improvement:

* BackgroundFileTransferablePolicy uses ThreadLocal<Worker> now
* support exception handling in BackgroundFileTransferablePolicy
changes:
* ChecksumComputationTask will only calculate one HashType
* added ChecksumRow.dispose()
fix:
* honor convertValueToString() in SelectDialog

source/net/sourceforge/filebot/ui/SelectDialog.java

@@ -44,10 +44,7 @@ public class SelectDialog<T> extends JDialog {
 		list = new JList(new ArrayListModel(options));
 		list.setSelectedIndex(0);
 		
-		DefaultFancyListCellRenderer cellRenderer = new DefaultFancyListCellRenderer(4);
+		list.setCellRenderer(new SelectListCellRenderer());
-		cellRenderer.setHighlightingEnabled(false);
-		
-		list.setCellRenderer(cellRenderer);
 		list.addMouseListener(mouseListener);
 		
 		JComponent c = (JComponent) getContentPane();
@@ -121,4 +118,20 @@ public class SelectDialog<T> extends JDialog {
 			}
 		}
 	};
+	
+	
+	protected class SelectListCellRenderer extends DefaultFancyListCellRenderer {
+		
+		public SelectListCellRenderer() {
+			super(4);
+			setHighlightingEnabled(false);
+		}
+		
+
+		@Override
+		public void configureListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
+			super.configureListCellRendererComponent(list, convertValueToString(value), index, isSelected, cellHasFocus);
+		}
+	};
+	
 }

source/net/sourceforge/filebot/ui/panel/analyze/FileTreeTransferablePolicy.java

@@ -4,11 +4,13 @@ package net.sourceforge.filebot.ui.panel.analyze;
 
 import java.io.File;
 import java.util.List;
+import java.util.logging.Logger;
 
 import net.sourceforge.filebot.ui.panel.analyze.FileTree.AbstractTreeNode;
 import net.sourceforge.filebot.ui.panel.analyze.FileTree.FileNode;
 import net.sourceforge.filebot.ui.panel.analyze.FileTree.FolderNode;
 import net.sourceforge.filebot.ui.transfer.BackgroundFileTransferablePolicy;
+import net.sourceforge.tuned.ExceptionUtilities;
 import net.sourceforge.tuned.FileUtilities;
 
 
@@ -46,6 +48,12 @@ class FileTreeTransferablePolicy extends BackgroundFileTransferablePolicy<Abstra
 	}
 	
 
+	@Override
+	protected void process(Exception e) {
+		Logger.getLogger("ui").warning(ExceptionUtilities.getRootCause(e).getMessage());
+	}
+	
+
 	@Override
 	protected void load(List<File> files) {
 		try {

source/net/sourceforge/filebot/ui/panel/rename/RenamePanel.java

@@ -10,7 +10,6 @@ import java.awt.event.ActionEvent;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.swing.AbstractAction;
@@ -215,7 +214,7 @@ public class RenamePanel extends FileBotPanel {
 						model.names().addAll(names);
 						model.files().addAll(files);
 					} catch (Exception e) {
-						Logger.getLogger("ui").log(Level.WARNING, ExceptionUtilities.getRootCause(e).getMessage(), e);
+						Logger.getLogger("ui").warning(ExceptionUtilities.getRootCause(e).getMessage());
 					}
 				}
 			};

source/net/sourceforge/filebot/ui/panel/sfv/ChecksumCell.java

@@ -49,7 +49,7 @@ public class ChecksumCell {
 			public void propertyChange(PropertyChangeEvent evt) {
 				super.propertyChange(evt);
 				
-				propertyChangeSupport.firePropertyChange(evt.getPropertyName(), evt.getOldValue(), evt.getNewValue());
+				pcs.firePropertyChange(evt.getPropertyName(), evt.getOldValue(), evt.getNewValue());
 			}
 			
 
@@ -95,17 +95,6 @@ public class ChecksumCell {
 	}
 	
 
-	public void dispose() {
-		if (task != null) {
-			task.cancel(true);
-		}
-		
-		hashes = null;
-		error = null;
-		task = null;
-	}
-	
-
 	public State getState() {
 		if (hashes != null)
 			return State.READY;
@@ -121,21 +110,38 @@ public class ChecksumCell {
 	}
 	
