egui/crates/egui/src/widgets/slider.rs

958 lines
35 KiB
Rust

#![allow(clippy::needless_pass_by_value)] // False positives with `impl ToString`
use std::ops::RangeInclusive;
use crate::*;
// ----------------------------------------------------------------------------
type NumFormatter<'a> = Box<dyn 'a + Fn(f64, RangeInclusive<usize>) -> String>;
type NumParser<'a> = Box<dyn 'a + Fn(&str) -> Option<f64>>;
// ----------------------------------------------------------------------------
/// Combined into one function (rather than two) to make it easier
/// for the borrow checker.
type GetSetValue<'a> = Box<dyn 'a + FnMut(Option<f64>) -> f64>;
fn get(get_set_value: &mut GetSetValue<'_>) -> f64 {
(get_set_value)(None)
}
fn set(get_set_value: &mut GetSetValue<'_>, value: f64) {
(get_set_value)(Some(value));
}
// ----------------------------------------------------------------------------
#[derive(Clone)]
struct SliderSpec {
logarithmic: bool,
/// For logarithmic sliders, the smallest positive value we are interested in.
/// 1 for integer sliders, maybe 1e-6 for others.
smallest_positive: f64,
/// For logarithmic sliders, the largest positive value we are interested in
/// before the slider switches to `INFINITY`, if that is the higher end.
/// Default: INFINITY.
largest_finite: f64,
}
/// Specifies the orientation of a [`Slider`].
pub enum SliderOrientation {
Horizontal,
Vertical,
}
/// Control a number with a slider.
///
/// The slider range defines the values you get when pulling the slider to the far edges.
/// By default, the slider can still show values outside this range,
/// and still allows users to enter values outside the range by clicking the slider value and editing it.
/// If you want to clamp incoming and outgoing values, use [`Slider::clamp_to_range`].
///
/// The range can include any numbers, and go from low-to-high or from high-to-low.
///
/// The slider consists of three parts: a slider, a value display, and an optional text.
/// The user can click the value display to edit its value. It can be turned off with `.show_value(false)`.
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_f32: f32 = 0.0;
/// ui.add(egui::Slider::new(&mut my_f32, 0.0..=100.0).text("My value"));
/// # });
/// ```
///
/// The default [`Slider`] size is set by [`crate::style::Spacing::slider_width`].
#[must_use = "You should put this widget in an ui with `ui.add(widget);`"]
pub struct Slider<'a> {
get_set_value: GetSetValue<'a>,
range: RangeInclusive<f64>,
spec: SliderSpec,
clamp_to_range: bool,
smart_aim: bool,
show_value: bool,
orientation: SliderOrientation,
prefix: String,
suffix: String,
text: WidgetText,
/// Sets the minimal step of the widget value
step: Option<f64>,
min_decimals: usize,
max_decimals: Option<usize>,
custom_formatter: Option<NumFormatter<'a>>,
custom_parser: Option<NumParser<'a>>,
}
impl<'a> Slider<'a> {
/// Creates a new horizontal slider.
pub fn new<Num: emath::Numeric>(value: &'a mut Num, range: RangeInclusive<Num>) -> Self {
let range_f64 = range.start().to_f64()..=range.end().to_f64();
let slf = Self::from_get_set(range_f64, move |v: Option<f64>| {
if let Some(v) = v {
*value = Num::from_f64(v);
}
value.to_f64()
});
if Num::INTEGRAL {
slf.integer()
} else {
slf
}
}
pub fn from_get_set(
range: RangeInclusive<f64>,
get_set_value: impl 'a + FnMut(Option<f64>) -> f64,
) -> Self {
Self {
get_set_value: Box::new(get_set_value),
range,
spec: SliderSpec {
logarithmic: false,
smallest_positive: 1e-6,
largest_finite: f64::INFINITY,
},
clamp_to_range: true,
smart_aim: true,
show_value: true,
orientation: SliderOrientation::Horizontal,
prefix: Default::default(),
suffix: Default::default(),
text: Default::default(),
step: None,
min_decimals: 0,
max_decimals: None,
custom_formatter: None,
custom_parser: None,
}
}
/// Control whether or not the slider shows the current value.
