Ged rid of libfontconfig in Android. Query available fonts from Android system font configuration files.

7 files changed, 498 insertions, 11 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 4fb92f7ec9f..fce24203be9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1055,6 +1055,7 @@ dependencies = [
  "unicode-script 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "webrender_traits 0.39.0 (git+https://github.com/servo/webrender)",
  "xi-unicode 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml5ever 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
diff --git a/components/gfx/Cargo.toml b/components/gfx/Cargo.toml
index dfbe6ab582b..78b7f958650 100644
--- a/components/gfx/Cargo.toml
+++ b/components/gfx/Cargo.toml
@@ -50,8 +50,13 @@ core-text = "4.0"
 
 [target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
 freetype = "0.2"
+
+[target.'cfg(target_os = "linux")'.dependencies]
 servo-fontconfig = "0.2.1"
 
+[target.'cfg(target_os = "android")'.dependencies]
+xml5ever = {version = "0.7", features = ["unstable"]}
+
 [target.'cfg(any(target_feature = "sse2", target_feature = "neon"))'.dependencies]
 simd = "0.2.0"
 
diff --git a/components/gfx/lib.rs b/components/gfx/lib.rs
index b7e23df0d83..3f356bb0cea 100644
--- a/components/gfx/lib.rs
+++ b/components/gfx/lib.rs
@@ -33,7 +33,7 @@ extern crate bitflags;
 extern crate euclid;
 extern crate fnv;
 
-#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg(target_os = "linux")]
 extern crate fontconfig;
 extern crate fontsan;
 #[cfg(any(target_os = "linux", target_os = "android"))]
@@ -73,6 +73,8 @@ extern crate unicode_bidi;
 extern crate unicode_script;
 extern crate webrender_traits;
 extern crate xi_unicode;
+#[cfg(target_os = "android")]
+extern crate xml5ever;
 