 
+	public void dispose() {
+		// clear property change support first
+		for (PropertyChangeListener listener : pcs.getPropertyChangeListeners()) {
+			pcs.removePropertyChangeListener(listener);
+		}
+		
+		if (task != null) {
+			task.cancel(true);
+		}
+		
+		hashes = null;
+		error = null;
+		task = null;
+		pcs = null;
+	}
+	
+
 	@Override
 	public String toString() {
 		return String.format("%s %s", name, hashes);
 	}
 	
-	private final PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);
+	private PropertyChangeSupport pcs = new PropertyChangeSupport(this);
 	
 	
 	public void addPropertyChangeListener(PropertyChangeListener listener) {
-		propertyChangeSupport.addPropertyChangeListener(listener);
+		pcs.addPropertyChangeListener(listener);
 	}
 	
 
 	public void removePropertyChangeListener(PropertyChangeListener listener) {
-		propertyChangeSupport.removePropertyChangeListener(listener);
+		pcs.removePropertyChangeListener(listener);
 	}
 	
 }

source/net/sourceforge/filebot/ui/panel/sfv/ChecksumComputationTask.java

@@ -5,9 +5,8 @@ package net.sourceforge.filebot.ui.panel.sfv;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
-import java.util.EnumMap;
+import java.util.Collections;
 import java.util.Map;
-import java.util.Map.Entry;
 import javax.swing.SwingWorker;
 
 
@@ -16,21 +15,18 @@ class ChecksumComputationTask extends SwingWorker<Map<HashType, String>, Void> {
 	private static final int BUFFER_SIZE = 32 * 1024;
 	
 	private final File file;
+	private final HashType type;
 	
 	
-	public ChecksumComputationTask(File file) {
+	public ChecksumComputationTask(File file, HashType type) {
 		this.file = file;
+		this.type = type;
 	}
 	
 
 	@Override
 	protected Map<HashType, String> doInBackground() throws Exception {
-		Map<HashType, Hash> hashes = new EnumMap<HashType, Hash>(HashType.class);
+		Hash hash = type.newInstance();
-		
-		for (HashType type : HashType.values()) {
-			hashes.put(type, type.newInstance());
-		}
-		
 		long length = file.length();
 		
 		if (length > 0) {
@@ -45,15 +41,13 @@ class ChecksumComputationTask extends SwingWorker<Map<HashType, String>, Void> {
 				while ((len = in.read(buffer)) >= 0) {
 					position += len;
 					
-					for (Hash hash : hashes.values()) {
 					hash.update(buffer, 0, len);
-					}
 					
 					// update progress
 					setProgress((int) ((position * 100) / length));
 					
 					// check abort status
-					if (isCancelled() || Thread.interrupted()) {
+					if (isCancelled()) {
 						break;
 					}
 				}
@@ -62,18 +56,7 @@ class ChecksumComputationTask extends SwingWorker<Map<HashType, String>, Void> {
 			}
 		}
 		
-		return digest(hashes);
+		return Collections.singletonMap(type, hash.digest());
-	}
-	
-
-	private Map<HashType, String> digest(Map<HashType, Hash> hashes) {
-		Map<HashType, String> results = new EnumMap<HashType, String>(HashType.class);
-		
-		for (Entry<HashType, Hash> entry : hashes.entrySet()) {
-			results.put(entry.getKey(), entry.getValue().digest());
-		}
-		
-		return results;
 	}
 	
 }

source/net/sourceforge/filebot/ui/panel/sfv/ChecksumRow.java

@@ -2,6 +2,8 @@
 package net.sourceforge.filebot.ui.panel.sfv;
 
 
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
 import java.io.File;
 import java.util.Collection;
 import java.util.Collections;
@@ -56,30 +58,43 @@ public class ChecksumRow {
 	}
 	
 
-	public Collection<ChecksumCell> values() {
+	public void put(ChecksumCell cell) {
-		return Collections.unmodifiableCollection(hashes.values());
+		ChecksumCell old = hashes.put(cell.getRoot(), cell);
+		
+		// dispose of old map entry 
+		if (old != null) {
+			old.dispose();
 		}
 		
-
+		// update state immediately
-	public void add(ChecksumCell entry) {
-		hashes.put(entry.getRoot(), entry);
 		updateState();
+		
+		// keep state up-to-date
+		cell.addPropertyChangeListener(updateStateListener);
 	}
 	
 
 	public void updateState() {
-		// update state
 		state = getState(hashes.values());
 	}
 	
