JAL-3210 Improvements to eclipse detection. New src tree and SwingJS updated from...
[jalview.git] / src / jalview / gui / StructureChooser.java
index 10d3a9d..9c4f6c8 100644 (file)
@@ -21,6 +21,8 @@
 
 package jalview.gui;
 
+import jalview.api.structures.JalviewStructureDisplayI;
+import jalview.bin.Cache;
 import jalview.bin.Jalview;
 import jalview.datamodel.DBRefEntry;
 import jalview.datamodel.DBRefSource;
@@ -32,10 +34,10 @@ import jalview.fts.api.FTSRestClientI;
 import jalview.fts.core.FTSRestRequest;
 import jalview.fts.core.FTSRestResponse;
 import jalview.fts.service.pdb.PDBFTSRestClient;
+import jalview.io.DataSourceType;
 import jalview.jbgui.GStructureChooser;
 import jalview.structure.StructureSelectionManager;
 import jalview.util.MessageManager;
-import jalview.ws.sifts.SiftsSettings;
 
 import java.awt.event.ItemEvent;
 import java.util.ArrayList;
@@ -44,12 +46,14 @@ import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 import java.util.Vector;
 
 import javax.swing.JCheckBox;
 import javax.swing.JComboBox;
 import javax.swing.JLabel;
-import javax.swing.JOptionPane;
+import javax.swing.JTable;
+import javax.swing.SwingUtilities;
 import javax.swing.table.AbstractTableModel;
 
 /**
@@ -59,26 +63,30 @@ import javax.swing.table.AbstractTableModel;
  *
  */
 @SuppressWarnings("serial")
-public class StructureChooser extends GStructureChooser implements
-        IProgressIndicator
+public class StructureChooser extends GStructureChooser
+        implements IProgressIndicator
 {
-  private boolean structuresDiscovered = false;
+  private static final String AUTOSUPERIMPOSE = "AUTOSUPERIMPOSE";
 
-  private SequenceI selectedSequence;
+  private static final int MAX_QLENGTH = 7820;
 
-  private SequenceI[] selectedSequences;
+  protected SequenceI selectedSequence;
+
+  public SequenceI[] selectedSequences;
 
   private IProgressIndicator progressIndicator;
 
-  private Collection<FTSData> discoveredStructuresSet;
+  protected Collection<FTSData> discoveredStructuresSet;
+
+  protected FTSRestRequest lastPdbRequest;
 
-  private FTSRestRequest lastPdbRequest;
+  protected FTSRestClientI pdbRestClient;
 
-  private FTSRestClientI pdbRestCleint;
+  protected String selectedPdbFileName;
 
-  private String selectedPdbFileName;
+  protected boolean isValidPBDEntry;
 
-  private boolean isValidPBDEntry;
+  protected boolean cachedPDBExists;
 
   public StructureChooser(SequenceI[] selectedSeqs, SequenceI selectedSeq,
           AlignmentPanel ap)
@@ -93,13 +101,17 @@ public class StructureChooser extends GStructureChooser implements
   /**
    * Initializes parameters used by the Structure Chooser Panel
    */
-  public void init()
+  protected void init()
   {
     if (!Jalview.isHeadlessMode())
     {
       progressBar = new ProgressBar(this.statusPanel, this.statusBar);
     }
 
+    chk_superpose.setSelected(Cache.getDefault(AUTOSUPERIMPOSE, true));
+
+    // ensure a filter option is in force for search
+    populateFilterComboBox(true, cachedPDBExists);
     Thread discoverPDBStructuresThread = new Thread(new Runnable()
     {
       @Override
@@ -110,11 +122,12 @@ public class StructureChooser extends GStructureChooser implements
                 .getString("status.loading_cached_pdb_entries"), startTime);
         loadLocalCachedPDBEntries();
         updateProgressIndicator(null, startTime);
-        updateProgressIndicator(MessageManager
-                .getString("status.searching_for_pdb_structures"),
-                startTime);
+        updateProgressIndicator(MessageManager.getString(
+                "status.searching_for_pdb_structures"), startTime);
         fetchStructuresMetaData();
-        populateFilterComboBox();
+        // revise filter options if no results were found
+        populateFilterComboBox(isStructuresDiscovered(), cachedPDBExists);
+        discoverStructureViews();
         updateProgressIndicator(null, startTime);
         mainFrame.setVisible(true);
         updateCurrentView();
@@ -124,6 +137,62 @@ public class StructureChooser extends GStructureChooser implements
   }
 
   /**
+   * Builds a drop-down choice list of existing structure viewers to which new
+   * structures may be added. If this list is empty then it, and the 'Add'
+   * button, are hidden.
+   */
+  protected void discoverStructureViews()
+  {
+    Desktop desktop = Desktop.getInstance();
+    if (desktop != null)
+    {
+      targetView.removeAllItems();
+      if (desktop.lastTargetedView != null
+              && !desktop.lastTargetedView.isVisible())
+      {
+        desktop.lastTargetedView = null;
+      }
+      int linkedViewsAt = 0;
+      for (StructureViewerBase view : desktop
+              .getStructureViewers(null, null))
+      {
+        StructureViewer viewHandler = (desktop.lastTargetedView != null
+                && desktop.lastTargetedView.sview == view)
+                        ? desktop.lastTargetedView
+                        : StructureViewer.reconfigure(view);
+
+        if (view.isLinkedWith(ap))
+        {
+          targetView.insertItemAt(viewHandler,
+                  linkedViewsAt++);
+        }
+        else
+        {
+          targetView.addItem(viewHandler);
+        }
+      }
+
+      /*
+       * show option to Add to viewer if at least 1 viewer found
+       */
+      targetView.setVisible(false);
+      if (targetView.getItemCount() > 0)
+      {
+        targetView.setVisible(true);
+        if (desktop.lastTargetedView != null)
+        {
+          targetView.setSelectedItem(desktop.lastTargetedView);
+        }
+        else
+        {
+          targetView.setSelectedIndex(0);
+        }
+      }
+      btn_add.setVisible(targetView.isVisible());
+    }
+  }
+
+  /**
    * Updates the progress indicator with the specified message
    * 
    * @param message
@@ -131,7 +200,7 @@ public class StructureChooser extends GStructureChooser implements
    * @param id
    *          unique handle for this indicator
    */
-  public void updateProgressIndicator(String message, long id)
+  protected void updateProgressIndicator(String message, long id)
   {
     if (progressIndicator != null)
     {
@@ -143,28 +212,32 @@ public class StructureChooser extends GStructureChooser implements
    * Retrieve meta-data for all the structure(s) for a given sequence(s) in a
    * selection group
    */
-  public void fetchStructuresMetaData()
+  void fetchStructuresMetaData()
   {
     long startTime = System.currentTimeMillis();
-    pdbRestCleint = PDBFTSRestClient.getInstance();
-    Collection<FTSDataColumnI> wantedFields = pdbRestCleint
-            .getAllDefaulDisplayedDataColumns();
+    pdbRestClient = PDBFTSRestClient.getInstance();
+    Collection<FTSDataColumnI> wantedFields = pdbDocFieldPrefs
+            .getStructureSummaryFields();
 
