JAL-3551 save structure viewer session refactorings, PyMol added
[jalview.git] / src / jalview / gui / StructureViewerBase.java
index 3ba9947..0c5c5f0 100644 (file)
  */
 package jalview.gui;
 
-import jalview.bin.Cache;
-import jalview.datamodel.Alignment;
-import jalview.datamodel.AlignmentI;
-import jalview.datamodel.HiddenColumns;
-import jalview.datamodel.PDBEntry;
-import jalview.datamodel.SequenceI;
-import jalview.gui.StructureViewer.ViewerType;
-import jalview.gui.ViewSelectionMenu.ViewSetProvider;
-import jalview.io.DataSourceType;
-import jalview.io.JalviewFileChooser;
-import jalview.io.JalviewFileView;
-import jalview.jbgui.GStructureViewer;
-import jalview.schemes.ColourSchemeI;
-import jalview.schemes.ColourSchemes;
-import jalview.structures.models.AAStructureBindingModel;
-import jalview.util.MessageManager;
-
 import java.awt.Color;
 import java.awt.Component;
 import java.awt.event.ActionEvent;
@@ -51,6 +34,7 @@ import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Random;
 import java.util.Vector;
 
 import javax.swing.ButtonGroup;
@@ -62,6 +46,24 @@ import javax.swing.JRadioButtonMenuItem;
 import javax.swing.event.MenuEvent;
 import javax.swing.event.MenuListener;
 
+import jalview.api.AlignmentViewPanel;
+import jalview.bin.Cache;
+import jalview.datamodel.AlignmentI;
+import jalview.datamodel.PDBEntry;
+import jalview.datamodel.SequenceI;
+import jalview.gui.StructureViewer.ViewerType;
+import jalview.gui.ViewSelectionMenu.ViewSetProvider;
+import jalview.io.DataSourceType;
+import jalview.io.JalviewFileChooser;
+import jalview.io.JalviewFileView;
+import jalview.jbgui.GStructureViewer;
+import jalview.schemes.ColourSchemeI;
+import jalview.schemes.ColourSchemes;
+import jalview.structure.StructureMapping;
+import jalview.structures.models.AAStructureBindingModel;
+import jalview.util.MessageManager;
+import jalview.ws.dbsources.Pdb;
+
 /**
  * Base class with common functionality for JMol, Chimera or other structure
  * viewers.
@@ -83,18 +85,18 @@ public abstract class StructureViewerBase extends GStructureViewer
   /**
    * list of sequenceSet ids associated with the view
    */
-  protected List<String> _aps = new ArrayList<String>();
+  protected List<String> _aps = new ArrayList<>();
 
   /**
    * list of alignment panels to use for superposition
    */
-  protected Vector<AlignmentPanel> _alignwith = new Vector<AlignmentPanel>();
+  protected Vector<AlignmentViewPanel> _alignwith = new Vector<>();
 
   /**
    * list of alignment panels that are used for colouring structures by aligned
    * sequences
    */
-  protected Vector<AlignmentPanel> _colourwith = new Vector<AlignmentPanel>();
+  protected Vector<AlignmentViewPanel> _colourwith = new Vector<>();
 
   private String viewId = null;
 
@@ -102,9 +104,9 @@ public abstract class StructureViewerBase extends GStructureViewer
 
   protected boolean alignAddedStructures = false;
 
-  protected boolean _started = false;
+  protected volatile boolean _started = false;
 
-  protected boolean addingStructures = false;
+  protected volatile boolean addingStructures = false;
 
   protected Thread worker = null;
 
@@ -113,6 +115,17 @@ public abstract class StructureViewerBase extends GStructureViewer
   protected JMenu viewSelectionMenu;
 
   /**
+   * set after sequence colouring has been applied for this structure viewer.
+   * used to determine if the final sequence/structure mapping has been
+   * determined
+   */
+  protected volatile boolean seqColoursApplied = false;
+
+  private IProgressIndicator progressBar = null;
+
+  private Random random = new Random();
+
+  /**
    * Default constructor
    */
   public StructureViewerBase()
@@ -121,6 +134,26 @@ public abstract class StructureViewerBase extends GStructureViewer
   }
 