/// Default: `true`.
pub fn show_value(mut self, show_value: bool) -> Self {
self.show_value = show_value;
self
}
/// Show a prefix before the number, e.g. "x: "
pub fn prefix(mut self, prefix: impl ToString) -> Self {
self.prefix = prefix.to_string();
self
}
/// Add a suffix to the number, this can be e.g. a unit ("°" or " m")
pub fn suffix(mut self, suffix: impl ToString) -> Self {
self.suffix = suffix.to_string();
self
}
/// Show a text next to the slider (e.g. explaining what the slider controls).
pub fn text(mut self, text: impl Into<WidgetText>) -> Self {
self.text = text.into();
self
}
pub fn text_color(mut self, text_color: Color32) -> Self {
self.text = self.text.color(text_color);
self
}
/// Vertical or horizontal slider? The default is horizontal.
pub fn orientation(mut self, orientation: SliderOrientation) -> Self {
self.orientation = orientation;
self
}
/// Make this a vertical slider.
pub fn vertical(mut self) -> Self {
self.orientation = SliderOrientation::Vertical;
self
}
/// Make this a logarithmic slider.
/// This is great for when the slider spans a huge range,
/// e.g. from one to a million.
/// The default is OFF.
pub fn logarithmic(mut self, logarithmic: bool) -> Self {
self.spec.logarithmic = logarithmic;
self
}
/// For logarithmic sliders that includes zero:
/// what is the smallest positive value you want to be able to select?
/// The default is `1` for integer sliders and `1e-6` for real sliders.
pub fn smallest_positive(mut self, smallest_positive: f64) -> Self {
self.spec.smallest_positive = smallest_positive;
self
}
/// For logarithmic sliders, the largest positive value we are interested in
/// before the slider switches to `INFINITY`, if that is the higher end.
/// Default: INFINITY.
pub fn largest_finite(mut self, largest_finite: f64) -> Self {
self.spec.largest_finite = largest_finite;
self
}
/// If set to `true`, all incoming and outgoing values will be clamped to the slider range.
/// Default: `true`.
pub fn clamp_to_range(mut self, clamp_to_range: bool) -> Self {
self.clamp_to_range = clamp_to_range;
self
}
/// Turn smart aim on/off. Default is ON.
/// There is almost no point in turning this off.
pub fn smart_aim(mut self, smart_aim: bool) -> Self {
self.smart_aim = smart_aim;
self
}
/// Sets the minimal change of the value.
/// Value `0.0` effectively disables the feature. If the new value is out of range
/// and `clamp_to_range` is enabled, you would not have the ability to change the value.
///
/// Default: `0.0` (disabled).
pub fn step_by(mut self, step: f64) -> Self {
self.step = if step != 0.0 { Some(step) } else { None };
self
}
// TODO(emilk): we should also have a "min precision".
/// Set a minimum number of decimals to display.
/// Normally you don't need to pick a precision, as the slider will intelligently pick a precision for you.
/// Regardless of precision the slider will use "smart aim" to help the user select nice, round values.
pub fn min_decimals(mut self, min_decimals: usize) -> Self {
self.min_decimals = min_decimals;
self
}
// TODO(emilk): we should also have a "max precision".
/// Set a maximum number of decimals to display.
/// Values will also be rounded to this number of decimals.
/// Normally you don't need to pick a precision, as the slider will intelligently pick a precision for you.
/// Regardless of precision the slider will use "smart aim" to help the user select nice, round values.
pub fn max_decimals(mut self, max_decimals: usize) -> Self {
self.max_decimals = Some(max_decimals);
self
}
/// Set an exact number of decimals to display.
/// Values will also be rounded to this number of decimals.