-    discoveredStructuresSet = new LinkedHashSet<FTSData>();
-    HashSet<String> errors = new HashSet<String>();
+    discoveredStructuresSet = new LinkedHashSet<>();
+    HashSet<String> errors = new HashSet<>();
     for (SequenceI seq : selectedSequences)
     {
       FTSRestRequest pdbRequest = new FTSRestRequest();
       pdbRequest.setAllowEmptySeq(false);
       pdbRequest.setResponseSize(500);
       pdbRequest.setFieldToSearchBy("(");
+      FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
+              .getSelectedItem());
+      pdbRequest.setFieldToSortBy(selectedFilterOpt.getValue(),
+              !chk_invertFilter.isSelected());
       pdbRequest.setWantedFields(wantedFields);
       pdbRequest.setSearchTerm(buildQuery(seq) + ")");
       pdbRequest.setAssociatedSequence(seq);
       FTSRestResponse resultList;
       try
       {
-        resultList = pdbRestCleint.executeRequest(pdbRequest);
+        resultList = pdbRestClient.executeRequest(pdbRequest);
       } catch (Exception e)
       {
         e.printStackTrace();
@@ -185,9 +258,8 @@ public class StructureChooser extends GStructureChooser implements
     if (discoveredStructuresSet != null
             && !discoveredStructuresSet.isEmpty())
     {
-      tbl_summary.setModel(FTSRestResponse.getTableModel(lastPdbRequest,
-              discoveredStructuresSet));
-      structuresDiscovered = true;
+      getResultTable().setModel(FTSRestResponse
+              .getTableModel(lastPdbRequest, discoveredStructuresSet));
       noOfStructuresFound = discoveredStructuresSet.size();
       mainFrame.setTitle(MessageManager.formatMessage(
               "label.structure_chooser_no_of_structures",
@@ -204,16 +276,16 @@ public class StructureChooser extends GStructureChooser implements
         {
           errorMsg.append(error).append("\n");
         }
-        JOptionPane.showMessageDialog(this, errorMsg.toString(),
+        JvOptionPane.showMessageDialog(this, errorMsg.toString(),
                 MessageManager.getString("label.pdb_web-service_error"),
-                JOptionPane.ERROR_MESSAGE);
+                JvOptionPane.ERROR_MESSAGE);
       }
     }
   }
 
-  public void loadLocalCachedPDBEntries()
+  protected void loadLocalCachedPDBEntries()
   {
-    ArrayList<CachedPDB> entries = new ArrayList<CachedPDB>();
+    ArrayList<CachedPDB> entries = new ArrayList<>();
     for (SequenceI seq : selectedSequences)
     {
       if (seq.getDatasetSequence() != null
@@ -229,7 +301,7 @@ public class StructureChooser extends GStructureChooser implements
         }
       }
     }
-
+    cachedPDBExists = !entries.isEmpty();
     PDBEntryTableModel tableModelx = new PDBEntryTableModel(entries);
     tbl_local_pdb.setModel(tableModelx);
   }
@@ -242,53 +314,49 @@ public class StructureChooser extends GStructureChooser implements
    * @return the built query string
    */
 
-  public static String buildQuery(SequenceI seq)
+  static String buildQuery(SequenceI seq)
   {
     boolean isPDBRefsFound = false;
     boolean isUniProtRefsFound = false;
     StringBuilder queryBuilder = new StringBuilder();
-    HashSet<String> seqRefs = new LinkedHashSet<String>();
+    Set<String> seqRefs = new LinkedHashSet<>();
 
-    if (seq.getAllPDBEntries() != null)
+    if (seq.getAllPDBEntries() != null
+            && queryBuilder.length() < MAX_QLENGTH)
     {
       for (PDBEntry entry : seq.getAllPDBEntries())
       {
         if (isValidSeqName(entry.getId()))
         {
-          queryBuilder.append("pdb_id")
-                  .append(":")
-.append(entry.getId().toLowerCase())
+          queryBuilder.append("pdb_id:").append(entry.getId().toLowerCase())
                   .append(" OR ");
           isPDBRefsFound = true;
-          // seqRefs.add(entry.getId());
         }
       }
     }
 
-    if (seq.getDBRefs() != null && seq.getDBRefs().length != 0)
+    List<DBRefEntry> refs = seq.getDBRefs();
+    if (refs != null && refs.size() != 0)
     {
-      for (DBRefEntry dbRef : seq.getDBRefs())
+      for (int ib = 0, nb = refs.size(); ib < nb; ib++)
       {
-        if (isValidSeqName(getDBRefId(dbRef)))
+         DBRefEntry dbRef = refs.get(ib);
+        if (isValidSeqName(getDBRefId(dbRef))
+                && queryBuilder.length() < MAX_QLENGTH)
         {
           if (dbRef.getSource().equalsIgnoreCase(DBRefSource.UNIPROT))
           {
-            queryBuilder
-.append("uniprot_accession").append(":")
-                    .append(getDBRefId(dbRef))
-                    .append(" OR ");
-            queryBuilder
-.append("uniprot_id")
-                    .append(":")
+            queryBuilder.append("uniprot_accession:")
                     .append(getDBRefId(dbRef)).append(" OR ");
+            queryBuilder.append("uniprot_id:").append(getDBRefId(dbRef))
+                    .append(" OR ");
             isUniProtRefsFound = true;
           }
           else if (dbRef.getSource().equalsIgnoreCase(DBRefSource.PDB))
           {
 
-            queryBuilder.append("pdb_id")
-                    .append(":").append(getDBRefId(dbRef).toLowerCase())
-                    .append(" OR ");
+            queryBuilder.append("pdb_id:")
+                    .append(getDBRefId(dbRef).toLowerCase()).append(" OR ");
             isPDBRefsFound = true;
           }
           else
@@ -330,20 +398,19 @@ public class StructureChooser extends GStructureChooser implements
   }
 
