fix reload issues

plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/IWaveformDb.java

@@ -62,9 +62,4 @@ public interface IWaveformDb extends IHierNode {
 	 */
 	public boolean isLoaded();
 
-	/**
-	 * Clear.
-	 */
-	public void clear();
-
 }

plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/internal/WaveformDb.java

@@ -165,16 +165,6 @@ public class WaveformDb extends HierNode implements IWaveformDb, PropertyChangeL
 		return ext;
 	}
 
-	/**
-	 * Clear.
-	 */
-	@Override
-	public void clear() {
-		waveforms.clear();
-		childNodes.clear();
-		loaded = false;
-	}
-
 	/**
 	 * Checks if is loaded.
 	 *

plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/parts/WaveformViewer.java

@@ -613,7 +613,12 @@ public class WaveformViewer implements IFileChangeListener, IPreferenceChangeLis
 		Map<String, String> state = new HashMap<>();
 		saveWaveformViewerState(state);
 		waveformPane.getStreamList().clear();
-		database.clear();
+		database =  dbFactory.getDatabase();
+		database.addPropertyChangeListener(evt -> {
+			if (IHierNode.WAVEFORMS.equals(evt.getPropertyName())) { //$NON-NLS-1$
+				myParent.getDisplay().syncExec(() -> waveformPane.setMaxTime(database.getMaxTime()));
+			}
+		});
 		if (!filesToLoad.isEmpty())
 			loadDatabase(state, 0L);
 	}