/// Normally you don't need to pick a precision, as the slider will intelligently pick a precision for you.
/// Regardless of precision the slider will use "smart aim" to help the user select nice, round values.
pub fn fixed_decimals(mut self, num_decimals: usize) -> Self {
self.min_decimals = num_decimals;
self.max_decimals = Some(num_decimals);
self
}
/// Set custom formatter defining how numbers are converted into text.
///
/// A custom formatter takes a `f64` for the numeric value and a `RangeInclusive<usize>` representing
/// the decimal range i.e. minimum and maximum number of decimal places shown.
///
/// See also: [`DragValue::custom_parser`]
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_i32: i32 = 0;
/// ui.add(egui::Slider::new(&mut my_i32, 0..=((60 * 60 * 24) - 1))
/// .custom_formatter(|n, _| {
/// let n = n as i32;
/// let hours = n / (60 * 60);
/// let mins = (n / 60) % 60;
/// let secs = n % 60;
/// format!("{hours:02}:{mins:02}:{secs:02}")
/// })
/// .custom_parser(|s| {
/// let parts: Vec<&str> = s.split(':').collect();
/// if parts.len() == 3 {
/// parts[0].parse::<i32>().and_then(|h| {
/// parts[1].parse::<i32>().and_then(|m| {
/// parts[2].parse::<i32>().map(|s| {
/// ((h * 60 * 60) + (m * 60) + s) as f64
/// })
/// })
/// })
/// .ok()
/// } else {
/// None
/// }
/// }));
/// # });
/// ```
pub fn custom_formatter(
mut self,
formatter: impl 'a + Fn(f64, RangeInclusive<usize>) -> String,
) -> Self {
self.custom_formatter = Some(Box::new(formatter));
self
}
/// Set custom parser defining how the text input is parsed into a number.
///
/// A custom parser takes an `&str` to parse into a number and returns `Some` if it was successfully parsed
/// or `None` otherwise.
///
/// See also: [`DragValue::custom_formatter`]
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_i32: i32 = 0;
/// ui.add(egui::Slider::new(&mut my_i32, 0..=((60 * 60 * 24) - 1))
/// .custom_formatter(|n, _| {
/// let n = n as i32;
/// let hours = n / (60 * 60);
/// let mins = (n / 60) % 60;
/// let secs = n % 60;
/// format!("{hours:02}:{mins:02}:{secs:02}")
/// })
/// .custom_parser(|s| {
/// let parts: Vec<&str> = s.split(':').collect();
/// if parts.len() == 3 {
/// parts[0].parse::<i32>().and_then(|h| {
/// parts[1].parse::<i32>().and_then(|m| {
/// parts[2].parse::<i32>().map(|s| {
/// ((h * 60 * 60) + (m * 60) + s) as f64
/// })
/// })
/// })
/// .ok()
/// } else {
/// None
/// }
/// }));
/// # });
/// ```
pub fn custom_parser(mut self, parser: impl 'a + Fn(&str) -> Option<f64>) -> Self {
self.custom_parser = Some(Box::new(parser));
self
}
/// Set `custom_formatter` and `custom_parser` to display and parse numbers as binary integers. Floating point
/// numbers are *not* supported.
///
/// `min_width` specifies the minimum number of displayed digits; if the number is shorter than this, it will be
/// prefixed with additional 0s to match `min_width`.
///
/// If `twos_complement` is true, negative values will be displayed as the 2's complement representation. Otherwise
/// they will be prefixed with a '-' sign.
///
/// # Panics
///
/// Panics if `min_width` is 0.
