egui/egui/src/widgets/progress_bar.rs
Emil Ernerfeldt ffbd094f53 Improve docs
2021-08-23 21:47:00 +02:00

144 lines
4.4 KiB
Rust

use crate::*;
enum ProgressBarText {
Custom(String),
Percentage,
}
/// A simple progress bar.
pub struct ProgressBar {
progress: f32,
desired_width: Option<f32>,
text: Option<ProgressBarText>,
animate: bool,
}
impl ProgressBar {
/// Progress in the `[0, 1]` range, where `1` means "completed".
pub fn new(progress: f32) -> Self {
Self {
progress: progress.clamp(0.0, 1.0),
desired_width: None,
text: None,
animate: false,
}
}
/// The desired width of the bar. Will use all horizontal space if not set.
pub fn desired_width(mut self, desired_width: f32) -> Self {
self.desired_width = Some(desired_width);
self
}
/// A custom text to display on the progress bar.
#[allow(clippy::needless_pass_by_value)]
pub fn text(mut self, text: impl ToString) -> Self {
self.text = Some(ProgressBarText::Custom(text.to_string()));
self
}
/// Show the progress in percent on the progress bar.
pub fn show_percentage(mut self) -> Self {
self.text = Some(ProgressBarText::Percentage);
self
}
/// Whether to display a loading animation when progress `< 1`.
/// Note that this will cause the UI to be redrawn.
/// Defaults to `false`.
pub fn animate(mut self, animate: bool) -> Self {
self.animate = animate;
self
}
}
impl Widget for ProgressBar {
fn ui(self, ui: &mut Ui) -> Response {
let ProgressBar {
progress,
desired_width,
text,
animate,
} = self;
let animate = animate && progress < 1.0;
if animate {
ui.ctx().request_repaint();
}
let desired_width = desired_width.unwrap_or(ui.available_size_before_wrap().x);
let height = ui.spacing().interact_size.y;
let (outer_rect, response) =
ui.allocate_exact_size(vec2(desired_width, height), Sense::hover());
let visuals = ui.style().visuals.clone();
let corner_radius = outer_rect.height() / 2.0;
ui.painter().rect(
outer_rect,
corner_radius,
visuals.extreme_bg_color,
Stroke::none(),
);
let inner_rect = Rect::from_min_size(
outer_rect.min,
vec2(
(outer_rect.width() * progress).at_least(outer_rect.height()),
outer_rect.height(),
),
);
let (dark, bright) = (0.7, 1.0);
let color_factor = if animate {
lerp(dark..=bright, ui.input().time.cos().abs())
} else {
bright
};
ui.painter().rect(
inner_rect,
corner_radius,
Color32::from(Rgba::from(visuals.selection.bg_fill) * color_factor as f32),
Stroke::none(),
);
if animate {
let n_points = 20;
let start_angle = ui.input().time as f64 * 360f64.to_radians();
let end_angle = start_angle + 240f64.to_radians() * ui.input().time.sin();
let circle_radius = corner_radius - 2.0;
let points: Vec<Pos2> = (0..n_points)
.map(|i| {
let angle = lerp(start_angle..=end_angle, i as f64 / n_points as f64);
let (sin, cos) = angle.sin_cos();
inner_rect.right_center()
+ circle_radius * vec2(cos as f32, sin as f32)
+ vec2(-corner_radius, 0.0)
})
.collect();
ui.painter().add(Shape::Path {
points,
closed: false,
fill: Color32::TRANSPARENT,
stroke: Stroke::new(2.0, visuals.faint_bg_color),
});
}
if let Some(text_kind) = text {
let text = match text_kind {
ProgressBarText::Custom(string) => string,
ProgressBarText::Percentage => format!("{}%", (progress * 100.0) as usize),
};
ui.painter().sub_region(outer_rect).text(
outer_rect.left_center() + vec2(ui.spacing().item_spacing.x, 0.0),
Align2::LEFT_CENTER,
text,
TextStyle::Button,
visuals
.override_text_color
.unwrap_or(visuals.selection.stroke.color),
);
}
response
}
}