   /**
-   * Remove the following special characters from input string +, -, &, |, !, (,
-   * ), {, }, [, ], ^, ", ~, *, ?, :, \
+   * Remove the following special characters from input string +, -, &, !, (, ),
+   * {, }, [, ], ^, ", ~, *, ?, :, \
    * 
    * @param seqName
    * @return
    */
-  private static String sanitizeSeqName(String seqName)
+  static String sanitizeSeqName(String seqName)
   {
     Objects.requireNonNull(seqName);
     return seqName.replaceAll("\\[\\d*\\]", "")
-            .replaceAll("[^\\dA-Za-z|]", "").replaceAll("\\s+", "+");
+            .replaceAll("[^\\dA-Za-z|_]", "").replaceAll("\\s+", "+");
   }
 
-
   /**
    * Ensures sequence ref names are not less than 3 characters and does not
    * contain a database name
@@ -351,7 +418,7 @@ public class StructureChooser extends GStructureChooser implements
    * @param seqName
    * @return
    */
-  public static boolean isValidSeqName(String seqName)
+  static boolean isValidSeqName(String seqName)
   {
     // System.out.println("seqName : " + seqName);
     String ignoreList = "pdb,uniprot,swiss-prot";
@@ -374,7 +441,7 @@ public class StructureChooser extends GStructureChooser implements
     return true;
   }
 
-  public static String getDBRefId(DBRefEntry dbRef)
+  static String getDBRefId(DBRefEntry dbRef)
   {
     String ref = dbRef.getAccessionId().replaceAll("GO:", "");
     return ref;
@@ -386,7 +453,7 @@ public class StructureChooser extends GStructureChooser implements
    * @param fieldToFilterBy
    *          the field to filter by
    */
-  public void filterResultSet(final String fieldToFilterBy)
+  void filterResultSet(final String fieldToFilterBy)
   {
     Thread filterThread = new Thread(new Runnable()
     {
@@ -394,19 +461,18 @@ public class StructureChooser extends GStructureChooser implements
       public void run()
       {
         long startTime = System.currentTimeMillis();
-        pdbRestCleint = PDBFTSRestClient.getInstance();
+        pdbRestClient = PDBFTSRestClient.getInstance();
         lbl_loading.setVisible(true);
-        Collection<FTSDataColumnI> wantedFields = pdbRestCleint
-                .getAllDefaulDisplayedDataColumns();
-        Collection<FTSData> filteredResponse = new HashSet<FTSData>();
-        HashSet<String> errors = new HashSet<String>();
+        Collection<FTSDataColumnI> wantedFields = pdbDocFieldPrefs
+                .getStructureSummaryFields();
+        Collection<FTSData> filteredResponse = new HashSet<>();
+        HashSet<String> errors = new HashSet<>();
 
         for (SequenceI seq : selectedSequences)
         {
           FTSRestRequest pdbRequest = new FTSRestRequest();
           if (fieldToFilterBy.equalsIgnoreCase("uniprot_coverage"))
           {
-            System.out.println(">>>>>> Filtering with uniprot coverate");
             pdbRequest.setAllowEmptySeq(false);
             pdbRequest.setResponseSize(1);
             pdbRequest.setFieldToSearchBy("(");
@@ -431,7 +497,7 @@ public class StructureChooser extends GStructureChooser implements
           FTSRestResponse resultList;
           try
           {
-            resultList = pdbRestCleint.executeRequest(pdbRequest);
+            resultList = pdbRestClient.executeRequest(pdbRequest);
           } catch (Exception e)
           {
             e.printStackTrace();
@@ -451,18 +517,20 @@ public class StructureChooser extends GStructureChooser implements
         if (!filteredResponse.isEmpty())
         {
           final int filterResponseCount = filteredResponse.size();
-          Collection<FTSData> reorderedStructuresSet = new LinkedHashSet<FTSData>();
+          Collection<FTSData> reorderedStructuresSet = new LinkedHashSet<>();
           reorderedStructuresSet.addAll(filteredResponse);
           reorderedStructuresSet.addAll(discoveredStructuresSet);
-          tbl_summary.setModel(FTSRestResponse.getTableModel(
-                  lastPdbRequest, reorderedStructuresSet));
-
-          FTSRestResponse.configureTableColumn(tbl_summary, wantedFields);
-          tbl_summary.getColumn("Ref Sequence").setPreferredWidth(120);
-          tbl_summary.getColumn("Ref Sequence").setMinWidth(100);
-          tbl_summary.getColumn("Ref Sequence").setMaxWidth(200);
+          getResultTable().setModel(FTSRestResponse
+                  .getTableModel(lastPdbRequest, reorderedStructuresSet));
+
+          FTSRestResponse.configureTableColumn(getResultTable(),
+                  wantedFields, tempUserPrefs);
+          getResultTable().getColumn("Ref Sequence").setPreferredWidth(120);
+          getResultTable().getColumn("Ref Sequence").setMinWidth(100);
+          getResultTable().getColumn("Ref Sequence").setMaxWidth(200);
           // Update table selection model here
-          tbl_summary.addRowSelectionInterval(0, filterResponseCount - 1);
+          getResultTable().addRowSelectionInterval(0,
+                  filterResponseCount - 1);
           mainFrame.setTitle(MessageManager.formatMessage(
                   "label.structure_chooser_filter_time", totalTime));
         }
@@ -477,11 +545,9 @@ public class StructureChooser extends GStructureChooser implements
             {
               errorMsg.append(error).append("\n");
             }
-            JOptionPane.showMessageDialog(
-                    null,
-                    errorMsg.toString(),
+            JvOptionPane.showMessageDialog(null, errorMsg.toString(),
                     MessageManager.getString("label.pdb_web-service_error"),
-                    JOptionPane.ERROR_MESSAGE);
+                    JvOptionPane.ERROR_MESSAGE);
           }
         }
 
