Support for multiple legends

charming/src/component/legend.rs

@@ -7,6 +7,25 @@ use crate::{
     element::{Color, Icon, ItemStyle, LabelAlign, LineStyle, Orient, Padding, TextStyle},
 };
 
+#[derive(Debug, PartialEq, Serialize, Clone)]
+#[serde(untagged)]
+pub enum LegendConfig {
+    Single(Box<Legend>),
+    Multiple(Vec<Legend>),
+}
+
+impl From<Legend> for LegendConfig {
+    fn from(legend: Legend) -> Self {
+        Self::Single(Box::new(legend))
+    }
+}
+
+impl From<Vec<Legend>> for LegendConfig {
+    fn from(legends: Vec<Legend>) -> Self {
+        LegendConfig::Multiple(legends)
+    }
+}
+
 #[derive(Serialize, Debug, PartialEq, PartialOrd, Clone, Copy)]
 #[serde(rename_all = "snake_case")]
 pub enum LegendType {

charming/src/lib.rs

@@ -93,7 +93,7 @@ pub mod theme;
 pub use renderer::*;
 
 use component::{
-    AngleAxis, Aria, Axis, Axis3D, DataZoom, GeoMap, Grid, Grid3D, Legend, ParallelAxis,
+    AngleAxis, Aria, Axis, Axis3D, DataZoom, GeoMap, Grid, Grid3D, LegendConfig, ParallelAxis,
     ParallelCoordinate, PolarCoordinate, RadarCoordinate, RadiusAxis, SaveAsImageType, SingleAxis,
     Title, Toolbox, VisualMap,
 };
@@ -247,7 +247,7 @@ pub struct Chart {
     tooltip: Option<Tooltip>,
 
     #[serde(skip_serializing_if = "Option::is_none")]
-    legend: Option<Legend>,
+    legend: Option<LegendConfig>,
 
     #[serde(skip_serializing_if = "Option::is_none")]
     toolbox: Option<Toolbox>,
@@ -381,8 +381,8 @@ impl Chart {
         self
     }
 
-    pub fn legend(mut self, legend: Legend) -> Self {
-        self.legend = Some(legend);
+    pub fn legend<L: Into<LegendConfig>>(mut self, legend: L) -> Self {
+        self.legend = Some(legend.into());
         self
     }
 

gallery/src/lib.rs

@@ -123,6 +123,7 @@ lazy_static! {
         insert!(m, line, smoothed_line);
         insert!(m, line, stacked_area);
         insert!(m, line, stacked_line);
+        insert!(m, line, split_legend);
         insert!(m, line, step_line);
         insert!(m, line, temperature_change);
         insert!(m, line, two_value_axes_in_polar);

gallery/src/line/mod.rs

@@ -11,6 +11,7 @@ pub mod line_gradient;
 pub mod rainfall;
 pub mod rainfall_vs_evaporation;
 pub mod smoothed_line;
+pub mod split_legend;
 pub mod stacked_area;
 pub mod stacked_line;
 pub mod step_line;

gallery/src/line/split_legend.rs

@@ -0,0 +1,63 @@
+use charming::{
+    component::{Axis, Feature, Grid, Legend, SaveAsImage, Title, Toolbox},
+    element::{AxisType, Tooltip, Trigger},
+    series::Line,
+    Chart,
+};
+
+pub fn chart() -> Chart {
+    Chart::new()
+        .title(Title::new().text("Split Legend"))
+        .tooltip(Tooltip::new().trigger(Trigger::Axis))
+        .legend(vec![
+            Legend::new().data(vec![
+                "Penguins",
+                "Giraffes",
+                "Lions",
+                "Elephants",
+                "Monkeys",
+            ]),
+            Legend::new().data(vec!["Total"]).right("50"),
+        ])
+        .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).name("Sightings"))
+        .series(
+            Line::new()
+                .name("Penguins")
+                .data(vec![8, 12, 6, 9, 15, 16, 18]),
+        )
+        .series(
+            Line::new()
+                .name("Giraffes")
+                .data(vec![5, 4, 6, 7, 8, 10, 9]),
+        )
+        .series(Line::new().name("Lions").data(vec![3, 2, 4, 3, 5, 6, 4]))
+        .series(
+            Line::new()
+                .name("Elephants")
+                .data(vec![4, 5, 3, 6, 7, 8, 6]),
+        )
+        .series(
+            Line::new()
+                .name("Monkeys")
+                .data(vec![12, 15, 10, 14, 16, 18, 20]),
+        )
+        .series(
+            Line::new()
+                .name("Total")
+                .data(vec![32, 38, 29, 39, 51, 58, 57]),
+        )
+}