Progress bar for image loading (when generating overviews)

src/mustic/utils/image/reader/GDALImageReaderWrapper.java

 package mustic.utils.image.reader;
 
 
+import javax.swing.SwingWorker;
+
 import org.gdal.gdal.Band;
 import org.gdal.gdal.Dataset;
+import org.gdal.gdal.ProgressCallback;
 import org.gdal.gdal.gdal;
 import org.gdal.gdalconst.gdalconst;
 
 import jcl.utils.exceptions.MethodNotImplementedException;
+import mustic.gui.MainFrame;
+import mustic.utils.tools.ProgressPropertyChangeListener;
 
 /**
  * Reader tool used to access to the data using the gdal library
@@ -291,7 +296,7 @@ public class GDALImageReaderWrapper extends ReaderWrapper {
 		
 	}
 
-	/*
+	/**
 	 * Generates overviews if 
 	 * @param filePath
 	 * 			The image file path
@@ -306,16 +311,79 @@ public class GDALImageReaderWrapper extends ReaderWrapper {
 		if (dataSet == null) {
 			throw new Exception("GDAL : Error when opening the file");	
 		} else {
+			MainFrame.getProgressStatus().setMessage("Loading file ...");
 			// if    the overview list has not the same length   OR
 			//       the factor is the different (just tested for the first band)
 			if ((dataSet.GetRasterBand(1).GetOverviewCount() != overViewIDList.length) ||
 				((dataSet.GetRasterBand(1).GetOverview(0).getXSize() - dataSet.getRasterXSize()/2) > 1)) {
-				dataSet.BuildOverviews(overViewIDList);
-				
+				//Layers are generated in a background process using Swingworker. 
+				//A progress bar is incremented to display loading progress 
+				ImgLoadTask task = new ImgLoadTask(dataSet, overViewIDList);
+				task.addPropertyChangeListener(new ProgressPropertyChangeListener());
+				task.execute();
+				task.get();						
 			}
 		}
 	}
 	
+	/**
+	 * SwingWorker which generates pyramids layers in a background process
+	 * and updates a progress bar
+	 * 
+	 * @author Jean-Noël BALANCHE
+	 *
+	 */
+	static class ImgLoadTask extends SwingWorker<Void,Void> 
+	{
+		 
+		 private int[] overViewIDList = null;
+		 private Dataset dataSet = null;
+		 private int layer = 1;
+		 
+		 /**
+		  * task to generate pyramide layers in a background process
+		  * 
+		  * @param dataSet the dataset where to put the layers
+		  * @param overViewIDList list of layers to generate
+		  */
+		 public ImgLoadTask(Dataset dataSet, int[] overViewIDList) {
+		     //initialize
+			 this.dataSet = dataSet;
+			 this.overViewIDList = overViewIDList;
+		 }
+		
+		 @Override
+		 public Void doInBackground() throws Exception {
+			System.out.println("Nb layers to generate : " + overViewIDList.length);
+			MainFrame.getProgressStatus().setMessage("Generating overview "+layer+" of "+overViewIDList.length);
+			dataSet.BuildOverviews(overViewIDList,new ProgressCallback(){
+	            @Override
+	            public int run(double dfComplete, String message)
+	            {
+	            	/* If BuildOverviews is calling ProgressCallback.run() for each layer : */
+//	            	double totalProgress = layer*100/overViewIDList.length+dfComplete*100/overViewIDList.length;
+//	                setProgress((int) Math.min(totalProgress,100));
+//	            	if(dfComplete*100>=100) {
+//	    				layer++;
+//	    				MainFrame.getProgressStatus().setMessage("Generating overview "+layer+" of "+overViewIDList.length);
+//	                }
+	            	
+	            	/* If BuildOverviews is calling ProgressCallback.run() only one time :*/
+	    			MainFrame.getProgressStatus().setMessage("Generating overview "+layer+" of "+overViewIDList.length);
+	            	setProgress((int) (100 * dfComplete));
+	            	if(dfComplete*100>=layer*100/overViewIDList.length && dfComplete*100<100) {
+	    				layer++;
+	    				MainFrame.getProgressStatus().setMessage("Generating overview "+layer+" of "+overViewIDList.length);
+	                }
+	            	
+	            	return 1;
+	            }
+	        });
+			return null;
+		}
+		 
+	}
+	
 	public static void main(String[] args) {
 		
 		String path = "/home/baptiste/Data/malaoui/evi_2013_2014.tif";