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
|
use crate::canvas::mouse;
use crate::canvas::{Event, Geometry};
use crate::core::Rectangle;
use crate::graphics::geometry;
use crate::Action;
/// The state and logic of a [`Canvas`].
///
/// A [`Program`] can mutate internal state and produce messages for an
/// application.
///
/// [`Canvas`]: crate::Canvas
pub trait Program<Message, Theme = crate::Theme, Renderer = crate::Renderer>
where
Renderer: geometry::Renderer,
{
/// The internal state mutated by the [`Program`].
type State: Default + 'static;
/// Updates the [`State`](Self::State) of the [`Program`].
///
/// When a [`Program`] is used in a [`Canvas`], the runtime will call this
/// method for each [`Event`].
///
/// This method can optionally return an [`Action`] to either notify an
/// application of any meaningful interactions, capture the event, or
/// request a redraw.
///
/// By default, this method does and returns nothing.
///
/// [`Canvas`]: crate::Canvas
fn update(
&self,
_state: &mut Self::State,
_event: &Event,
_bounds: Rectangle,
_cursor: mouse::Cursor,
) -> Option<Action<Message>> {
None
}
/// Draws the state of the [`Program`], producing a bunch of [`Geometry`].
///
/// [`Geometry`] can be easily generated with a [`Frame`] or stored in a
/// [`Cache`].
///
/// [`Geometry`]: crate::canvas::Geometry
/// [`Frame`]: crate::canvas::Frame
/// [`Cache`]: crate::canvas::Cache
fn draw(
&self,
state: &Self::State,
renderer: &Renderer,
theme: &Theme,
bounds: Rectangle,
cursor: mouse::Cursor,
) -> Vec<Geometry<Renderer>>;
/// Returns the current mouse interaction of the [`Program`].
///
/// The interaction returned will be in effect even if the cursor position
/// is out of bounds of the program's [`Canvas`].
///
/// [`Canvas`]: crate::Canvas
fn mouse_interaction(
&self,
_state: &Self::State,
_bounds: Rectangle,
_cursor: mouse::Cursor,
) -> mouse::Interaction {
mouse::Interaction::default()
}
}
impl<Message, Theme, Renderer, T> Program<Message, Theme, Renderer> for &T
where
Renderer: geometry::Renderer,
T: Program<Message, Theme, Renderer>,
{
type State = T::State;
fn update(
&self,
state: &mut Self::State,
event: &Event,
bounds: Rectangle,
cursor: mouse::Cursor,
) -> Option<Action<Message>> {
T::update(self, state, event, bounds, cursor)
}
fn draw(
&self,
state: &Self::State,
renderer: &Renderer,
theme: &Theme,
bounds: Rectangle,
cursor: mouse::Cursor,
) -> Vec<Geometry<Renderer>> {
T::draw(self, state, renderer, theme, bounds, cursor)
}
fn mouse_interaction(
&self,
state: &Self::State,
bounds: Rectangle,
cursor: mouse::Cursor,
) -> mouse::Interaction {
T::mouse_interaction(self, state, bounds, cursor)
}
}
|