 
-	protected State getState(Collection<ChecksumCell> entries) {
+	public void dispose() {
+		for (ChecksumCell cell : hashes.values()) {
+			cell.dispose();
+		}
+		
+		hashes.clear();
+	}
+	
+
+	protected State getState(Collection<ChecksumCell> cells) {
 		// check states before we bother comparing the hash values
-		for (ChecksumCell entry : entries) {
+		for (ChecksumCell cell : cells) {
-			if (entry.getState() == ChecksumCell.State.ERROR) {
+			if (cell.getState() == ChecksumCell.State.ERROR) {
 				// one error cell -> error state
 				return State.ERROR;
-			} else if (entry.getState() != ChecksumCell.State.READY) {
+			} else if (cell.getState() != ChecksumCell.State.READY) {
 				// one cell that is not ready yet -> unknown state
 				return State.UNKNOWN;
 			}
@@ -92,8 +107,8 @@ public class ChecksumRow {
 		for (HashType type : HashType.values()) {
 			checksumSet.clear();
 			
-			for (ChecksumCell entry : entries) {
+			for (ChecksumCell cell : cells) {
-				String checksum = entry.getChecksum(type);
+				String checksum = cell.getChecksum(type);
 				
 				if (checksum != null) {
 					checksumSet.add(checksum);
@@ -134,4 +149,12 @@ public class ChecksumRow {
 	public String toString() {
 		return String.format("%s %s", name, hashes);
 	}
+	
+	private final PropertyChangeListener updateStateListener = new PropertyChangeListener() {
+		
+		public void propertyChange(PropertyChangeEvent evt) {
+			updateState();
+		}
+	};
+	
 }

source/net/sourceforge/filebot/ui/panel/sfv/ChecksumTableExportHandler.java

@@ -24,19 +24,19 @@ public class ChecksumTableExportHandler extends TextFileExportHandler {
 
 	@Override
 	public boolean canExport() {
-		return model.getRowCount() > 0 && model.getChecksumList().size() > 0;
+		return model.getRowCount() > 0 && model.getChecksumColumns().size() > 0;
 	}
 	
 
 	@Override
 	public void export(Formatter out) {
-		export(out, model.getChecksumList().get(0));
+		export(out, model.getChecksumColumns().get(0));
 	}
 	
 
 	@Override
 	public String getDefaultFileName() {
-		return getDefaultFileName(model.getChecksumList().get(0));
+		return getDefaultFileName(model.getChecksumColumns().get(0));
 	}
 	
 

source/net/sourceforge/filebot/ui/panel/sfv/ChecksumTableModel.java

@@ -75,7 +75,7 @@ class ChecksumTableModel extends AbstractTableModel implements Iterable<Checksum
 	}
 	
 
-	public List<File> getChecksumList() {
+	public List<File> getChecksumColumns() {
 		return Collections.unmodifiableList(columns);
 	}
 	
@@ -118,7 +118,7 @@ class ChecksumTableModel extends AbstractTableModel implements Iterable<Checksum
 				rows.add(row);
 			}
 			
-			row.add(entry);
+			row.put(entry);
 			
 			// listen to changes (progress, state)
 			entry.addPropertyChangeListener(progressListener);
@@ -139,10 +139,7 @@ class ChecksumTableModel extends AbstractTableModel implements Iterable<Checksum
 
 	public void remove(int... index) {
 		for (int i : index) {
-			for (ChecksumCell entry : rows.get(i).values()) {
+			rows.get(i).dispose();
-				entry.removePropertyChangeListener(progressListener);
-				entry.dispose();
-			}
 		}
 		
 		// remove rows

source/net/sourceforge/filebot/ui/panel/sfv/SfvPanel.java

@@ -5,19 +5,24 @@ package net.sourceforge.filebot.ui.panel.sfv;
 import java.awt.event.ActionEvent;
 import java.io.File;
 import java.io.IOException;
+import java.util.List;
+
 import javax.swing.AbstractAction;
 import javax.swing.JButton;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.KeyStroke;
+import javax.swing.SwingUtilities;
 import javax.swing.border.TitledBorder;
 
