From c08b522d34ef3bfae37342ba1bff897cb320971e Mon Sep 17 00:00:00 2001
From: EdJoPaTo
 <rfc-conform-git-commit-email@funny-long-domain-label-everyone-hates-as-it-is-too-long.edjopato.de>
Date: Mon, 5 Aug 2024 01:41:20 +0200
Subject: [PATCH] fix(chart): allow removing all the axis labels (#1282)

`axis.labels(vec![])` removes all the labels correctly.

This makes calling axis.labels with an empty Vec the equivalent
of not calling axis.labels. It's likely that this is never used, but it
prevents weird cases by removing the mix-up of `Option::None`
and `Vec::is_empty`, and simplifies the implementation code.
---
 src/widgets/chart.rs | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/src/widgets/chart.rs b/src/widgets/chart.rs
index 080349b3..e0972de8 100644
--- a/src/widgets/chart.rs
+++ b/src/widgets/chart.rs
@@ -1,4 +1,4 @@
-use std::cmp::max;
+use std::{cmp::max, ops::Not};
 
 use strum::{Display, EnumString};
 
@@ -39,7 +39,7 @@ pub struct Axis<'a> {
     /// Bounds for the axis (all data points outside these limits will not be represented)
     bounds: [f64; 2],
     /// A list of labels to put to the left or below the axis
-    labels: Option<Vec<Line<'a>>>,
+    labels: Vec<Line<'a>>,
     /// The style used to draw the axis itself
     style: Style,
     /// The alignment of the labels of the Axis
@@ -102,7 +102,7 @@ impl<'a> Axis<'a> {
     /// ```
     #[must_use = "method moves the value of self and returns the modified value"]
     pub fn labels<T: Into<Line<'a>>>(mut self, labels: Vec<T>) -> Self {
-        self.labels = Some(labels.into_iter().map(Into::into).collect());
+        self.labels = labels.into_iter().map(Into::into).collect();
         self
     }
 
@@ -708,22 +708,22 @@ impl<'a> Chart<'a> {
         let mut y = area.bottom() - 1;
 
         let mut label_x = None;
-        if self.x_axis.labels.is_some() && y > area.top() {
+        if !self.x_axis.labels.is_empty() && y > area.top() {
             label_x = Some(y);
             y -= 1;
         }
 
-        let label_y = self.y_axis.labels.as_ref().and(Some(x));
-        x += self.max_width_of_labels_left_of_y_axis(area, self.y_axis.labels.is_some());
+        let label_y = self.y_axis.labels.is_empty().not().then_some(x);
+        x += self.max_width_of_labels_left_of_y_axis(area, !self.y_axis.labels.is_empty());
 
         let mut axis_x = None;
-        if self.x_axis.labels.is_some() && y > area.top() {
+        if !self.x_axis.labels.is_empty() && y > area.top() {
             axis_x = Some(y);
             y -= 1;
         }
 
         let mut axis_y = None;
-        if self.y_axis.labels.is_some() && x + 1 < area.right() {
+        if !self.y_axis.labels.is_empty() && x + 1 < area.right() {
             axis_y = Some(x);
             x += 1;
         }
@@ -811,16 +811,12 @@ impl<'a> Chart<'a> {
         let mut max_width = self
             .y_axis
             .labels
-            .as_ref()
-            .map(|l| l.iter().map(Line::width).max().unwrap_or_default() as u16)
-            .unwrap_or_default();
+            .iter()
+            .map(Line::width)
+            .max()
+            .unwrap_or_default() as u16;
 
-        if let Some(first_x_label) = self
-            .x_axis
-            .labels
-            .as_ref()
-            .and_then(|labels| labels.first())
-        {
+        if let Some(first_x_label) = self.x_axis.labels.first() {
             let first_label_width = first_x_label.width() as u16;
             let width_left_of_y_axis = match self.x_axis.labels_alignment {
                 Alignment::Left => {
@@ -846,7 +842,7 @@ impl<'a> Chart<'a> {
         graph_area: Rect,
     ) {
         let Some(y) = layout.label_x else { return };
-        let labels = self.x_axis.labels.as_ref().unwrap();
+        let labels = &self.x_axis.labels;
         let labels_len = labels.len() as u16;
         if labels_len < 2 {
             return;
@@ -925,7 +921,7 @@ impl<'a> Chart<'a> {
         graph_area: Rect,
     ) {
         let Some(x) = layout.label_y else { return };
-        let labels = self.y_axis.labels.as_ref().unwrap();
+        let labels = &self.y_axis.labels;
         let labels_len = labels.len() as u16;
         for (i, label) in labels.iter().enumerate() {
             let dy = i as u16 * (graph_area.height - 1) / (labels_len - 1);