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_i32: i32 = 0;
/// ui.add(egui::Slider::new(&mut my_i32, -100..=100).binary(64, false));
/// # });
/// ```
pub fn binary(self, min_width: usize, twos_complement: bool) -> Self {
assert!(
min_width > 0,
"Slider::binary: `min_width` must be greater than 0"
);
if twos_complement {
self.custom_formatter(move |n, _| format!("{:0>min_width$b}", n as i64))
} else {
self.custom_formatter(move |n, _| {
let sign = if n < 0.0 { "-" } else { "" };
format!("{sign}{:0>min_width$b}", n.abs() as i64)
})
}
.custom_parser(|s| i64::from_str_radix(s, 2).map(|n| n as f64).ok())
}
/// Set `custom_formatter` and `custom_parser` to display and parse numbers as octal integers. Floating point
/// numbers are *not* supported.
///
/// `min_width` specifies the minimum number of displayed digits; if the number is shorter than this, it will be
/// prefixed with additional 0s to match `min_width`.
///
/// If `twos_complement` is true, negative values will be displayed as the 2's complement representation. Otherwise
/// they will be prefixed with a '-' sign.
///
/// # Panics
///
/// Panics if `min_width` is 0.
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_i32: i32 = 0;
/// ui.add(egui::Slider::new(&mut my_i32, -100..=100).octal(22, false));
/// # });
/// ```
pub fn octal(self, min_width: usize, twos_complement: bool) -> Self {
assert!(
min_width > 0,
"Slider::octal: `min_width` must be greater than 0"
);
if twos_complement {
self.custom_formatter(move |n, _| format!("{:0>min_width$o}", n as i64))
} else {
self.custom_formatter(move |n, _| {
let sign = if n < 0.0 { "-" } else { "" };
format!("{sign}{:0>min_width$o}", n.abs() as i64)
})
}
.custom_parser(|s| i64::from_str_radix(s, 8).map(|n| n as f64).ok())
}
/// Set `custom_formatter` and `custom_parser` to display and parse numbers as hexadecimal integers. Floating point
/// numbers are *not* supported.
///
/// `min_width` specifies the minimum number of displayed digits; if the number is shorter than this, it will be
/// prefixed with additional 0s to match `min_width`.
///
/// If `twos_complement` is true, negative values will be displayed as the 2's complement representation. Otherwise
/// they will be prefixed with a '-' sign.
///
/// # Panics
///
/// Panics if `min_width` is 0.
///
/// ```
/// # egui::__run_test_ui(|ui| {
/// # let mut my_i32: i32 = 0;
/// ui.add(egui::Slider::new(&mut my_i32, -100..=100).hexadecimal(16, false, true));
/// # });
/// ```
pub fn hexadecimal(self, min_width: usize, twos_complement: bool, upper: bool) -> Self {
assert!(
min_width > 0,
"Slider::hexadecimal: `min_width` must be greater than 0"
);
match (twos_complement, upper) {
(true, true) => {
self.custom_formatter(move |n, _| format!("{:0>min_width$X}", n as i64))
}
(true, false) => {
self.custom_formatter(move |n, _| format!("{:0>min_width$x}", n as i64))
}
(false, true) => self.custom_formatter(move |n, _| {
let sign = if n < 0.0 { "-" } else { "" };
format!("{sign}{:0>min_width$X}", n.abs() as i64)
}),
(false, false) => self.custom_formatter(move |n, _| {
let sign = if n < 0.0 { "-" } else { "" };
format!("{sign}{:0>min_width$x}", n.abs() as i64)
}),
}
.custom_parser(|s| i64::from_str_radix(s, 16).map(|n| n as f64).ok())
}
/// Helper: equivalent to `self.precision(0).smallest_positive(1.0)`.
/// If you use one of the integer constructors (e.g. `Slider::i32`) this is called for you,
/// but if you want to have a slider for picking integer values in an `Slider::f64`, use this.
