Enable simple prototypical implementation of using an icon font inste…

…ad of pngs

src/main/java/net/sf/jabref/gui/IconTheme.java

@@ -3,21 +3,133 @@
 import net.sf.jabref.logic.l10n.Localization;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jdesktop.swingx.HorizontalLayout;
 
 import javax.swing.*;
+import java.awt.*;
+import java.awt.image.BufferedImage;
 import java.io.BufferedReader;
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Objects;
+import java.util.*;
 
 public class IconTheme {
 
+    public static Font FONT;
+    public static Font FONT_16;
+
+    static {
+        try {
+            FONT = Font.createFont(Font.TRUETYPE_FONT, FontBasedIcon.class.getResourceAsStream("/fonts/fontawesome-webfont.ttf"));
+            FONT_16 = FONT.deriveFont(16f);
+        } catch (FontFormatException | IOException e) {
+            // PROBLEM!
+            e.printStackTrace();
+        }
+    }
+
+    public enum JabRefIcon {
+
+        ADD("\uf067", Color.GREEN),
+        FOLDER("\uf07b"),
+        REMOVE("\uf068", Color.RED);
+
+        private final String code;
+        private final Color color;
+
+        JabRefIcon(String code) {
+            this(code, Color.BLACK);
+        }
+
+        JabRefIcon(String code, Color color) {
+            this.code = code;
+            this.color = color;
+        }
+
+        public FontBasedIcon getIcon() {
+            return new FontBasedIcon(this.code, this.color);
+        }
+
+        public ImageIcon getImageIcon() {
+            return new ImageIcon() {
+
+                private FontBasedIcon icon = getIcon();
+
+                @Override
+                public synchronized void paintIcon(Component c, Graphics g, int x, int y) {
+                    icon.paintIcon(c, g, x, y);
+                }
+
+                @Override
+                public int getIconWidth() {
+                    return icon.getIconWidth();
+                }
+
+                @Override
+                public int getIconHeight() {
+                    return icon.getIconHeight();
+                }
+
+                @Override
+                public Image getImage() {
+                    int w = icon.getIconWidth();
+                    int h = icon.getIconHeight();
+                    GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
+                    GraphicsDevice gd = ge.getDefaultScreenDevice();
+                    GraphicsConfiguration gc = gd.getDefaultConfiguration();
+                    BufferedImage image = gc.createCompatibleImage(w, h);
+                    Graphics2D g = image.createGraphics();
+                    icon.paintIcon(null, g, 0, 0);
+                    g.dispose();
+                    return image;
+                }
+            };
+        }
+
+        public JLabel getLabel() {
+            JLabel label = new JLabel(this.code);
+            label.setForeground(this.color);
+            label.setFont(FONT_16);
+            return label;
+        }
+    }
+
+    public static class FontBasedIcon implements Icon {
+
+        private final String iconCode;
+        private final Color iconColor;
+
+        public FontBasedIcon(String code, Color iconColor) {
+            this.iconCode = code;
+            this.iconColor = iconColor;
+        }
+
+        @Override
+        public void paintIcon(Component c, Graphics g, int x, int y) {
+            Graphics2D g2 = (Graphics2D) g.create();
+
+            g2.setFont(FONT_16);
+            g2.setColor(iconColor);
+            FontMetrics fm = g2.getFontMetrics();
+
+            g2.translate(x, y + fm.getAscent());
+            g2.drawString(iconCode, 0, 0);
+
+            g2.dispose();
+        }
+
+        @Override
+        public int getIconWidth() {
+            return 16;
+        }
+
+        @Override
+        public int getIconHeight() {
+            return 16;
+        }
+    }
+
     private static final Log LOGGER = LogFactory.getLog(IconTheme.class);
 
     private static final Map<String, String> KEY_TO_ICON = readIconThemeFile(IconTheme.class.getResource("/images/crystal_16/Icons.properties"), "/images/crystal_16/");
@@ -40,7 +152,8 @@ public static Map<String, String> getAllIcons() {
      * @return The ImageIcon for the function.
      */
     public static ImageIcon getImage(String name) {
-        return new ImageIcon(getIconUrl(name));
+        return JabRefIcon.values()[new Random().nextInt(JabRefIcon.values().length)].getImageIcon();
+        //return new ImageIcon(getIconUrl(name));
     }
 
     /**
@@ -52,7 +165,7 @@ public static ImageIcon getImage(String name) {
      */
     private static URL getIconUrl(String name) {
         String key = Objects.requireNonNull(name, "icon name");
-        if(!KEY_TO_ICON.containsKey(key)) {
+        if (!KEY_TO_ICON.containsKey(key)) {
             LOGGER.warn("could not find icon url by name " + name + ", so falling back on default icon " + DEFAULT_ICON_PATH);
         }
         String path = KEY_TO_ICON.getOrDefault(key, DEFAULT_ICON_PATH);
@@ -64,7 +177,7 @@ private static URL getIconUrl(String name) {
      * of the '=' character - it simply looks for the first '=' to determine where the key ends.
      * Both the key and the value is trimmed for whitespace at the ends.
      *
-     * @param url   The URL to read information from.
+     * @param url    The URL to read information from.
      * @param prefix A String to prefix to all values read. Can represent e.g. the directory
      *               where icon files are to be found.
      * @return A Map containing all key-value pairs found.
@@ -77,8 +190,8 @@ private static Map<String, String> readIconThemeFile(URL url, String prefix) {
 
         try (BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()))) {
             String line;
-            while((line = in.readLine()) != null) {
-                if(!line.contains("=")) {
+            while ((line = in.readLine()) != null) {
+                if (!line.contains("=")) {
                     continue;
                 }