   /**
+   * @return true if added structures should be aligned to existing one(s)
+   */
+  @Override
+  public boolean isAlignAddedStructures()
+  {
+    return alignAddedStructures;
+  }
+
+  /**
+   * 
+   * @param true
+   *          if added structures should be aligned to existing one(s)
+   */
+  @Override
+  public void setAlignAddedStructures(boolean alignAdded)
+  {
+    alignAddedStructures = alignAdded;
+  }
+
+  /**
    * 
    * @param ap2
    * @return true if this Jmol instance is linked with the given alignPanel
@@ -130,13 +163,14 @@ public abstract class StructureViewerBase extends GStructureViewer
     return _aps.contains(ap2.av.getSequenceSetId());
   }
 
-  public boolean isUsedforaligment(AlignmentPanel ap2)
+  public boolean isUsedforaligment(AlignmentViewPanel ap2)
   {
 
     return (_alignwith != null) && _alignwith.contains(ap2);
   }
 
-  public boolean isUsedforcolourby(AlignmentPanel ap2)
+  @Override
+  public boolean isUsedForColourBy(AlignmentViewPanel ap2)
   {
     return (_colourwith != null) && _colourwith.contains(ap2);
   }
@@ -164,13 +198,11 @@ public abstract class StructureViewerBase extends GStructureViewer
     this.viewId = viewId;
   }
 
-  public abstract String getStateInfo();
-
   protected void buildActionMenu()
   {
     if (_alignwith == null)
     {
-      _alignwith = new Vector<AlignmentPanel>();
+      _alignwith = new Vector<>();
     }
     if (_alignwith.size() == 0 && ap != null)
     {
@@ -186,6 +218,7 @@ public abstract class StructureViewerBase extends GStructureViewer
     }
   }
 
+  @Override
   public AlignmentPanel getAlignmentPanel()
   {
     return ap;
@@ -238,7 +271,8 @@ public abstract class StructureViewerBase extends GStructureViewer
    * 
    * @param nap
    */
-  public void removeAlignmentPanel(AlignmentPanel nap)
+  @Override
+  public void removeAlignmentPanel(AlignmentViewPanel nap)
   {
     try
     {
@@ -324,7 +358,7 @@ public abstract class StructureViewerBase extends GStructureViewer
    */
   protected void addStructure(final PDBEntry pdbentry,
           final SequenceI[] seqs, final String[] chains,
-          final boolean align, final IProgressIndicator alignFrame)
+          final IProgressIndicator alignFrame)
   {
     if (pdbentry.getFile() == null)
     {
@@ -348,7 +382,7 @@ public abstract class StructureViewerBase extends GStructureViewer
               }
             }
             // and call ourselves again.
-            addStructure(pdbentry, seqs, chains, align, alignFrame);
+            addStructure(pdbentry, seqs, chains, alignFrame);
           }
         }).start();
         return;
@@ -360,87 +394,42 @@ public abstract class StructureViewerBase extends GStructureViewer
             { seqs }, new String[][] { chains });
     addingStructures = true;
     _started = false;
-    alignAddedStructures = align;
     worker = new Thread(this);
     worker.start();
     return;
   }
 
-  /**
-   * Presents a dialog with the option to add an align a structure to an
-   * existing structure view
-   * 
-   * @param pdbId
-   * @param view
-   * @return YES, NO or CANCEL JvOptionPane code
-   */
-  protected int chooseAlignStructureToViewer(String pdbId,
-          StructureViewerBase view)
-  {
-    int option = JvOptionPane.showInternalConfirmDialog(Desktop.desktop,
-            MessageManager.formatMessage("label.add_pdbentry_to_view",
-                    new Object[]
-                    { pdbId, view.getTitle() }),
-            MessageManager
-                    .getString("label.align_to_existing_structure_view"),
-            JvOptionPane.YES_NO_CANCEL_OPTION);
-    return option;
-  }
-
   protected boolean hasPdbId(String pdbId)
   {
     return getBinding().hasPdbId(pdbId);
   }
 