pub fn integer(self) -> Self {
self.fixed_decimals(0).smallest_positive(1.0)
}
fn get_value(&mut self) -> f64 {
let value = get(&mut self.get_set_value);
if self.clamp_to_range {
let start = *self.range.start();
let end = *self.range.end();
value.clamp(start.min(end), start.max(end))
} else {
value
}
}
fn set_value(&mut self, mut value: f64) {
if self.clamp_to_range {
let start = *self.range.start();
let end = *self.range.end();
value = value.clamp(start.min(end), start.max(end));
}
if let Some(max_decimals) = self.max_decimals {
value = emath::round_to_decimals(value, max_decimals);
}
if let Some(step) = self.step {
value = (value / step).round() * step;
}
set(&mut self.get_set_value, value);
}
fn clamp_range(&self) -> RangeInclusive<f64> {
if self.clamp_to_range {
self.range()
} else {
f64::NEG_INFINITY..=f64::INFINITY
}
}
fn range(&self) -> RangeInclusive<f64> {
self.range.clone()
}
/// For instance, `position` is the mouse position and `position_range` is the physical location of the slider on the screen.
fn value_from_position(&self, position: f32, position_range: RangeInclusive<f32>) -> f64 {
let normalized = remap_clamp(position, position_range, 0.0..=1.0) as f64;
value_from_normalized(normalized, self.range(), &self.spec)
}
fn position_from_value(&self, value: f64, position_range: RangeInclusive<f32>) -> f32 {
let normalized = normalized_from_value(value, self.range(), &self.spec);
lerp(position_range, normalized as f32)
}
}
impl<'a> Slider<'a> {
/// Just the slider, no text
fn allocate_slider_space(&self, ui: &mut Ui, thickness: f32) -> Response {
let desired_size = match self.orientation {
SliderOrientation::Horizontal => vec2(ui.spacing().slider_width, thickness),
SliderOrientation::Vertical => vec2(thickness, ui.spacing().slider_width),
};
ui.allocate_response(desired_size, Sense::drag())
}
/// Just the slider, no text
fn slider_ui(&mut self, ui: &mut Ui, response: &Response) {
let rect = &response.rect;
let position_range = self.position_range(rect);
if let Some(pointer_position_2d) = response.interact_pointer_pos() {
let position = self.pointer_position(pointer_position_2d);
let new_value = if self.smart_aim {
let aim_radius = ui.input().aim_radius();
emath::smart_aim::best_in_range_f64(
self.value_from_position(position - aim_radius, position_range.clone()),
self.value_from_position(position + aim_radius, position_range.clone()),
)
} else {
self.value_from_position(position, position_range.clone())
};
self.set_value(new_value);
}
let mut decrement = 0usize;
let mut increment = 0usize;
if response.has_focus() {
let (dec_key, inc_key) = match self.orientation {
SliderOrientation::Horizontal => (Key::ArrowLeft, Key::ArrowRight),
// Note that this is for moving the slider position,
// so up = decrement y coordinate:
SliderOrientation::Vertical => (Key::ArrowUp, Key::ArrowDown),
};
decrement += ui.input().num_presses(dec_key);
increment += ui.input().num_presses(inc_key);
}
#[cfg(feature = "accesskit")]
{
use accesskit::Action;
decrement += ui
.input()
.num_accesskit_action_requests(response.id, Action::Decrement);
increment += ui
.input()
.num_accesskit_action_requests(response.id, Action::Increment);
}
let kb_step = increment as f32 - decrement as f32;
if kb_step != 0.0 {
let prev_value = self.get_value();
let prev_position = self.position_from_value(prev_value, position_range.clone());
let new_position = prev_position + kb_step;
