mirror of
https://github.com/ratatui-org/ratatui
synced 2024-11-29 16:10:34 +00:00
815757fcbb
Many widgets can be rendered without changing their state.
This commit implements The `Widget` trait for references to
widgets and changes their implementations to be immutable.
This allows us to render widgets without consuming them by passing a ref
to the widget when calling `Frame::render_widget()`.
```rust
// this might be stored in a struct
let paragraph = Paragraph::new("Hello world!");
let [left, right] = area.split(&Layout::horizontal([20, 20]));
frame.render_widget(¶graph, left);
frame.render_widget(¶graph, right); // we can reuse the widget
```
Implemented for all widgets except BarChart (which has an implementation
that modifies the internal state and requires a rewrite to fix.
Other widgets will be implemented in follow up commits.
Fixes: https://github.com/ratatui-org/ratatui/discussions/164
Replaces PRs: https://github.com/ratatui-org/ratatui/pull/122 and
https://github.com/ratatui-org/ratatui/pull/16
Enables: https://github.com/ratatui-org/ratatui/issues/132
Validated as a viable working solution by:
https://github.com/ratatui-org/ratatui/pull/836
34 lines
1.5 KiB
Rust
34 lines
1.5 KiB
Rust
use palette::{IntoColor, Okhsv, Srgb};
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use ratatui::prelude::*;
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/// A widget that renders a color swatch of RGB colors.
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///
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/// The widget is rendered as a rectangle with the hue changing along the x-axis from 0.0 to 360.0
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/// and the value changing along the y-axis (from 1.0 to 0.0). Each pixel is rendered as a block
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/// character with the top half slightly lighter than the bottom half.
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pub struct RgbSwatch;
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impl Widget for RgbSwatch {
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fn render(self, area: Rect, buf: &mut Buffer) {
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for (yi, y) in (area.top()..area.bottom()).enumerate() {
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let value = area.height as f32 - yi as f32;
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let value_fg = value / (area.height as f32);
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let value_bg = (value - 0.5) / (area.height as f32);
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for (xi, x) in (area.left()..area.right()).enumerate() {
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let hue = xi as f32 * 360.0 / area.width as f32;
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let fg = color_from_oklab(hue, Okhsv::max_saturation(), value_fg);
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let bg = color_from_oklab(hue, Okhsv::max_saturation(), value_bg);
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buf.get_mut(x, y).set_char('▀').set_fg(fg).set_bg(bg);
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}
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}
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}
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}
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/// Convert a hue and value into an RGB color via the OkLab color space.
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///
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/// See <https://bottosson.github.io/posts/oklab/> for more details.
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pub fn color_from_oklab(hue: f32, saturation: f32, value: f32) -> Color {
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let color: Srgb = Okhsv::new(hue, saturation, value).into_color();
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let color = color.into_format();
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Color::Rgb(color.red, color.green, color.blue)
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}
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