diff --git a/Cargo.lock b/Cargo.lock
index ce9b028..d904de0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1564,6 +1564,15 @@ dependencies = [
  "winit",
 ]
 
+[[package]]
+name = "egui_ltreeview"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6afc56194563064faa79d5acc18f2a4d32bd6dfacc949e1d5b5c8058a46e82cf"
+dependencies = [
+ "egui",
+]
+
 [[package]]
 name = "egui_plot"
 version = "0.35.0"
@@ -5439,6 +5448,7 @@ dependencies = [
  "can-dbc",
  "eframe",
  "egui",
+ "egui_ltreeview",
  "egui_plot",
  "libsvld",
 ]
diff --git a/svldplotter/Cargo.toml b/svldplotter/Cargo.toml
index 3e723a5..74e71c7 100644
--- a/svldplotter/Cargo.toml
+++ b/svldplotter/Cargo.toml
@@ -15,3 +15,4 @@ can-dbc = "9.1"
 eframe = "0.34"
 egui = "0.34"
 egui_plot = "0.35"
+egui_ltreeview = "0.7"
diff --git a/svldplotter/src/main.rs b/svldplotter/src/main.rs
index dea6410..3d3d468 100644
--- a/svldplotter/src/main.rs
+++ b/svldplotter/src/main.rs
@@ -2,8 +2,9 @@ use std::{fs, path::Path};
 
 use can_dbc::Dbc;
 use eframe::egui;
-use egui::Vec2b;
-use egui_plot::{Line, Plot, PlotPoint, PlotPoints};
+use egui::{ScrollArea, Vec2b};
+use egui_ltreeview::{Action, TreeView};
+use egui_plot::{AxisHints, Legend, Line, Plot, PlotPoint, PlotPoints, VPlacement};
 use libsvld::DecodeResult;
 
 fn main() {
@@ -11,10 +12,30 @@ fn main() {
     eframe::run_native("My egui App", native_options, Box::new(|cc| Ok(Box::new(MyEguiApp::new(cc))))).unwrap();
 }
 
+struct SigNode {
+    id: u64,
+    name: String,
+}
+
+struct MsgNode {
+    id: u64,
+    label: String,
+    signals: Vec<SigNode>,
+}
+
+struct PlottedSignal {
+    id: u64,
+    label: String,
+    unit: String,
+    points: Vec<PlotPoint>,
+}
+
 struct MyEguiApp {
     data: DecodeResult,
-    points: Vec<PlotPoint>,
-    buffer: Vec<PlotPoint>,
+    tree: Vec<MsgNode>,
+    filter: String,
+    plotted: Vec<PlottedSignal>,
+    cursor_x: Option<f64>,
 }
 
 impl MyEguiApp {
@@ -29,31 +50,88 @@ impl MyEguiApp {
 
         let data = libsvld::decode(&dbc, asc_path);
 
-        let mut points = Vec::<PlotPoint>::new();
-        let apps_sig = data
-            .metadata
-            .get(&48)
-            .unwrap()
-            .signals
-            .iter()
-            .find(|x| x.name == "AS_Torque_Vector")
-            .unwrap();
-        for frame in data.data.get(&48).unwrap() {
-            let bytes = u64::from_le_bytes(frame.data);
-            points.push(PlotPoint {
-                x: frame.timestamp,
-                y: libsvld::motec::extract_signal(bytes, &apps_sig.signal)
-            });
-        }
+        let tree = build_tree(&dbc, &data);
 
         Self {
             data,
-            points,
-            buffer: Vec::new(),
+            tree,
+            filter: String::new(),
+            plotted: Vec::new(),
+            cursor_x: None,
         }
     }
 }
 