let new_value = match self.step {
Some(step) => prev_value + (kb_step as f64 * step),
None if self.smart_aim => {
let aim_radius = ui.input().aim_radius();
emath::smart_aim::best_in_range_f64(
self.value_from_position(new_position - aim_radius, position_range.clone()),
self.value_from_position(new_position + aim_radius, position_range.clone()),
)
}
_ => self.value_from_position(new_position, position_range.clone()),
};
self.set_value(new_value);
}
#[cfg(feature = "accesskit")]
{
use accesskit::{Action, ActionData};
for request in ui
.input()
.accesskit_action_requests(response.id, Action::SetValue)
{
if let Some(ActionData::NumericValue(new_value)) = request.data {
self.set_value(new_value);
}
}
}
// Paint it:
if ui.is_rect_visible(response.rect) {
let value = self.get_value();
let rail_radius = ui.painter().round_to_pixel(self.rail_radius_limit(rect));
let rail_rect = self.rail_rect(rect, rail_radius);
let position_1d = self.position_from_value(value, position_range);
let visuals = ui.style().interact(response);
ui.painter().add(epaint::RectShape {
rect: rail_rect,
rounding: ui.visuals().widgets.inactive.rounding,
fill: ui.visuals().widgets.inactive.bg_fill,
// fill: visuals.bg_fill,
// fill: ui.visuals().extreme_bg_color,
stroke: Default::default(),
// stroke: visuals.bg_stroke,
// stroke: ui.visuals().widgets.inactive.bg_stroke,
});
let center = self.marker_center(position_1d, &rail_rect);
ui.painter().add(epaint::CircleShape {
center,
radius: self.handle_radius(rect) + visuals.expansion,
fill: visuals.bg_fill,
stroke: visuals.fg_stroke,
});
}
}
fn marker_center(&self, position_1d: f32, rail_rect: &Rect) -> Pos2 {
match self.orientation {
SliderOrientation::Horizontal => pos2(position_1d, rail_rect.center().y),
SliderOrientation::Vertical => pos2(rail_rect.center().x, position_1d),
}
}
fn pointer_position(&self, pointer_position_2d: Pos2) -> f32 {
match self.orientation {
SliderOrientation::Horizontal => pointer_position_2d.x,
SliderOrientation::Vertical => pointer_position_2d.y,
}
}
fn position_range(&self, rect: &Rect) -> RangeInclusive<f32> {
let handle_radius = self.handle_radius(rect);
match self.orientation {
SliderOrientation::Horizontal => {
(rect.left() + handle_radius)..=(rect.right() - handle_radius)
}
SliderOrientation::Vertical => {
(rect.bottom() - handle_radius)..=(rect.top() + handle_radius)
}
}
}
fn rail_rect(&self, rect: &Rect, radius: f32) -> Rect {
match self.orientation {
SliderOrientation::Horizontal => Rect::from_min_max(
pos2(rect.left(), rect.center().y - radius),
pos2(rect.right(), rect.center().y + radius),
),
SliderOrientation::Vertical => Rect::from_min_max(
pos2(rect.center().x - radius, rect.top()),
pos2(rect.center().x + radius, rect.bottom()),
),
}
}
fn handle_radius(&self, rect: &Rect) -> f32 {
let limit = match self.orientation {
SliderOrientation::Horizontal => rect.height(),
SliderOrientation::Vertical => rect.width(),
};
limit / 2.5
}
fn rail_radius_limit(&self, rect: &Rect) -> f32 {
match self.orientation {
SliderOrientation::Horizontal => (rect.height() / 4.0).at_least(2.0),
SliderOrientation::Vertical => (rect.width() / 4.0).at_least(2.0),
}
}
fn value_ui(&mut self, ui: &mut Ui, position_range: RangeInclusive<f32>) -> Response {
// If [`DragValue`] is controlled from the keyboard and `step` is defined, set speed to `step`
let change = {
// Hold one lock rather than 4 (see https://github.com/emilk/egui/pull/1380).