 import net.miginfocom.swing.MigLayout;
 import net.sourceforge.filebot.ResourceManager;
 import net.sourceforge.filebot.ui.FileBotPanel;
 import net.sourceforge.filebot.ui.FileTransferableMessageHandler;
+import net.sourceforge.filebot.ui.SelectDialog;
 import net.sourceforge.filebot.ui.transfer.LoadAction;
 import net.sourceforge.filebot.ui.transfer.SaveAction;
+import net.sourceforge.tuned.FileUtilities;
 import net.sourceforge.tuned.MessageHandler;
 import net.sourceforge.tuned.ui.TunedUtilities;
 

source/net/sourceforge/filebot/ui/panel/sfv/SfvTransferablePolicy.java

@@ -19,6 +19,7 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import net.sourceforge.filebot.ui.transfer.BackgroundFileTransferablePolicy;
+import net.sourceforge.tuned.ExceptionUtilities;
 
 
 class SfvTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCell> {
@@ -52,6 +53,12 @@ class SfvTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCel
 	}
 	
 
+	@Override
+	protected void process(Exception e) {
+		Logger.getLogger("ui").warning(ExceptionUtilities.getRootCause(e).getMessage());
+	}
+	
+
 	protected void loadSfvFile(File sfvFile, Executor executor) {
 		try {
 			// don't use new Scanner(File) because of BUG 6368019 (http://bugs.sun.com/view_bug.do?bug_id=6368019)
@@ -60,6 +67,9 @@ class SfvTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCel
 			try {
 				Pattern pattern = Pattern.compile("(.+)\\s+(\\p{XDigit}{8})");
 				
+				// root for relative file paths in sfv file
+				File root = sfvFile.getParentFile();
+				
 				while (scanner.hasNextLine()) {
 					String line = scanner.nextLine();
 					
@@ -71,21 +81,13 @@ class SfvTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCel
 					if (!matcher.matches())
 						continue;
 					
-					String filename = matcher.group(1);
+					String name = matcher.group(1);
 					String checksum = matcher.group(2);
 					
-					publish(new ChecksumCell(filename, sfvFile, Collections.singletonMap(HashType.CRC32, checksum)));
+					ChecksumCell correct = new ChecksumCell(name, sfvFile, Collections.singletonMap(HashType.CRC32, checksum));
+					ChecksumCell current = createChecksumCell(name, root, new File(root, name), executor);
 					
-					File column = sfvFile.getParentFile();
+					publish(correct, current);
-					File file = new File(column, filename);
-					
-					if (file.exists()) {
-						ChecksumComputationTask task = new ChecksumComputationTask(file);
-						
-						publish(new ChecksumCell(filename, column, task));
-						
-						executor.execute(task);
-					}
 					
 					if (Thread.interrupted()) {
 						break;
@@ -150,11 +152,17 @@ class SfvTransferablePolicy extends BackgroundFileTransferablePolicy<ChecksumCel
 				load(f, root, newPrefix, executor);
 			}
 		} else if (file.isFile()) {
-			ChecksumComputationTask task = new ChecksumComputationTask(file);
+			publish(createChecksumCell(prefix + file.getName(), root, file, executor));
-			
-			publish(new ChecksumCell(prefix + file.getName(), root, task));
-			
-			executor.execute(task);
 		}
 	}
+	
+
+	protected ChecksumCell createChecksumCell(String name, File root, File file, Executor executor) {
+		ChecksumCell cell = new ChecksumCell(name, root, new ChecksumComputationTask(new File(root, name), HashType.CRC32));
+		
+		// start computation task
+		executor.execute(cell.getTask());
+		
+		return cell;
+	}
 }

source/net/sourceforge/filebot/ui/transfer/BackgroundFileTransferablePolicy.java

@@ -7,100 +7,94 @@ import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.beans.PropertyChangeSupport;
 import java.io.File;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.logging.Level;
+import javax.swing.SwingUtilities;
-import java.util.logging.Logger;
-
 import javax.swing.SwingWorker;
 
-import net.sourceforge.tuned.ui.SwingWorkerPropertyChangeAdapter;
-
 
 public abstract class BackgroundFileTransferablePolicy<V> extends FileTransferablePolicy {
 	
 	public static final String LOADING_PROPERTY = "loading";
 	
-	private BackgroundWorker worker = null;
+	private final ThreadLocal<BackgroundWorker> threadLocalWorker = new ThreadLocal<BackgroundWorker>() {
-	
 		
