From 849e7503ab840ee6b548d26dfc4320c22fc62947 Mon Sep 17 00:00:00 2001
From: Maccesch <maccesch@synphonyte.com>
Date: Wed, 31 May 2023 05:56:32 +0100
Subject: [PATCH] finished use_resize_observer

---
 .cargo/config.toml                            |   2 +
 .idea/leptos-use.iml                          |   2 +
 Cargo.toml                                    |   1 +
 docs/book/src/SUMMARY.md                      |   4 +
 docs/book/src/demo.css                        |   5 +
 docs/book/src/elements/use_resize_observer.md |   3 +
 docs/book/src/getting_started/functions.md    |   2 +
 examples/use_debounce_fn/src/main.rs          |   4 +-
 .../use_resize_observer/.cargo/config.toml    |   2 +
 examples/use_resize_observer/Cargo.toml       |  16 +
 examples/use_resize_observer/README.md        |  23 ++
 examples/use_resize_observer/Trunk.toml       |   2 +
 examples/use_resize_observer/index.html       |   7 +
 examples/use_resize_observer/input.css        |   3 +
 .../use_resize_observer/rust-toolchain.toml   |   2 +
 examples/use_resize_observer/src/main.rs      |  32 ++
 examples/use_resize_observer/style/output.css | 353 ++++++++++++++++++
 .../use_resize_observer/tailwind.config.js    |  15 +
 examples/use_throttle_fn/src/main.rs          |   4 +-
 src/docs/mod.rs                               |   2 +
 src/docs/note.rs                              |  10 +
 src/use_resize_observer.rs                    | 128 +++++--
 22 files changed, 593 insertions(+), 29 deletions(-)
 create mode 100644 .cargo/config.toml
 create mode 100644 docs/book/src/elements/use_resize_observer.md
 create mode 100644 examples/use_resize_observer/.cargo/config.toml
 create mode 100644 examples/use_resize_observer/Cargo.toml
 create mode 100644 examples/use_resize_observer/README.md
 create mode 100644 examples/use_resize_observer/Trunk.toml
 create mode 100644 examples/use_resize_observer/index.html
 create mode 100644 examples/use_resize_observer/input.css
 create mode 100644 examples/use_resize_observer/rust-toolchain.toml
 create mode 100644 examples/use_resize_observer/src/main.rs
 create mode 100644 examples/use_resize_observer/style/output.css
 create mode 100644 examples/use_resize_observer/tailwind.config.js
 create mode 100644 src/docs/note.rs

diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 0000000..8467175
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,2 @@
+[build]
+rustflags = ["--cfg=web_sys_unstable_apis"]
diff --git a/.idea/leptos-use.iml b/.idea/leptos-use.iml
index 0935529..7e9f411 100644
--- a/.idea/leptos-use.iml
+++ b/.idea/leptos-use.iml
@@ -13,6 +13,7 @@
       <sourceFolder url="file://$MODULE_DIR$/examples/use_throttle_fn/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/examples/use_debounce_fn/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/examples/use_scroll/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/examples/use_resize_observer/src" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/examples/use_event_listener/target" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
       <excludeFolder url="file://$MODULE_DIR$/docs/book/book" />
@@ -22,6 +23,7 @@
       <excludeFolder url="file://$MODULE_DIR$/examples/use_debounce_fn/dist" />
       <excludeFolder url="file://$MODULE_DIR$/examples/use_debounce_fn/target" />
       <excludeFolder url="file://$MODULE_DIR$/examples/use_scroll/target" />
+      <excludeFolder url="file://$MODULE_DIR$/examples/use_resize_observer/target" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
diff --git a/Cargo.toml b/Cargo.toml
index cedd725..2c80b9f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,6 +30,7 @@ features = [
     "ResizeObserverSize",
     "ResizeObserverEntry",
     "Navigator",
+    "DomRectReadOnly",
 ]
 
