1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

//! A widget for plotting a series of lines using the given function *x -> y*.

use graph;
use num;
use utils;
use widget;
use {Color, Colorable, Point, Positionable, Scalar, Sizeable, Theme, Widget};

/// A widget that plots a series of lines using the given function *x -> y*.
///
/// The function is sampled once per pixel and the result is mapped to the widget's height.
///
/// The resulting "path" is drawn using conrod's `PointPath` primitive widget.
#[derive(WidgetCommon_)]
pub struct PlotPath<X, Y, F> {
    #[conrod(common_builder)]
    common: widget::CommonBuilder,
    style: Style,
    min_x: X,
    max_x: X,
    min_y: Y,
    max_y: Y,
    f: F,
}

/// Unique styling parameters for the `PlotPath` widget.
#[derive(Copy, Clone, Debug, Default, PartialEq, WidgetStyle_)]
pub struct Style {
    /// The thickness of the plotted line.
    #[conrod(default = "1.0")]
    pub thickness: Option<Scalar>,
    /// The color of the line.
    #[conrod(default = "theme.shape_color")]
    pub color: Option<Color>,
}

widget_ids! {
    struct Ids {
        point_path,
    }
}

/// Unique state stored between updates for the `PlotPath` widget.
pub struct State {
    ids: Ids,
}

impl<X, Y, F> PlotPath<X, Y, F> {
    /// Begin building a new `PlotPath` widget instance.
    pub fn new(min_x: X, max_x: X, min_y: Y, max_y: Y, f: F) -> Self {
        PlotPath {
            common: widget::CommonBuilder::default(),
            style: Style::default(),
            min_x: min_x,
            max_x: max_x,
            min_y: min_y,
            max_y: max_y,
            f: f,
        }
    }

    /// The thickness of the point path used to draw the plot.
    pub fn thickness(mut self, thickness: Scalar) -> Self {
        self.style.thickness = Some(thickness);
        self
    }
}

impl<X, Y, F> Widget for PlotPath<X, Y, F>
where
    X: num::NumCast + Clone,
    Y: num::NumCast + Clone,
    F: FnMut(X) -> Y,
{
    type State = State;
    type Style = Style;
    type Event = ();

    fn init_state(&self, id_gen: widget::id::Generator) -> Self::State {
        State {
            ids: Ids::new(id_gen),
        }
    }

    fn style(&self) -> Self::Style {
        self.style.clone()
    }

    fn is_over(&self) -> widget::IsOverFn {
        fn is_over_widget(widget: &graph::Container, _: Point, _: &Theme) -> widget::IsOver {
            let unique = widget.state_and_style::<State, Style>().unwrap();
            unique.state.ids.point_path.into()
        }
        is_over_widget
    }

    /// Update the state of the PlotPath.
    fn update(self, args: widget::UpdateArgs<Self>) -> Self::Event {
        let widget::UpdateArgs {
            id,
            state,
            style,
            rect,
            ui,
            ..
        } = args;
        let PlotPath {
            min_x,
            max_x,
            min_y,
            max_y,
            mut f,
            ..
        } = self;

        let y_to_scalar =
            |y| utils::map_range(y, min_y.clone(), max_y.clone(), rect.bottom(), rect.top());
        let scalar_to_x =
            |s| utils::map_range(s, rect.left(), rect.right(), min_x.clone(), max_x.clone());

        let point_iter = (0..rect.w() as usize).map(|x_scalar| {
            let x_scalar = x_scalar as Scalar + rect.x.start;
            let x = scalar_to_x(x_scalar);
            let y = f(x);
            let y_scalar = y_to_scalar(y);
            [x_scalar, y_scalar]
        });

        let thickness = style.thickness(ui.theme());
        let color = style.color(ui.theme());
        widget::PointPath::new(point_iter)
            .wh(rect.dim())
            .xy(rect.xy())
            .color(color)
            .thickness(thickness)
            .parent(id)
            .graphics_for(id)
            .set(state.ids.point_path, ui);
    }
}

impl<X, Y, F> Colorable for PlotPath<X, Y, F> {
    builder_method!(color { style.color = Some(Color) });
}