+fn compute_signal(
+    data: &DecodeResult,
+    msg_id: u32,
+    sig_idx: usize,
+    id: u64,
+) -> Option<PlottedSignal> {
+    let meta = data.metadata.get(&msg_id)?;
+    let sig = meta.signals.get(sig_idx)?;
+    let frames = data.data.get(&msg_id)?;
+    let mut points = Vec::with_capacity(frames.len());
+    for frame in frames {
+        let bytes = u64::from_le_bytes(frame.data);
+        points.push(PlotPoint {
+            x: frame.timestamp,
+            y: libsvld::motec::extract_signal(bytes, &sig.signal),
+        });
+    }
+    Some(PlottedSignal {
+        id,
+        label: sig.name.clone(),
+        unit: sig.unit.clone(),
+        points,
+    })
+}
+
+fn build_tree(dbc: &Dbc, data: &DecodeResult) -> Vec<MsgNode> {
+    let mut msgs: Vec<&libsvld::motec::MessageMetadata> = data.metadata.values().collect();
+    msgs.sort_by_key(|m| m.id);
+    msgs.into_iter()
+        .map(|m| {
+            let name = dbc
+                .messages
+                .iter()
+                .find(|x| x.id.raw() == m.id)
+                .map(|x| x.name.as_str())
+                .unwrap_or("?");
+            let label = format!("0x{:X}  {}", m.id, name);
+            let signals = m
+                .signals
+                .iter()
+                .enumerate()
+                .map(|(i, s)| SigNode {
+                    id: (1u64 << 63) | ((m.id as u64) << 16) | (i as u64),
+                    name: s.name.clone(),
+                })
+                .collect();
+            MsgNode {
+                id: m.id as u64,
+                label,
+                signals,
+            }
+        })
+        .collect()
+}
+
+fn nearest_y(points: &[PlotPoint], x: f64) -> Option<f64> {
+    if points.is_empty() {
+        return None;
+    }
+    let i = points.partition_point(|p| p.x < x);
+    let cand = [
+        i.checked_sub(1).map(|j| &points[j]),
+        points.get(i),
+    ];
+    cand.into_iter()
+        .flatten()
+        .min_by(|a, b| (a.x - x).abs().total_cmp(&(b.x - x).abs()))
+        .map(|p| p.y)
+}
+
 // Min/max bucketing: for each horizontal pixel column in [x_min, x_max], emit
 // the min-y and max-y point so spikes survive decimation. Pushed in x order
 // (min/max swapped if needed) to keep the line monotonically increasing in x.
@@ -108,22 +186,165 @@ fn decimate(
 
