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use crate::Intent;
use implicit_clone::{unsync::IArray, ImplicitClone};
use std::marker::PhantomData;
use wasm_bindgen::JsCast;
use web_sys::Element;
use yew::prelude::*;
pub struct Slider<T: ImplicitClone + PartialEq + 'static> {
slider_ref: NodeRef,
handle_ref: NodeRef,
track_ref: NodeRef,
is_moving: bool,
// The value we had just before we started moving. We need to track it
// in case the gesture turns from something we handle (dragging left/right)
// into something the user-agent should be handling (pan-y = scrolling up/down)
value_before_move: Option<T>,
focus_handle: bool,
phantom: PhantomData<T>,
}
#[derive(Clone, PartialEq, Properties)]
pub struct SliderProps<T: ImplicitClone + PartialEq + 'static> {
#[prop_or_default]
pub class: Classes,
#[prop_or_default]
pub vertical: bool,
#[prop_or_default]
pub intent: Option<Intent>,
#[prop_or_default]
pub value_label: Option<AttrValue>,
pub onchange: Callback<T>,
pub values: IArray<(T, Option<AttrValue>)>,
pub selected: Option<T>,
}
#[derive(Debug)]
pub enum Msg {
// started a gesture, either via mouse ("desktop") or touch ("mobile")
PointerDown,
// pointer moved, we only track X for now (vertical isn't supported for now)
PointerMove { client_x: i32 },
// gesture cancelled: turns out we were scrolling or something
PointerCancel,
// gesture completed successfully
PointerUp,
// adjusting via keyboard, completely independent from mouse gestures
Keyboard(KeyboardEvent),
}
impl<T: ImplicitClone + PartialEq + 'static> Component for Slider<T> {
type Message = Msg;
type Properties = SliderProps<T>;
fn create(_ctx: &Context<Self>) -> Self {
Self {
slider_ref: NodeRef::default(),
handle_ref: NodeRef::default(),
track_ref: NodeRef::default(),
is_moving: false,
value_before_move: None,
focus_handle: false,
phantom: PhantomData,
}
}
fn update(&mut self, ctx: &Context<Self>, msg: Self::Message) -> bool {
match msg {
Msg::PointerDown if ctx.props().values.len() > 1 => {
self.is_moving = true;
if let Some(selected) = ctx.props().selected.as_ref() {
// save the current value in case we need to restore it
self.value_before_move = Some(selected.clone());
}
true
}
Msg::PointerDown => false,
Msg::PointerMove { client_x } if ctx.props().values.len() > 1 => {
if !self.is_moving {
return false;
}
let track_rect = self.track_ref.cast::<Element>().expect("no track ref");
let tick_size = (track_rect.client_width() as f64)
/ ctx.props().values.len().saturating_sub(1) as f64;
let pixel_delta = (client_x as f64) - track_rect.get_bounding_client_rect().left();
let position = (pixel_delta / tick_size).round() as usize;
let (value, _) = ctx.props().values.get(position).unwrap_or_else(|| {
ctx.props()
.values
.last()
.cloned()
.expect("No value in the array")
});
if Some(&value) != ctx.props().selected.as_ref() {
ctx.props().onchange.emit(value);
}
true
}
Msg::PointerMove { .. } => false,
Msg::PointerCancel => {
self.is_moving = false;
if let Some(value_before_move) = self.value_before_move.take() {
// there's a slight bug here: if the value was None before
// the cancelled gesture started, we have no way to restore
// it to None since `onchange` only accepts `T`, not `Option<T>`.
// fixing this requires breaking the API
ctx.props().onchange.emit(value_before_move);
true
} else {
false
}
}
Msg::PointerUp => {
// gesture completed successfully
self.is_moving = false;
self.value_before_move = None;
true
}
Msg::Keyboard(event) if ctx.props().values.len() > 1 => match event.key().as_str() {
"ArrowDown" | "ArrowLeft" => {
self.focus_handle = true;
event.prevent_default();
let index = ctx
.props()
.values
.iter()
.position(|(value, _)| Some(value) == ctx.props().selected)
.map(|i| i.saturating_sub(1))
.unwrap_or(0);
let (value, _) = ctx.props().values[index].clone();
ctx.props().onchange.emit(value);
true
}
"ArrowUp" | "ArrowRight" => {
self.focus_handle = true;
event.prevent_default();
let index = ctx
.props()
.values
.iter()
.position(|(value, _)| Some(value) == ctx.props().selected)
.map(|i| i.saturating_add(1))
.unwrap_or(0);
let (value, _) = ctx.props().values.get(index).unwrap_or_else(|| {
let (value, label) = ctx.props().values.last().expect(
"Already check, \
there are at least 2 values in ctx.props().options; qed",
);