let input = ui.input();
input.num_presses(Key::ArrowUp) as i32 + input.num_presses(Key::ArrowRight) as i32
- input.num_presses(Key::ArrowDown) as i32
- input.num_presses(Key::ArrowLeft) as i32
};
let speed = match self.step {
Some(step) if change != 0 => step,
_ => self.current_gradient(&position_range),
};
let mut value = self.get_value();
let response = ui.add({
let mut dv = DragValue::new(&mut value)
.speed(speed)
.clamp_range(self.clamp_range())
.min_decimals(self.min_decimals)
.max_decimals_opt(self.max_decimals)
.suffix(self.suffix.clone())
.prefix(self.prefix.clone());
if let Some(fmt) = &self.custom_formatter {
dv = dv.custom_formatter(fmt);
};
if let Some(parser) = &self.custom_parser {
dv = dv.custom_parser(parser);
}
dv
});
if value != self.get_value() {
self.set_value(value);
}
response
}
/// delta(value) / delta(points)
fn current_gradient(&mut self, position_range: &RangeInclusive<f32>) -> f64 {
// TODO(emilk): handle clamping
let value = self.get_value();
let value_from_pos =
|position: f32| self.value_from_position(position, position_range.clone());
let pos_from_value = |value: f64| self.position_from_value(value, position_range.clone());
let left_value = value_from_pos(pos_from_value(value) - 0.5);
let right_value = value_from_pos(pos_from_value(value) + 0.5);
right_value - left_value
}
fn add_contents(&mut self, ui: &mut Ui) -> Response {
let old_value = self.get_value();
let thickness = ui
.text_style_height(&TextStyle::Body)
.at_least(ui.spacing().interact_size.y);
let mut response = self.allocate_slider_space(ui, thickness);
self.slider_ui(ui, &response);
let value = self.get_value();
response.changed = value != old_value;
response.widget_info(|| WidgetInfo::slider(value, self.text.text()));
#[cfg(feature = "accesskit")]
if let Some(mut node) = ui.ctx().accesskit_node(response.id) {
use accesskit::Action;
node.min_numeric_value = Some(*self.range.start());
node.max_numeric_value = Some(*self.range.end());
node.numeric_value_step = self.step;
node.actions |= Action::SetValue;
let clamp_range = self.clamp_range();
if value < *clamp_range.end() {
node.actions |= Action::Increment;
}
if value > *clamp_range.start() {
node.actions |= Action::Decrement;
}
}
let slider_response = response.clone();
let value_response = if self.show_value {
let position_range = self.position_range(&response.rect);
let value_response = self.value_ui(ui, position_range);
if value_response.gained_focus()
|| value_response.has_focus()
|| value_response.lost_focus()
{
// Use the [`DragValue`] id as the id of the whole widget,
// so that the focus events work as expected.
response = value_response.union(response);
} else {
// Use the slider id as the id for the whole widget
response = response.union(value_response.clone());
}
Some(value_response)
} else {
None
};
if !self.text.is_empty() {
let label_response = ui.add(Label::new(self.text.clone()).wrap(false));
// The slider already has an accessibility label via widget info,
// but sometimes it's useful for a screen reader to know
// that a piece of text is a label for another widget,
// e.g. so the text itself can be excluded from navigation.
slider_response.labelled_by(label_response.id);
if let Some(value_response) = value_response {
value_response.labelled_by(label_response.id);
}
}
response
}
}
impl<'a> Widget for Slider<'a> {
fn ui(mut self, ui: &mut Ui) -> Response {
let inner_response = match self.orientation {
SliderOrientation::Horizontal => ui.horizontal(|ui| self.add_contents(ui)),
SliderOrientation::Vertical => ui.vertical(|ui| self.add_contents(ui)),
};
inner_response.inner | inner_response.response
}
}
// ----------------------------------------------------------------------------
// Helpers for converting slider range to/from normalized [0-1] range.
// Always clamps.
// Logarithmic sliders are allowed to include zero and infinity,
// even though mathematically it doesn't make sense.
use std::f64::INFINITY;
/// When the user asks for an infinitely large range (e.g. logarithmic from zero),
/// give a scale that this many orders of magnitude in size.