 #[deny(unsafe_code)]
 pub mod display_list;
diff --git a/components/gfx/platform/freetype/android/font_list.rs b/components/gfx/platform/freetype/android/font_list.rs
new file mode 100644
index 00000000000..358b9a2104b
--- /dev/null
+++ b/components/gfx/platform/freetype/android/font_list.rs
@@ -0,0 +1,481 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::cell::RefCell;
+use std::fs::File;
+use std::io::{self, Read};
+use std::path::Path;
+use xml5ever::Attribute;
+use xml5ever::driver::parse_document;
+use xml5ever::rcdom::*;
+use xml5ever::rcdom::{Node, RcDom};
+use xml5ever::tendril::TendrilSink;
+
+lazy_static! {
+    static ref FONT_LIST: FontList = FontList::new();
+}
+
+// Android doesn't provide an API to query system fonts until Android O:
+// https://developer.android.com/reference/android/text/FontConfig.html
+// System font configuration files must be parsed until Android O version is set as the minimum target.
+// Android uses XML files to handle font mapping configurations.
+// On Android API 21+ font mappings are loaded from /etc/fonts.xml.
+// Each entry consists of a family with various font names, or a font alias.
+// Example:
+//   <familyset>
+//       <!-- first font is default -->
+//       <family name="sans-serif">
+//           <font weight="100" style="normal">Roboto-Thin.ttf</font>
+//           <font weight="100" style="italic">Roboto-ThinItalic.ttf</font>
+//           <font weight="300" style="normal">Roboto-Light.ttf</font>
+//           <font weight="300" style="italic">Roboto-LightItalic.ttf</font>
+//           <font weight="400" style="normal">Roboto-Regular.ttf</font>
+//           <font weight="400" style="italic">Roboto-Italic.ttf</font>
+//           <font weight="500" style="normal">Roboto-Medium.ttf</font>
+//           <font weight="500" style="italic">Roboto-MediumItalic.ttf</font>
+//           <font weight="900" style="normal">Roboto-Black.ttf</font>
+//           <font weight="900" style="italic">Roboto-BlackItalic.ttf</font>
+//           <font weight="700" style="normal">Roboto-Bold.ttf</font>
+//           <font weight="700" style="italic">Roboto-BoldItalic.ttf</font>
+//       </family>//
+
+//       <!-- Note that aliases must come after the fonts they reference. -->
+//       <alias name="sans-serif-thin" to="sans-serif" weight="100" />
+//       <alias name="sans-serif-light" to="sans-serif" weight="300" />
+//       <alias name="sans-serif-medium" to="sans-serif" weight="500" />
+//       <alias name="sans-serif-black" to="sans-serif" weight="900" />
+//       <alias name="arial" to="sans-serif" />
+//       <alias name="helvetica" to="sans-serif" />
+//       <alias name="tahoma" to="sans-serif" />
+//       <alias name="verdana" to="sans-serif" />
+
+//       <family name="sans-serif-condensed">
+//           <font weight="300" style="normal">RobotoCondensed-Light.ttf</font>
+//           <font weight="300" style="italic">RobotoCondensed-LightItalic.ttf</font>
+//           <font weight="400" style="normal">RobotoCondensed-Regular.ttf</font>
+//           <font weight="400" style="italic">RobotoCondensed-Italic.ttf</font>
+//           <font weight="700" style="normal">RobotoCondensed-Bold.ttf</font>
+//           <font weight="700" style="italic">RobotoCondensed-BoldItalic.ttf</font>
+//       </family>
+//       <alias name="sans-serif-condensed-light" to="sans-serif-condensed" weight="300" />
+//   </familyset>
+// On Android API 17-20 font mappings are loaded from /system/etc/system_fonts.xml
+// Each entry consists of a family with a nameset and a fileset.
+// Example:
+//  <familyset>
+//      <family>
+//          <nameset>
+//              <name>sans-serif</name>
+//              <name>arial</name>
+//              <name>helvetica</name>
+//              <name>tahoma</name>
+//              <name>verdana</name>
+//          </nameset>
+//          <fileset>
+//              <file>Roboto-Regular.ttf</file>
+//              <file>Roboto-Bold.ttf</file>
+//              <file>Roboto-Italic.ttf</file>
+//              <file>Roboto-BoldItalic.ttf</file>
+//          </fileset>
+//      </family>//
+
+//      <family>
+//          <nameset>
+//              <name>sans-serif-light</name>
+//          </nameset>
+//          <fileset>
+//              <file>Roboto-Light.ttf</file>
+//              <file>Roboto-LightItalic.ttf</file>
+//          </fileset>
+//      </family>//
+
+//      <family>
+//          <nameset>
+//              <name>sans-serif-thin</name>
+//          </nameset>
+//          <fileset>
+//              <file>Roboto-Thin.ttf</file>
+//              <file>Roboto-ThinItalic.ttf</file>
+//          </fileset>
+//      </family>
+//  </familyset>
+
+struct Font {
+    filename: String,
+    weight: Option<i32>,
+}
+
+struct FontFamily {
+    name: String,
+    fonts: Vec<Font>,
+}
+
+struct FontAlias {
+    from: String,
+    to: String,
+    weight: Option<i32>
+}
+
+struct FontList {
+    families: Vec<FontFamily>,
+    aliases: Vec<FontAlias>
+}
+
+impl FontList {
+    fn new() -> FontList {
+        // Possible paths containing the font mapping xml file.
+        let paths = [
+            "/etc/fonts.xml",
+            "/system/etc/system_fonts.xml"
+        ];
+
+        // Try to load and parse paths until one of them success.
+        let mut result = None;
+        paths.iter().all(|path| {
+            result = Self::from_path(path);
+            !result.is_some()
+        });
+
+        match result {
+            Some(result) => result,
+            // If no xml mapping file is found fallback to some default
+            // fonts expected to be on all Android devices.
+            None => FontList {
+                families: Self::fallback_font_families(),
+                aliases: Vec::new(),
+            }
+        }
+    }
+
