Add accessor for chart_area drawing area

Author: siefkenj

examples/layout.rs

@@ -11,20 +11,44 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut chart = ChartLayout::new(&root);
     chart
         .set_chart_title_text("Chart Title")?
-        .set_top_label_text("A label at the top")?
         .set_chart_title_style(("serif", 60.).into_font().with_color(&RED))?
-        .set_left_label_text("Left label")?
+        .set_left_label_text("Ratio of Sides")?
         .set_right_label_text("Right label")?
-        .set_bottom_label_text("Bottom label")?
+        .set_bottom_label_text("Radians")?
         .set_bottom_label_margin(10.)?
-        .set_top_label_margin(10.)?
-    .draw()?;
-
-    let extent = chart.get_chart_area_extent()?;
-    root.draw(&Rectangle::new(extent.into_array_of_tuples(), &BLUE))?;
-    let extent = chart.get_chart_title_extent()?;
-    root.draw(&Rectangle::new(extent.into_array_of_tuples(), &BLUE))?;
-    //dbg!();
+        .set_left_label_margin(10.)?
+        .set_right_label_margin(10.)?
+        .draw()?;
+
+    // If we extract a drawing area corresponding to a chart area, we can
+    // use the usual chart API to draw.
+    let da_chart = chart.get_chart_drawing_area()?;
+    let x_axis = (-3.4f32..3.4).step(0.1);
+    let mut cc = ChartBuilder::on(&da_chart)
+        .margin(5)
+        .set_all_label_area_size(15)
+        .build_cartesian_2d(-3.4f32..3.4, -1.2f32..1.2f32)?;
+
+    cc.configure_mesh()
+        .x_labels(20)
+        .y_labels(10)
+        .disable_mesh()
+        .x_label_formatter(&|v| format!("{:.1}", v))
+        .y_label_formatter(&|v| format!("{:.1}", v))
+        .draw()?;
+
+    cc.draw_series(LineSeries::new(x_axis.values().map(|x| (x, x.sin())), &RED))?
+        .label("Sine")
+        .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &RED));
+
+    cc.draw_series(LineSeries::new(
+        x_axis.values().map(|x| (x, x.cos())),
+        &BLUE,
+    ))?
+    .label("Cosine")
+    .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &BLUE));
+
+    cc.configure_series_labels().border_style(&BLACK).draw()?;
 
     Ok(())
 }

src/chart/context.rs

@@ -311,7 +311,7 @@ impl<'a, DB: DrawingBackend, X: Ranged, Y: Ranged> ChartContext<'a, DB, Cartesia
                         .map(|(w, _)| w)
                         .unwrap_or(0) as i32
                 } else {
-                    // Don't ever do the layout estimationfor the drawing area that is either not
+                    // Don't ever do the layout estimation for the drawing area that is either not
                     // the right one or the tick mark is inward.
                     0
                 }

src/chart/layout/mod.rs

@@ -256,6 +256,18 @@ impl<'a, 'b, DB: DrawingBackend> ChartLayout<'a, 'b, DB> {
         Ok(self)
     }
 
+    /// Return a drawing area which corresponds to the `chart_area` of the current layout.
+    /// [`layout`] should be called before this function.
+    pub fn get_chart_drawing_area(
+        &mut self,
+    ) -> Result<DrawingArea<DB, Shift>, DrawingAreaErrorKind<DB::ErrorType>> {
+        let chart_area_extent = self.get_chart_area_extent()?;
+        Ok(DrawingArea::clone(self.root_area).shrink(
+            (chart_area_extent.x0, chart_area_extent.y0),
+            chart_area_extent.size(),
+        ))
+    }
+
     /// Set the text of a label. If the text is a blank screen, the label is cleared.
     #[inline(always)]
     fn set_text<S: AsRef<str>>(elm: &mut Label, text: S) {

src/chart/layout/nodes.rs

@@ -1,5 +1,4 @@
 use paste::paste;
-use std::iter::once;
 use std::{
     collections::HashMap,
     ops::{Add, Sub},

src/coord/ranged1d/mod.rs

@@ -109,7 +109,7 @@ impl KeyPointWeight {
 /// The trait for a hint provided to the key point algorithm used by the coordinate specs.
 /// The most important constraint is the `max_num_points` which means the algorithm could emit no more than specific number of key points
 /// `weight` is used to determine if this is used as a bold grid line or light grid line
-/// `bold_points` returns the max number of coresponding bold grid lines
+/// `bold_points` returns the max number of corresponding bold grid lines
 pub trait KeyPointHint {
     /// Returns the max number of key points
     fn max_num_points(&self) -> usize;
@@ -178,12 +178,12 @@ impl KeyPointHint for LightPoints {
 /// Which is used to describe any 1D axis.
 pub trait Ranged {
     /// This marker decides if Plotters default [ValueFormatter](trait.ValueFormatter.html) implementation should be used.
-    /// This assicated type can be one of follow two types:
+    /// This associated type can be one of follow two types:
     /// - [DefaultFormatting](struct.DefaultFormatting.html) will allow Plotters automatically impl
     /// the formatter based on `Debug` trait, if `Debug` trait is not impl for the `Self::Value`,
     /// [ValueFormatter](trait.ValueFormatter.html) will not impl unless you impl it manually.
     ///
-    /// - [NoDefaultFormatting](struct.NoDefaultFormatting.html) Disable the automatical `Debug`
+    /// - [NoDefaultFormatting](struct.NoDefaultFormatting.html) Disable the automatic `Debug`
     /// based value formatting. Thus you have to impl the
     /// [ValueFormatter](trait.ValueFormatter.html) manually.
     ///

src/coord/ranged2d/cartesian.rs

@@ -2,7 +2,7 @@
  The 2-dimensional cartesian coordinate system.
 
  This module provides the 2D cartesian coordinate system, which is composed by two independent
- ranged 1D coordinate sepcification.
+ ranged 1D coordinate specification.
 
  This types of coordinate system is used by the chart constructed with [ChartBuilder::build_cartesian_2d](../../chart/ChartBuilder.html#method.build_cartesian_2d).
 */