Add FontCacheImpl

src/main/java/net/kemitix/fontface/FontCacheImpl.java

@@ -0,0 +1,74 @@
+package net.kemitix.fontface;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.awt.*;
+import java.net.URI;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.logging.Logger;
+
+@RequiredArgsConstructor
+public class FontCacheImpl implements FontCache {
+
+    private static final Logger LOGGER =
+            Logger.getLogger(
+                    FontCacheImpl.class.getName());
+
+    private final Map<URI, Font> fileCache = new HashMap<>();
+
+    private final Map<FontAndSize, Font> fontCache = new HashMap<>();
+
+    private final FontLoader fontLoader;
+
+    @Override
+    public Font loadFont(final FontFace fontFace) {
+        LOGGER.finest(String.format("Requesting %s %d",
+                fontFace.getFontLocation(), fontFace.getSize()));
+        final Font baseFont =
+                fileCache.computeIfAbsent(
+                        fontFace.getFontLocation(),
+                        loadNewFontFile(fontFace));
+        return fontCache.computeIfAbsent(
+                FontAndSize.of(baseFont, fontFace.getSize()),
+                resizeFont());
+    }
+
+    private Function<URI, Font> loadNewFontFile(
+            final FontFace fontFace
+    ) {
+        return uri -> {
+            LOGGER.fine(String.format("Loading %s", uri));
+            return fontLoader.loadFont(fontFace);
+        };
+    }
+
+
+    private Function<FontAndSize, Font> resizeFont() {
+        return fontAndSize -> {
+            LOGGER.finer(String.format("Resizing %s to %d",
+                    fontAndSize.getFont().getName(), fontAndSize.getSize()));
+            return fontAndSize.font
+                    .deriveFont(Font.PLAIN, fontAndSize.getSize());
+        };
+    }
+
+    @Getter
+    @EqualsAndHashCode
+    private static class FontAndSize {
+        private final Font font;
+        private final int size;
+
+        private FontAndSize(final Font font, final int size) {
+            this.font = font;
+            this.size = size;
+        }
+
+        static FontAndSize of(final Font font, final int size) {
+            return new FontAndSize(font, size);
+        }
+    }
+}