 [features]
diff --git a/docs/book/src/SUMMARY.md b/docs/book/src/SUMMARY.md
index 8d86c14..17971d3 100644
--- a/docs/book/src/SUMMARY.md
+++ b/docs/book/src/SUMMARY.md
@@ -8,6 +8,10 @@
 - [Get Started](getting_started/get_started.md)
 - [Functions](getting_started/functions.md)
 
+# Elements
+
+- [use_resize_observer](elements/use_resize_observer.md)
+
 # Browser
 
 - [use_event_listener](browser/use_event_listener.md)
diff --git a/docs/book/src/demo.css b/docs/book/src/demo.css
index 7adf66a..16b06a8 100644
--- a/docs/book/src/demo.css
+++ b/docs/book/src/demo.css
@@ -73,4 +73,9 @@
     color: var(--text-color);
     min-width: 20rem;
     margin: .5rem 0;
+}
+
+.demo-container textarea {
+    background: var(--bg);
+    border: 1px solid var(--theme-popup-border);
 }
\ No newline at end of file
diff --git a/docs/book/src/elements/use_resize_observer.md b/docs/book/src/elements/use_resize_observer.md
new file mode 100644
index 0000000..1fc17bc
--- /dev/null
+++ b/docs/book/src/elements/use_resize_observer.md
@@ -0,0 +1,3 @@
+# use_resize_observer
+
+<!-- cmdrun python3 ../extract_doc_comment.py use_resize_observer -->
diff --git a/docs/book/src/getting_started/functions.md b/docs/book/src/getting_started/functions.md
index e3d8d25..6679ddf 100644
--- a/docs/book/src/getting_started/functions.md
+++ b/docs/book/src/getting_started/functions.md
@@ -1,5 +1,7 @@
 # Functions
 
+<!-- cmdrun python3 generate_function_overview.py elements -->
+
 <!-- cmdrun python3 generate_function_overview.py browser -->
 
 <!-- cmdrun python3 generate_function_overview.py sensors -->
diff --git a/examples/use_debounce_fn/src/main.rs b/examples/use_debounce_fn/src/main.rs
index 9416a02..ab9c589 100644
--- a/examples/use_debounce_fn/src/main.rs
+++ b/examples/use_debounce_fn/src/main.rs
@@ -1,5 +1,5 @@
 use leptos::*;
-use leptos_use::docs::demo_or_body;
+use leptos_use::docs::{demo_or_body, Note};
 use leptos_use::{use_debounce_fn_with_options, DebounceOptions};
 