const INF_RANGE_MAGNITUDE: f64 = 10.0;
fn value_from_normalized(normalized: f64, range: RangeInclusive<f64>, spec: &SliderSpec) -> f64 {
let (min, max) = (*range.start(), *range.end());
if min.is_nan() || max.is_nan() {
f64::NAN
} else if min == max {
min
} else if min > max {
value_from_normalized(1.0 - normalized, max..=min, spec)
} else if normalized <= 0.0 {
min
} else if normalized >= 1.0 {
max
} else if spec.logarithmic {
if max <= 0.0 {
// non-positive range
-value_from_normalized(normalized, -min..=-max, spec)
} else if 0.0 <= min {
let (min_log, max_log) = range_log10(min, max, spec);
let log = lerp(min_log..=max_log, normalized);
10.0_f64.powf(log)
} else {
assert!(min < 0.0 && 0.0 < max);
let zero_cutoff = logaritmic_zero_cutoff(min, max);
if normalized < zero_cutoff {
// negative
value_from_normalized(
remap(normalized, 0.0..=zero_cutoff, 0.0..=1.0),
min..=0.0,
spec,
)
} else {
// positive
value_from_normalized(
remap(normalized, zero_cutoff..=1.0, 0.0..=1.0),
0.0..=max,
spec,
)
}
}
} else {
crate::egui_assert!(
min.is_finite() && max.is_finite(),
"You should use a logarithmic range"
);
lerp(range, normalized.clamp(0.0, 1.0))
}
}
fn normalized_from_value(value: f64, range: RangeInclusive<f64>, spec: &SliderSpec) -> f64 {
let (min, max) = (*range.start(), *range.end());
if min.is_nan() || max.is_nan() {
f64::NAN
} else if min == max {
0.5 // empty range, show center of slider
} else if min > max {
1.0 - normalized_from_value(value, max..=min, spec)
} else if value <= min {
0.0
} else if value >= max {
1.0
} else if spec.logarithmic {
if max <= 0.0 {
// non-positive range
normalized_from_value(-value, -min..=-max, spec)
} else if 0.0 <= min {
let (min_log, max_log) = range_log10(min, max, spec);
let value_log = value.log10();
remap_clamp(value_log, min_log..=max_log, 0.0..=1.0)
} else {
assert!(min < 0.0 && 0.0 < max);
let zero_cutoff = logaritmic_zero_cutoff(min, max);
if value < 0.0 {
// negative
remap(
normalized_from_value(value, min..=0.0, spec),
0.0..=1.0,
0.0..=zero_cutoff,
)
} else {
// positive side
remap(
normalized_from_value(value, 0.0..=max, spec),
0.0..=1.0,
zero_cutoff..=1.0,
)
}
}
} else {
crate::egui_assert!(
min.is_finite() && max.is_finite(),
"You should use a logarithmic range"
);
remap_clamp(value, range, 0.0..=1.0)
}
}
fn range_log10(min: f64, max: f64, spec: &SliderSpec) -> (f64, f64) {
assert!(spec.logarithmic);
assert!(min <= max);
if min == 0.0 && max == INFINITY {
(spec.smallest_positive.log10(), INF_RANGE_MAGNITUDE)
} else if min == 0.0 {
if spec.smallest_positive < max {
(spec.smallest_positive.log10(), max.log10())
} else {
(max.log10() - INF_RANGE_MAGNITUDE, max.log10())
}
} else if max == INFINITY {
if min < spec.largest_finite {
(min.log10(), spec.largest_finite.log10())
} else {
(min.log10(), min.log10() + INF_RANGE_MAGNITUDE)
}
} else {
(min.log10(), max.log10())
}
}
/// where to put the zero cutoff for logarithmic sliders
/// that crosses zero ?
fn logaritmic_zero_cutoff(min: f64, max: f64) -> f64 {
assert!(min < 0.0 && 0.0 < max);
let min_magnitude = if min == -INFINITY {
INF_RANGE_MAGNITUDE
} else {
min.abs().log10().abs()
};
let max_magnitude = if max == INFINITY {
INF_RANGE_MAGNITUDE
} else {
max.log10().abs()
};
let cutoff = min_magnitude / (min_magnitude + max_magnitude);
crate::egui_assert!(0.0 <= cutoff && cutoff <= 1.0);
cutoff
}