1// Copyright © SixtyFPS GmbH <info@slint.dev>
2// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
3
4use std::path::Path;
5
6fn main() {
7 println!("cargo:rustc-check-cfg=cfg(no_qt)");
8
9 // This is part code tries to detect automatically what default style to use and tries to
10 // use the native style automatically if Qt is available.
11 //
12 // The way this work is this
13 // 1. `qttypes`' crate's build script already detects Qt and set the DEP_QT_VERSION
14 // 2. The qt rendering backend's build script will check if the qttype crates found Qt and
15 // look at the SLINT_NO_QT env variable, and sets the DEP_i_slint_backend_qt_SUPPORTS_NATIVE_STYLE
16 // env variable so that the default rendering backend can know if Qt was there.
17 // 3. here, in the default rendering backend, we know if we depends on the qt backend and if it
18 // has set the DEP_i_slint_backend_qt_SUPPORTS_NATIVE_STYLE env variable.
19 // We then write a file in the build directory with the default style that depends on the
20 // Qt availability
21 // 4a. When using the slint-build crate from a build script, it will be able to read this file
22 // from `slint_build::compile_with_config`
23 // 4b. Same when using the `slint!` macro,
24
25 let has_native_style =
26 std::env::var("DEP_I_SLINT_BACKEND_QT_SUPPORTS_NATIVE_STYLE").unwrap_or_default() == "1";
27
28 if !has_native_style {
29 println!("cargo:rustc-cfg=no_qt");
30 }
31
32 let style = i_slint_common::get_native_style(
33 has_native_style,
34 &std::env::var("TARGET").unwrap_or_default(),
35 );
36 let out_dir = std::env::var_os("OUT_DIR").unwrap();
37 // out_dir is something like
38 // <target_dir>/build/i-slint-backend-selector-1fe5c4ab61eb0584/out
39 // and we want to write to a common directory, so write in the build/ dir
40 let target_path =
41 Path::new(&out_dir).parent().unwrap().parent().unwrap().join("SLINT_DEFAULT_STYLE.txt");
42 std::fs::write(target_path, style).unwrap();
43}
44