Add step line

README.md

@@ -245,6 +245,7 @@ You can also clone the repo and run `cargo run --bin gallery` to view the intera
 <a href="./gallery/src/line/smoothed_line.rs"><img src="./img/line/smoothed_line.svg" width="40%" alt="Smoothed Line" /></a>
 <a href="./gallery/src/line/stacked_area.rs"><img src="./img/line/stacked_area.svg" width="40%" alt="Stacked Area" /></a>
 <a href="./gallery/src/line/stacked_line.rs"><img src="./img/line/stacked_line.svg" width="40%" alt="Stacked Line" /></a>
+<a href="./gallery/src/line/step_line.rs"><img src="./img/line/step_line.svg" width="40%" alt="Step Line" /></a>
 <a href="./gallery/src/line/temperature_change.rs"><img src="./img/line/temperature_change.svg" width="40%" alt="Temperature Change" /></a>
 <a href="./gallery/src/line/two_value_axes_in_polar.rs"><img src="./img/line/two_value_axes_in_polar.svg" width="40%" alt="Two Value-Axes in Polar" /></a>
 </div>

charming/src/element/mod.rs

@@ -40,6 +40,7 @@ pub mod smoothness;
 pub mod sort;
 pub mod split_area;
 pub mod split_line;
+pub mod step;
 pub mod symbol;
 pub mod symbol_size;
 pub mod text_align;
@@ -87,6 +88,7 @@ pub use shape::*;
 pub use sort::*;
 pub use split_area::*;
 pub use split_line::*;
+pub use step::*;
 pub use symbol::*;
 pub use symbol_size::*;
 pub use text_align::*;

charming/src/element/step.rs

@@ -0,0 +1,9 @@
+use serde::Serialize;
+
+#[derive(Serialize, Debug, PartialEq, PartialOrd, Clone)]
+#[serde(rename_all = "snake_case")]
+pub enum Step {
+    Start,
+    Middle,
+    End,
+}

charming/src/series/line.rs

@@ -4,7 +4,7 @@ use crate::{
     datatype::{DataFrame, DataPoint},
     element::{
         smoothness::Smoothness, AreaStyle, CoordinateSystem, DimensionEncode, Emphasis, ItemStyle,
-        Label, LineStyle, MarkArea, MarkLine, MarkPoint, Symbol, SymbolSize, Tooltip,
+        Label, LineStyle, MarkArea, MarkLine, MarkPoint, Step, Symbol, SymbolSize, Tooltip,
     },
 };
 
@@ -53,6 +53,9 @@ pub struct Line {
     #[serde(skip_serializing_if = "Option::is_none")]
     smooth: Option<Smoothness>,
 
+    #[serde(skip_serializing_if = "Option::is_none")]
+    step: Option<Step>,
+
     #[serde(skip_serializing_if = "Option::is_none")]
     connect_nulls: Option<bool>,
 
@@ -107,6 +110,7 @@ impl Line {
             item_style: None,
             emphasis: None,
             smooth: None,
+            step: None,
             connect_nulls: None,
             mark_point: None,
             mark_line: None,
@@ -187,6 +191,11 @@ impl Line {
         self
     }
 
+    pub fn step<S: Into<Step>>(mut self, step: S) -> Self {
+        self.step = Some(step.into());
+        self
+    }
+
     pub fn connect_nulls(mut self, connect_nulls: bool) -> Self {
         self.connect_nulls = Some(connect_nulls);
         self

gallery/src/lib.rs

@@ -122,6 +122,7 @@ lazy_static! {
         insert!(m, line, smoothed_line);
         insert!(m, line, stacked_area);
         insert!(m, line, stacked_line);
+        insert!(m, line, step_line);
         insert!(m, line, temperature_change);
         insert!(m, line, two_value_axes_in_polar);
         m

gallery/src/line/mod.rs

@@ -13,5 +13,6 @@ pub mod rainfall_vs_evaporation;
 pub mod smoothed_line;
 pub mod stacked_area;
 pub mod stacked_line;
+pub mod step_line;
 pub mod temperature_change;
 pub mod two_value_axes_in_polar;

gallery/src/line/step_line.rs

@@ -0,0 +1,46 @@
+use charming::{
+    component::{Axis, Feature, Grid, Legend, SaveAsImage, Title, Toolbox},
+    element::{AxisType, Step, Tooltip, Trigger},
+    series::Line,
+    Chart,
+};
+
+pub fn chart() -> Chart {
+    Chart::new()
+        .title(Title::new().text("Step Line"))
+        .tooltip(Tooltip::new().trigger(Trigger::Axis))
+        .legend(Legend::new())
+        .grid(
+            Grid::new()
+                .left("3%")
+                .right("4%")
+                .bottom("3%")
+                .contain_label(true),
+        )
+        .toolbox(Toolbox::new().feature(Feature::new().save_as_image(SaveAsImage::new())))
+        .x_axis(
+            Axis::new()
+                .type_(AxisType::Category)
+                .boundary_gap(false)
+                .data(vec!["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]),
+        )
+        .y_axis(Axis::new().type_(AxisType::Value))
+        .series(
+            Line::new()
+                .name("Step Start")
+                .step(Step::Start)
+                .data(vec![120, 132, 101, 134, 90, 230, 210]),
+        )
+        .series(
+            Line::new()
+                .name("Step Middle")
+                .step(Step::Middle)
+                .data(vec![220, 282, 201, 234, 290, 430, 410]),
+        )
+        .series(
+            Line::new()
+                .name("Step End")
+                .step(Step::End)
+                .data(vec![450, 432, 401, 454, 590, 530, 510]),
+        )
+}