 #[component]
@@ -22,7 +22,7 @@ fn Demo(cx: Scope) -> impl IntoView {
         >
             "Smash me!"
         </button>
-        <div class="note">"Delay is set to 1000ms and max_wait is set to 5000ms for this demo."</div>
+        <Note>"Delay is set to 1000ms and max_wait is set to 5000ms for this demo."</Note>
         <p>"Button clicked: " { click_count }</p>
         <p>"Event handler called: " { debounced_count }</p>
     }
diff --git a/examples/use_resize_observer/.cargo/config.toml b/examples/use_resize_observer/.cargo/config.toml
new file mode 100644
index 0000000..8467175
--- /dev/null
+++ b/examples/use_resize_observer/.cargo/config.toml
@@ -0,0 +1,2 @@
+[build]
+rustflags = ["--cfg=web_sys_unstable_apis"]
diff --git a/examples/use_resize_observer/Cargo.toml b/examples/use_resize_observer/Cargo.toml
new file mode 100644
index 0000000..0078693
--- /dev/null
+++ b/examples/use_resize_observer/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "use_resize_observer"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+leptos = "0.3"
+console_error_panic_hook = "0.1"
+console_log = "1"
+log = "0.4"
+leptos-use = { path = "../..", features = ["docs"] }
+web-sys = "0.3"
+
+[dev-dependencies]
+wasm-bindgen = "0.2"
+wasm-bindgen-test = "0.3.0"
diff --git a/examples/use_resize_observer/README.md b/examples/use_resize_observer/README.md
new file mode 100644
index 0000000..a8d6387
--- /dev/null
+++ b/examples/use_resize_observer/README.md
@@ -0,0 +1,23 @@
+A simple example for `use_resize_observer`.
+
+If you don't have it installed already, install [Trunk](https://trunkrs.dev/) and [Tailwind](https://tailwindcss.com/docs/installation)
+as well as the nightly toolchain for Rust and the wasm32-unknown-unknown target:
+
+```bash
+cargo install trunk
+npm install -D tailwindcss @tailwindcss/forms
+rustup toolchain install nightly
+rustup target add wasm32-unknown-unknown
+```
+
+Then, open two terminals. In the first one, run:
+
+```
+npx tailwindcss -i ./input.css -o ./style/output.css --watch
+```
+
+In the second one, run:
+
+```bash
+trunk serve --open
+```
\ No newline at end of file
diff --git a/examples/use_resize_observer/Trunk.toml b/examples/use_resize_observer/Trunk.toml
new file mode 100644
index 0000000..3e4be08
--- /dev/null
+++ b/examples/use_resize_observer/Trunk.toml
@@ -0,0 +1,2 @@
+[build]
+public_url = "/demo/"
\ No newline at end of file
diff --git a/examples/use_resize_observer/index.html b/examples/use_resize_observer/index.html
new file mode 100644
index 0000000..ae249a6
--- /dev/null
+++ b/examples/use_resize_observer/index.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <link data-trunk rel="css" href="style/output.css">
+  </head>
+  <body></body>
+</html>
diff --git a/examples/use_resize_observer/input.css b/examples/use_resize_observer/input.css
new file mode 100644
index 0000000..bd6213e
--- /dev/null
+++ b/examples/use_resize_observer/input.css
@@ -0,0 +1,3 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
\ No newline at end of file
diff --git a/examples/use_resize_observer/rust-toolchain.toml b/examples/use_resize_observer/rust-toolchain.toml
new file mode 100644
index 0000000..271800c
--- /dev/null
+++ b/examples/use_resize_observer/rust-toolchain.toml
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"
\ No newline at end of file
diff --git a/examples/use_resize_observer/src/main.rs b/examples/use_resize_observer/src/main.rs
new file mode 100644
index 0000000..f1d34fe
--- /dev/null
+++ b/examples/use_resize_observer/src/main.rs
@@ -0,0 +1,32 @@
+use leptos::*;
+use leptos_use::docs::{demo_or_body, BooleanDisplay, Note};
+use leptos_use::{use_resize_observer, UseResizeReturn};
+
+#[component]
+fn Demo(cx: Scope) -> impl IntoView {
+    let el = create_node_ref(cx);
+    let (text, set_text) = create_signal(cx, "".to_string());
+
+    use_resize_observer(cx, el, move |entries, observer| {
+        let rect = entries[0].content_rect();
+        set_text(format!(
+            "width: {:.0}\nheight: {:.0}",
+            rect.width(),
+            rect.height()
+        ));
+    });
+
+    view! { cx,
+        <Note class="mb-2">"Resize the box to see changes"</Note>
+        <textarea node_ref=el class="resize rounded-md p-4 w-[200px] h-[100px] text-2xl leading-10" disabled prop:value=text />
+    }
+}
+
+fn main() {
+    _ = console_log::init_with_level(log::Level::Debug);
+    console_error_panic_hook::set_once();
+
+    mount_to(demo_or_body(), |cx| {
+        view! { cx, <Demo /> }
+    })
+}
diff --git a/examples/use_resize_observer/style/output.css b/examples/use_resize_observer/style/output.css
new file mode 100644
index 0000000..45e5f83
--- /dev/null
+++ b/examples/use_resize_observer/style/output.css
@@ -0,0 +1,353 @@
+[type='text'],[type='email'],[type='url'],[type='password'],[type='number'],[type='date'],[type='datetime-local'],[type='month'],[type='search'],[type='tel'],[type='time'],[type='week'],[multiple],textarea,select {
