Created an icon manager for loading icons from tilesets using a

configuration file to map icon set identifiers to tileset images and
metrics.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@924 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/IconManager.java

@@ -0,0 +1,161 @@
+//
+// $Id: IconManager.java,v 1.1 2002/02/03 22:43:54 mdb Exp $
+
+package com.threerings.media;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Properties;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Graphics;
+import java.awt.Image;
+
+import javax.swing.Icon;
+import javax.swing.ImageIcon;
+
+import com.samskivert.util.ConfigUtil;
+import com.samskivert.util.StringUtil;
+
+import com.threerings.media.tile.NoSuchTileException;
+import com.threerings.media.tile.TileManager;
+import com.threerings.media.tile.TileSet;
+
+/**
+ * Manages the creation of icons from tileset images. The icon manager is
+ * provided with a configuration file, which maps icon set identifiers to
+ * uniform tilesets and provides the metric information for said tilesets.
+ * UI code can subsequently request icons from the icon manager based on
+ * icon set identifier and index.
+ *
+ * <p> The configuration might look like the following:
+ *
+ * <pre>
+ * arrows.path = /rsrc/media/icons/arrows.png
+ * arrows.metrics = 4, 20, 20  # 4 icons that are 20x20
+ *
+ * smileys.path = /rsrc/media/icons/smileys.png
+ * smileys.metrics = 10, 16, 16  # 16 icons that are 16x16
+ * </pre>
+ *
+ * A user could then request an <code>arrows</code> icon like so:
+ *
+ * <pre>
+ * ImageIcon icon = iconmgr.getIcon("arrows", 2);
+ * </pre>
+ */
+public class IconManager
+{
+    /**
+     * Creates an icon manager that will obtain tilesets from the supplied
+     * tile manager and which will load its configuration information from
+     * the specified properties file.
+     *
+     * @param tmgr the tile manager to use when fetching tilesets.
+     * @param configPath the path (relative to the classpath) from which
+     * the icon manager configuration can be loaded.
+     *
+     * @exception IOException thrown if an error occurs loading the
+     * configuration file.
+     */
+    public IconManager (TileManager tmgr, String configPath)
+        throws IOException
+    {
+        this(tmgr, ConfigUtil.loadProperties(configPath));
+    }
+
+    /**
+     * Creates an icon manager that will obtain tilesets from the supplied
+     * tile manager and which will read its configuration information from
+     * the supplied properties file.
+     */
+    public IconManager (TileManager tmgr, Properties config)
+    {
+        // save these for later
+        _tilemgr = tmgr;
+        _config = config;
+    }
+
+    /**
+     * Fetches the icon with the specified index from the named icon set.
+     */
+    public Icon getIcon (String iconSet, int index)
+    {
+        try {
+            // see if the tileset is already loaded
+            TileSet set = (TileSet)_icons.get(iconSet);
+
+            // load it up if not
+            if (set == null) {
+                String path = _config.getProperty(iconSet + PATH_SUFFIX);
+                if (StringUtil.blank(path)) {
+                    throw new Exception("No path specified for icon set");
+                }
+
+                String metstr = _config.getProperty(iconSet + METRICS_SUFFIX);
+                if (StringUtil.blank(metstr)) {
+                    throw new Exception("No metrics specified for icon set");
+                }
+
+                int[] metrics = StringUtil.parseIntArray(metstr);
+                if (metrics == null || metrics.length != 3) {
+                    throw new Exception("Invalid icon set metrics " +
+                                        "[metrics=" + metstr + "]");
+                }
+
+                // load up the tileset
+                set = _tilemgr.loadTileSet(
+                    path, metrics[0], metrics[1], metrics[2]);
+
+                // cache it
+                _icons.put(iconSet, set);
+            }
+
+            // fetch the appropriate image and create an image icon
+            return new ImageIcon(set.getTileImage(index));
+
+        } catch (NoSuchTileException nste) {
+            Log.warning("Unable to load icon [iconSet=" + iconSet +
+                        ", index=" + index + "]. Image index out of bounds.");
+
+        } catch (Exception e) {
+            Log.warning("Unable to load icon [iconSet=" + iconSet +
+                        ", index=" + index + ", error=" + e + "].");
+        }
+
+        return _errorIcon;
+    }
+
+    /** The tile manager we use to load tilesets. */
+    protected TileManager _tilemgr;
+
+    /** Our configuration information. */
+    protected Properties _config;
+
+    /** A cache of our icon tilesets. TODO: use a real LRU cache instead
+     * of a hash map. */
+    protected HashMap _icons = new HashMap();
+    
+    /** The icon we return when we are unable to load a requested icon. */
+    protected Icon _errorIcon = new Icon() {
+        public void paintIcon (Component c, Graphics g, int x, int y) {
+            g.setColor(Color.black);
+            g.fillRect(x, y, 16, 16);
+        }
+        public int getIconWidth () {
+            return 16;
+        }
+        public int getIconHeight () {
+            return 16;
+        }
+    };
+
+    /** The suffix we append to an icon set name to obtain the tileset
+     * image path configuration parameter. */
+    protected static final String PATH_SUFFIX = ".path";
+
+    /** The suffix we append to an icon set name to obtain the tileset
+     * metrics configuration parameter. */
+    protected static final String METRICS_SUFFIX = ".metrics";
+}