kui_core/metrics.rs
1//! [`Metrics`]: the sizes the stock widgets are built from, one struct
2//! beside the palette.
3//!
4//! Every field is logical px (or a text size in logical px), applied
5//! before `env.scale`, which the renderer multiplies everything by.
6//! Density is the app's choice, as the palette is: [`Metrics::compact`]
7//! is a tighter set, [`Metrics::scaled`] multiplies every length for a
8//! density slider, and `Core::set_metrics` makes one the frame's. An app
9//! that never sets one gets [`Metrics::default`], the stock geometry.
10//!
11//! Fields are roles, like the palette's: `control_pad_x` is a button's
12//! horizontal padding, not "spacing unit 3", and a view that wants a
13//! number between two has arithmetic.
14
15/// The titlebar's height on Windows and everywhere else: the caption
16/// height the OS draws, so the one metric that is the platform's rather
17/// than a density's. Named here so [`Metrics::comfortable`] picks the
18/// running one and the schema row (`MetricRole::platform`) carries both,
19/// which is what keeps a generated table from saying which machine wrote
20/// it.
21pub const TITLEBAR_H_WINDOWS: f32 = 32.0;
22pub const TITLEBAR_H_ELSEWHERE: f32 = 34.0;
23
24/// The sizes the stock widgets are built from. Plain data and [`Copy`]: a
25/// view reads it off `ui.metrics()` and may keep or change its own copy,
26/// and `Core::set_metrics` makes one the frame's.
27#[derive(Clone, Copy, Debug, PartialEq)]
28pub struct Metrics {
29 // -- text ----------------------------------------------------------
30 /// A stock control's label: the button's text size.
31 pub control_text: f32,
32 /// The chrome's text: a menu row, a menu-bar title, the titlebar's
33 /// title.
34 pub chrome_text: f32,
35 /// A tooltip's text.
36 pub hint_text: f32,
37
38 // -- corners -------------------------------------------------------
39 /// The corner of every stock surface: a button, a field, a menu, a
40 /// tooltip.
41 pub radius: f32,
42 /// The corner of a row inside one: a menu row, a menu-bar title.
43 pub radius_inner: f32,
44
45 // -- padding, x then y -----------------------------------------------
46 /// A button's.
47 pub control_pad_x: f32,
48 pub control_pad_y: f32,
49 /// A text field's.
50 pub field_pad_x: f32,
51 pub field_pad_y: f32,
52 /// A tooltip's.
53 pub hint_pad_x: f32,
54 pub hint_pad_y: f32,
55 /// A menu row's; a menu-bar title's is two px shorter, so the bar's
56 /// height and not the title's padding decides the strip.
57 pub menu_pad_x: f32,
58 pub menu_pad_y: f32,
59
60 // -- extents -------------------------------------------------------
61 /// A menu panel's width.
62 pub menu_width: f32,
63 /// The drawn menu bar's height.
64 pub menu_bar_h: f32,
65 /// The titlebar's height where the strip is the app's alone: the
66 /// platform's caption height (32 on Windows, 34 elsewhere), which
67 /// [`Metrics::compact`] leaves alone. Where the OS keeps controls of
68 /// its own over the strip — the macOS traffic lights under custom
69 /// chrome — the strip is as tall as the OS's titlebar, which the
70 /// driver measures into `env.window.native_controls`, and this row
71 /// is not read (`widgets::titlebar_height`).
72 pub titlebar_h: f32,
73}
74
75impl Default for Metrics {
76 /// What the widgets have always drawn: the constants `widgets.rs`
77 /// carried, restated once.
78 fn default() -> Self {
79 Self::comfortable()
80 }
81}
82
83impl Metrics {
84 /// The stock set — [`Default`], named.
85 pub const fn comfortable() -> Self {
86 Metrics {
87 control_text: 15.0,
88 chrome_text: 13.0,
89 hint_text: 12.0,
90 radius: 6.0,
91 radius_inner: 4.0,
92 control_pad_x: 14.0,
93 control_pad_y: 8.0,
94 field_pad_x: 10.0,
95 field_pad_y: 8.0,
96 hint_pad_x: 10.0,
97 hint_pad_y: 6.0,
98 menu_pad_x: 8.0,
99 menu_pad_y: 5.0,
100 menu_width: 200.0,
101 menu_bar_h: 26.0,
102 titlebar_h: if cfg!(target_os = "windows") {
103 TITLEBAR_H_WINDOWS
104 } else {
105 TITLEBAR_H_ELSEWHERE
106 },
107 }
108 }
109
110 /// A tighter set for a dense tool — a mux, an inspector, a table of
111 /// controls: smaller text, shallower padding, sharper corners. The
112 /// titlebar keeps the platform's height, since that is the OS's
113 /// number and not a density.
114 pub const fn compact() -> Self {
115 Metrics {
116 control_text: 13.0,
117 chrome_text: 12.0,
118 hint_text: 11.0,
119 radius: 4.0,
120 radius_inner: 3.0,
121 control_pad_x: 10.0,
122 control_pad_y: 5.0,
123 field_pad_x: 8.0,
124 field_pad_y: 5.0,
125 hint_pad_x: 8.0,
126 hint_pad_y: 4.0,
127 menu_pad_x: 8.0,
128 menu_pad_y: 3.0,
129 menu_width: 180.0,
130 menu_bar_h: 22.0,
131 ..Self::comfortable()
132 }
133 }
134
135 /// Every density multiplied by `factor` — a density slider, or an OS
136 /// text-size setting the day one is plumbed. Logical px in, logical
137 /// px out: `env.scale` is applied after this by the renderer and is
138 /// never folded in here. A row the schema marks the platform's
139 /// (`titlebar_h`: the OS's caption height, which the traffic lights
140 /// are drawn against) is left alone, as [`Metrics::compact`] leaves
141 /// it — a 1.5 slider drew a 51 px strip beside 34 px buttons.
142 pub fn scaled(self, factor: f32) -> Self {
143 let mut m = self;
144 for row in crate::schema::METRIC_ROLES {
145 if row.platform.is_some() {
146 continue;
147 }
148 (row.set)(&mut m, (row.get)(&self) * factor);
149 }
150 m
151 }
152}