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
use crate::core::IntoElementsMaybeSignal;
use cfg_if::cfg_if;
use default_struct_builder::DefaultBuilder;
use leptos::reactive::wrappers::read::Signal;
cfg_if! { if #[cfg(not(feature = "ssr"))] {
use crate::{sendwrap_fn, use_supported};
use std::cell::RefCell;
use std::rc::Rc;
use wasm_bindgen::prelude::*;
use leptos::prelude::*;
}}
/// Reports changes to the dimensions of an Element's content or the border-box.
///
/// Please refer to [ResizeObserver on MDN](https://developer.mozilla.org/en-US/docs/Web/API/ResizeObserver)
/// for more details.
///
/// ## Demo
///
/// [Link to Demo](https://github.com/Synphonyte/leptos-use/tree/main/examples/use_resize_observer)
///
/// ## Usage
///
/// ```
/// # use leptos::{html::Div, prelude::*};
/// # use leptos_use::use_resize_observer;
/// #
/// # #[component]
/// # fn Demo() -> impl IntoView {
/// let el = NodeRef::<Div>::new();
/// let (text, set_text) = signal("".to_string());
///
/// use_resize_observer(
/// el,
/// move |entries, observer| {
/// let rect = entries[0].content_rect();
/// set_text.set(format!("width: {}\nheight: {}", rect.width(), rect.height()));
/// },
/// );
///
/// view! {
/// <div node_ref=el>{ move || text.get() }</div>
/// }
/// # }
/// ```
///
/// ## SendWrapped Return
///
/// The returned closure `stop` is a sendwrapped function. It can
/// only be called from the same thread that called `use_resize_observer`.
///
/// ## Server-Side Rendering
///
/// On the server this amounts to a no-op.
///
/// ## See also
///
/// * [`fn@crate::use_element_size`]
pub fn use_resize_observer<Els, M, F>(
target: Els,
callback: F,
) -> UseResizeObserverReturn<impl Fn() + Clone + Send + Sync>
where
Els: IntoElementsMaybeSignal<web_sys::Element, M>,
F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + 'static,
{
use_resize_observer_with_options(target, callback, UseResizeObserverOptions::default())
}
/// Version of [`use_resize_observer`] that takes a `web_sys::ResizeObserverOptions`. See [`use_resize_observer`] for how to use.
#[cfg_attr(feature = "ssr", allow(unused_variables, unused_mut))]
pub fn use_resize_observer_with_options<Els, M, F>(
target: Els,
mut callback: F,
options: UseResizeObserverOptions,
) -> UseResizeObserverReturn<impl Fn() + Clone + Send + Sync>
where
Els: IntoElementsMaybeSignal<web_sys::Element, M>,
F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + 'static,
{
#[cfg(feature = "ssr")]
{
UseResizeObserverReturn {
is_supported: Signal::derive(|| true),
stop: || {},
}
}
#[cfg(not(feature = "ssr"))]
{
use crate::js;
let closure_js = Closure::<dyn FnMut(js_sys::Array, web_sys::ResizeObserver)>::new(
move |entries: js_sys::Array, observer| {
#[cfg(debug_assertions)]
let _z = leptos::reactive::diagnostics::SpecialNonReactiveZone::enter();
callback(
entries
.to_vec()
.into_iter()
.map(|v| v.unchecked_into::<web_sys::ResizeObserverEntry>())
.collect(),
observer,
);
},
)
.into_js_value();
let observer: Rc<RefCell<Option<web_sys::ResizeObserver>>> = Rc::new(RefCell::new(None));
let is_supported = use_supported(|| js!("ResizeObserver" in &window()));
let cleanup = {
let observer = Rc::clone(&observer);
move || {
let mut observer = observer.borrow_mut();
if let Some(o) = observer.as_ref() {
o.disconnect();
*observer = None;
}
}
};
let targets = target.into_elements_maybe_signal();
let stop_watch = {
let cleanup = cleanup.clone();
let stop = Effect::watch(
move || targets.get(),
move |targets, _, _| {
cleanup();
if is_supported.get_untracked() && !targets.is_empty() {
let obs = web_sys::ResizeObserver::new(
closure_js.clone().as_ref().unchecked_ref(),
)
.expect("failed to create ResizeObserver");
for target in targets.iter().flatten() {
let target = target.clone();
obs.observe_with_options(&target, &options.clone().into());
}
observer.replace(Some(obs));
}
},
true,
);
move || stop.stop()
};
let stop = sendwrap_fn!(move || {
cleanup();
stop_watch();
});
on_cleanup({
let stop = stop.clone();
#[allow(clippy::redundant_closure)]
move || stop()
});
UseResizeObserverReturn { is_supported, stop }
}
}
/// Options for [`use_resize_observer_with_options`].
#[derive(DefaultBuilder, Clone, Default)]
pub struct UseResizeObserverOptions {
/// The box that is used to determine the dimensions of the target. Defaults to `ContentBox`.
#[builder(into)]
pub box_: Option<web_sys::ResizeObserverBoxOptions>,
}
impl From<UseResizeObserverOptions> for web_sys::ResizeObserverOptions {
fn from(val: UseResizeObserverOptions) -> Self {
let options = web_sys::ResizeObserverOptions::new();
options.set_box(
val.box_
.unwrap_or(web_sys::ResizeObserverBoxOptions::ContentBox),
);
options
}
}
/// The return value of [`use_resize_observer`].
pub struct UseResizeObserverReturn<F: Fn() + Clone + Send + Sync> {
/// Whether the browser supports the ResizeObserver API
pub is_supported: Signal<bool>,
/// A function to stop and detach the ResizeObserver
pub stop: F,
}