+  -webkit-appearance: none;
+     -moz-appearance: none;
+          appearance: none;
+  background-color: #fff;
+  border-color: #6b7280;
+  border-width: 1px;
+  border-radius: 0px;
+  padding-top: 0.5rem;
+  padding-right: 0.75rem;
+  padding-bottom: 0.5rem;
+  padding-left: 0.75rem;
+  font-size: 1rem;
+  line-height: 1.5rem;
+  --tw-shadow: 0 0 #0000;
+}
+
+[type='text']:focus, [type='email']:focus, [type='url']:focus, [type='password']:focus, [type='number']:focus, [type='date']:focus, [type='datetime-local']:focus, [type='month']:focus, [type='search']:focus, [type='tel']:focus, [type='time']:focus, [type='week']:focus, [multiple]:focus, textarea:focus, select:focus {
+  outline: 2px solid transparent;
+  outline-offset: 2px;
+  --tw-ring-inset: var(--tw-empty,/*!*/ /*!*/);
+  --tw-ring-offset-width: 0px;
+  --tw-ring-offset-color: #fff;
+  --tw-ring-color: #2563eb;
+  --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);
+  --tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(1px + var(--tw-ring-offset-width)) var(--tw-ring-color);
+  box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow);
+  border-color: #2563eb;
+}
+
+input::-moz-placeholder, textarea::-moz-placeholder {
+  color: #6b7280;
+  opacity: 1;
+}
+
+input::placeholder,textarea::placeholder {
+  color: #6b7280;
+  opacity: 1;
+}
+
+::-webkit-datetime-edit-fields-wrapper {
+  padding: 0;
+}
+
+::-webkit-date-and-time-value {
+  min-height: 1.5em;
+}
+
+::-webkit-datetime-edit,::-webkit-datetime-edit-year-field,::-webkit-datetime-edit-month-field,::-webkit-datetime-edit-day-field,::-webkit-datetime-edit-hour-field,::-webkit-datetime-edit-minute-field,::-webkit-datetime-edit-second-field,::-webkit-datetime-edit-millisecond-field,::-webkit-datetime-edit-meridiem-field {
+  padding-top: 0;
+  padding-bottom: 0;
+}
+
+select {
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
+  background-position: right 0.5rem center;
+  background-repeat: no-repeat;
+  background-size: 1.5em 1.5em;
+  padding-right: 2.5rem;
+  -webkit-print-color-adjust: exact;
+          print-color-adjust: exact;
+}
+
+[multiple] {
+  background-image: initial;
+  background-position: initial;
+  background-repeat: unset;
+  background-size: initial;
+  padding-right: 0.75rem;
+  -webkit-print-color-adjust: unset;
+          print-color-adjust: unset;
+}
+
+[type='checkbox'],[type='radio'] {
+  -webkit-appearance: none;
+     -moz-appearance: none;
+          appearance: none;
+  padding: 0;
+  -webkit-print-color-adjust: exact;
+          print-color-adjust: exact;
+  display: inline-block;
+  vertical-align: middle;
+  background-origin: border-box;
+  -webkit-user-select: none;
+     -moz-user-select: none;
+          user-select: none;
+  flex-shrink: 0;
+  height: 1rem;
+  width: 1rem;
+  color: #2563eb;
+  background-color: #fff;
+  border-color: #6b7280;
+  border-width: 1px;
+  --tw-shadow: 0 0 #0000;
+}
+
+[type='checkbox'] {
+  border-radius: 0px;
+}
+
+[type='radio'] {
+  border-radius: 100%;
+}
+
+[type='checkbox']:focus,[type='radio']:focus {
+  outline: 2px solid transparent;
+  outline-offset: 2px;
+  --tw-ring-inset: var(--tw-empty,/*!*/ /*!*/);
+  --tw-ring-offset-width: 2px;
+  --tw-ring-offset-color: #fff;
+  --tw-ring-color: #2563eb;
+  --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);
+  --tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(2px + var(--tw-ring-offset-width)) var(--tw-ring-color);
+  box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow);
+}
+
+[type='checkbox']:checked,[type='radio']:checked {
+  border-color: transparent;
+  background-color: currentColor;
+  background-size: 100% 100%;
+  background-position: center;
+  background-repeat: no-repeat;
+}
+
+[type='checkbox']:checked {
+  background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 16 16' fill='white' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M12.207 4.793a1 1 0 010 1.414l-5 5a1 1 0 01-1.414 0l-2-2a1 1 0 011.414-1.414L6.5 9.086l4.293-4.293a1 1 0 011.414 0z'/%3e%3c/svg%3e");
+}
+
+[type='radio']:checked {
+  background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 16 16' fill='white' xmlns='http://www.w3.org/2000/svg'%3e%3ccircle cx='8' cy='8' r='3'/%3e%3c/svg%3e");
+}
+
+[type='checkbox']:checked:hover,[type='checkbox']:checked:focus,[type='radio']:checked:hover,[type='radio']:checked:focus {
+  border-color: transparent;
+  background-color: currentColor;
+}
+
+[type='checkbox']:indeterminate {
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 16 16'%3e%3cpath stroke='white' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 8h8'/%3e%3c/svg%3e");
+  border-color: transparent;
+  background-color: currentColor;
+  background-size: 100% 100%;
+  background-position: center;
+  background-repeat: no-repeat;
+}
+
+[type='checkbox']:indeterminate:hover,[type='checkbox']:indeterminate:focus {
+  border-color: transparent;
+  background-color: currentColor;
