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
// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
use std::path::Path;
fn main() {
println!("cargo:rustc-check-cfg=cfg(no_qt)");
// This is part code tries to detect automatically what default style to use and tries to
// use the native style automatically if Qt is available.
//
// The way this work is this
// 1. `qttypes`' crate's build script already detects Qt and set the DEP_QT_VERSION
// 2. The qt rendering backend's build script will check if the qttype crates found Qt and
// look at the SLINT_NO_QT env variable, and sets the DEP_i_slint_backend_qt_SUPPORTS_NATIVE_STYLE
// env variable so that the default rendering backend can know if Qt was there.
// 3. here, in the default rendering backend, we know if we depends on the qt backend and if it
// has set the DEP_i_slint_backend_qt_SUPPORTS_NATIVE_STYLE env variable.
// We then write a file in the build directory with the default style that depends on the
// Qt availability
// 4a. When using the slint-build crate from a build script, it will be able to read this file
// from `slint_build::compile_with_config`
// 4b. Same when using the `slint!` macro,
let has_native_style =
std::env::var("DEP_I_SLINT_BACKEND_QT_SUPPORTS_NATIVE_STYLE").unwrap_or_default() == "1";
if !has_native_style {
println!("cargo:rustc-cfg=no_qt");
}
let style = i_slint_common::get_native_style(
has_native_style,
&std::env::var("TARGET").unwrap_or_default(),
);
let out_dir = std::env::var_os("OUT_DIR").unwrap();
// out_dir is something like
// <target_dir>/build/i-slint-backend-selector-1fe5c4ab61eb0584/out
// and we want to write to a common directory, so write in the build/ dir
let target_path =
Path::new(&out_dir).parent().unwrap().parent().unwrap().join("SLINT_DEFAULT_STYLE.txt");
std::fs::write(target_path, style).unwrap();
}