-  protected abstract List<StructureViewerBase> getViewersFor(
-          AlignmentPanel alp);
-
   /**
-   * Check for any existing views involving this alignment and give user the
-   * option to add and align this molecule to one of them
-   * 
-   * @param pdbentry
-   * @param seq
-   * @param chains
-   * @param apanel
-   * @param pdbId
-   * @return true if user adds to a view, or cancels entirely, else false
+   * Returns a list of any viewer of the instantiated type. The list is
+   * restricted to those linked to the given alignment panel if it is not null.
    */
-  protected boolean addToExistingViewer(PDBEntry pdbentry, SequenceI[] seq,
-          String[] chains, final AlignmentPanel apanel, String pdbId)
+  protected List<StructureViewerBase> getViewersFor(AlignmentPanel alp)
   {
-    for (StructureViewerBase view : getViewersFor(apanel))
-    {
-      // TODO: highlight the view somehow
-      /*
-       * JAL-1742 exclude view with this structure already mapped (don't offer
-       * to align chain B to chain A of the same structure)
-       */
-      if (view.hasPdbId(pdbId))
-      {
-        continue;
-      }
-      int option = chooseAlignStructureToViewer(pdbId, view);
-      if (option == JvOptionPane.CANCEL_OPTION)
-      {
-        return true;
-      }
-      else if (option == JvOptionPane.YES_OPTION)
-      {
-        view.useAlignmentPanelForSuperposition(apanel);
-        view.addStructure(pdbentry, seq, chains, true, apanel.alignFrame);
-        return true;
-      }
-      else
-      {
-        // NO_OPTION - offer the next viewer if any
-      }
-    }
+    return Desktop.instance.getStructureViewers(alp, this.getClass());
+  }
 
+  @Override
+  public void addToExistingViewer(PDBEntry pdbentry, SequenceI[] seq,
+          String[] chains, final AlignmentViewPanel apanel, String pdbId)
+  {
     /*
-     * nothing offered and selected
+     * JAL-1742 exclude view with this structure already mapped (don't offer
+     * to align chain B to chain A of the same structure); code may defend
+     * against this possibility before we reach here
      */
-    return false;
+    if (hasPdbId(pdbId))
+    {
+      return;
+    }
+    AlignmentPanel alignPanel = (AlignmentPanel) apanel; // Implementation error if this
+                                                 // cast fails
+    useAlignmentPanelForSuperposition(alignPanel);
+    addStructure(pdbentry, seq, chains, alignPanel.alignFrame);
   }
 
   /**
@@ -452,15 +441,18 @@ public abstract class StructureViewerBase extends GStructureViewer
    * @param apanel
    * @param pdbFilename
    */
-  protected void addSequenceMappingsToStructure(SequenceI[] seq,
-          String[] chains, final AlignmentPanel apanel, String pdbFilename)
+  public void addSequenceMappingsToStructure(SequenceI[] seq,
+          String[] chains, final AlignmentViewPanel alpanel,
+          String pdbFilename)
   {
+    AlignmentPanel apanel = (AlignmentPanel) alpanel;
+
     // TODO : Fix multiple seq to one chain issue here.
     /*
      * create the mappings
      */
     apanel.getStructureSelectionManager().setMapping(seq, chains,
-            pdbFilename, DataSourceType.FILE);
+            pdbFilename, DataSourceType.FILE, getProgressIndicator());
 
     /*
      * alert the FeatureRenderer to show new (PDB RESNUM) features
@@ -468,7 +460,9 @@ public abstract class StructureViewerBase extends GStructureViewer
     if (apanel.getSeqPanel().seqCanvas.fr != null)
     {
       apanel.getSeqPanel().seqCanvas.fr.featuresAdded();
-      apanel.paintAlignment(true);
+      // note - we don't do a refresh for structure here because we do it
+      // explicitly for all panels later on
+      apanel.paintAlignment(true, false);
     }
 
