }
     }
 
-    fn handle_input(&mut self, key: &crossterm::event::KeyEvent) {
+    fn handle_input(&mut self, key: &crossterm::event::KeyEvent) -> HandleKeydownResult {
         match key.code {
             KeyCode::Char('f') => {
                 self.float_numbers = !self.float_numbers;
-                return;
+                return HandleKeydownResult::Handled;
             }
             KeyCode::Char('u') => {
                 self.unsigned_numbers = !self.unsigned_numbers;
-                return;
+                return HandleKeydownResult::Handled;
             }
             _ => (),
         }
 
         let active_route = self.ctx.get_active_route();
 
+        if let Route::CharacteristicView {
+            historical_view_index,
+            history,
+            ..
+        } = active_route.deref()
+        {
+            let update_index = |new_index| {
+                historical_view_index.write(new_index);
+            };
+
+            match (
+                key.code,
+                history.read().ok().as_ref(),
+                historical_view_index.deref().read(),
+            ) {
+                (KeyCode::Left, _, Some(current_historical_index)) => {
+                    if current_historical_index >= 1 {
+                        update_index(current_historical_index - 1);
+                    }
+                }
+                (KeyCode::Left, Some(history), None) => {
+                    update_index(history.len() - 1);
+                }
+                (KeyCode::Right, Some(history), Some(current_historical_index))
+                    if current_historical_index == history.len() - 2 =>
+                {
+                    historical_view_index.annulate();
+                }
+                (KeyCode::Right, Some(history), Some(current_historical_index)) => {
+                    if history.len() > current_historical_index {
+                        update_index(current_historical_index + 1);
+                    }
+                }
+                _ => (),
+            }
+
+            if matches!(key.code, KeyCode::Left | KeyCode::Right) {
+                // on this view we always handing arrows as history navigation and preventing other view's actions
+                return HandleKeydownResult::Handled;
+            }
+        }
+
         match (active_route.deref(), self.clipboard.as_mut()) {
             (Route::CharacteristicView { characteristic, .. }, Some(clipboard)) => match key.code {
                 KeyCode::Char('c') => {
@@ -96,6 +189,8 @@ impl AppRoute for ConnectionView {
             },
             _ => (),
         }
+
+        HandleKeydownResult::Continue
     }
 
     fn render(
@@ -105,35 +200,47 @@ impl AppRoute for ConnectionView {
         f: &mut tui::Frame<super::TerminalBackend>,
     ) -> crate::error::Result<()> {
         let active_route = self.ctx.active_route.read()?;
-        let (_, characteristic, value) = if let Route::CharacteristicView {
-            peripheral,
-            characteristic,
-            value,
-        } = active_route.deref()
-        {
-            (peripheral, characteristic, value)
-        } else {
-            tracing::error!(
-                "ConnectionView::render called when active route is not CharacteristicView"
-            );
+        let (_, characteristic, history, historical_view_index) =
+            if let Route::CharacteristicView {
+                peripheral,
+                characteristic,
+                history,
+                historical_view_index,
+            } = active_route.deref()
+            {
+                (peripheral, characteristic, history, historical_view_index)
+            } else {
+                tracing::error!(
+                    "ConnectionView::render called when active route is not CharacteristicView"
+                );
 
-            return Ok(());
-        };
+                return Ok(());
+            };
 
-        let mut text = vec![];
-        text.push(Line::from(""));
+        let history = history.read()?;
+        let historical_index = historical_view_index.deref().read();
 
-        text.push(Line::from(format!(
-            "Properties: {}",
-            display_properties(characteristic.ble_characteristic.properties)
-        )));
+        let active_value = match historical_index {
+            Some(index) => history.get(index),
+            None => history.last(),
+        };
 
-        if let Some(value) = value.read().unwrap().as_ref() {
+        let mut text = vec![];
+        if let Some(value) = active_value.as_ref() {
             text.push(Line::from(""));
 
             text.push(Line::from(format!(
-                "Last updated: {}",
-                value.time.format("%Y-%m-%d %H:%M:%S")
+                "{label}: {}",
+                value.time.format("%Y-%m-%d %H:%M:%S"),
+                label = if let Some(index) = historical_index {
+                    format!(
+                        "Historical data ({} of {}) viewing data of\n",
+                        index + 1,
+                        history.len()
+                    )
+                } else {
+                    "Latest value received".to_owned()
+                },
             )));
 
             text.push(Line::from(""));
@@ -210,10 +317,12 @@ impl AppRoute for ConnectionView {
                 .block(tui::widgets::Block::from(BlendrBlock {
                     route_active,
                     focused: route_active,
-                    title: format!(
-                        "Characteristic {} / Service {}",
-                        characteristic.char_name(),
-                        characteristic.service_name()
+                    title_alignment: tui::layout::Alignment::Center,
+                    title: render_title_with_navigation_controls(
+                        &area,
+                        characteristic,
+                        historical_index,
+                        &history,
                     ),
                     ..Default::default()
                 }));
@@ -222,6 +331,8 @@ impl AppRoute for ConnectionView {
         if chunks[1].height > 0 {
             f.render_widget(
                 block::render_help([
+                    Some(("<-", "Previous value", false)),
+                    Some(("->", "Next value", false)),
                     Some(("d", "Disconnect from device", false)),
                     Some(("u", "Parse numeric as unsigned", self.unsigned_numbers)),
                     Some(("f", "Parse numeric as floats", self.float_numbers)),

src/tui/error_popup.rs

@@ -1,6 +1,6 @@
 use crate::{
     error,
-    tui::{ui::BlendrBlock, AppRoute, TerminalBackend},
+    tui::{ui::BlendrBlock, AppRoute, HandleKeydownResult, TerminalBackend},
     Ctx,
 };
 use crossterm::event::KeyCode;
@@ -51,18 +51,19 @@ impl AppRoute for ErrorView {
         ErrorView { ctx }
     }
 
-    fn handle_input(&mut self, key: &crossterm::event::KeyEvent) {
+    fn handle_input(&mut self, key: &crossterm::event::KeyEvent) -> HandleKeydownResult {
         // unwrap here because we are already in error state and if can not get out of it – it means a super serious race condition
         let mut global_error_lock = self.ctx.global_error.lock().unwrap();
         if global_error_lock.deref().is_none() {
-            return;
+            return HandleKeydownResult::Errored;
         }
 
         match key.code {
             KeyCode::Esc | KeyCode::Enter | KeyCode::Tab | KeyCode::Char(' ') => {
-                *global_error_lock.deref_mut() = None
+                *global_error_lock.deref_mut() = None;
+                HandleKeydownResult::Handled
             }
-            _ => {}
+            _ => HandleKeydownResult::Continue,
         }
     }
 
@@ -88,6 +89,7 @@ impl AppRoute for ErrorView {
                 route_active: true,
                 title: "Error",
                 color: Some(tui::style::Color::Red),
+                ..Default::default()
             }),
         );