Make refactor into library

examples/text/src/font/system.rs

@@ -0,0 +1,61 @@
+use super::{Font, FontMatches};
+
+pub struct FontSystem<'a> {
+    fonts: Vec<Font<'a>>,
+}
+
+impl<'a> FontSystem<'a> {
+    pub fn new() -> Self {
+        Self {
+            fonts: Vec::new(),
+        }
+    }
+
+    pub fn add(&mut self, font: Font<'a>) {
+        self.fonts.push(font);
+    }
+
+    pub fn matches(&'a self, patterns: &[&str]) -> Option<FontMatches<'a>> {
+        let mut fonts = Vec::new();
+        for font in self.fonts.iter() {
+            for rec in font.rustybuzz.names() {
+                if rec.name_id == 4 && rec.is_unicode() {
+                    let mut words: Vec<u16> = Vec::new();
+
+                    let mut i = 0;
+                    while i + 1 < rec.name.len() {
+                        words.push(
+                            (rec.name[i + 1] as u16) |
+                            ((rec.name[i] as u16) << 8)
+                        );
+                        i += 2;
+                    }
+
+                    match String::from_utf16(&words) {
+                        Ok(name) => {
+                            let mut matched = false;
+                            for pattern in patterns.iter() {
+                                println!("Matching font name '{}' with pattern '{}'", name, pattern);
+                                if name.contains(pattern) {
+                                    matched = true;
+                                }
+                            }
+                            if matched {
+                                println!("Matched font name '{}'", name);
+                                fonts.push(font);
+                            } else {
+                                println!("Did not match font name '{}'", name);
+                            }
+                        },
+                        Err(_) => ()
+                    }
+                }
+            }
+        }
+        if ! fonts.is_empty() {
+            Some(FontMatches { fonts })
+        } else {
+            None
+        }
+    }
+}