+    // Creates a new FontList from a path to the font mapping xml file.
+    fn from_path(path: &str) -> Option<FontList> {
+        let xml = match Self::load_file(path) {
+            Ok(xml) => xml,
+            _=> { return None; },
+        };
+
+        let dom: RcDom = parse_document(RcDom::default(), Default::default())
+                         .one(xml);
+        let doc = &dom.document;
+
+        // find familyset root node
+        let children = doc.children.borrow();
+        let familyset = children.iter().find(|child| {
+            match child.data {
+                NodeData::Element { ref name, .. } => &*name.local == "familyset",
+                _ => false,
+            }
+        });
+
+        let familyset = match familyset {
+            Some(node) => node,
+            _ => { return None; }
+        };
+
+        // Parse familyset node
+        let mut families = Vec::new();
+        let mut aliases = Vec::new();
+
+        for node in familyset.children.borrow().iter() {
+            match node.data {
+                NodeData::Element { ref name, ref attrs, .. } => {
+                    if &*name.local == "family" {
+                        Self::parse_family(&node, attrs, &mut families);
+                    } else if &*name.local == "alias" {
+                        // aliases come after the fonts they reference. -->
+                        if !families.is_empty() {
+                            Self::parse_alias(attrs, &mut aliases);
+                        }
+                    }
+                },
+                _=> {}
+            }
+        }
+
+        Some(FontList {
+            families: families,
+            aliases: aliases
+        })
+    }
+
+    // Fonts expected to exist in Android devices.
+    // Only used in the unlikely case where no font xml mapping files are found.
+    fn fallback_font_families() -> Vec<FontFamily> {
+        let alternatives = [
+            ("san-serif", "Roboto-Regular.ttf"),
+            ("Droid Sans", "DroidSans.ttf"),
+        ];
+
+        alternatives.iter().filter(|item| {
+            Path::new(&Self::font_absolute_path(item.1)).exists()
+        }).map(|item| {
+            FontFamily {
+                name: item.0.into(),
+                fonts: vec![Font {
+                    filename: item.1.into(),
+                    weight: None,
+                }]
+            }
+        }). collect()
+    }
+
+    // All Android fonts are located in /system/fonts
+    fn font_absolute_path(filename: &str) -> String {
+        format!("/system/fonts/{}", filename)
+    }
+
+    fn find_family(&self, name: &str) -> Option<&FontFamily>{
+        self.families.iter().find(|f| f.name == name)
+    }
+
+    fn find_alias(&self, name: &str) -> Option<&FontAlias>{
+        self.aliases.iter().find(|f| f.from == name)
+    }
+
+
+    fn load_file(path: &str) -> Result<String, io::Error> {
+        let mut file = try!(File::open(path));
+        let mut content = String::new();
+        try!(file.read_to_string(&mut content));
+
+        Ok(content)
+    }
+
+    // Parse family and font file names
+    // Example:
+    // <family name="sans-serif">
+    //     <font weight="100" style="normal">Roboto-Thin.ttf</font>
+    //     <font weight="100" style="italic">Roboto-ThinItalic.ttf</font>
+    //     <font weight="300" style="normal">Roboto-Light.ttf</font>
+    //     <font weight="300" style="italic">Roboto-LightItalic.ttf</font>
+    //     <font weight="400" style="normal">Roboto-Regular.ttf</font>
+    // </family>
+    fn parse_family(familyset: &Node, attrs: &RefCell<Vec<Attribute>>, out:&mut Vec<FontFamily>) {
+        // Fallback to old Android API v17 xml format if required
+        let using_api_17 = familyset.children.borrow().iter().any(|node| {
+            match node.data {
+                NodeData::Element { ref name, .. } => &*name.local == "nameset",
+                _=> false,
+            }
+        });
+        if using_api_17 {
+            Self::parse_family_v17(familyset, out);
+            return;
+        }
+
+        // Parse family name
+        let name = match Self::find_attrib("name", attrs) {
+            Some(name) => name,
+            _ => { return; },
+        };
+
+        let mut fonts = Vec::new();
+        // Parse font variants
+        for node in familyset.children.borrow().iter() {
+            match node.data {
+                NodeData::Element { ref name, ref attrs, .. } => {
+                    if &*name.local == "font" {
+                        FontList::parse_font(&node, attrs, &mut fonts);
+                    }
+                },
+                _=> {}
+            }
+        }
+
+        out.push(FontFamily {
+            name: name,
+            fonts: fonts
+        });
+    }
+
+    // Parse family and font file names for Androi API < 21
+    // Example:
+    // <family>
+    //     <nameset>
+    //         <name>sans-serif</name>
+    //         <name>arial</name>
+    //         <name>helvetica</name>
+    //         <name>tahoma</name>
+    //         <name>verdana</name>
+    //     </nameset>
+    //     <fileset>
+    //         <file>Roboto-Regular.ttf</file>
+    //         <file>Roboto-Bold.ttf</file>
+    //         <file>Roboto-Italic.ttf</file>
+    //         <file>Roboto-BoldItalic.ttf</file>
+    //     </fileset>
+    // </family>
+    fn parse_family_v17(familyset: &Node, out:&mut Vec<FontFamily>) {
+        let mut nameset = Vec::new();
+        let mut fileset = Vec::new();
+        for node in familyset.children.borrow().iter() {
+            match node.data {
+                NodeData::Element { ref name, .. } => {
+                    if &*name.local == "nameset" {
+                        Self::collect_contents_with_tag(node, "name", &mut nameset);
+                    } else if &*name.local == "fileset" {