+}
+
+[type='file'] {
+  background: unset;
+  border-color: inherit;
+  border-width: 0;
+  border-radius: 0;
+  padding: 0;
+  font-size: unset;
+  line-height: inherit;
+}
+
+[type='file']:focus {
+  outline: 1px solid ButtonText;
+  outline: 1px auto -webkit-focus-ring-color;
+}
+
+*, ::before, ::after {
+  --tw-border-spacing-x: 0;
+  --tw-border-spacing-y: 0;
+  --tw-translate-x: 0;
+  --tw-translate-y: 0;
+  --tw-rotate: 0;
+  --tw-skew-x: 0;
+  --tw-skew-y: 0;
+  --tw-scale-x: 1;
+  --tw-scale-y: 1;
+  --tw-pan-x:  ;
+  --tw-pan-y:  ;
+  --tw-pinch-zoom:  ;
+  --tw-scroll-snap-strictness: proximity;
+  --tw-gradient-from-position:  ;
+  --tw-gradient-via-position:  ;
+  --tw-gradient-to-position:  ;
+  --tw-ordinal:  ;
+  --tw-slashed-zero:  ;
+  --tw-numeric-figure:  ;
+  --tw-numeric-spacing:  ;
+  --tw-numeric-fraction:  ;
+  --tw-ring-inset:  ;
+  --tw-ring-offset-width: 0px;
+  --tw-ring-offset-color: #fff;
+  --tw-ring-color: rgb(59 130 246 / 0.5);
+  --tw-ring-offset-shadow: 0 0 #0000;
+  --tw-ring-shadow: 0 0 #0000;
+  --tw-shadow: 0 0 #0000;
+  --tw-shadow-colored: 0 0 #0000;
+  --tw-blur:  ;
+  --tw-brightness:  ;
+  --tw-contrast:  ;
+  --tw-grayscale:  ;
+  --tw-hue-rotate:  ;
+  --tw-invert:  ;
+  --tw-saturate:  ;
+  --tw-sepia:  ;
+  --tw-drop-shadow:  ;
+  --tw-backdrop-blur:  ;
+  --tw-backdrop-brightness:  ;
+  --tw-backdrop-contrast:  ;
+  --tw-backdrop-grayscale:  ;
+  --tw-backdrop-hue-rotate:  ;
+  --tw-backdrop-invert:  ;
+  --tw-backdrop-opacity:  ;
+  --tw-backdrop-saturate:  ;
+  --tw-backdrop-sepia:  ;
+}
+
+::backdrop {
+  --tw-border-spacing-x: 0;
+  --tw-border-spacing-y: 0;
+  --tw-translate-x: 0;
+  --tw-translate-y: 0;
+  --tw-rotate: 0;
+  --tw-skew-x: 0;
+  --tw-skew-y: 0;
+  --tw-scale-x: 1;
+  --tw-scale-y: 1;
+  --tw-pan-x:  ;
+  --tw-pan-y:  ;
+  --tw-pinch-zoom:  ;
+  --tw-scroll-snap-strictness: proximity;
+  --tw-gradient-from-position:  ;
+  --tw-gradient-via-position:  ;
+  --tw-gradient-to-position:  ;
+  --tw-ordinal:  ;
+  --tw-slashed-zero:  ;
+  --tw-numeric-figure:  ;
+  --tw-numeric-spacing:  ;
+  --tw-numeric-fraction:  ;
+  --tw-ring-inset:  ;
+  --tw-ring-offset-width: 0px;
+  --tw-ring-offset-color: #fff;
+  --tw-ring-color: rgb(59 130 246 / 0.5);
+  --tw-ring-offset-shadow: 0 0 #0000;
+  --tw-ring-shadow: 0 0 #0000;
+  --tw-shadow: 0 0 #0000;
+  --tw-shadow-colored: 0 0 #0000;
+  --tw-blur:  ;
+  --tw-brightness:  ;
+  --tw-contrast:  ;
+  --tw-grayscale:  ;
+  --tw-hue-rotate:  ;
+  --tw-invert:  ;
+  --tw-saturate:  ;
+  --tw-sepia:  ;
+  --tw-drop-shadow:  ;
+  --tw-backdrop-blur:  ;
+  --tw-backdrop-brightness:  ;
+  --tw-backdrop-contrast:  ;
+  --tw-backdrop-grayscale:  ;
+  --tw-backdrop-hue-rotate:  ;
+  --tw-backdrop-invert:  ;
+  --tw-backdrop-opacity:  ;
+  --tw-backdrop-saturate:  ;
+  --tw-backdrop-sepia:  ;
+}
+
+.mb-2 {
+  margin-bottom: 0.5rem;
+}
+
+.h-\[200px\] {
+  height: 200px;
+}
+
+.h-\[100px\] {
+  height: 100px;
+}
+
+.w-\[200px\] {
+  width: 200px;
+}
+
+.resize {
+  resize: both;
+}
+
+.rounded {
+  border-radius: 0.25rem;
+}
+
+.rounded-md {
+  border-radius: 0.375rem;
+}
+
+.border {
+  border-width: 1px;
+}
+
+.border-\[--theme-popup-border\] {
+  border-color: var(--theme-popup-border);
+}
+
+.p-4 {
+  padding: 1rem;
+}
+
+.text-base {
+  font-size: 1rem;
+  line-height: 1.5rem;
+}
+
+.text-lg {
+  font-size: 1.125rem;
+  line-height: 1.75rem;
+}
+
+.text-xl {
+  font-size: 1.25rem;
+  line-height: 1.75rem;
+}
+
+.text-2xl {
+  font-size: 1.5rem;
+  line-height: 2rem;
+}
+
+.leading-6 {
+  line-height: 1.5rem;
+}
+
+.leading-10 {
+  line-height: 2.5rem;
+}
+
+.text-\[--brand-color\] {
+  color: var(--brand-color);
+}
+
+.text-green-600 {
+  --tw-text-opacity: 1;
+  color: rgb(22 163 74 / var(--tw-text-opacity));
+}
+
+.opacity-75 {
+  opacity: 0.75;
+}
+
+@media (prefers-color-scheme: dark) {
+  .dark\:text-green-500 {
+    --tw-text-opacity: 1;
+    color: rgb(34 197 94 / var(--tw-text-opacity));
+  }
+}
\ No newline at end of file
diff --git a/examples/use_resize_observer/tailwind.config.js b/examples/use_resize_observer/tailwind.config.js
new file mode 100644
index 0000000..bc09f5e
--- /dev/null
+++ b/examples/use_resize_observer/tailwind.config.js
@@ -0,0 +1,15 @@
+/** @type {import('tailwindcss').Config} */
+module.exports = {
+    content: {
+        files: ["*.html", "./src/**/*.rs", "../../src/docs/**/*.rs"],
+    },
+    theme: {
+        extend: {},
+    },
+    corePlugins: {
+        preflight: false,
+    },
+    plugins: [
+        require('@tailwindcss/forms'),
+    ],
+}
\ No newline at end of file
diff --git a/examples/use_throttle_fn/src/main.rs b/examples/use_throttle_fn/src/main.rs
index 225ed4e..6c9e043 100644
--- a/examples/use_throttle_fn/src/main.rs
+++ b/examples/use_throttle_fn/src/main.rs
@@ -1,5 +1,5 @@
 use leptos::*;
-use leptos_use::docs::demo_or_body;
+use leptos_use::docs::{demo_or_body, Note};
 use leptos_use::use_throttle_fn;
 
