Redefine canvas widget and add shapes

* Give the canvas widget a proper modules and define a standard way to
draw to it (Shape trait)
* Add Points, Line, Rectangle and Map shapes

examples/prototype.rs

@@ -22,7 +22,8 @@ use log4rs::config::{Appender, Config, Root};
 
 use tui::Terminal;
 use tui::widgets::{Widget, Block, List, Gauge, Sparkline, Text, border, Chart, Axis, Dataset,
-                   BarChart, Marker, Tabs, Map};
+                   BarChart, Marker, Tabs};
+use tui::widgets::canvas::{Canvas, Shape, Line, Map, MapResolution};
 use tui::layout::{Group, Direction, Size, Rect};
 use tui::style::Color;
 
@@ -286,8 +287,18 @@ fn draw(t: &mut Terminal, app: &App) {
                     draw_main(t, app, &chunks[1]);
                 }
                 1 => {
-                    Map::default()
+                    Canvas::default()
                         .block(Block::default().title("World").borders(border::ALL))
+                        .layers(&[&[Map::default().resolution(MapResolution::High)],
+                                  &[&Line {
+                                        x1: 0.0,
+                                        y1: 0.0,
+                                        x2: 10.0,
+                                        y2: 10.0,
+                                        color: Color::Red,
+                                    }]])
+                        .x_bounds([180.0, 0.0])
+                        .y_bounds([0.0, 90.0])
                         .render(&chunks[1], t);
                 }
                 _ => {}

src/widgets/canvas/line.rs

@@ -23,10 +23,11 @@ pub struct LineIterator {
 impl Iterator for LineIterator {
     type Item = (f64, f64);
     fn next(&mut self) -> Option<Self::Item> {
-        self.current += 1.0;
-        if self.current < self.end + 1.0 {
-            Some((self.x + (self.current * self.dx) / self.end * self.dir_x,
-                  self.y + (self.current * self.dy) / self.end * self.dir_y))
+        if self.current < self.end {
+            let pos = (self.x + (self.current * self.dx) / self.end * self.dir_x,
+                       self.y + (self.current * self.dy) / self.end * self.dir_y);
+            self.current += 1.0;
+            Some(pos)
         } else {
             None
         }

src/widgets/canvas/map.rs

@@ -0,0 +1,57 @@
+use widgets::canvas::Shape;
+use widgets::canvas::points::PointsIterator;
+use widgets::canvas::world::{WORLD_HIGH_RESOLUTION, WORLD_LOW_RESOLUTION};
+use style::Color;
+
+#[derive(Clone, Copy)]
+pub enum MapResolution {
+    Low,
+    High,
+}
+
+impl MapResolution {
+    fn data(&self) -> &'static [(f64, f64)] {
+        match *self {
+            MapResolution::Low => &WORLD_LOW_RESOLUTION,
+            MapResolution::High => &WORLD_HIGH_RESOLUTION,
+        }
+    }
+}
+
+pub struct Map {
+    resolution: MapResolution,
+    color: Color,
+}
+
+impl Default for Map {
+    fn default() -> Map {
+        Map {
+            resolution: MapResolution::Low,
+            color: Color::Reset,
+        }
+    }
+}
+
+impl<'a> Shape<'a> for Map {
+    fn color(&self) -> Color {
+        self.color
+    }
+    fn points(&'a self) -> Box<Iterator<Item = (f64, f64)> + 'a> {
+        Box::new(self.into_iter())
+    }
+}
+
+impl Map {
+    pub fn resolution(&mut self, resolution: MapResolution) -> &mut Map {
+        self.resolution = resolution;
+        self
+    }
+}
+
+impl<'a> IntoIterator for &'a Map {
+    type Item = (f64, f64);
+    type IntoIter = PointsIterator<'a>;
+    fn into_iter(self) -> Self::IntoIter {
+        PointsIterator::from(self.resolution.data())
+    }
+}

