Moved source into separate src directory due to popular request

[GpsPrune.git] / src / tim / prune / gui / map / TileDownloader.java

diff --git a/src/tim/prune/gui/map/TileDownloader.java b/src/tim/prune/gui/map/TileDownloader.java
new file mode 100644 (file)
index 0000000..7c75400
--- /dev/null
+++ b/src/tim/prune/gui/map/TileDownloader.java
@@ -0,0 +1,114 @@
+package tim.prune.gui.map;
+
+import java.awt.Image;
+import java.awt.Toolkit;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.HashSet;
+
+import tim.prune.GpsPrune;
+
+/**
+ * Class to asynchronously download a tile from a url
+ * and populate an Image object with the contents
+ */
+public class TileDownloader implements Runnable
+{
+       private MapTileManager _manager = null;
+       private URL _url = null;
+       private int _layer = 0;
+       private int _x = 0, _y = 0;
+       private int _zoom = 0;
+       /** Hashset of all blocked / 404 tiles to avoid requesting them again */
+       private static final HashSet<String> BLOCKED_URLS = new HashSet<String>();
+       /** Hashset of all currently loading tiles to avoid requesting them again */
+       private static final HashSet<String> LOADING_URLS = new HashSet<String>();
+
+
+       /**
+        * Constructor (private)
+        * @param inManager parent manager for callback
+        * @param inUrl URL to load
+        * @param inLayer layer index from 0
+        * @param inX x coordinate of tile
+        * @param inY y coordinate of tile
+        * @param inZoom zoom level
+        */
+       private TileDownloader(MapTileManager inManager, URL inUrl, int inLayer, int inX, int inY, int inZoom)
+       {
+               _manager = inManager;
+               _url = inUrl;
+               _layer = inLayer;
+               _x = inX; _y = inY;
+               _zoom = inZoom;
+       }
+
+       /**
+        * Trigger a download in a new thread
+        * @param inManager manager to callback when image is loaded
+        * @param inUrl URL to load
+        * @param inLayer layer index from 0
+        * @param inX x coordinate of tile
+        * @param inY y coordinate of tile
+        * @param inZoom current zoom level
+        */
+       public static synchronized void triggerLoad(MapTileManager inManager, URL inUrl, int inLayer,
+               int inX, int inY, int inZoom)
+       {
+               if (inManager != null && inUrl != null)
+               {
+                       String url = inUrl.toString();
+                       // System.out.println("Trigger load: " + url);
+                       if (!BLOCKED_URLS.contains(url) && !LOADING_URLS.contains(url))
+                       {
+                               // System.out.println("Not blocked: " + url);
+                               LOADING_URLS.add(url);
+                               new Thread(new TileDownloader(inManager, inUrl, inLayer, inX, inY, inZoom)).start();
+                       }
+               }
+       }
+
+       /**
+        * Run method, called in separate thread
+        */
+       public void run()
+       {
+               InputStream in = null;
+               try
+               {
+                       // System.out.println("TD Running thread to get: " + _url.toString());
+                       // Set http user agent on connection
+                       URLConnection conn = _url.openConnection();
+                       conn.setRequestProperty("User-Agent", "GpsPrune v" + GpsPrune.VERSION_NUMBER);
+                       in = conn.getInputStream();
+                       int len = conn.getContentLength();
+                       if (len > 0)
+                       {
+                               byte[] data = new byte[len];
+                               int totalRead = 0;
+                               while (totalRead < len)
+                               {
+                                       int numRead = in.read(data, totalRead, len-totalRead);
+                                       totalRead += numRead;
+                               }
+                               Image tile = Toolkit.getDefaultToolkit().createImage(data);
+                               in.close();
+
+                               // Pass back to manager so it can be stored in its memory cache
+                               _manager.notifyImageLoaded(tile, _layer, _x, _y, _zoom);
+                       }
+               }
+               catch (IOException e)
+               {
+                       System.err.println("IOE: " + e.getClass().getName() + " - " + e.getMessage());
+                       synchronized(this.getClass())
+                       {
+                               BLOCKED_URLS.add(_url.toString());
+                       }
+                       try {in.close();} catch (Exception e2) {}
+               }
+               LOADING_URLS.remove(_url.toString());
+       }
+}