@@ -497,14 +563,16 @@ public class StructureChooser extends GStructureChooser implements
    * Handles action event for btn_pdbFromFile
    */
   @Override
-  public void pdbFromFile_actionPerformed()
+  protected void pdbFromFile_actionPerformed()
   {
+    // TODO: JAL-3048 not needed for Jalview-JS until JSmol dep and StructureChooser
+    // works
     jalview.io.JalviewFileChooser chooser = new jalview.io.JalviewFileChooser(
             jalview.bin.Cache.getProperty("LAST_DIRECTORY"));
     chooser.setFileView(new jalview.io.JalviewFileView());
-    chooser.setDialogTitle(MessageManager.formatMessage(
-            "label.select_pdb_file_for",
-            selectedSequence.getDisplayId(false)));
+    chooser.setDialogTitle(
+            MessageManager.formatMessage("label.select_pdb_file_for",
+                    selectedSequence.getDisplayId(false)));
     chooser.setToolTipText(MessageManager.formatMessage(
             "label.load_pdb_file_associate_with_sequence",
             selectedSequence.getDisplayId(false)));
@@ -522,36 +590,55 @@ public class StructureChooser extends GStructureChooser implements
    * Populates the filter combo-box options dynamically depending on discovered
    * structures
    */
-  @Override
-  protected void populateFilterComboBox()
+  protected void populateFilterComboBox(boolean haveData,
+          boolean cachedPDBExist)
   {
-    if (isStructuresDiscovered())
+    /*
+     * temporarily suspend the change listener behaviour
+     */
+    cmb_filterOption.removeItemListener(this);
+
+    cmb_filterOption.removeAllItems();
+    if (haveData)
     {
-      cmb_filterOption.addItem(new FilterOption("Best Quality",
-              "overall_quality", VIEWS_FILTER));
-      cmb_filterOption.addItem(new FilterOption("Most UniProt Coverage",
-              "uniprot_coverage", VIEWS_FILTER));
-      cmb_filterOption.addItem(new FilterOption("Best Resolution",
-              "resolution", VIEWS_FILTER));
-      cmb_filterOption.addItem(new FilterOption("Most Protein Chain",
-              "number_of_protein_chains", VIEWS_FILTER));
-      cmb_filterOption.addItem(new FilterOption("Most Bound Molecules",
-              "number_of_bound_molecules", VIEWS_FILTER));
-      cmb_filterOption.addItem(new FilterOption("Most Polymer Residues",
-              "number_of_polymer_residues", VIEWS_FILTER));
+      cmb_filterOption.addItem(new FilterOption(
+              MessageManager.getString("label.best_quality"),
+              "overall_quality", VIEWS_FILTER, false));
+      cmb_filterOption.addItem(new FilterOption(
+              MessageManager.getString("label.best_resolution"),
+              "resolution", VIEWS_FILTER, false));
+      cmb_filterOption.addItem(new FilterOption(
+              MessageManager.getString("label.most_protein_chain"),
+              "number_of_protein_chains", VIEWS_FILTER, false));
+      cmb_filterOption.addItem(new FilterOption(
+              MessageManager.getString("label.most_bound_molecules"),
+              "number_of_bound_molecules", VIEWS_FILTER, false));
+      cmb_filterOption.addItem(new FilterOption(
+              MessageManager.getString("label.most_polymer_residues"),
+              "number_of_polymer_residues", VIEWS_FILTER, true));
     }
-    cmb_filterOption.addItem(new FilterOption("Enter PDB Id", "-",
-            VIEWS_ENTER_ID));
-    cmb_filterOption.addItem(new FilterOption("From File", "-",
-            VIEWS_FROM_FILE));
-    cmb_filterOption.addItem(new FilterOption("Cached PDB Entries", "-",
-            VIEWS_LOCAL_PDB));
+    cmb_filterOption.addItem(
+            new FilterOption(MessageManager.getString("label.enter_pdb_id"),
+                    "-", VIEWS_ENTER_ID, false));
+    cmb_filterOption.addItem(
+            new FilterOption(MessageManager.getString("label.from_file"),
+                    "-", VIEWS_FROM_FILE, false));
+
+    if (cachedPDBExist)
+    {
+      FilterOption cachedOption = new FilterOption(
+              MessageManager.getString("label.cached_structures"),
+              "-", VIEWS_LOCAL_PDB, false);
+      cmb_filterOption.addItem(cachedOption);
+      cmb_filterOption.setSelectedItem(cachedOption);
+    }
+
+    cmb_filterOption.addItemListener(this);
   }
 
   /**
    * Updates the displayed view based on the selected filter option
    */
-  @Override
   protected void updateCurrentView()
   {
     FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
@@ -579,28 +666,37 @@ public class StructureChooser extends GStructureChooser implements
   }
 
   /**
-   * Validates user selection and activates the view button if all parameters
-   * are correct
+   * Validates user selection and enables the 'Add' and 'New View' buttons if
+   * all parameters are correct (the Add button will only be visible if there is
+   * at least one existing structure viewer open). This basically means at least
+   * one structure selected and no error messages.
+   * <p>
+   * The 'Superpose Structures' option is enabled if either more than one
+   * structure is selected, or the 'Add' to existing view option is enabled, and
+   * disabled if the only option is to open a new view of a single structure.
    */
   @Override
-  public void validateSelections()
+  protected void validateSelections()
   {
     FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
             .getSelectedItem());
-    btn_view.setEnabled(false);
+    btn_add.setEnabled(false);
     String currentView = selectedFilterOpt.getView();
+    int selectedCount = 0;
     if (currentView == VIEWS_FILTER)
     {
-      if (tbl_summary.getSelectedRows().length > 0)
+      selectedCount = getResultTable().getSelectedRows().length;
+      if (selectedCount > 0)
       {
-        btn_view.setEnabled(true);
+        btn_add.setEnabled(true);
       }
     }
     else if (currentView == VIEWS_LOCAL_PDB)
     {
-      if (tbl_local_pdb.getSelectedRows().length > 0)
+      selectedCount = tbl_local_pdb.getSelectedRows().length;
+      if (selectedCount > 0)
       {
-        btn_view.setEnabled(true);
+        btn_add.setEnabled(true);
       }
     }
     else if (currentView == VIEWS_ENTER_ID)
@@ -611,12 +707,21 @@ public class StructureChooser extends GStructureChooser implements
     {
       validateAssociationFromFile();
     }
+
+    btn_newView.setEnabled(btn_add.isEnabled());
+
+    /*
+     * enable 'Superpose' option if more than one structure is selected,
+     * or there are view(s) available to add structure(s) to
+     */
+    chk_superpose
+            .setEnabled(selectedCount > 1 || targetView.getItemCount() > 0);
   }
 