src/widgets/canvas/mod.rs

@@ -1,8 +1,13 @@
 mod points;
 mod line;
+mod rectangle;
+mod map;
+mod world;
 
 pub use self::points::Points;
 pub use self::line::Line;
+pub use self::rectangle::Rectangle;
+pub use self::map::{Map, MapResolution};
 
 use style::Color;
 use buffer::Buffer;
@@ -23,7 +28,7 @@ pub struct Canvas<'a> {
     block: Option<Block<'a>>,
     x_bounds: [f64; 2],
     y_bounds: [f64; 2],
-    shapes: &'a [&'a Shape<'a>],
+    layers: &'a [&'a [&'a Shape<'a>]],
 }
 
 impl<'a> Default for Canvas<'a> {
@@ -32,7 +37,7 @@ impl<'a> Default for Canvas<'a> {
             block: None,
             x_bounds: [0.0, 0.0],
             y_bounds: [0.0, 0.0],
-            shapes: &[],
+            layers: &[],
         }
     }
 }
@@ -50,8 +55,8 @@ impl<'a> Canvas<'a> {
         self.y_bounds = bounds;
         self
     }
-    pub fn shapes(&mut self, shapes: &'a [&'a Shape<'a>]) -> &mut Canvas<'a> {
-        self.shapes = shapes;
+    pub fn layers(&mut self, layers: &'a [&'a [&'a Shape<'a>]]) -> &mut Canvas<'a> {
+        self.layers = layers;
         self
     }
 }
@@ -69,38 +74,43 @@ impl<'a> Widget for Canvas<'a> {
         let width = canvas_area.width as usize;
         let height = canvas_area.height as usize;
 
-        let mut grid: Vec<u16> = vec![BRAILLE_OFFSET; width * height + 1];
-        let mut colors: Vec<Color> = vec![Color::Reset; width * height + 1];
 
         let mut x_bounds = self.x_bounds;
         x_bounds.sort_by(|a, b| a.partial_cmp(b).unwrap());
         let mut y_bounds = self.y_bounds;
         y_bounds.sort_by(|a, b| a.partial_cmp(b).unwrap());
 
-        for shape in self.shapes {
-            for (x, y) in shape.points().filter(|&(x, y)| {
-                !(x < x_bounds[0] || x > x_bounds[1] || y < y_bounds[0] || y > y_bounds[1])
-            }) {
-                let dy = ((self.y_bounds[1] - y) * canvas_area.height as f64 * 4.0 /
-                          (self.y_bounds[1] - self.y_bounds[0])) as usize;
-                let dx = ((self.x_bounds[1] - x) * canvas_area.width as f64 * 2.0 /
-                          (self.x_bounds[1] - self.x_bounds[0])) as usize;
-                let index = dy / 4 * width + dx / 2;
-                grid[index] |= DOTS[dy % 4][dx % 2];
-                colors[index] = shape.color();
-            }
-        }
+        for layer in self.layers {
+            let mut grid: Vec<u16> = vec![BRAILLE_OFFSET; width * height + 1];
+            let mut colors: Vec<Color> = vec![Color::Reset; width * height + 1];
 
