From 4a35ffbde175df259780de32bfc2dcdaa00f84d0 Mon Sep 17 00:00:00 2001
From: Ilya Zlobintsev <ilya.zl@protonmail.com>
Date: Sun, 12 Jan 2025 11:23:35 +0200
Subject: [PATCH] fix: avoid crashing history graph on empty plot with
 throttling data

---
 lact-gui/src/app/graphs_window/plot/imp.rs    |  6 +-
 .../app/graphs_window/plot/render_thread.rs   | 58 ++++++++++---------
 2 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/lact-gui/src/app/graphs_window/plot/imp.rs b/lact-gui/src/app/graphs_window/plot/imp.rs
index 18b6ebc..fe5d7ce 100644
--- a/lact-gui/src/app/graphs_window/plot/imp.rs
+++ b/lact-gui/src/app/graphs_window/plot/imp.rs
@@ -105,7 +105,7 @@ impl PlotData {
         self.push_secondary_line_series_with_time(name, point, chrono::Local::now().naive_local());
     }
 
-    pub fn push_line_series_with_time(&mut self, name: &str, point: f64, time: NaiveDateTime) {
+    fn push_line_series_with_time(&mut self, name: &str, point: f64, time: NaiveDateTime) {
         self.line_series
             .entry(name.to_owned())
             .or_default()
@@ -183,4 +183,8 @@ impl PlotData {
         self.throttling
             .retain(|(time_point, _)| ((maximum_point - *time_point) / 1000) < last_seconds);
     }
+
+    pub fn is_empty(&self) -> bool {
+        self.line_series.is_empty() && self.secondary_line_series.is_empty()
+    }
 }
diff --git a/lact-gui/src/app/graphs_window/plot/render_thread.rs b/lact-gui/src/app/graphs_window/plot/render_thread.rs
index b776015..fc2dce6 100644
--- a/lact-gui/src/app/graphs_window/plot/render_thread.rs
+++ b/lact-gui/src/app/graphs_window/plot/render_thread.rs
@@ -293,34 +293,36 @@ impl RenderRequest {
             .context("Failed to draw mesh")?;
 
         // Draw the throttling histogram as a series of bars.
-        chart
-            .draw_series(
-                data.throttling_iter()
-                    .chunk_by(|(_, _, point)| *point)
-                    .into_iter()
-                    .filter_map(|(point, group_iter)| point.then_some(group_iter))
-                    .filter_map(|mut group_iter| {
-                        let first = group_iter.next()?;
-                        Some((first, group_iter.last().unwrap_or(first)))
-                    })
-                    .map(|((start, name, _), (end, _, _))| ((start, end), name))
-                    .map(|((start_time, end_time), _)| (start_time, end_time))
-                    .sorted_by_key(|&(start_time, _)| start_time)
-                    .coalesce(|(start1, end1), (start2, end2)| {
-                        if end1 >= start2 {
-                            Ok((start1, std::cmp::max(end1, end2)))
-                        } else {
-                            Err(((start1, end1), (start2, end2)))
-                        }
-                    })
-                    .map(|(start_time, end_time)| {
-                        Rectangle::new(
-                            [(start_time, 0f64), (end_time, maximum_value)],
-                            DEEPORANGE_100.filled(),
-                        )
-                    }),
-            )
-            .context("Failed to draw throttling histogram")?;
+        if !data.is_empty() {
+            chart
+                .draw_series(
+                    data.throttling_iter()
+                        .chunk_by(|(_, _, point)| *point)
+                        .into_iter()
+                        .filter_map(|(point, group_iter)| point.then_some(group_iter))
+                        .filter_map(|mut group_iter| {
+                            let first = group_iter.next()?;
+                            Some((first, group_iter.last().unwrap_or(first)))
+                        })
+                        .map(|((start, name, _), (end, _, _))| ((start, end), name))
+                        .map(|((start_time, end_time), _)| (start_time, end_time))
+                        .sorted_by_key(|&(start_time, _)| start_time)
+                        .coalesce(|(start1, end1), (start2, end2)| {
+                            if end1 >= start2 {
+                                Ok((start1, std::cmp::max(end1, end2)))
+                            } else {
+                                Err(((start1, end1), (start2, end2)))
+                            }
+                        })
+                        .map(|(start_time, end_time)| {
+                            Rectangle::new(
+                                [(start_time, 0f64), (end_time, maximum_value)],
+                                DEEPORANGE_100.filled(),
+                            )
+                        }),
+                )
+                .context("Failed to draw throttling histogram")?;
+        }
 
         // Draw the main line series using cubic spline interpolation.
         for (idx, (caption, data)) in (0..).zip(data.line_series_iter()) {