altosuilib: Rewrite map GUI bits

[fw/altos] / altosuilib / AltosUIMapCache.java

diff --git a/altosuilib/AltosUIMapCache.java b/altosuilib/AltosUIMapCache.java
new file mode 100644 (file)
index 0000000..e849da7
--- /dev/null
+++ b/altosuilib/AltosUIMapCache.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright © 2010 Anthony Towns <aj@erisian.com.au>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+package org.altusmetrum.altosuilib_2;
+
+import javax.swing.*;
+import javax.imageio.ImageIO;
+import java.awt.image.*;
+import java.awt.*;
+import java.io.*;
+import java.net.*;
+
+public class AltosUIMapCache {
+       static final int        success = 0;
+       static final int        loading = 1;
+       static final int        failed = 2;
+       static final int        bad_request = 3;
+       static final int        forbidden = 4;
+
+       static private Object fetch_lock = new Object();
+
+       static final int                min_cache_size = 9;
+       static final int                max_cache_size = 24;
+
+       static int                      cache_size = min_cache_size;
+
+       static AltosUIMapImage[]        images = new AltosUIMapImage[cache_size];
+
+       static Object cache_lock = new Object();
+
+       public  static void set_cache_size(int new_size) {
+               if (new_size < min_cache_size)
+                       new_size = min_cache_size;
+               if (new_size > max_cache_size)
+                       new_size = max_cache_size;
+               if (new_size == cache_size)
+                       return;
+
+               synchronized(cache_lock) {
+                       AltosUIMapImage[]       new_images = new AltosUIMapImage[new_size];
+
+                       for (int i = 0; i < cache_size; i++) {
+                               if (i < new_size)
+                                       new_images[i] = images[i];
+                               else if (images[i] != null)
+                                       images[i].flush();
+                       }
+                       images = new_images;
+                       cache_size = new_size;
+               }
+       }
+
+       static long                     used;
+
+       public static Image get(AltosUIMapTile tile, AltosUIMapStore store, int width, int height) {
+               int             oldest = -1;
+               long            age = used;
+
+               synchronized(cache_lock) {
+                       AltosUIMapImage image = null;
+                       for (int i = 0; i < cache_size; i++) {
+                               image = images[i];
+
+                               if (image == null) {
+                                       oldest = i;
+                                       break;
+                               }
+                               if (store.equals(image.store)) {
+                                       image.used = used++;
+                                       return image.image;
+                               }
+                               if (image.used < age) {
+                                       oldest = i;
+                                       age = image.used;
+                               }
+                       }
+
+                       try {
+                               image = new AltosUIMapImage(tile, store);
+                               image.used = used++;
+                               if (images[oldest] != null)
+                                       images[oldest].flush();
+
+                               images[oldest] = image;
+
+                               if (image.image == null)
+                                       tile.set_status(loading);
+                               else
+                                       tile.set_status(success);
+
+                               return image.image;
+                       } catch (IOException e) {
+                               tile.set_status(failed);
+                               return null;
+                       }
+               }
+       }
+}