 #[component]
@@ -18,7 +18,7 @@ fn Demo(cx: Scope) -> impl IntoView {
         >
             "Smash me!"
         </button>
-        <div class="note">"Delay is set to 1000ms for this demo."</div>
+        <Note>"Delay is set to 1000ms for this demo."</Note>
         <p>"Button clicked: " { click_count }</p>
         <p>"Event handler called: " { throttled_count }</p>
     }
diff --git a/src/docs/mod.rs b/src/docs/mod.rs
index 961c8fa..f205682 100644
--- a/src/docs/mod.rs
+++ b/src/docs/mod.rs
@@ -1,5 +1,7 @@
 mod boolean_display;
 mod demo;
+mod note;
 
 pub use boolean_display::*;
 pub use demo::*;
+pub use note::*;
diff --git a/src/docs/note.rs b/src/docs/note.rs
new file mode 100644
index 0000000..4430119
--- /dev/null
+++ b/src/docs/note.rs
@@ -0,0 +1,10 @@
+use leptos::*;
+
+#[component]
+pub fn Note(cx: Scope, #[prop(optional, into)] class: String, children: Children) -> impl IntoView {
+    let class = format!("note {class}");
+
+    view! { cx,
+        <div class=class>{ children(cx) }</div>
+    }
+}
diff --git a/src/use_resize_observer.rs b/src/use_resize_observer.rs
index 8c980c7..10cb19a 100644
--- a/src/use_resize_observer.rs
+++ b/src/use_resize_observer.rs
@@ -1,20 +1,67 @@
 use crate::core::ElementMaybeSignal;
-use crate::use_supported;
-use default_struct_builder::DefaultBuilder;
+use crate::{use_supported, watch};
 use leptos::*;
 use std::cell::RefCell;
 use std::rc::Rc;
-use wasm_bindgen::{JsCast, JsValue};
+use wasm_bindgen::prelude::*;
 
