cranpose 0.1.70

Cranpose runtime and UI facade
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

//! Browser accessibility bridge for the canvas renderer.

use crate::accessibility::{self, AccessibilityElement, AccessibilityRole};
use cranpose_app_shell::AppShell;
use cranpose_render_wgpu::WgpuRenderer;
use std::cell::RefCell;
use std::rc::Rc;
use wasm_bindgen::closure::Closure;
use wasm_bindgen::{JsCast, JsValue};
use web_sys::{Document, Element, HtmlCanvasElement, HtmlElement, MouseEvent};

/// Transparent DOM nodes mirroring the semantic controls painted on canvas.
pub(crate) struct WebAccessibilityBridge {
    root: HtmlElement,
    canvas: HtmlCanvasElement,
    previous: Vec<AccessibilityElement>,
}

impl WebAccessibilityBridge {
    pub(crate) fn install(
        document: &Document,
        canvas: HtmlCanvasElement,
        app: Rc<RefCell<AppShell<WgpuRenderer>>>,
    ) -> Result<Self, JsValue> {
        let root = document.create_element("div")?.dyn_into::<HtmlElement>()?;
        root.set_attribute("data-cranpose-accessibility", "")?;
        root.set_attribute("aria-label", "Application controls")?;
        let style = root.style();
        style.set_property("position", "fixed")?;
        style.set_property("inset", "0")?;
        style.set_property("z-index", "2147483647")?;
        style.set_property("pointer-events", "none")?;

        let click = Closure::wrap(Box::new(move |event: MouseEvent| {
            let Some(target) = event
                .target()
                .and_then(|target| target.dyn_into::<Element>().ok())
            else {
                return;
            };
            let Some(x) = target
                .get_attribute("data-cranpose-x")
                .and_then(|value| value.parse::<f32>().ok())
            else {
                return;
            };
            let Some(y) = target
                .get_attribute("data-cranpose-y")
                .and_then(|value| value.parse::<f32>().ok())
            else {
                return;
            };
            if let Ok(mut shell) = app.try_borrow_mut() {
                shell.set_cursor(x, y);
                shell.pointer_pressed();
                shell.pointer_released_at_position(x, y);
            }
        }) as Box<dyn FnMut(_)>);
        root.add_event_listener_with_callback("click", click.as_ref().unchecked_ref())?;
        click.forget();

        document
            .body()
            .ok_or("document has no body")?
            .append_child(&root)?;
        Ok(Self {
            root,
            canvas,
            previous: Vec::new(),
        })
    }

    pub(crate) fn sync(
        &mut self,
        document: &Document,
        shell: &mut AppShell<WgpuRenderer>,
    ) -> Result<(), JsValue> {
        let elements = accessibility::snapshot(shell);
        if elements == self.previous {
            return Ok(());
        }
        self.previous.clone_from(&elements);
        self.root.set_inner_html("");

        let canvas_rect = self.canvas.get_bounding_client_rect();
        let viewport = shell.viewport_size();
        let scale_x = canvas_rect.width() / viewport.0.max(1.0) as f64;
        let scale_y = canvas_rect.height() / viewport.1.max(1.0) as f64;

        for element in elements {
            let node = document
                .create_element(if element.clickable { "button" } else { "span" })?
                .dyn_into::<HtmlElement>()?;
            node.set_attribute("aria-label", &element.label)?;
            node.set_attribute("data-cranpose-node", &element.node_id.to_string())?;
            match element.role {
                AccessibilityRole::Button => node.set_attribute("role", "button")?,
                AccessibilityRole::StaticText => {
                    node.set_attribute("role", "text")?;
                    node.set_text_content(Some(&element.label));
                }
                AccessibilityRole::TextField => {
                    node.set_attribute("role", "textbox")?;
                    if let Some(value) = &element.value {
                        node.set_attribute("aria-valuetext", value)?;
                    }
                }
            }
            if element.clickable {
                let (x, y) = element.bounds.center();
                node.set_attribute("data-cranpose-x", &x.to_string())?;
                node.set_attribute("data-cranpose-y", &y.to_string())?;
            } else {
                node.set_attribute("tabindex", "-1")?;
            }
            let style = node.style();
            style.set_property("position", "fixed")?;
            style.set_property(
                "left",
                &format!(
                    "{}px",
                    canvas_rect.left() + element.bounds.x as f64 * scale_x
                ),
            )?;
            style.set_property(
                "top",
                &format!(
                    "{}px",
                    canvas_rect.top() + element.bounds.y as f64 * scale_y
                ),
            )?;
            style.set_property(
                "width",
                &format!("{}px", element.bounds.width as f64 * scale_x),
            )?;
            style.set_property(
                "height",
                &format!("{}px", element.bounds.height as f64 * scale_y),
            )?;
            style.set_property("opacity", "0.001")?;
            style.set_property("pointer-events", "none")?;
            style.set_property("overflow", "hidden")?;
            self.root.append_child(&node)?;
        }
        Ok(())
    }
}