 impl eframe::App for MyEguiApp {
    fn ui(&mut self, ui: &mut egui::Ui, _frame: &mut eframe::Frame) {
-       egui::CentralPanel::default().show_inside(ui, |ui| {
-           let full_min = self.points.first().map(|p| p.x).unwrap_or(0.0);
-           let full_max = self.points.last().map(|p| p.x).unwrap_or(1.0);
-           let plot = Plot::new("APPS")
-               .include_x(full_min)
-               .include_x(full_max)
-               .allow_zoom(Vec2b{x: true, y: false});
-           plot.show(ui, |pui| {
-               let bounds = pui.plot_bounds();
-               let x_min = bounds.min()[0];
-               let x_max = bounds.max()[0];
-               let px_w = pui.transform().frame().width() as usize;
-               decimate(&self.points, x_min, x_max, px_w.max(1), &mut self.buffer);
-               let ppoints = PlotPoints::Borrowed(&self.buffer);
-               pui.line(Line::new("AS_Torque_Vector", ppoints));
+       egui::Panel::left(egui::Id::new("Signals"))
+           .resizable(true)
+           .show_inside(ui, |ui| {
+               ui.add(
+                   egui::TextEdit::singleline(&mut self.filter)
+                       .hint_text("Filter messages/signals")
+                       .desired_width(f32::INFINITY),
+               );
+               let needle = self.filter.trim().to_lowercase();
+               let mut toggles: Vec<u64> = Vec::new();
+               ScrollArea::both()
+                   .scroll([
+                       true,
+                       true
+                   ])
+                   .scroll_bar_visibility(
+                       egui::scroll_area::ScrollBarVisibility::VisibleWhenNeeded
+                   )
+                   .show(ui, |ui| {
+                       let (_resp, actions) = TreeView::<u64>::new(
+                           ui.make_persistent_id("SignalsTree"),
+                       )
+                       .show(ui, |builder| {
+                           for msg in &self.tree {
+                               let msg_hit = needle.is_empty()
+                                   || msg.label.to_lowercase().contains(&needle);
+                               let matching_sigs: Vec<&SigNode> = if msg_hit {
+                                   msg.signals.iter().collect()
+                               } else {
+                                   msg.signals
+                                       .iter()
+                                       .filter(|s| s.name.to_lowercase().contains(&needle))
+                                       .collect()
+                               };
+                               if !msg_hit && matching_sigs.is_empty() {
+                                   continue;
+                               }
+                               builder.dir(msg.id, msg.label.as_str());
+                               for sig in matching_sigs {
+                                   builder.leaf(sig.id, sig.name.as_str());
+                               }
+                               builder.close_dir();
+                           }
+                       });
+                       for action in actions {
+                           if let Action::SetSelected(ids) = action {
+                               for id in ids {
+                                   if id & (1u64 << 63) != 0 {
+                                       toggles.push(id);
+                                   }
+                               }
+                           }
+                       }
+                   });
+               for id in toggles {
+                   if let Some(pos) = self.plotted.iter().position(|p| p.id == id) {
+                       self.plotted.remove(pos);
+                   } else {
+                       let msg_id = ((id >> 16) & 0xFFFF_FFFF) as u32;
+                       let sig_idx = (id & 0xFFFF) as usize;
+                       if let Some(sig) = compute_signal(&self.data, msg_id, sig_idx, id) {
+                           self.plotted.push(sig);
+                       }
+                   }
+               }
            });
+       egui::CentralPanel::default().show_inside(ui, |ui| {
+           if self.plotted.is_empty() {
+               ui.centered_and_justified(|ui| {
+                   ui.label("Click a signal in the tree to plot it.");
+               });
+               return;
+           }
+
+           // Group signals by unit, preserving the order each unit first appeared.
+           let mut groups: Vec<(String, Vec<usize>)> = Vec::new();
+           for (i, sig) in self.plotted.iter().enumerate() {
+               if let Some(g) = groups.iter_mut().find(|(u, _)| u == &sig.unit) {
+                   g.1.push(i);
+               } else {
+                   groups.push((sig.unit.clone(), vec![i]));
+               }
+           }
+
+           let full_min = self
+               .plotted
+               .iter()
+               .filter_map(|s| s.points.first().map(|p| p.x))
+               .fold(f64::INFINITY, f64::min);
+           let full_max = self
+               .plotted
+               .iter()
+               .filter_map(|s| s.points.last().map(|p| p.x))
+               .fold(f64::NEG_INFINITY, f64::max);
+
+           let link_group = ui.id().with("plot-link");
+           let n = groups.len();
+           // ui.spacing_mut().item_spacing.y = 0.0;
+           let h = (ui.available_height() / n as f32).max(80.0);
+
+           let cursor_x = self.cursor_x;
+           let mut new_cursor_x: Option<f64> = None;
+
+           for (gi, (unit, idxs)) in groups.iter().enumerate() {
+               let is_first = gi == 0;
+               let is_last = gi + 1 == n;
+
+               let mut x_axes: Vec<AxisHints> = Vec::new();
+               if is_first {
+                   x_axes.push(AxisHints::new_x().placement(VPlacement::Top));
+               }
+               if is_last {
+                   x_axes.push(AxisHints::new_x().placement(VPlacement::Bottom));
+               }
+
+               let title = if unit.is_empty() { "(no unit)" } else { unit.as_str() };
+
+               let plot = Plot::new(("plot", title))
+                   .height(h)
+                   .include_x(full_min)
+                   .include_x(full_max)
+                   .allow_zoom(Vec2b { x: true, y: true })
+                   .link_axis(link_group, Vec2b { x: true, y: false })
+                   .link_cursor(link_group, Vec2b { x: true, y: false })
+                   .legend(Legend::default())
+                   .custom_x_axes(x_axes)
+                   .custom_y_axes(vec![AxisHints::new_y().min_thickness(48.0)]);
+
+               let plotted = &self.plotted;
+               let plot_resp = plot.show(ui, |pui| {
+                   let bounds = pui.plot_bounds();
+                   let x_min = bounds.min()[0];
+                   let x_max = bounds.max()[0];
+                   let px_w = pui.transform().frame().width() as usize;
+                   let mut buf = Vec::new();
+                   for &i in idxs {
+                       let sig = &plotted[i];
+                       decimate(&sig.points, x_min, x_max, px_w.max(1), &mut buf);
+                       let ppoints = PlotPoints::Owned(std::mem::take(&mut buf));
+                       let unit_s = if sig.unit.is_empty() {
+                           String::new()
+                       } else {
+                           format!(" [{}]", sig.unit)
+                       };
+                       let name = match cursor_x.and_then(|x| nearest_y(&sig.points, x)) {
+                           Some(v) => format!("{}: {:.4}{}", sig.label, v, unit_s),
+                           None => format!("{}{}", sig.label, unit_s),
+                       };
+                       pui.line(Line::new(name, ppoints));
+                   }
+
+                   pui.pointer_coordinate().map(|c| c.x)
+               });
+               if let Some(x) = plot_resp.inner {
+                   new_cursor_x = Some(x);
+               }
+           }
+
+           self.cursor_x = new_cursor_x;
        });
    }
 }