-        let string = String::from_utf16(&grid).unwrap();
-        for (i, (ch, color)) in string.chars().zip(colors.into_iter()).enumerate() {
-            if ch != BRAILLE_BLANK {
-                let (x, y) = (i % width, i / width);
-                buf.update_cell(x as u16 + canvas_area.left(), y as u16 + area.top(), |c| {
-                    c.symbol.clear();
-                    c.symbol.push(ch);
-                    c.fg = color;
-                    c.bg = Color::Reset;
-                });
+            for shape in layer.iter() {
+                for (x, y) in shape.points().filter(|&(x, y)| {
+                    !(x < x_bounds[0] || x > x_bounds[1] || y < y_bounds[0] || y > y_bounds[1])
+                }) {
+                    let dy = ((self.y_bounds[1] - y) * canvas_area.height as f64 * 4.0 /
+                              (self.y_bounds[1] -
+                               self.y_bounds[0])) as usize;
+                    let dx = ((self.x_bounds[1] - x) * canvas_area.width as f64 * 2.0 /
+                              (self.x_bounds[1] -
+                               self.x_bounds[0])) as usize;
+                    let index = dy / 4 * width + dx / 2;
+                    grid[index] |= DOTS[dy % 4][dx % 2];
+                    colors[index] = shape.color();
+                }
+            }
+
+            let string = String::from_utf16(&grid).unwrap();
+            for (i, (ch, color)) in string.chars().zip(colors.into_iter()).enumerate() {
+                if ch != BRAILLE_BLANK {
+                    let (x, y) = (i % width, i / width);
+                    buf.update_cell(x as u16 + canvas_area.left(), y as u16 + area.top(), |c| {
+                        c.symbol.clear();
+                        c.symbol.push(ch);
+                        c.fg = color;
+                        c.bg = Color::Reset;
+                    });
+                }
             }
         }
     }

src/widgets/canvas/points.rs

@@ -1,3 +1,5 @@
+use std::slice;
+
 use super::Shape;
 use style::Color;
 
@@ -28,27 +30,26 @@ impl<'a> IntoIterator for &'a Points<'a> {
     type Item = (f64, f64);
     type IntoIter = PointsIterator<'a>;
     fn into_iter(self) -> Self::IntoIter {
-        PointsIterator {
-            coords: self.coords,
-            index: 0,
-        }
+        PointsIterator { iter: self.coords.iter() }
     }
 }
 
 pub struct PointsIterator<'a> {
-    coords: &'a [(f64, f64)],
-    index: usize,
+    iter: slice::Iter<'a, (f64, f64)>,
+}
+
+impl<'a> From<&'a [(f64, f64)]> for PointsIterator<'a> {
+    fn from(data: &'a [(f64, f64)]) -> PointsIterator<'a> {
+        PointsIterator { iter: data.iter() }
+    }
 }
 
 impl<'a> Iterator for PointsIterator<'a> {
     type Item = (f64, f64);
     fn next(&mut self) -> Option<Self::Item> {
-        let point = if self.index < self.coords.len() {
-            Some(self.coords[self.index])
-        } else {
-            None
-        };
-        self.index += 1;
-        point
+        match self.iter.next() {
+            Some(p) => Some(*p),
+            None => None,
+        }
     }
 }

src/widgets/canvas/rectangle.rs

@@ -0,0 +1,76 @@
+use super::Shape;
+use style::Color;
+
+/// # Examples
+///
+/// ```
+/// use tui::style::Color;
+/// use tui::widgets::canvas::{Shape, Rectangle};
+///
+/// let rectangle = Rectangle { x: 4.0, y: 4.0, width: 4.0, height: 4.0, color: Color::Red };
+/// let points = rectangle.points().collect::<Vec<(f64, f64)>>();
+/// assert_eq!(&points, &[(4.0, 4.0), (5.0, 4.0), (6.0, 4.0), (7.0, 4.0), (4.0, 5.0), (7.0, 5.0),
+/// (4.0, 6.0), (7.0, 6.0), (4.0, 7.0), (5.0, 7.0), (6.0, 7.0), (7.0, 7.0)]);
+/// ```
+pub struct Rectangle {
+    pub x: f64,
+    pub y: f64,
+    pub width: f64,
+    pub height: f64,
+    pub color: Color,
+}
+
+pub struct RectangleIterator<'a> {
+    rect: &'a Rectangle,
+    x: f64,
+    y: f64,
+    right: f64,
+    bottom: f64,
+}
+
+impl<'a> Iterator for RectangleIterator<'a> {
+    type Item = (f64, f64);
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.y < self.bottom {
+            let pos = (self.x, self.y);
+            let dx = if self.y == self.rect.y || self.y == self.bottom - 1.0 {
+                1.0
+            } else {
+                self.rect.width - 1.0
+            };
+            self.x += dx;
+            if self.x >= self.right {
+                self.x = self.rect.x;
+                self.y += 1.0;
+            }
+            Some(pos)
+        } else {
+            None
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a Rectangle {
+    type Item = (f64, f64);
+    type IntoIter = RectangleIterator<'a>;
+    fn into_iter(self) -> Self::IntoIter {
+        let right = self.x + self.width;
+        let bottom = self.y + self.height;
+        RectangleIterator {
+            rect: self,
+            x: self.x,
+            y: self.y,
+            right: right,
+            bottom: bottom,
+        }
+    }
+}
+
+impl<'a> Shape<'a> for Rectangle {
+    fn color(&self) -> Color {
+        self.color
+    }
+    fn points(&'a self) -> Box<Iterator<Item = (f64, f64)> + 'a> {
+        Box::new(self.into_iter())
+    }
+}

