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
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190

//! Runtime hint describing the user's primary input device.
//!
//! Distinct from [`crate::platform::Platform`] (which tracks the OS family
//! for shortcut labels — Cmd vs. Ctrl) because a Mac user with a
//! touchscreen MacBook and an iPad user both run `Platform::MacOS` but
//! need very different text-entry experiences.
//!
//! The input profile drives features that should only exist on mobile
//! touch devices:
//!
//! - The agg-gui on-screen software keyboard
//!   ([`crate::widgets::on_screen_keyboard`])
//! - Hit-target padding around small interactive widgets (future)
//! - Long-press gesture timing (future)
//!
//! Native builds default to [`InputProfile::Desktop`]. WASM hosts call
//! [`set_input_profile`] after sniffing `navigator.userAgent` +
//! `matchMedia("(pointer: coarse)")` so the agg-gui-side mobile features
//! activate. The host can also call [`platform_from_name`] /
//! [`set_platform`](crate::platform::set_platform) so shortcut labels match
//! the user's keyboard while the on-screen keyboard mimics their phone OS.

use std::sync::atomic::{AtomicU8, Ordering};

/// Where keyboard / pointer events originate and how text entry should
/// behave.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum InputProfile {
    /// Physical keyboard + precise pointer (mouse / trackpad). The default.
    /// No on-screen keyboard.
    Desktop,
    /// iPhone / iPad / iPad-mode Safari. Touch primary, no physical
    /// keyboard. On-screen keyboard renders with iOS-style chrome
    /// (rounded keys, light surface, blue accent).
    MobileIOS,
    /// Android phone or tablet (Chrome / Firefox / Samsung Internet).
    /// On-screen keyboard renders with Material-style chrome (flatter
    /// keys, system accent).
    MobileAndroid,
    /// Touch device we can't otherwise classify — e.g. a Linux tablet.
    /// On-screen keyboard renders with a neutral default.
    MobileOther,
}

impl InputProfile {
    /// `true` when the profile implies the user has no physical keyboard
    /// and the on-screen keyboard should be available.
    pub fn is_mobile_touch(self) -> bool {
        matches!(
            self,
            InputProfile::MobileIOS | InputProfile::MobileAndroid | InputProfile::MobileOther
        )
    }

    /// Recommended [`crate::ux_scale`] multiplier for this profile.
    /// `1.0` for desktop; ~`1.7` for mobile touch (phones held at
    /// arm's length need ~44 px touch targets and ~17 px body text,
    /// which is roughly 1.7× what reads well on a desktop monitor).
    ///
    /// Apps that want a different feel can override with
    /// [`crate::ux_scale::set_ux_scale`] *after* the profile is
    /// applied — accessibility settings, for example.
    pub fn recommended_ux_scale(self) -> f64 {
        match self {
            InputProfile::Desktop => 1.0,
            InputProfile::MobileIOS | InputProfile::MobileAndroid | InputProfile::MobileOther => {
                1.7
            }
        }
    }
}

static CURRENT: AtomicU8 = AtomicU8::new(profile_code(InputProfile::Desktop));

/// Replace the global input profile. Call once at startup from the
/// platform shell after detecting the device, and at most once more
/// if the device changes (e.g. a tablet docked into a desktop mode).
///
/// **Deliberately does NOT change [`crate::ux_scale`].** Earlier
/// drafts auto-applied [`InputProfile::recommended_ux_scale`] here,
/// but that meant programmatic profile changes (e.g. a demo's
/// "preview as iPhone" radio) silently resized the entire UI, which
/// is a surprise. The platform shell is the only place that knows
/// whether the user is really on a touch device; it calls
/// `set_ux_scale` explicitly. Demos / sandboxes can flip
/// `InputProfile` without affecting on-screen UI scale.
pub fn set_input_profile(profile: InputProfile) {
    CURRENT.store(profile_code(profile), Ordering::Relaxed);
}

/// Read the global input profile.
pub fn current_input_profile() -> InputProfile {
    profile_from_code(CURRENT.load(Ordering::Relaxed))
}

/// Convenience: detect mobile-touch from current profile.
pub fn is_mobile_touch() -> bool {
    current_input_profile().is_mobile_touch()
}

/// Parse a coarse browser identifier ("iPhone", "iPad", "Android", …)
/// into an [`InputProfile`]. Defaults to [`InputProfile::Desktop`] so a
/// non-matching string (any desktop UA) keeps mobile features disabled.
///
/// `pointer_coarse` should reflect `window.matchMedia('(pointer: coarse)')`
/// — true on iPad-mode Safari that hides "iPad" from the UA, false on a
/// MacBook trackpad. Set it to `false` if you don't have a reliable read.
pub fn input_profile_from_hint(user_agent_or_platform: &str, pointer_coarse: bool) -> InputProfile {
    let ua = user_agent_or_platform.to_ascii_lowercase();
    if ua.contains("iphone") || ua.contains("ipad") || ua.contains("ipod") {
        return InputProfile::MobileIOS;
    }
    if ua.contains("android") {
        return InputProfile::MobileAndroid;
    }
    // iPad-mode Safari masquerades as macOS in the UA. Coarse-pointer +
    // mac signals an iPad-class device in practice.
    if pointer_coarse && (ua.contains("mac") || ua.contains("darwin")) {
        return InputProfile::MobileIOS;
    }
    if pointer_coarse {
        return InputProfile::MobileOther;
    }
    InputProfile::Desktop
}

const fn profile_code(p: InputProfile) -> u8 {
    match p {
        InputProfile::Desktop => 0,
        InputProfile::MobileIOS => 1,
        InputProfile::MobileAndroid => 2,
        InputProfile::MobileOther => 3,
    }
}

fn profile_from_code(c: u8) -> InputProfile {
    match c {
        1 => InputProfile::MobileIOS,
        2 => InputProfile::MobileAndroid,
        3 => InputProfile::MobileOther,
        _ => InputProfile::Desktop,
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn ua_routes_to_correct_profile() {
        assert_eq!(
            input_profile_from_hint("Mozilla/5.0 (iPhone; CPU iPhone OS 17_4)", true),
            InputProfile::MobileIOS
        );
        assert_eq!(
            input_profile_from_hint("Mozilla/5.0 (Linux; Android 14; Pixel 8)", true),
            InputProfile::MobileAndroid
        );
        // iPad-mode Safari reports macOS in the UA but the pointer-coarse
        // hint pulls us back to MobileIOS.
        assert_eq!(
            input_profile_from_hint(
                "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit",
                true
            ),
            InputProfile::MobileIOS
        );
        // Same UA without a coarse pointer = desktop Mac.
        assert_eq!(
            input_profile_from_hint(
                "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit",
                false
            ),
            InputProfile::Desktop
        );
        // Unknown touch device.
        assert_eq!(
            input_profile_from_hint("CrOS x86_64", true),
            InputProfile::MobileOther
        );
    }

    #[test]
    fn is_mobile_touch_helper() {
        assert!(!InputProfile::Desktop.is_mobile_touch());
        assert!(InputProfile::MobileIOS.is_mobile_touch());
        assert!(InputProfile::MobileAndroid.is_mobile_touch());
        assert!(InputProfile::MobileOther.is_mobile_touch());
    }
}