 		@Override
-	public boolean accept(Transferable tr) {
+		protected BackgroundWorker initialValue() {
-		if (isActive())
+			// fail if a non-background-worker thread is trying to access the thread-local worker object
-			return false;
+			throw new IllegalThreadStateException("Illegal access thread");
-		
-		return super.accept(tr);
 		}
+	};
+	
+	private final List<BackgroundWorker> workers = new ArrayList<BackgroundWorker>(2);
 	
 	
 	@Override
-	public synchronized void handleTransferable(Transferable tr, TransferAction action) {
+	public void handleTransferable(Transferable tr, TransferAction action) {
 		List<File> files = getFilesFromTransferable(tr);
 		
 		if (action != TransferAction.ADD)
 			clear();
 		
-		worker = new BackgroundWorker(files);
+		// create and start worker
-		worker.addPropertyChangeListener(backgroundWorkerListener);
+		new BackgroundWorker(files).execute();
-		worker.execute();
 	}
 	
 
-	public synchronized boolean isActive() {
+	public void reset() {
-		return worker != null && !worker.isDone();
+		synchronized (workers) {
-	}
+			for (BackgroundWorker worker : workers) {
-	
-
-	public synchronized void reset() {
-		if (isActive()) {
 				worker.cancel(true);
 			}
+			
+			workers.clear();
+		}
 	}
 	
 
-	/**
-	 * Receives data chunks from the publish method asynchronously on the Event Dispatch
-	 * Thread.
-	 * 
-	 * @param chunks
-	 */
 	protected abstract void process(List<V> chunks);
 	
 
-	/**
+	protected abstract void process(Exception e);
-	 * Sends data chunks to the process method.
+	
-	 * 
+
-	 * @param chunks
+	protected final void publish(V... chunks) {
-	 */
+		threadLocalWorker.get().offer(chunks);
-	protected synchronized void publish(V... chunks) {
-		if (worker != null) {
-			worker.publishChunks(chunks);
-		}
 	}
 	
 	
-	private class BackgroundWorker extends SwingWorker<Void, V> {
+	protected class BackgroundWorker extends SwingWorker<Object, V> {
 		
 		private final List<File> files;
 		
 		
 		public BackgroundWorker(List<File> files) {
 			this.files = files;
+			// register this worker
+			synchronized (workers) {
+				if (workers.add(this) && workers.size() == 1) {
+					swingPropertyChangeSupport.firePropertyChange(LOADING_PROPERTY, false, true);
+				}
+			}
 		}
 		
 
 		@Override
-		protected Void doInBackground() {
+		protected Object doInBackground() {
+			// associate this worker with the current (background) thread
+			threadLocalWorker.set(this);
+			
 			try {
 				load(files);
-			} catch (Exception e) {
+			} finally {
-				Logger.getLogger("global").log(Level.WARNING, e.getMessage(), e);
+				threadLocalWorker.remove();
 			}
 			
 			return null;
 		}
 		
 
-		public void publishChunks(V... chunks) {
+		public void offer(V... chunks) {
 			if (!isCancelled()) {
 				publish(chunks);
 			}
@@ -113,31 +107,54 @@ public abstract class BackgroundFileTransferablePolicy<V> extends FileTransferab
 				BackgroundFileTransferablePolicy.this.process(chunks);
 			}
 		}
-	}
-	
-	private final PropertyChangeListener backgroundWorkerListener = new SwingWorkerPropertyChangeAdapter() {
-		
-		@Override
-		public void started(PropertyChangeEvent evt) {
-			propertyChangeSupport.firePropertyChange(LOADING_PROPERTY, false, true);
-		}
 		
 
 		@Override
-		public void done(PropertyChangeEvent evt) {
+		protected void done() {
-			propertyChangeSupport.firePropertyChange(LOADING_PROPERTY, true, false);
+			// unregister worker
+			synchronized (workers) {
+				if (workers.remove(this) && workers.isEmpty()) {
+					swingPropertyChangeSupport.firePropertyChange(LOADING_PROPERTY, true, false);
 				}
+			}
+			
+			if (!isCancelled()) {
+				try {
+					// check for exception
+					get();
+				} catch (Exception e) {
+					BackgroundFileTransferablePolicy.this.process(e);
+				}
+			}
+		}
+	}
+	
+	protected final PropertyChangeSupport swingPropertyChangeSupport = new PropertyChangeSupport(this) {
+		
+		@Override
+		public void firePropertyChange(final PropertyChangeEvent evt) {
+			if (SwingUtilities.isEventDispatchThread()) {
+				super.firePropertyChange(evt);
+			} else {
+				SwingUtilities.invokeLater(new Runnable() {
+					
+					@Override
+					public void run() {
+						swingPropertyChangeSupport.firePropertyChange(evt);
+					}
+				});
+			}
+		}
+		
 	};
 	