+                        Self::collect_contents_with_tag(node, "file", &mut fileset);
+                    }
+                },
+                _=> {}
+            }
+        }
+
+        // Create a families for each variation
+        for name in nameset {
+            let fonts: Vec<Font> = fileset.iter().map(|f| Font {
+                filename: f.clone(),
+                weight: None,
+            }).collect();
+
+            if !fonts.is_empty() {
+                out.push(FontFamily {
+                    name: name,
+                    fonts: fonts
+                })
+            }
+        }
+    }
+
+    // Example:
+    // <font weight="100" style="normal">Roboto-Thin.ttf</font>
+    fn parse_font(node: &Node, attrs: &RefCell<Vec<Attribute>>, out:&mut Vec<Font>) {
+        // Parse font filename
+        let filename = match Self::text_content(node) {
+            Some(filename) => filename,
+            _ => { return; }
+        };
+
+        // Parse font weight
+        let weight = Self::find_attrib("weight", attrs).and_then(|w| w.parse().ok());
+
+        out.push(Font {
+            filename: filename,
+            weight: weight,
+        })
+    }
+
+    // Example:
+    // <alias name="sans-serif-thin" to="sans-serif" weight="100" />
+    // <alias name="sans-serif-light" to="sans-serif" weight="300" />
+    // <alias name="sans-serif-medium" to="sans-serif" weight="500" />
+    // <alias name="sans-serif-black" to="sans-serif" weight="900" />
+    // <alias name="arial" to="sans-serif" />
+    // <alias name="helvetica" to="sans-serif" />
+    // <alias name="tahoma" to="sans-serif" />
+    // <alias name="verdana" to="sans-serif" />
+    fn parse_alias(attrs: &RefCell<Vec<Attribute>>, out:&mut Vec<FontAlias>) {
+        // Parse alias name and referenced font
+        let from = match Self::find_attrib("name", attrs) {
+            Some(from) => from,
+            _ => { return; },
+        };
+
+        // Parse referenced font
+        let to = match Self::find_attrib("to", attrs) {
+            Some(to) => to,
+            _ => { return; },
+        };
+
+        // Parse optional weight filter
+        let weight = Self::find_attrib("weight", attrs).and_then(|w| w.parse().ok());
+
+        out.push(FontAlias {
+            from: from,
+            to: to,
+            weight: weight,
+        })
+    }
+
+    fn find_attrib(name: &str, attrs: &RefCell<Vec<Attribute>>) -> Option<String> {
+        attrs.borrow().iter().find(|attr| &*attr.name.local == name).map(|s| String::from(&s.value))
+    }
+
+    fn text_content(node: &Node) -> Option<String> {
+        node.children.borrow().get(0).and_then(|child| {
+            match child.data {
+                NodeData::Text { ref contents } => {
+                    let mut result = String::new();
+                    result.push_str(&contents.borrow());
+                    Some(result)
+                },
+                _ => None
+            }
+        })
+    }
+
+    fn collect_contents_with_tag(node: &Node, tag: &str, out:&mut Vec<String>) {
+        for child in node.children.borrow().iter() {
+            match child.data {
+                NodeData::Element { ref name, .. } => {
+                    if &*name.local == tag {
+                        if let Some(content) = Self::text_content(child) {
+                            out.push(content);
+                        }
+                    }
+                },
+                _=> {}
+            }
+        }
+    }
+}
+
+// Functions used by FontCacheThread
+pub fn for_each_available_family<F>(mut callback: F) where F: FnMut(String) {
+    for family in &FONT_LIST.families {
+        callback(family.name.clone());
+    }
+    for alias in &FONT_LIST.aliases {
+        callback(alias.from.clone());
+    }
+}
+
+pub fn for_each_variation<F>(family_name: &str, mut callback: F)
+    where F: FnMut(String)
+{
+    println!("Variatioooon {:?}", family_name);
+    if let Some(family) = FONT_LIST.find_family(family_name) {
+        for font in &family.fonts {
+            callback(FontList::font_absolute_path(&font.filename));
+        }
+        return;
+    }
+
+    if let Some(alias) = FONT_LIST.find_alias(family_name) {
+        if let Some(family) = FONT_LIST.find_family(&alias.to) {
+            for font in &family.fonts {
+                match (alias.weight, font.weight) {
+                    (None, _) => callback(FontList::font_absolute_path(&font.filename)),
+                    (Some(w1), Some(w2)) => {
+                        if w1 == w2 {
+                            callback(FontList::font_absolute_path(&font.filename))
+                        }
+                    },
+                    _ => {}
+                }
+            }
+        }
+    }
+}
+
+pub fn system_default_family(generic_name: &str) -> Option<String> {
+    if let Some(family) = FONT_LIST.find_family(&generic_name) {
+        Some(family.name.clone())
+    } else if let Some(alias) = FONT_LIST.find_alias(&generic_name) {
+        Some(alias.from.clone())
+    } else {
+        //  First font defined in the fonts.xml is the default on Android.
+        FONT_LIST.families.get(0).map(|family| family.name.clone())
+    }
+}
+
+pub fn last_resort_font_families() -> Vec<String> {
+    vec!(
+        "sans-serif".to_owned(),
+        "Droid Sans".to_owned(),
+        "serif".to_owned(),
+    )
+}
+
+pub static SANS_SERIF_FONT_FAMILY: &'static str = "sans-serif";
diff --git a/components/gfx/platform/freetype/font_list.rs b/components/gfx/platform/freetype/font_list.rs
index 1b87a18221d..8f2898ae680 100644
--- a/components/gfx/platform/freetype/font_list.rs
+++ b/components/gfx/platform/freetype/font_list.rs
@@ -141,11 +141,6 @@ pub fn last_resort_font_families() -> Vec<String> {
     )
 }
 
