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use crate::core::IntoElementMaybeSignal;
use crate::core::Size;
use cfg_if::cfg_if;
use default_struct_builder::DefaultBuilder;
use leptos::prelude::*;
use leptos::reactive::wrappers::read::Signal;
cfg_if! { if #[cfg(not(feature = "ssr"))] {
use crate::{use_resize_observer_with_options, UseResizeObserverOptions};
use crate::{watch_with_options, WatchOptions};
use wasm_bindgen::JsCast;
}}
/// Reactive size of an HTML element.
///
/// 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_element_size)
///
/// ## Usage
///
/// ```
/// # use leptos::{html::Div, prelude::*};
/// # use leptos_use::{use_element_size, UseElementSizeReturn};
/// #
/// # #[component]
/// # fn Demo() -> impl IntoView {
/// let el = NodeRef::<Div>::new();
///
/// let UseElementSizeReturn { width, height } = use_element_size(el);
///
/// view! {
/// <div node_ref=el>
/// "Width: " {width}
/// "Height: " {height}
/// </div>
/// }
/// # }
/// ```
///
/// ## Server-Side Rendering
///
/// On the server the returned signals always contain the value of the `initial_size` option.
///
/// ## See also
///
/// - [`fn@crate::use_resize_observer`]
pub fn use_element_size<El, M>(target: El) -> UseElementSizeReturn
where
El: IntoElementMaybeSignal<web_sys::Element, M>,
{
use_element_size_with_options(target, UseElementSizeOptions::default())
}
/// Version of [`use_element_size`] that takes a `UseElementSizeOptions`. See [`use_element_size`] for how to use.
#[cfg_attr(feature = "ssr", allow(unused_variables))]
pub fn use_element_size_with_options<El, M>(
target: El,
options: UseElementSizeOptions,
) -> UseElementSizeReturn
where
El: IntoElementMaybeSignal<web_sys::Element, M>,
{
let UseElementSizeOptions { box_, initial_size } = options;
let (width, set_width) = signal(initial_size.width);
let (height, set_height) = signal(initial_size.height);
#[cfg(not(feature = "ssr"))]
{
let box_ = box_.unwrap_or(web_sys::ResizeObserverBoxOptions::ContentBox);
let target = target.into_element_maybe_signal();
let is_svg = move || {
if let Some(target) = target.get_untracked() {
target
.namespace_uri()
.map(|ns| ns.contains("svg"))
.unwrap_or(false)
} else {
false
}
};
let _ = use_resize_observer_with_options(
target,
move |entries, _| {
let entry = &entries[0];
let box_size = match box_ {
web_sys::ResizeObserverBoxOptions::ContentBox => entry.content_box_size(),
web_sys::ResizeObserverBoxOptions::BorderBox => entry.border_box_size(),
web_sys::ResizeObserverBoxOptions::DevicePixelContentBox => {
entry.device_pixel_content_box_size()
}
_ => unreachable!(),
};
if is_svg() {
if let Some(target) = target.get() {
if let Ok(Some(styles)) = window().get_computed_style(&target) {
set_height.set(
styles
.get_property_value("height")
.map(|v| v.parse().unwrap_or_default())
.unwrap_or_default(),
);
set_width.set(
styles
.get_property_value("width")
.map(|v| v.parse().unwrap_or_default())
.unwrap_or_default(),
);
}
}
} else if !box_size.is_null() && !box_size.is_undefined() && box_size.length() > 0 {
let format_box_size = if box_size.is_array() {
box_size.to_vec()
} else {
vec![box_size.into()]
};
set_width.set(format_box_size.iter().fold(0.0, |acc, v| {
acc + v
.as_ref()
.clone()
.unchecked_into::<web_sys::ResizeObserverSize>()
.inline_size()
}));
set_height.set(format_box_size.iter().fold(0.0, |acc, v| {
acc + v
.as_ref()
.clone()
.unchecked_into::<web_sys::ResizeObserverSize>()
.block_size()
}))
} else {
// fallback
set_width.set(entry.content_rect().width());
set_height.set(entry.content_rect().height())
}
},
UseResizeObserverOptions::default().box_(box_),
);
let _ = watch_with_options(
move || target.get(),
move |ele, _, _| {
if ele.is_some() {
set_width.set(initial_size.width);
set_height.set(initial_size.height);
} else {
set_width.set(0.0);
set_height.set(0.0);
}
},
WatchOptions::default().immediate(false),
);
}
UseElementSizeReturn {
width: width.into(),
height: height.into(),
}
}
#[derive(DefaultBuilder, Default)]
/// Options for [`use_element_size_with_options`].
pub struct UseElementSizeOptions {
/// Initial size returned before any measurements on the `target` are done. Also the value reported
/// at first when the `target` is a signal and changes.
initial_size: Size,
/// The box that is used to determine the dimensions of the target. Defaults to `ContentBox`.
#[builder(into)]
pub box_: Option<web_sys::ResizeObserverBoxOptions>,
}
/// The return value of [`use_element_size`].
pub struct UseElementSizeReturn {
/// The width of the element.
pub width: Signal<f64>,
/// The height of the element.
pub height: Signal<f64>,
}