src/widgets/chart.rs

@@ -2,7 +2,8 @@ use std::cmp::max;
 
 use unicode_width::UnicodeWidthStr;
 
-use widgets::{Widget, Block, Canvas, Points};
+use widgets::{Widget, Block};
+use widgets::canvas::{Canvas, Points};
 use buffer::Buffer;
 use layout::Rect;
 use style::Color;
@@ -270,11 +271,11 @@ impl<'a> Widget for Chart<'a> {
         if let Some(x) = layout.label_y {
             let labels = self.y_axis.labels.unwrap();
             let labels_len = labels.len() as u16;
-            if labels_len > 1 {
-                for (i, label) in labels.iter().enumerate() {
+            for (i, label) in labels.iter().enumerate() {
+                let dy = i as u16 * (graph_area.height - 1) / (labels_len - 1);
+                if dy < graph_area.bottom() {
                     buf.set_string(x,
-                                   graph_area.bottom() -
-                                   i as u16 * (graph_area.height - 1) / (labels_len - 1),
+                                   graph_area.bottom() - 1 - dy,
                                    label,
                                    self.y_axis.labels_color,
                                    self.bg);
@@ -325,10 +326,10 @@ impl<'a> Widget for Chart<'a> {
                     Canvas::default()
                         .x_bounds(self.x_axis.bounds)
                         .y_bounds(self.y_axis.bounds)
-                        .shapes(&[&Points {
-                                      coords: dataset.data,
-                                      color: dataset.color,
-                                  }])
+                        .layers(&[&[&Points {
+                                        coords: dataset.data,
+                                        color: dataset.color,
+                                    }]])
                         .buffer(&graph_area, buf);
                 }
             }

src/widgets/gauge.rs

@@ -14,8 +14,8 @@ use layout::Rect;
 /// use tui::widgets::{Widget, Gauge, Block, border};
 ///
 /// fn main() {
-///     Gauge::new()
-///         .block(*Block::default().borders(border::ALL).title("Progress"))
+///     Gauge::default()
+///         .block(Block::default().borders(border::ALL).title("Progress"))
 ///         .percent(20);
 /// }
 /// ```

src/widgets/mod.rs

@@ -6,8 +6,7 @@ mod sparkline;
 mod chart;
 mod barchart;
 mod tabs;
-mod canvas;
-mod map;
+pub mod canvas;
 
 pub use self::block::Block;
 pub use self::text::Text;
@@ -17,8 +16,6 @@ pub use self::sparkline::Sparkline;
 pub use self::chart::{Chart, Axis, Dataset, Marker};
 pub use self::barchart::BarChart;
 pub use self::tabs::Tabs;
-pub use self::canvas::{Canvas, Shape, Line, Points};
-pub use self::map::Map;
 
 use buffer::Buffer;
 use layout::Rect;