1 files changed, 57 insertions, 0 deletions
diff --git a/src/list_fonts.rs b/src/list_fonts.rs
new file mode 100644
index 00000000..9b15ea3d
--- /dev/null
+++ b/src/list_fonts.rs
@@ -0,0 +1,57 @@
+use std::ffi::CStr;
+use std::ptr;
+use std::str;
+
+use libc::{c_char, c_int};
+
+use fontconfig::fontconfig::{FcConfigGetCurrent, FcConfigGetFonts, FcSetSystem};
+use fontconfig::fontconfig::{FcPatternGetString};
+use fontconfig::fontconfig::{FcResultMatch};
+use fontconfig::fontconfig::{FcChar8};
+
+pub fn list_font_names() -> Vec<String> {
+    let mut fonts = Vec::new();
+    unsafe {
+        // https://www.freedesktop.org/software/fontconfig/fontconfig-devel/fcconfiggetcurrent.html
+        let config = FcConfigGetCurrent(); // *mut FcConfig
+
+        // https://www.freedesktop.org/software/fontconfig/fontconfig-devel/fcconfiggetfonts.html
+        let font_set = FcConfigGetFonts(config, FcSetSystem); // *mut FcFontSet
+
+        let nfont = (*font_set).nfont as isize;
+        for i in 0..nfont {
+            let font = (*font_set).fonts.offset(i); // *mut FcPattern
+            let id = 0 as c_int;
+            let mut fullname: *mut FcChar8 = ptr::null_mut();
+
+            // The second parameter here (fullname) is from the "FONT PROPERTIES" table:
+            // https://www.freedesktop.org/software/fontconfig/fontconfig-devel/x19.html
+            let result = FcPatternGetString(*font,
+                                            b"fullname\0".as_ptr() as *mut c_char,
+                                            id,
+                                            &mut fullname);
+            if result != FcResultMatch {
+                continue;
+            }
+
+            let s = str::from_utf8(CStr::from_ptr(fullname as *const c_char).to_bytes())
+                        .unwrap().to_owned();
+            fonts.push(s);
+        }
+    }
+
+    fonts
+}
+
+#[cfg(test)]
+mod tests {
+    use super::list_font_names;
+
+    #[test]
+    fn list_fonts() {
+        let fonts = list_font_names();
+        assert!(!fonts.is_empty());
+
+        println!("fonts: {:?}", fonts);
+    }
+}