   /**
    * Validates inputs from the Manual PDB entry panel
    */
-  public void validateAssociationEnterPdb()
+  protected void validateAssociationEnterPdb()
   {
     AssociateSeqOptions assSeqOpt = (AssociateSeqOptions) idInputAssSeqPanel
             .getCmb_assSeq().getSelectedItem();
@@ -624,27 +729,25 @@ public class StructureChooser extends GStructureChooser implements
     lbl_pdbManualFetchStatus.setToolTipText("");
     if (txt_search.getText().length() > 0)
     {
-      lbl_pdbManualFetchStatus
-              .setToolTipText(JvSwingUtils.wrapTooltip(true, MessageManager
-                      .formatMessage("info.no_pdb_entry_found_for",
-                              txt_search.getText())));
+      lbl_pdbManualFetchStatus.setToolTipText(JvSwingUtils.wrapTooltip(true,
+              MessageManager.formatMessage("info.no_pdb_entry_found_for",
+                      txt_search.getText())));
     }
 
     if (errorWarning.length() > 0)
     {
       lbl_pdbManualFetchStatus.setIcon(warningImage);
-      lbl_pdbManualFetchStatus.setToolTipText(JvSwingUtils.wrapTooltip(
-              true, errorWarning.toString()));
+      lbl_pdbManualFetchStatus.setToolTipText(
+              JvSwingUtils.wrapTooltip(true, errorWarning.toString()));
     }
 
-    if (selectedSequences.length == 1
-            || !assSeqOpt.getName().equalsIgnoreCase(
-                    "-Select Associated Seq-"))
+    if (selectedSequences.length == 1 || !assSeqOpt.getName()
+            .equalsIgnoreCase("-Select Associated Seq-"))
     {
       txt_search.setEnabled(true);
       if (isValidPBDEntry)
       {
-        btn_view.setEnabled(true);
+        btn_add.setEnabled(true);
         lbl_pdbManualFetchStatus.setToolTipText("");
         lbl_pdbManualFetchStatus.setIcon(goodImage);
       }
@@ -659,19 +762,18 @@ public class StructureChooser extends GStructureChooser implements
   /**
    * Validates inputs for the manual PDB file selection options
    */
-  public void validateAssociationFromFile()
+  protected void validateAssociationFromFile()
   {
     AssociateSeqOptions assSeqOpt = (AssociateSeqOptions) fileChooserAssSeqPanel
             .getCmb_assSeq().getSelectedItem();
     lbl_fromFileStatus.setIcon(errorImage);
-    if (selectedSequences.length == 1
-            || (assSeqOpt != null && !assSeqOpt.getName().equalsIgnoreCase(
-                    "-Select Associated Seq-")))
+    if (selectedSequences.length == 1 || (assSeqOpt != null && !assSeqOpt
+            .getName().equalsIgnoreCase("-Select Associated Seq-")))
     {
       btn_pdbFromFile.setEnabled(true);
       if (selectedPdbFileName != null && selectedPdbFileName.length() > 0)
       {
-        btn_view.setEnabled(true);
+        btn_add.setEnabled(true);
         lbl_fromFileStatus.setIcon(goodImage);
       }
     }
@@ -683,7 +785,7 @@ public class StructureChooser extends GStructureChooser implements
   }
 
   @Override
-  public void cmbAssSeqStateChanged()
+  protected void cmbAssSeqStateChanged()
   {
     validateSelections();
   }
@@ -710,131 +812,226 @@ public class StructureChooser extends GStructureChooser implements
   }
 