+/// Reports changes to the dimensions of an Element's content or the border-box.
+///
+/// > This function requires `--cfg=web_sys_unstable_apis` to be activated as
+/// [described in the wasm-bindgen guide](https://rustwasm.github.io/docs/wasm-bindgen/web-sys/unstable-apis.html).
+///
+/// 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::*;
+/// # use leptos_use::use_resize_observer;
+/// #
+/// # #[component]
+/// # fn Demo(cx: Scope) -> impl IntoView {
+/// let el = create_node_ref(cx);
+/// let (text, set_text) = create_signal(cx, "");
+///
+/// use_resize_observer(
+///     cx,
+///     el,
+///     move |entries, observer| {
+///         let rect = entries[0].content_rect();
+///         set_text(format!("width: {}\nheight: {}", rect.width(), rect.height()));
+///     },
+/// );
+/// # }
+/// ```
+pub fn use_resize_observer<El, T, F>(
+    cx: Scope,
+    target: El, // TODO : multiple elements?
+    callback: F,
+) -> UseResizeReturn
+where
+    (Scope, El): Into<ElementMaybeSignal<T, web_sys::Element>>,
+    T: Into<web_sys::Element> + Clone + 'static,
+    F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + Clone + 'static,
+{
+    use_resize_observer_with_options(cx, target, callback, web_sys::ResizeObserverOptions::new())
+}
+
+/// Version of [`use_resize_observer`] that takes a `ResizeObserverOptions`. See [`use_resize_observer`] for how to use.
 pub fn use_resize_observer_with_options<El, T, F>(
     cx: Scope,
     target: El, // TODO : multiple elements?
     callback: F,
     options: web_sys::ResizeObserverOptions,
-) where
+) -> UseResizeReturn
+where
     (Scope, El): Into<ElementMaybeSignal<T, web_sys::Element>>,
     T: Into<web_sys::Element> + Clone + 'static,
-    F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + 'static,
+    F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + Clone + 'static,
 {
     let observer: Rc<RefCell<Option<web_sys::ResizeObserver>>> = Rc::new(RefCell::new(None));
 
