perspective-viewer 5.5.0

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// ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
// ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
// ┃ This file is part of the Perspective library, distributed under the terms ┃
// ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
// ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

use web_sys::Element;

/// The computed value of custom property `name` on `elem`, trimmed, or
/// `None` when undefined/empty.
pub fn read_custom_property(elem: &Element, name: &str) -> Option<String> {
    let value = web_sys::window()?
        .get_computed_style(elem)
        .ok()??
        .get_property_value(name)
        .ok()?;

    let value = value.trim();
    (!value.is_empty()).then(|| value.to_owned())
}

/// The intl string `--psp-label--{slug}--content` as inherited by `elem`,
/// unquoted, or `None` when no theme defines it.
pub fn read_intl_string(elem: &Element, slug: &str) -> Option<String> {
    let raw = read_custom_property(elem, &format!("--psp-label--{slug}--content"))?;
    let unquoted = raw
        .strip_prefix('"')
        .and_then(|x| x.strip_suffix('"'))
        .or_else(|| raw.strip_prefix('\'').and_then(|x| x.strip_suffix('\'')))
        .unwrap_or(&raw);

    Some(unquoted.replace("\\\"", "\""))
}