Add braille mode for the chart widget

examples/prototype.rs

@@ -22,7 +22,7 @@ use log4rs::config::{Appender, Config, Root};
 
 use tui::Terminal;
 use tui::widgets::{Widget, Block, List, Gauge, Sparkline, Text, border, Chart, Axis, Dataset,
-                   BarChart};
+                   BarChart, Marker};
 use tui::layout::{Group, Direction, Size, Rect};
 use tui::style::Color;
 
@@ -51,14 +51,16 @@ impl Iterator for RandomSignal {
 #[derive(Clone)]
 struct SinSignal {
     x: f64,
+    interval: f64,
     period: f64,
     scale: f64,
 }
 
 impl SinSignal {
-    fn new(period: f64, scale: f64) -> SinSignal {
+    fn new(interval: f64, period: f64, scale: f64) -> SinSignal {
         SinSignal {
             x: 0.0,
+            interval: interval,
             period: period,
             scale: scale,
         }
@@ -68,7 +70,7 @@ impl SinSignal {
 impl Iterator for SinSignal {
     type Item = (f64, f64);
     fn next(&mut self) -> Option<(f64, f64)> {
-        self.x += 1.0;
+        self.x += self.interval;
         Some((self.x, ((self.x * 1.0 / self.period).sin() + 1.0) * self.scale))
     }
 }
@@ -110,8 +112,8 @@ fn main() {
     info!("Start");
 
     let mut rand_signal = RandomSignal::new(Range::new(0, 100));
-    let mut sin_signal = SinSignal::new(4.0, 20.0);
+    let mut sin_signal = SinSignal::new(1.0, 4.0, 20.0);
-    let mut sin_signal2 = SinSignal::new(2.0, 10.0);
+    let mut sin_signal2 = SinSignal::new(0.1, 2.0, 10.0);
 
     let mut app = App {
         size: Rect::default(),
@@ -125,7 +127,7 @@ fn main() {
         progress: 0,
         data: rand_signal.clone().take(200).collect(),
         data2: sin_signal.clone().take(20).collect(),
-        data3: sin_signal2.clone().take(20).collect(),
+        data3: sin_signal2.clone().take(200).collect(),
         data4: vec![("B1", 9),
                     ("B2", 12),
                     ("B3", 5),
@@ -150,6 +152,8 @@ fn main() {
 
     for _ in 0..20 {
         sin_signal.next();
+    }
+    for _ in 0..200 {
         sin_signal2.next();
     }
 
@@ -215,8 +219,12 @@ fn main() {
                 app.data.pop();
                 app.data2.remove(0);
                 app.data2.push(sin_signal.next().unwrap());
+                for _ in 0..10 {
                     app.data3.remove(0);
+                }
+                for _ in 0..10 {
                     app.data3.push(sin_signal2.next().unwrap());
+                }
                 let i = app.data4.pop().unwrap();
                 app.data4.insert(0, i);
                 app.window[0] += 1.0;
@@ -311,8 +319,14 @@ fn draw(t: &mut Terminal, app: &App) {
                                 .color(Color::Gray)
                                 .bounds([0.0, 40.0])
                                 .labels(&["0", "20", "40"]))
-                            .datasets(&[Dataset::default().color(Color::Cyan).data(&app.data2),
+                            .datasets(&[Dataset::default()
-                                        Dataset::default().color(Color::Yellow).data(&app.data3)])
+                                            .marker(Marker::Dot)
+                                            .color(Color::Cyan)
+                                            .data(&app.data2),
+                                        Dataset::default()
+                                            .marker(Marker::Braille)
+                                            .color(Color::Yellow)
+                                            .data(&app.data3)])
                             .render(&chunks[1], t);
                     }
                 });

src/widgets/chart.rs

@@ -8,6 +8,12 @@ use layout::Rect;
 use style::Color;
 use symbols;
 
+pub const DOTS: [[u16; 2]; 4] =
+    [[0x0001, 0x0008], [0x0002, 0x0010], [0x0004, 0x0020], [0x0040, 0x0080]];
+pub const BRAILLE_OFFSET: u16 = 0x2800;
+pub const BRAILLE_BLANK: char = '⠀';
+
+
 pub struct Axis<'a> {
     title: Option<&'a str>,
     title_color: Color,
@@ -62,8 +68,14 @@ impl<'a> Axis<'a> {
     }
 }
 
+pub enum Marker {
+    Dot,
+    Braille,
+}
+
 pub struct Dataset<'a> {
     data: &'a [(f64, f64)],
+    marker: Marker,
     color: Color,
 }
 
@@ -71,6 +83,7 @@ impl<'a> Default for Dataset<'a> {
     fn default() -> Dataset<'a> {
         Dataset {
             data: &[],
+            marker: Marker::Dot,
             color: Color::Reset,
         }
     }
@@ -82,32 +95,17 @@ impl<'a> Dataset<'a> {
         self
     }
 
+    pub fn marker(mut self, marker: Marker) -> Dataset<'a> {
+        self.marker = marker;
+        self
+    }
+
     pub fn color(mut self, color: Color) -> Dataset<'a> {
         self.color = color;
         self
     }
 }
 
-pub struct Chart<'a> {
-    block: Option<Block<'a>>,
-    x_axis: Axis<'a>,
-    y_axis: Axis<'a>,
-    datasets: &'a [Dataset<'a>],
-    bg: Color,
-}
-
-impl<'a> Default for Chart<'a> {
-    fn default() -> Chart<'a> {
-        Chart {
-            block: None,
-            x_axis: Axis::default(),
-            y_axis: Axis::default(),
-            bg: Color::Reset,
-            datasets: &[],
-        }
-    }
-}
-
 #[derive(Debug)]
 struct ChartLayout {
     legend_x: Option<(u16, u16)>,
@@ -133,6 +131,26 @@ impl Default for ChartLayout {
     }
 }
 