-#[cfg(target_os = "android")]
-pub fn last_resort_font_families() -> Vec<String> {
-    vec!("Roboto".to_owned())
-}
-
 #[cfg(target_os = "windows")]
 pub fn last_resort_font_families() -> Vec<String> {
     vec!(
@@ -153,9 +148,6 @@ pub fn last_resort_font_families() -> Vec<String> {
     )
 }
 
-#[cfg(target_os = "android")]
-pub static SANS_SERIF_FONT_FAMILY: &'static str = "Roboto";
-
 #[cfg(target_os = "linux")]
 pub static SANS_SERIF_FONT_FAMILY: &'static str = "DejaVu Sans";
 
diff --git a/components/gfx/platform/mod.rs b/components/gfx/platform/mod.rs
index 9a505c14284..897fbe9e8d3 100644
--- a/components/gfx/platform/mod.rs
+++ b/components/gfx/platform/mod.rs
@@ -29,8 +29,14 @@ mod freetype {
     pub mod font;
     pub mod font_context;
 
-    #[cfg(any(target_os = "linux", target_os = "android"))]
+    #[cfg(target_os = "linux")]
     pub mod font_list;
+    #[cfg(target_os = "android")]
+    mod android {
+        pub mod font_list;
+    }
+    #[cfg(target_os = "android")]
+    pub use self::android::font_list;
 
     #[cfg(any(target_os = "linux", target_os = "android"))]
     pub mod font_template;
diff --git a/ports/servo/main.rs b/ports/servo/main.rs
index bec8ffa8089..7d390988be0 100644
--- a/ports/servo/main.rs
+++ b/ports/servo/main.rs
@@ -204,7 +204,7 @@ impl app::NestedEventLoopListener for BrowserWrapper {
 #[cfg(target_os = "android")]
 fn setup_logging() {
     // Piping logs from stdout/stderr to logcat happens in android_injected_glue.
-    ::std::env::set_var("RUST_LOG", "debug");
+    ::std::env::set_var("RUST_LOG", "error");
 
     unsafe { android_injected_glue::ffi::app_dummy() };
 }