   /**
-   * Handles action event for btn_ok
+   * select structures for viewing by their PDB IDs
+   * 
+   * @param pdbids
+   * @return true if structures were found and marked as selected
+   */
+  public boolean selectStructure(String... pdbids)
+  {
+    boolean found = false;
+
+    FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
+            .getSelectedItem());
+    String currentView = selectedFilterOpt.getView();
+    JTable restable = (currentView == VIEWS_FILTER) ? getResultTable()
+            : (currentView == VIEWS_LOCAL_PDB) ? tbl_local_pdb : null;
+
+    if (restable == null)
+    {
+      // can't select (enter PDB ID, or load file - need to also select which
+      // sequence to associate with)
+      return false;
+    }
+
+    int pdbIdColIndex = restable.getColumn("PDB Id").getModelIndex();
+    for (int r = 0; r < restable.getRowCount(); r++)
+    {
+      for (int p = 0; p < pdbids.length; p++)
+      {
+        if (String.valueOf(restable.getValueAt(r, pdbIdColIndex))
+                .equalsIgnoreCase(pdbids[p]))
+        {
+          restable.setRowSelectionInterval(r, r);
+          found = true;
+        }
+      }
+    }
+    return found;
+  }
+  
+  /**
+   * Handles the 'New View' action
    */
   @Override
-  public void ok_ActionPerformed()
+  protected void newView_ActionPerformed()
   {
-    final long progressSessionId = System.currentTimeMillis();
-    final StructureSelectionManager ssm = ap.getStructureSelectionManager();
-    ssm.setProgressIndicator(this);
-    ssm.setProgressSessionId(progressSessionId);
-    new Thread(new Runnable()
+    targetView.setSelectedItem(null);
+    showStructures(false);
+  }
+
+  /**
+   * Handles the 'Add to existing viewer' action
+   */
+  @Override
+  protected void add_ActionPerformed()
+  {
+    showStructures(false);
+  }
+
+  /**
+   * structure viewer opened by this dialog, or null
+   */
+  protected StructureViewer sViewer = null;
+
+  public void showStructures(boolean waitUntilFinished)
+  {
+
+    final int preferredHeight = pnl_filter.getHeight();
+
+    Runnable viewStruc = new Runnable()
     {
       @Override
       public void run()
       {
-    FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
-            .getSelectedItem());
-    String currentView = selectedFilterOpt.getView();
-    if (currentView == VIEWS_FILTER)
-    {
-          int pdbIdColIndex = tbl_summary.getColumn("PDB Id")
+        FilterOption selectedFilterOpt = ((FilterOption) cmb_filterOption
+                .getSelectedItem());
+        String currentView = selectedFilterOpt.getView();
+        JTable restable = (currentView == VIEWS_FILTER) ? getResultTable()
+                : tbl_local_pdb;
+
+        if (currentView == VIEWS_FILTER)
+        {
+          int pdbIdColIndex = restable.getColumn("PDB Id")
                   .getModelIndex();
-      int refSeqColIndex = tbl_summary.getColumn("Ref Sequence")
-              .getModelIndex();
-      int[] selectedRows = tbl_summary.getSelectedRows();
-      PDBEntry[] pdbEntriesToView = new PDBEntry[selectedRows.length];
-      int count = 0;
-      ArrayList<SequenceI> selectedSeqsToView = new ArrayList<SequenceI>();
-      for (int row : selectedRows)
-      {
-        String pdbIdStr = tbl_summary.getValueAt(row, pdbIdColIndex)
-                .toString();
-        SequenceI selectedSeq = (SequenceI) tbl_summary.getValueAt(row,
-                refSeqColIndex);
-        selectedSeqsToView.add(selectedSeq);
+          int refSeqColIndex = restable.getColumn("Ref Sequence")
+                  .getModelIndex();
+          int[] selectedRows = restable.getSelectedRows();
+          PDBEntry[] pdbEntriesToView = new PDBEntry[selectedRows.length];
+          int count = 0;
+          List<SequenceI> selectedSeqsToView = new ArrayList<>();
+          for (int row : selectedRows)
+          {
+            String pdbIdStr = restable
+                    .getValueAt(row, pdbIdColIndex).toString();
+            SequenceI selectedSeq = (SequenceI) restable
+                    .getValueAt(row, refSeqColIndex);
+            selectedSeqsToView.add(selectedSeq);
             PDBEntry pdbEntry = selectedSeq.getPDBEntry(pdbIdStr);
             if (pdbEntry == null)
             {
               pdbEntry = getFindEntry(pdbIdStr,
                       selectedSeq.getAllPDBEntries());
             }
-        if (pdbEntry == null)
-        {
-          pdbEntry = new PDBEntry();
-          pdbEntry.setId(pdbIdStr);
-          pdbEntry.setType(PDBEntry.Type.PDB);
-          selectedSeq.getDatasetSequence().addPDBId(pdbEntry);
+
+            if (pdbEntry == null)
+            {
+              pdbEntry = new PDBEntry();
+              pdbEntry.setId(pdbIdStr);
+              pdbEntry.setType(PDBEntry.Type.PDB);
+              selectedSeq.getDatasetSequence().addPDBId(pdbEntry);
+            }
+            pdbEntriesToView[count++] = pdbEntry;
+          }
+          SequenceI[] selectedSeqs = selectedSeqsToView
+                  .toArray(new SequenceI[selectedSeqsToView.size()]);
+          sViewer = launchStructureViewer(ap, pdbEntriesToView,
+                  selectedSeqs);
         }
-        pdbEntriesToView[count++] = pdbEntry;
-      }
-      SequenceI[] selectedSeqs = selectedSeqsToView
-              .toArray(new SequenceI[selectedSeqsToView.size()]);
-          launchStructureViewer(ssm, pdbEntriesToView, ap, selectedSeqs);
-    }
-    else if (currentView == VIEWS_LOCAL_PDB)
-    {
-      int[] selectedRows = tbl_local_pdb.getSelectedRows();
-      PDBEntry[] pdbEntriesToView = new PDBEntry[selectedRows.length];
-      int count = 0;
+        else if (currentView == VIEWS_LOCAL_PDB)
+        {
+          int[] selectedRows = tbl_local_pdb.getSelectedRows();
+          PDBEntry[] pdbEntriesToView = new PDBEntry[selectedRows.length];
+          int count = 0;
           int pdbIdColIndex = tbl_local_pdb.getColumn("PDB Id")
                   .getModelIndex();
-      int refSeqColIndex = tbl_local_pdb.getColumn("Ref Sequence")
-              .getModelIndex();
-      ArrayList<SequenceI> selectedSeqsToView = new ArrayList<SequenceI>();
-      for (int row : selectedRows)
-      {
-        PDBEntry pdbEntry = (PDBEntry) tbl_local_pdb.getValueAt(row,
-                pdbIdColIndex);
-        pdbEntriesToView[count++] = pdbEntry;
-        SequenceI selectedSeq = (SequenceI) tbl_local_pdb.getValueAt(row,
-                refSeqColIndex);
-        selectedSeqsToView.add(selectedSeq);
-      }
-      SequenceI[] selectedSeqs = selectedSeqsToView
-              .toArray(new SequenceI[selectedSeqsToView.size()]);
-          launchStructureViewer(ssm, pdbEntriesToView, ap, selectedSeqs);
-    }
-    else if (currentView == VIEWS_ENTER_ID)
-    {
-      SequenceI userSelectedSeq = ((AssociateSeqOptions) idInputAssSeqPanel
-              .getCmb_assSeq().getSelectedItem()).getSequence();
-      if (userSelectedSeq != null)
-      {
-        selectedSequence = userSelectedSeq;
-      }
-
-      String pdbIdStr = txt_search.getText();
-      PDBEntry pdbEntry = selectedSequence.getPDBEntry(pdbIdStr);
-      if (pdbEntry == null)
-      {
-        pdbEntry = new PDBEntry();
+          int refSeqColIndex = tbl_local_pdb.getColumn("Ref Sequence")
+                  .getModelIndex();
+          List<SequenceI> selectedSeqsToView = new ArrayList<>();
+          for (int row : selectedRows)
+          {
+            PDBEntry pdbEntry = (PDBEntry) tbl_local_pdb.getValueAt(row,
+                    pdbIdColIndex);
+            pdbEntriesToView[count++] = pdbEntry;
+            SequenceI selectedSeq = (SequenceI) tbl_local_pdb
+                    .getValueAt(row, refSeqColIndex);
+            selectedSeqsToView.add(selectedSeq);
+          }
+          SequenceI[] selectedSeqs = selectedSeqsToView
+                  .toArray(new SequenceI[selectedSeqsToView.size()]);
+          sViewer = launchStructureViewer(ap, pdbEntriesToView,
+                  selectedSeqs);
+        }
+        else if (currentView == VIEWS_ENTER_ID)
+        {
+          SequenceI userSelectedSeq = ((AssociateSeqOptions) idInputAssSeqPanel
+                  .getCmb_assSeq().getSelectedItem()).getSequence();
+          if (userSelectedSeq != null)
+          {
+            selectedSequence = userSelectedSeq;
+          }
+          String pdbIdStr = txt_search.getText();
+          PDBEntry pdbEntry = selectedSequence.getPDBEntry(pdbIdStr);
+          if (pdbEntry == null)
+          {
+            pdbEntry = new PDBEntry();
             if (pdbIdStr.split(":").length > 1)
             {
-              pdbEntry.setChainCode(pdbIdStr.split(":")[1]);
+              pdbEntry.setId(pdbIdStr.split(":")[0]);
+              pdbEntry.setChainCode(pdbIdStr.split(":")[1].toUpperCase());
             }
-        pdbEntry.setId(pdbIdStr);
-        pdbEntry.setType(PDBEntry.Type.PDB);
-        selectedSequence.getDatasetSequence().addPDBId(pdbEntry);
-      }
+            else
+            {
+              pdbEntry.setId(pdbIdStr);
+            }
+            pdbEntry.setType(PDBEntry.Type.PDB);
+            selectedSequence.getDatasetSequence().addPDBId(pdbEntry);
+          }
 