+pub struct Chart<'a> {
+    block: Option<Block<'a>>,
+    x_axis: Axis<'a>,
+    y_axis: Axis<'a>,
+    datasets: &'a [Dataset<'a>],
+    bg: Color,
+}
+
+impl<'a> Default for Chart<'a> {
+    fn default() -> Chart<'a> {
+        Chart {
+            block: None,
+            x_axis: Axis::default(),
+            y_axis: Axis::default(),
+            bg: Color::Reset,
+            datasets: &[],
+        }
+    }
+}
+
 impl<'a> Chart<'a> {
     pub fn block(&'a mut self, block: Block<'a>) -> &mut Chart<'a> {
         self.block = Some(block);
@@ -159,6 +177,7 @@ impl<'a> Chart<'a> {
         self
     }
 
+
     fn layout(&self, area: &Rect) -> ChartLayout {
         let mut layout = ChartLayout::default();
         if area.height == 0 || area.width == 0 {
@@ -271,38 +290,78 @@ impl<'a> Widget for Chart<'a> {
 
         if let Some(y) = layout.axis_x {
             for x in graph_area.left()..graph_area.right() {
-                buf.update_cell(x, y, symbols::line::HORIZONTAL, self.x_axis.color, self.bg);
+                buf.set_cell(x, y, symbols::line::HORIZONTAL, self.x_axis.color, self.bg);
             }
         }
 
         if let Some(x) = layout.axis_y {
             for y in graph_area.top()..graph_area.bottom() {
-                buf.update_cell(x, y, symbols::line::VERTICAL, self.y_axis.color, self.bg);
+                buf.set_cell(x, y, symbols::line::VERTICAL, self.y_axis.color, self.bg);
             }
         }
 
         if let Some(y) = layout.axis_x {
             if let Some(x) = layout.axis_y {
-                buf.update_cell(x, y, symbols::line::BOTTOM_LEFT, self.x_axis.color, self.bg);
+                buf.set_cell(x, y, symbols::line::BOTTOM_LEFT, self.x_axis.color, self.bg);
             }
         }
 
         for dataset in self.datasets {
+            match dataset.marker {
+                Marker::Dot => {
                     for &(x, y) in dataset.data.iter() {
                         if x < self.x_axis.bounds[0] || x > self.x_axis.bounds[1] ||
-                   y < self.y_axis.bounds[0] || y > self.y_axis.bounds[1] {
+                           y < self.y_axis.bounds[0] ||
+                           y > self.y_axis.bounds[1] {
                             continue;
                         }
                         let dy = (self.y_axis.bounds[1] - y) * graph_area.height as f64 /
                                  (self.y_axis.bounds[1] - self.y_axis.bounds[0]);
                         let dx = (self.x_axis.bounds[1] - x) * graph_area.width as f64 /
                                  (self.x_axis.bounds[1] - self.x_axis.bounds[0]);
-                buf.update_cell(dx as u16 + graph_area.left(),
+                        buf.set_cell(dx as u16 + graph_area.left(),
                                      dy as u16 + graph_area.top(),
                                      symbols::BLACK_CIRCLE,
                                      dataset.color,
                                      self.bg);
                     }
                 }
+                Marker::Braille => {
+                    let width = graph_area.width as usize;
+                    let height = graph_area.height as usize;
+                    let mut grid: Vec<u16> = vec![BRAILLE_OFFSET; width * height + 1];
+                    for &(x, y) in dataset.data.iter() {
+                        if x < self.x_axis.bounds[0] || x > self.x_axis.bounds[1] ||
+                           y < self.y_axis.bounds[0] ||
+                           y > self.y_axis.bounds[1] {
+                            continue;
+                        }
+                        let dy =
+                            ((self.y_axis.bounds[1] - y) * graph_area.height as f64 * 4.0 /
+                             (self.y_axis.bounds[1] -
+                              self.y_axis.bounds[0])) as usize;
+                        let dx =
+                            ((self.x_axis.bounds[1] - x) * graph_area.width as f64 * 2.0 /
+                             (self.x_axis.bounds[1] -
+                              self.x_axis.bounds[0])) as usize;
+                        grid[dy / 4 * width + dx / 2] |= DOTS[dy % 4][dx % 2];
+                    }
+                    let string = String::from_utf16(&grid).unwrap();
+                    for (i, ch) in string.chars().enumerate() {
+                        if ch != BRAILLE_BLANK {
+                            let (x, y) = (i % width, i / width);
+                            buf.update_cell(x as u16 + graph_area.left(),
+                                            y as u16 + graph_area.top(),
+                                            |c| {
+                                                c.symbol.clear();
+                                                c.symbol.push(ch);
+                                                c.fg = dataset.color;
+                                                c.bg = self.bg;
+                                            });
+                        }
+                    }
+                }
+            }
+        }
     }
 }

src/widgets/mod.rs

@@ -11,7 +11,7 @@ pub use self::text::Text;
 pub use self::list::List;
 pub use self::gauge::Gauge;
 pub use self::sparkline::Sparkline;
-pub use self::chart::{Chart, Axis, Dataset};
+pub use self::chart::{Chart, Axis, Dataset, Marker};
 pub use self::barchart::BarChart;
 
 use buffer::Buffer;