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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
use crate::event::{self, Event};
use crate::layout::{self, Layout};
use crate::mouse;
use crate::renderer;
use crate::{
Clipboard, Element, Hasher, Length, Point, Rectangle, Shell, Size, Widget,
};
use std::cell::RefCell;
use std::hash::Hasher as _;
#[derive(Debug, Clone, Default)]
pub struct State {
last_size: Option<Size>,
last_layout: layout::Node,
last_layout_hash: u64,
}
impl State {
pub fn new() -> State {
State::default()
}
}
#[allow(missing_debug_implementations)]
pub struct Responsive<'a, Message, Renderer>(
RefCell<Internal<'a, Message, Renderer>>,
);
impl<'a, Message, Renderer> Responsive<'a, Message, Renderer> {
pub fn new(
state: &'a mut State,
view: impl FnOnce(Size) -> Element<'a, Message, Renderer> + 'a,
) -> Self {
Self(RefCell::new(Internal {
state,
content: Content::Pending(Some(Box::new(view))),
}))
}
}
impl<'a, Message, Renderer> Widget<Message, Renderer>
for Responsive<'a, Message, Renderer>
where
Renderer: crate::Renderer,
{
fn width(&self) -> Length {
Length::Fill
}
fn height(&self) -> Length {
Length::Fill
}
fn hash_layout(&self, _hasher: &mut Hasher) {}
fn layout(
&self,
_renderer: &Renderer,
limits: &layout::Limits,
) -> layout::Node {
let size = limits.max();
self.0.borrow_mut().state.last_size = Some(size);
layout::Node::new(size)
}
fn on_event(
&mut self,
event: Event,
layout: Layout<'_>,
cursor_position: Point,
renderer: &Renderer,
clipboard: &mut dyn Clipboard,
shell: &mut Shell<'_, Message>,
) -> event::Status {
let mut internal = self.0.borrow_mut();
if internal.state.last_size != Some(internal.state.last_layout.size()) {
shell.invalidate_widgets();
}
let (content, content_layout) = internal.content(layout, renderer);
content.on_event(
event,
content_layout,
cursor_position,
renderer,
clipboard,
shell,
)
}
fn draw(
&self,
renderer: &mut Renderer,
style: &renderer::Style,
layout: Layout<'_>,
cursor_position: Point,
viewport: &Rectangle,
) {
let mut internal = self.0.borrow_mut();
let (content, content_layout) = internal.content(layout, renderer);
content.draw(renderer, style, content_layout, cursor_position, viewport)
}
fn mouse_interaction(
&self,
layout: Layout<'_>,
cursor_position: Point,
viewport: &Rectangle,
renderer: &Renderer,
) -> mouse::Interaction {
let mut internal = self.0.borrow_mut();
let (content, content_layout) = internal.content(layout, renderer);
content.mouse_interaction(
content_layout,
cursor_position,
viewport,
renderer,
)
}
}
struct Internal<'a, Message, Renderer> {
state: &'a mut State,
content: Content<'a, Message, Renderer>,
}
impl<'a, Message, Renderer> Internal<'a, Message, Renderer>
where
Renderer: crate::Renderer,
{
fn content(
&mut self,
layout: Layout<'_>,
renderer: &Renderer,
) -> (&mut Element<'a, Message, Renderer>, Layout<'_>) {
let content = self.content.resolve(&mut self.state, renderer);
let content_layout = Layout::with_offset(
layout.position() - Point::ORIGIN,
&self.state.last_layout,
);
(content, content_layout)
}
}
enum Content<'a, Message, Renderer> {
Pending(
Option<Box<dyn FnOnce(Size) -> Element<'a, Message, Renderer> + 'a>>,
),
Ready(Element<'a, Message, Renderer>),
}
impl<'a, Message, Renderer> Content<'a, Message, Renderer>
where
Renderer: crate::Renderer,
{
fn resolve(
&mut self,
state: &mut State,
renderer: &Renderer,
) -> &mut Element<'a, Message, Renderer> {
match self {
Content::Ready(element) => element,
Content::Pending(view) => {
let element =
view.take().unwrap()(state.last_size.unwrap_or(Size::ZERO));
let new_layout_hash = {
let mut hasher = Hasher::default();
element.hash_layout(&mut hasher);
hasher.finish()
};
if new_layout_hash != state.last_layout_hash {
state.last_layout = element.layout(
renderer,
&layout::Limits::new(
Size::ZERO,
state.last_size.unwrap_or(Size::ZERO),
),
);
state.last_layout_hash = new_layout_hash;
}
*self = Content::Ready(element);
self.resolve(state, renderer)
}
}
}
}
impl<'a, Message, Renderer> From<Responsive<'a, Message, Renderer>>
for Element<'a, Message, Renderer>
where
Renderer: crate::Renderer + 'a,
Message: 'a,
{
fn from(responsive: Responsive<'a, Message, Renderer>) -> Self {
Self::new(responsive)
}
}
|