-      PDBEntry[] pdbEntriesToView = new PDBEntry[] { pdbEntry };
-          launchStructureViewer(ssm, pdbEntriesToView, ap,
-                  new SequenceI[] { selectedSequence });
-    }
-    else if (currentView == VIEWS_FROM_FILE)
+          PDBEntry[] pdbEntriesToView = new PDBEntry[] { pdbEntry };
+          sViewer = launchStructureViewer(ap, pdbEntriesToView,
+                  new SequenceI[]
+                  { selectedSequence });
+        }
+        else if (currentView == VIEWS_FROM_FILE)
+        {
+          SequenceI userSelectedSeq = ((AssociateSeqOptions) fileChooserAssSeqPanel
+                  .getCmb_assSeq().getSelectedItem()).getSequence();
+          if (userSelectedSeq != null)
+          {
+            selectedSequence = userSelectedSeq;
+          }
+          PDBEntry fileEntry = AssociatePdbFileWithSeq
+                  .associatePdbWithSeq(selectedPdbFileName,
+                          DataSourceType.FILE, selectedSequence, true);
+
+          sViewer = launchStructureViewer(
+                  ap, new PDBEntry[]
+                  { fileEntry },
+                  new SequenceI[]
+                  { selectedSequence });
+        }
+        SwingUtilities.invokeLater(new Runnable()
+        {
+          @Override
+          public void run()
+          {
+            closeAction(preferredHeight);
+            mainFrame.dispose();
+          }
+        });
+      }
+    };
+    Thread runner = new Thread(viewStruc);
+    runner.start();
+    if (waitUntilFinished)
     {
-      SequenceI userSelectedSeq = ((AssociateSeqOptions) fileChooserAssSeqPanel
-              .getCmb_assSeq().getSelectedItem()).getSequence();
-      if (userSelectedSeq != null)
+      while (sViewer == null ? runner.isAlive()
+              : (sViewer.sview == null ? true
+                      : !sViewer.sview.hasMapping()))
       {
-        selectedSequence = userSelectedSeq;
-      }
-      PDBEntry fileEntry = new AssociatePdbFileWithSeq()
-              .associatePdbWithSeq(selectedPdbFileName,
-                      jalview.io.AppletFormatAdapter.FILE,
-                      selectedSequence, true, Desktop.instance);
+        try
+        {
+          Thread.sleep(300);
+        } catch (InterruptedException ie)
+        {
 
-          launchStructureViewer(ssm, new PDBEntry[] { fileEntry }, ap,
-                  new SequenceI[] { selectedSequence });
-    }
-    mainFrame.dispose();
+        }
       }
-    }).start();
+    }
   }
 
-  private PDBEntry getFindEntry(String id, Vector<PDBEntry> pdbEntries)
+  protected PDBEntry getFindEntry(String id, Vector<PDBEntry> pdbEntries)
   {
     Objects.requireNonNull(id);
     Objects.requireNonNull(pdbEntries);
@@ -849,46 +1046,41 @@ public class StructureChooser extends GStructureChooser implements
     return foundEntry;
   }
 
-  private void launchStructureViewer(StructureSelectionManager ssm,
-          final PDBEntry[] pdbEntriesToView,
-          final AlignmentPanel alignPanel, SequenceI[] sequences)
+  /**
+   * Answers a structure viewer (new or existing) configured to superimpose
+   * added structures or not according to the user's choice
+   * 
+   * @return
+   */
+  StructureViewer getTargetedStructureViewer()
   {
-    ssm.setProgressBar("Launching PDB structure viewer..");
-    final StructureViewer sViewer = new StructureViewer(ssm);
+    final StructureSelectionManager ssm = ap.getStructureSelectionManager();
+    Object sv = (targetView == null ? null : targetView.getSelectedItem());
 
-    if (SiftsSettings.isMapWithSifts())
-    {
-      for (SequenceI seq : sequences)
-      {
-        if (seq.getSourceDBRef() == null)
-        {
-          ssm.setProgressBar(null);
-          ssm.setProgressBar("Fetching Database refs..");
-          new jalview.ws.DBRefFetcher(sequences, null, null, null, false)
-                  .fetchDBRefs(true);
-          break;
-        }
-      }
-    }
-        if (pdbEntriesToView.length > 1)
-        {
-          ArrayList<SequenceI[]> seqsMap = new ArrayList<SequenceI[]>();
-          for (SequenceI seq : sequences)
-          {
-            seqsMap.add(new SequenceI[] { seq });
-          }
-          SequenceI[][] collatedSeqs = seqsMap.toArray(new SequenceI[0][0]);
-      ssm.setProgressBar(null);
-      ssm.setProgressBar("Fetching PDB Structures for selected entries..");
-          sViewer.viewStructures(pdbEntriesToView, collatedSeqs, alignPanel);
-        }
-        else
-        {
-      ssm.setProgressBar(null);
-      ssm.setProgressBar("Fetching PDB Structure for "
-              + pdbEntriesToView[0].getId());
-          sViewer.viewStructures(pdbEntriesToView[0], sequences, alignPanel);
-        }
+    return sv == null ? new StructureViewer(ssm) : (StructureViewer) sv;
+  }
+
+  /**
+   * Adds PDB structures to a new or existing structure viewer
+   * 
+   * @param ap
+   * @param pdbEntriesToView
+   * @param sequences
+   * @param superimpose
+   * @return viewer
+   */
+  protected StructureViewer launchStructureViewer(
+          AlignmentPanel ap, PDBEntry[] pdbEntriesToView,
+          SequenceI[] selectedSeqs)
+  {
+    boolean superimpose = chk_superpose.isSelected();
+    /*
+     * remember user's choice of superimpose or not
+     */
+    Cache.setProperty(AUTOSUPERIMPOSE,
+            Boolean.valueOf(superimpose).toString());
+    return StructureViewer.launchStructureViewer(ap, pdbEntriesToView, selectedSeqs,
+            superimpose, getTargetedStructureViewer(), progressBar);
   }
 