@@ -22,38 +69,69 @@ pub fn use_resize_observer_with_options<El, T, F>(
 
     let obs = Rc::clone(&observer);
     let cleanup = move || {
-        let observer = obs.borrow_mut();
-        if let Some(o) = *observer {
+        let mut observer = obs.borrow_mut();
+        if let Some(o) = observer.as_ref() {
             o.disconnect();
             *observer = None;
         }
     };
 
-    let target = target.into();
+    let target = (cx, target).into();
 
     let clean = cleanup.clone();
-    create_effect(cx, move |_| {
-        clean();
+    let stop_watch = watch(
+        cx,
+        move || target.get(),
+        move |target, _, _| {
+            clean();
 
-        if is_supported() {
-            let obs = web_sys::ResizeObserver::new(move |entries: &js_sys::Array, observer| {
-                callback(
-                    entries
-                        .to_vec()
-                        .into_iter()
-                        .map(|v| v.unchecked_into::<web_sys::ResizeObserver>(&options)),
-                    observer,
-                );
-            })
-            .expect("failed to create ResizeObserver");
+            if is_supported() {
+                if let Some(target) = target {
+                    let mut callback = callback.clone();
+                    let closure = Closure::<dyn FnMut(js_sys::Array, web_sys::ResizeObserver)>::new(
+                        move |entries: js_sys::Array, observer| {
+                            callback(
+                                entries
+                                    .to_vec()
+                                    .into_iter()
+                                    .map(|v| v.unchecked_into::<web_sys::ResizeObserverEntry>())
+                                    .collect(),
+                                observer,
+                            );
+                        },
+                    );
+                    let obs = web_sys::ResizeObserver::new(closure.as_ref().unchecked_ref())
+                        .expect("failed to create ResizeObserver");
 
-            observer.observe(&target.get());
+                    closure.forget();
 
-            observer.replace(obs);
-        }
-    });
+                    let target: web_sys::Element = target.clone().into();
+                    obs.observe_with_options(&target, &options);
+
+                    observer.replace(Some(obs));
+                }
+            }
+        },
+        true,
+    );
 
     let stop = move || {
         cleanup();
+        stop_watch();
+    };
+
+    on_cleanup(cx, stop.clone());
+
+    return UseResizeReturn {
+        is_supported,
+        stop: Box::new(stop),
     };
 }
+
+/// The return value of [`use_resize_observer`].
+pub struct UseResizeReturn {
+    /// Whether the browser supports the ResizeObserver API
+    pub is_supported: Signal<bool>,
+    /// A function to stop and detach the ResizeObserver
+    pub stop: Box<dyn Fn()>,
+}