agg-gui 0.2.1

Immediate-mode Rust GUI library with AGG rendering, Y-up layout, widgets, text, SVG, and native/WASM adapters
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76

//! Slider editor renderer — slider track + thumb + right-aligned
//! value text inside an editor pill.
//!
//! Both [`paint_editor`] (for `EditorKind::Slider`) and
//! [`paint_editor_drag`] (for `EditorKind::NumberDrag`) live here.
//! Both paint the same pill + numeric text; only Slider draws the
//! track-fill underlay showing the current value position between
//! `min` and `max`.

use crate::{DrawCtx, Rect};

use super::super::editor::NumberAttrs;
use super::super::value::RowValue;
use super::{editor_pill_rect, format_number, paint_pill_bg};

pub(crate) fn paint_editor(
    ctx: &mut dyn DrawCtx,
    editor_area: Rect,
    value: RowValue,
    attrs: &NumberAttrs,
    scale: f64,
) {
    let pill = editor_pill_rect(editor_area, scale);
    paint_pill_bg(ctx, pill, scale);

    if let RowValue::Number(n) = value {
        // Fill bar — fraction of the track from `min` to current.
        if let (Some(mn), Some(mx)) = (attrs.min, attrs.max) {
            if mx > mn {
                let t = ((n - mn) / (mx - mn)).clamp(0.0, 1.0);
                let visuals = ctx.visuals().clone();
                let mut fill = visuals.accent;
                fill.a = 0.35;
                let fill_w = pill.width * t;
                if fill_w > 0.0 {
                    ctx.set_fill_color(fill);
                    ctx.begin_path();
                    ctx.rounded_rect(pill.x, pill.y, fill_w, pill.height, 3.0 * scale);
                    ctx.fill();
                }
            }
        }

        paint_centred_value(ctx, pill, n, attrs, scale);
    }
}

/// Drag-value variant — pill + centred numeric text, no track fill.
pub(crate) fn paint_editor_drag(
    ctx: &mut dyn DrawCtx,
    editor_area: Rect,
    value: RowValue,
    attrs: &NumberAttrs,
    scale: f64,
) {
    let pill = editor_pill_rect(editor_area, scale);
    paint_pill_bg(ctx, pill, scale);

    if let RowValue::Number(n) = value {
        paint_centred_value(ctx, pill, n, attrs, scale);
    }
}

/// Shared value-text paint used by both slider and drag variants —
/// horizontally centred in `pill`, vertically centred using the
/// label-baseline convention.
fn paint_centred_value(ctx: &mut dyn DrawCtx, pill: Rect, n: f64, attrs: &NumberAttrs, scale: f64) {
    let s = format_number(n, Some(attrs));
    let visuals = ctx.visuals().clone();
    ctx.set_fill_color(visuals.text_color);
    ctx.set_font_size(11.0 * scale);
    let est_w = (s.len() as f64) * 6.5 * scale;
    let text_x = (pill.x + (pill.width - est_w) * 0.5).max(pill.x + 4.0 * scale);
    let text_y = pill.y + pill.height * 0.5 - 4.0 * scale;
    ctx.fill_text(&s, text_x, text_y);
}