[librsvg: 17/23] (#356): Add --accept-language option to rsvg-convert

[Federico Mena Quintero <federico src gnome org>]

commit d1658a7ab3c5427986cbe8f5d0be7a40e351f0a1
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri May 21 19:57:14 2021 -0500

    (#356): Add --accept-language option to rsvg-convert
    
    This takes a string formatted like an HTTP Accept-Language header:
    
      rsvg-convert --accept-language=es-MX,en,fr foo.svg
    
    Fixes https://gitlab.gnome.org/GNOME/librsvg/-/issues/356

 src/api.rs                                         |   4 +--
 src/bin/rsvg-convert.rs                            |  29 ++++++++++++++++++---
 tests/fixtures/cmdline/accept-language-de.png      | Bin 0 -> 173 bytes
 tests/fixtures/cmdline/accept-language-es.png      | Bin 0 -> 172 bytes
 .../fixtures/cmdline/accept-language-fallback.png  | Bin 0 -> 173 bytes
 tests/fixtures/cmdline/accept-language.svg         |   7 +++++
 tests/src/cmdline/rsvg_convert.rs                  |  26 ++++++++++++++++++
 7 files changed, 61 insertions(+), 5 deletions(-)
---
diff --git a/src/api.rs b/src/api.rs
index 1500f732..31199aef 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -324,8 +324,8 @@ impl<'a> CairoRenderer<'a> {
     /// `Language::FromEnvironment`, which means that the set of preferred languages will
     /// be obtained from the program's environment.  To set an explicit list of languages,
     /// you can use `Language::AcceptLanguage` instead.
-    pub fn with_language(self, language: Language) -> Self {
-        let user_language = UserLanguage::new(&language);
+    pub fn with_language(self, language: &Language) -> Self {
+        let user_language = UserLanguage::new(language);
 
         CairoRenderer {
             user_language,
diff --git a/src/bin/rsvg-convert.rs b/src/bin/rsvg-convert.rs
index 78a6e22e..8d76a1c5 100644
--- a/src/bin/rsvg-convert.rs
+++ b/src/bin/rsvg-convert.rs
@@ -21,7 +21,7 @@ mod windows_imports {
 use self::windows_imports::*;
 
 use librsvg::rsvg_convert_only::{LegacySize, PathOrUrl};
-use librsvg::{CairoRenderer, Color, Loader, Parse, RenderingError};
+use librsvg::{AcceptLanguage, CairoRenderer, Color, Language, Loader, Parse, RenderingError};
 use once_cell::unsync::OnceCell;
 use std::ops::Deref;
 use std::path::PathBuf;
@@ -435,7 +435,6 @@ arg_enum! {
     }
 }
 
-#[derive(Debug)]
 struct Converter {
     pub dpi: (f64, f64),
     pub zoom: Scale,
@@ -446,6 +445,7 @@ struct Converter {
     pub keep_aspect_ratio: bool,
     pub background_color: Option<Color>,
     pub stylesheet: Option<PathBuf>,
+    pub language: Language,
     pub unlimited: bool,
     pub keep_image_data: bool,
     pub input: Vec<Input>,
@@ -487,7 +487,9 @@ impl Converter {
                     .map_err(|e| error!("Error applying stylesheet: {}", e))?;
             }
 
-            let renderer = CairoRenderer::new(&handle).with_dpi(self.dpi.0, self.dpi.1);
+            let renderer = CairoRenderer::new(&handle)
+                .with_dpi(self.dpi.0, self.dpi.1)
+                .with_language(&self.language);
 
             let geometry = self.natural_geometry(&renderer, input)?;
             let natural_size = Size::new(geometry.width, geometry.height);
@@ -689,6 +691,14 @@ fn parse_args() -> Result<Converter, Error> {
                 .value_name("object id")
                 .help("SVG id of object to export [default is to export all objects]"),
         )
+        .arg(
+            clap::Arg::with_name("accept-language")
+                .short("l")
+                .long("accept-language")
+                .empty_values(false)
+                .value_name("languages")
+                .help("Languages to accept, for example \"es-MX,de,en\" [default uses language from the 
environment]"),
+        )
         .arg(
             clap::Arg::with_name("keep_aspect")
                 .short("a")
@@ -741,6 +751,18 @@ fn parse_args() -> Result<Converter, Error> {
         _ => matches.is_present("keep_image_data"),
     };
 
