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

use crate::{Backend, Defaults, Primitive};
use iced_native::layout::{self, Layout};
use iced_native::mouse;
use iced_native::{
    Background, Color, Element, Point, Rectangle, Vector, Widget,
};

/// A backend-agnostic renderer that supports all the built-in widgets.
#[derive(Debug)]
pub struct Renderer<B: Backend> {
    backend: B,
}

impl<B: Backend> Renderer<B> {
    /// Creates a new [`Renderer`] from the given [`Backend`].
    ///
    /// [`Renderer`]: struct.Renderer.html
    /// [`Backend`]: backend/trait.Backend.html
    pub fn new(backend: B) -> Self {
        Self { backend }
    }

    /// Returns a reference to the [`Backend`] of the [`Renderer`].
    ///
    /// [`Renderer`]: struct.Renderer.html
    /// [`Backend`]: backend/trait.Backend.html
    pub fn backend(&self) -> &B {
        &self.backend
    }

    /// Returns a mutable reference to the [`Backend`] of the [`Renderer`].
    ///
    /// [`Renderer`]: struct.Renderer.html
    /// [`Backend`]: backend/trait.Backend.html
    pub fn backend_mut(&mut self) -> &mut B {
        &mut self.backend
    }
}

impl<B> iced_native::Renderer for Renderer<B>
where
    B: Backend,
{
    type Output = (Primitive, mouse::Interaction);
    type Defaults = Defaults;

    fn layout<'a, Message>(
        &mut self,
        element: &Element<'a, Message, Self>,
        limits: &layout::Limits,
    ) -> layout::Node {
        let layout = element.layout(self, limits);

        self.backend.trim_measurements();

        layout
    }

    fn overlay(
        &mut self,
        (base_primitive, base_cursor): (Primitive, mouse::Interaction),
        (overlay_primitives, overlay_cursor): (Primitive, mouse::Interaction),
        overlay_bounds: Rectangle,
    ) -> (Primitive, mouse::Interaction) {
        (
            Primitive::Group {
                primitives: vec![
                    base_primitive,
                    Primitive::Clip {
                        bounds: Rectangle {
                            width: overlay_bounds.width + 0.5,
                            height: overlay_bounds.height + 0.5,
                            ..overlay_bounds
                        },
                        offset: Vector::new(0, 0),
                        content: Box::new(overlay_primitives),
                    },
                ],
            },
            if base_cursor > overlay_cursor {
                base_cursor
            } else {
                overlay_cursor
            },
        )
    }
}

impl<B> layout::Debugger for Renderer<B>
where
    B: Backend,
{
    fn explain<Message>(
        &mut self,
        defaults: &Defaults,
        widget: &dyn Widget<Message, Self>,
        layout: Layout<'_>,
        cursor_position: Point,
        color: Color,
    ) -> Self::Output {
        let (primitive, cursor) =
            widget.draw(self, defaults, layout, cursor_position);

        let mut primitives = Vec::new();

        explain_layout(layout, color, &mut primitives);
        primitives.push(primitive);

        (Primitive::Group { primitives }, cursor)
    }
}

fn explain_layout(
    layout: Layout<'_>,
    color: Color,
    primitives: &mut Vec<Primitive>,
) {
    primitives.push(Primitive::Quad {
        bounds: layout.bounds(),
        background: Background::Color(Color::TRANSPARENT),
        border_radius: 0,
        border_width: 1,
        border_color: [0.6, 0.6, 0.6, 0.5].into(),
    });

    for child in layout.children() {
        explain_layout(child, color, primitives);
    }
}