(value.clone(), label.clone())
});
ctx.props().onchange.emit(value);
true
}
_ => false,
},
Msg::Keyboard(_) => false,
}
}
fn view(&self, ctx: &Context<Self>) -> Html {
let value_index = ctx
.props()
.values
.iter()
.position(|(value, _)| Some(value) == ctx.props().selected);
let labels = if ctx.props().values.len() > 1 {
ctx.props()
.values
.iter()
.enumerate()
.filter_map(|(i, (_, label))| {
label.map(|x| {
html! {
<div
class={classes!("bp3-slider-label")}
style={format!(
"left: {}%;", (i as f64) * 100.0
/ ((ctx.props().values.len() as f64) - 1.0)
)}
>
{x}
</div>
}
})
})
.collect::<Html>()
} else if let Some((_, Some(label))) = ctx.props().values.first() {
html! {
<div
class={classes!("bp3-slider-label")}
style={"left: 50%;"}
>
{label}
</div>
}
} else {
html!()
};
let value_label = ctx.props().value_label.clone().map(|x| {
html! {
<span class={classes!("bp3-slider-label")}>
{x}
</span>
}
});
html! {
<div
class={classes!(
"bp3-slider",
ctx.props().vertical.then_some("bp3-vertical"),
)}
ref={self.slider_ref.clone()}
style={"touch-action: pan-y pinch-zoom; -webkit-touch-callout: none;"}
onpointerdown={{
let slider_ref = self.slider_ref.clone();
(ctx.props().values.len() > 1).then(
move || ctx.link().batch_callback(
move |event: PointerEvent| {
if event.is_primary() {
if let Some(slider) = slider_ref.cast::<Element>() {
slider.set_pointer_capture(event.pointer_id()).unwrap();
}
let down = Msg::PointerDown;
if event.pointer_type() == "touch" {
// for touch devices, wait for some dragging
// to occur to know if we're dragging the
// slider or scrolling the page. this avoids
// some jumps on pointercancel, in most
// cases. it also doesn't affect "clicks"
// which do one-time adjustments.
vec![down]
} else {
vec![down, Msg::PointerMove { client_x: event.client_x() }]
}
} else {
vec![]
}
}
)
)
}}
onpointermove={(ctx.props().values.len() > 1).then(
|| ctx.link().batch_callback(
|event: PointerEvent| {
if let Some(target) = event.target() {
if let Some(el) = target.dyn_ref::<web_sys::Element>() {
if el.has_pointer_capture(event.pointer_id()) {
return vec![
Msg::PointerMove { client_x: event.client_x() }
];
}
}
}
vec![]
}
)
)}
onpointerup={(ctx.props().values.len() > 1).then(
|| ctx.link().callback(
|_event: PointerEvent| {
Msg::PointerUp
}
)
)}
onpointercancel={(ctx.props().values.len() > 1).then(
|| ctx.link().callback(
|_event: PointerEvent| {
Msg::PointerCancel
}
)
)}
onclick={(ctx.props().values.len() > 1).then(
|| ctx.link().batch_callback(
|event: MouseEvent| {
vec![
Msg::PointerDown,
Msg::PointerMove { client_x: event.client_x() },
Msg::PointerUp
]
}
)
)}
>
<div
class={classes!("bp3-slider-track")}
ref={self.track_ref.clone()}
>
{
if value_index.is_none() && !ctx.props().values.is_empty() {
html! {
<div
class={classes!("bp3-slider-progress")}
style="top: 0px;"
onkeydown={ctx.link().callback(|event| Msg::Keyboard(event))}
tabindex=0
>
</div>
}
} else {
html! {
<div
class={classes!("bp3-slider-progress")}
style="top: 0px;"
>
</div>
}
}
}
{
match value_index {
Some(index) if ctx.props().values.len() > 1
&& ctx.props().intent.is_some() => {
html! {
<div
class={classes!("bp3-slider-progress", ctx.props().intent)}
style={format!(
"left: 0%; right: {}%; top: 0px;",
100.0 - (
100.0 * (index as f64)
/ (ctx.props().values.len() as f64 - 1.0)
)
)}
>
</div>
}
}
_ => html! {},
}
}
</div>
<div class={classes!("bp3-slider-axis")}>
{labels}
</div>
{
match value_index {
Some(index) if ctx.props().values.len() > 1 =>
{
html! {
<span
class={classes!(
"bp3-slider-handle",
self.is_moving.then_some("bp3-active"),
)}
ref={self.handle_ref.clone()}
style={format!(
"-webkit-touch-callout: none; left: calc({}% - 8px);",
100.0 * (index as f64)
/ (ctx.props().values.len() as f64 - 1.0),
)}
onkeydown={ctx.link().callback(|event| Msg::Keyboard(event))}
tabindex=0
>
{value_label.clone()}
</span>
}
}
Some(_) => {
html! {
<span
class={classes!(
"bp3-slider-handle",
self.is_moving.then_some("bp3-active"),
)}
ref={self.handle_ref.clone()}
style="left: calc(50% - 8px);"
>
{value_label.clone()}
</span>
}
}
None => html!(),
}
}
</div>
}
}
fn rendered(&mut self, _ctx: &Context<Self>, _: bool) {
if self.focus_handle {
if let Some(element) = self.handle_ref.cast::<web_sys::HtmlElement>() {
let _ = element.focus();
}
self.focus_handle = false;
}
}
}