   /**
@@ -896,12 +1088,13 @@ public class StructureChooser extends GStructureChooser implements
    * a unique sequence when more than one sequence selection is made.
    */
   @Override
-  public void populateCmbAssociateSeqOptions(
-          JComboBox<AssociateSeqOptions> cmb_assSeq, JLabel lbl_associateSeq)
+  protected void populateCmbAssociateSeqOptions(
+          JComboBox<AssociateSeqOptions> cmb_assSeq,
+          JLabel lbl_associateSeq)
   {
     cmb_assSeq.removeAllItems();
-    cmb_assSeq.addItem(new AssociateSeqOptions("-Select Associated Seq-",
-            null));
+    cmb_assSeq.addItem(
+            new AssociateSeqOptions("-Select Associated Seq-", null));
     lbl_associateSeq.setVisible(false);
     if (selectedSequences.length > 1)
     {
@@ -920,51 +1113,49 @@ public class StructureChooser extends GStructureChooser implements
     }
   }
 
-  public boolean isStructuresDiscovered()
-  {
-    return structuresDiscovered;
-  }
-
-  public void setStructuresDiscovered(boolean structuresDiscovered)
+  protected boolean isStructuresDiscovered()
   {
-    this.structuresDiscovered = structuresDiscovered;
+    return discoveredStructuresSet != null
+            && !discoveredStructuresSet.isEmpty();
   }
 
-  public Collection<FTSData> getDiscoveredStructuresSet()
-  {
-    return discoveredStructuresSet;
-  }
+  protected int PDB_ID_MIN = 3;// or: (Jalview.isJS() ? 3 : 1); // Bob proposes this. 
+  // Doing a search for "1" or "1c" is valuable?
+  // Those work but are enormously slow.
 
   @Override
   protected void txt_search_ActionPerformed()
   {
+    String text = txt_search.getText().trim();
+       if (text.length() >= PDB_ID_MIN)
+  {
     new Thread()
     {
-      @Override
+
+       @Override
       public void run()
       {
         errorWarning.setLength(0);
         isValidPBDEntry = false;
-        if (txt_search.getText().length() > 0)
+        if (text.length() > 0)
         {
-          String searchTerm = txt_search.getText().toLowerCase();
+          String searchTerm = text.toLowerCase();
           searchTerm = searchTerm.split(":")[0];
-          System.out.println(">>>>> search term : " + searchTerm);
-          List<FTSDataColumnI> wantedFields = new ArrayList<FTSDataColumnI>();
+          // System.out.println(">>>>> search term : " + searchTerm);
+          List<FTSDataColumnI> wantedFields = new ArrayList<>();
           FTSRestRequest pdbRequest = new FTSRestRequest();
           pdbRequest.setAllowEmptySeq(false);
           pdbRequest.setResponseSize(1);
           pdbRequest.setFieldToSearchBy("(pdb_id:");
           pdbRequest.setWantedFields(wantedFields);
-          pdbRequest
-.setSearchTerm(searchTerm + ")");
+          pdbRequest.setSearchTerm(searchTerm + ")");
           pdbRequest.setAssociatedSequence(selectedSequence);
-          pdbRestCleint = PDBFTSRestClient.getInstance();
-          wantedFields.add(pdbRestCleint.getPrimaryKeyColumn());
+          pdbRestClient = PDBFTSRestClient.getInstance();
+          wantedFields.add(pdbRestClient.getPrimaryKeyColumn());
           FTSRestResponse resultList;
           try
           {
-            resultList = pdbRestCleint.executeRequest(pdbRequest);
+            resultList = pdbRestClient.executeRequest(pdbRequest);
           } catch (Exception e)
           {
             errorWarning.append(e.getMessage());
@@ -983,9 +1174,10 @@ public class StructureChooser extends GStructureChooser implements
       }
     }.start();
   }
+  }
 
   @Override
-  public void tabRefresh()
+  protected void tabRefresh()
   {
     if (selectedSequences != null)
     {
@@ -995,8 +1187,9 @@ public class StructureChooser extends GStructureChooser implements
         public void run()
         {
           fetchStructuresMetaData();
-          filterResultSet(((FilterOption) cmb_filterOption
-                  .getSelectedItem()).getValue());
+          filterResultSet(
+                  ((FilterOption) cmb_filterOption.getSelectedItem())
+                          .getValue());
         }
       });
       refreshThread.start();
@@ -1005,13 +1198,14 @@ public class StructureChooser extends GStructureChooser implements
 
   public class PDBEntryTableModel extends AbstractTableModel
   {
-    String[] columns = { "Ref Sequence", "PDB Id", "Chain", "Type", "File" };
+    String[] columns = { "Ref Sequence", "PDB Id", "Chain", "Type",
+        "File" };
 
     private List<CachedPDB> pdbEntries;
 
     public PDBEntryTableModel(List<CachedPDB> pdbEntries)
     {
-      this.pdbEntries = new ArrayList<CachedPDB>(pdbEntries);
+      this.pdbEntries = new ArrayList<>(pdbEntries);
     }
 
     @Override
@@ -1052,8 +1246,8 @@ public class StructureChooser extends GStructureChooser implements
         value = entry.getPdbEntry();
         break;
       case 2:
-        value = entry.getPdbEntry().getChainCode() == null ? "_" : entry
-                .getPdbEntry().getChainCode();
+        value = entry.getPdbEntry().getChainCode() == null ? "_"
+                : entry.getPdbEntry().getChainCode();
         break;
       case 3:
         value = entry.getPdbEntry().getType();
@@ -1107,7 +1301,10 @@ public class StructureChooser extends GStructureChooser implements
   @Override
   public void setProgressBar(String message, long id)
   {
-    progressBar.setProgressBar(message, id);
+    if (progressBar != null)
+    {
+      progressBar.setProgressBar(message, id);
+    }
   }
 
   @Override
@@ -1121,4 +1318,9 @@ public class StructureChooser extends GStructureChooser implements
   {
     return progressBar.operationInProgress();
   }
+
+  public JalviewStructureDisplayI getOpenedStructureViewer()
+  {
+    return sViewer == null ? null : sViewer.sview;
+  }
 }