-	private final PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);
-	
 	
 	public void addPropertyChangeListener(PropertyChangeListener listener) {
-		propertyChangeSupport.addPropertyChangeListener(listener);
+		swingPropertyChangeSupport.addPropertyChangeListener(listener);
 	}
 	
 
 	public void removePropertyChangeListener(PropertyChangeListener listener) {
-		propertyChangeSupport.removePropertyChangeListener(listener);
+		swingPropertyChangeSupport.removePropertyChangeListener(listener);
 	}
 }

source/net/sourceforge/tuned/ui/ArrayListModel.java

@@ -2,7 +2,6 @@
 package net.sourceforge.tuned.ui;
 
 
-import java.util.ArrayList;
 import java.util.Collection;
 
 import javax.swing.ListModel;
@@ -11,23 +10,23 @@ import javax.swing.event.ListDataListener;
 
 public class ArrayListModel implements ListModel {
 	
-	private final ArrayList<Object> data;
+	private final Object[] data;
 	
 	
 	public ArrayListModel(Collection<? extends Object> data) {
-		this.data = new ArrayList<Object>(data);
+		this.data = data.toArray();
 	}
 	
 
 	@Override
 	public Object getElementAt(int index) {
-		return data.get(index);
+		return data[index];
 	}
 	
 
 	@Override
 	public int getSize() {
-		return data.size();
+		return data.length;
 	}
 	
 

source/net/sourceforge/tuned/ui/LoadingOverlayPane.java

@@ -32,7 +32,7 @@ public class LoadingOverlayPane extends JComponent {
 		animationComponent = new ProgressIndicator();
 		animationComponent.setVisible(false);
 		
-		add(animationComponent, String.format("pos n %s 100%%-%s n", offsetY != null ? offsetY : "8px", offsetX != null ? offsetX : "18px"));
+		add(animationComponent, String.format("pos n %s 100%%-%s n", offsetY != null ? offsetY : "8px", offsetX != null ? offsetX : "20px"));
 		add(component, "grow");
 		
 		if (propertyChangeSource != null) {

source/net/sourceforge/tuned/ui/ProgressIndicator.java

@@ -37,22 +37,9 @@ public class ProgressIndicator extends JComponent {
 	private final Dimension baseSize = new Dimension(32, 32);
 	
 	private double alpha = 0;
-	private double speed = 1.2;
+	private double speed = 24;
 	
-	private final Timer updateTimer = new Timer(20, new ActionListener() {
+	private Timer updateTimer;
-		
-		@Override
-		public void actionPerformed(ActionEvent e) {
-			Timer timer = (Timer) e.getSource();
-			
-			alpha += (timer.getDelay() * speed) / 1000;
-			
-			if (alpha >= 1)
-				alpha -= Math.floor(alpha);
-			
-			repaint();
-		}
-	});
 	
 	
 	public ProgressIndicator() {
@@ -74,6 +61,13 @@ public class ProgressIndicator extends JComponent {
 	}
 	
 
+	public void animateOnce() {
+		if ((alpha += (speed / 1000)) >= 1) {
+			alpha -= Math.floor(alpha);
+		}
+	}
+	
+
 	@Override
 	public void paintComponent(Graphics g) {
 		Graphics2D g2d = (Graphics2D) g;
@@ -123,12 +117,26 @@ public class ProgressIndicator extends JComponent {
 	
 
 	public void startAnimation() {
-		updateTimer.restart();
+		if (updateTimer == null) {
+			updateTimer = new Timer(20, new ActionListener() {
+				
+				@Override
+				public void actionPerformed(ActionEvent e) {
+					animateOnce();
+					repaint();
+				}
+			});
+			
+			updateTimer.start();
+		}
 	}
 	
 
 	public void stopAnimation() {
+		if (updateTimer != null) {
 			updateTimer.stop();
+			updateTimer = null;
+		}
 	}