+    let language = value_t!(matches, "accept-language", String)
+        .or_none()
+        .and_then(|lang_str| match lang_str {
+            None => Ok(Language::FromEnvironment),
+            Some(s) => AcceptLanguage::parse(&s)
+                .map(Language::AcceptLanguage)
+                .map_err(|e| {
+                    let desc = format!("{}", e);
+                    clap::Error::with_description(&desc, clap::ErrorKind::InvalidValue)
+                }),
+        });
+
     let background_color = value_t!(matches, "background", String).and_then(parse_color_string);
 
     // librsvg expects ids starting with '#', so it can lookup ids in externs like "subfile.svg#subid".
@@ -793,6 +815,7 @@ fn parse_args() -> Result<Converter, Error> {
         stylesheet: matches.value_of_os("stylesheet").map(PathBuf::from),
         unlimited: matches.is_present("unlimited"),
         keep_image_data,
+        language: language?,
         input,
         output: matches
             .value_of_os("output")
diff --git a/tests/fixtures/cmdline/accept-language-de.png b/tests/fixtures/cmdline/accept-language-de.png
new file mode 100644
index 00000000..cc797dc2
Binary files /dev/null and b/tests/fixtures/cmdline/accept-language-de.png differ
diff --git a/tests/fixtures/cmdline/accept-language-es.png b/tests/fixtures/cmdline/accept-language-es.png
new file mode 100644
index 00000000..4cf3a21f
Binary files /dev/null and b/tests/fixtures/cmdline/accept-language-es.png differ
diff --git a/tests/fixtures/cmdline/accept-language-fallback.png 
b/tests/fixtures/cmdline/accept-language-fallback.png
new file mode 100644
index 00000000..43b20f01
Binary files /dev/null and b/tests/fixtures/cmdline/accept-language-fallback.png differ
diff --git a/tests/fixtures/cmdline/accept-language.svg b/tests/fixtures/cmdline/accept-language.svg
new file mode 100644
index 00000000..c132b65d
--- /dev/null
+++ b/tests/fixtures/cmdline/accept-language.svg
@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg"; width="100" height="100">
+  <switch allowReorder="yes">
+    <rect systemLanguage="de" fill="red" width="10" height="10" />
+    <rect systemLanguage="es" fill="lime" width="10" height="10" />
+    <rect fill="yellow" id="rect3" width="10" height="10" />
+  </switch>
+</svg>
diff --git a/tests/src/cmdline/rsvg_convert.rs b/tests/src/cmdline/rsvg_convert.rs
index 64c79510..5dbdb65c 100644
--- a/tests/src/cmdline/rsvg_convert.rs
+++ b/tests/src/cmdline/rsvg_convert.rs
@@ -708,6 +708,32 @@ fn overflowing_size_is_detected() {
         ));
 }
 
+#[test]
+fn accept_language_given() {
+    RsvgConvert::new_with_input("tests/fixtures/cmdline/accept-language.svg")
+        .arg("--accept-language=es-MX")
+        .assert()
+        .success()
+        .stdout(file::is_png().with_contents("tests/fixtures/cmdline/accept-language-es.png"));
+
+    RsvgConvert::new_with_input("tests/fixtures/cmdline/accept-language.svg")
+        .arg("--accept-language=de")
+        .assert()
+        .success()
+        .stdout(file::is_png().with_contents("tests/fixtures/cmdline/accept-language-de.png"));
+}
+
+#[test]
+fn accept_language_fallback() {
+    RsvgConvert::new_with_input("tests/fixtures/cmdline/accept-language.svg")
+        .arg("--accept-language=fr")
+        .assert()
+        .success()
+        .stdout(
+            file::is_png().with_contents("tests/fixtures/cmdline/accept-language-fallback.png"),
+        );
+}
+
 #[test]
 fn keep_image_data_option() {
     RsvgConvert::accepts_arg("--keep-image-data");