     /*
@@ -499,47 +493,20 @@ public abstract class StructureViewerBase extends GStructureViewer
     }
   }
 
-  /**
-   * Check if the PDB file is already loaded, if so offer to add it to the
-   * existing viewer
-   * 
-   * @param seq
-   * @param chains
-   * @param apanel
-   * @param pdbId
-   * @return true if the user chooses to add to a viewer, or to cancel entirely
-   */
-  protected boolean addAlreadyLoadedFile(SequenceI[] seq, String[] chains,
-          final AlignmentPanel apanel, String pdbId)
+  @Override
+  public boolean addAlreadyLoadedFile(SequenceI[] seq, String[] chains,
+          final AlignmentViewPanel apanel, String pdbId)
   {
-    boolean finished = false;
     String alreadyMapped = apanel.getStructureSelectionManager()
             .alreadyMappedToFile(pdbId);
 
-    if (alreadyMapped != null)
+    if (alreadyMapped == null)
     {
-      /*
-       * the PDB file is already loaded
-       */
-      int option = JvOptionPane.showInternalConfirmDialog(Desktop.desktop,
-              MessageManager.formatMessage(
-                      "label.pdb_entry_is_already_displayed", new Object[]
-                      { pdbId }),
-              MessageManager.formatMessage(
-                      "label.map_sequences_to_visible_window", new Object[]
-                      { pdbId }),
-              JvOptionPane.YES_NO_CANCEL_OPTION);
-      if (option == JvOptionPane.CANCEL_OPTION)
-      {
-        finished = true;
-      }
-      else if (option == JvOptionPane.YES_OPTION)
-      {
-        addSequenceMappingsToStructure(seq, chains, apanel, alreadyMapped);
-        finished = true;
-      }
+      return false;
     }
-    return finished;
+
+    addSequenceMappingsToStructure(seq, chains, apanel, alreadyMapped);
+    return true;
   }
 
   void setChainMenuItems(List<String> chainNames)
@@ -590,8 +557,6 @@ public abstract class StructureViewerBase extends GStructureViewer
     }
   }
 
-  abstract void showSelectedChains();
-
   /**
    * Action on selecting one of Jalview's registered colour schemes
    */
@@ -600,8 +565,9 @@ public abstract class StructureViewerBase extends GStructureViewer
   {
     AlignmentI al = getAlignmentPanel().av.getAlignment();
     ColourSchemeI cs = ColourSchemes.getInstance()
-            .getColourScheme(colourSchemeName, al, null);
-    getBinding().setJalviewColourScheme(cs);
+            .getColourScheme(colourSchemeName, getAlignmentPanel().av, al,
+                    null);
+    getBinding().colourByJalviewColourScheme(cs);
   }
 
   /**
@@ -635,7 +601,7 @@ public abstract class StructureViewerBase extends GStructureViewer
       @Override
       public void actionPerformed(ActionEvent actionEvent)
       {
-        viewerColour_actionPerformed(actionEvent);
+        viewerColour_actionPerformed();
       }
     });
     colourMenu.add(viewerColour);
@@ -651,7 +617,7 @@ public abstract class StructureViewerBase extends GStructureViewer
       @Override
       public void actionPerformed(ActionEvent actionEvent)
       {
-        background_actionPerformed(actionEvent);
+        background_actionPerformed();
       }
     });
     colourMenu.add(backGround);
@@ -682,7 +648,7 @@ public abstract class StructureViewerBase extends GStructureViewer
       @Override
       public void actionPerformed(ActionEvent actionEvent)
       {
-        seqColour_actionPerformed(actionEvent);
+        seqColour_actionPerformed();
       }
     });
 
@@ -694,7 +660,7 @@ public abstract class StructureViewerBase extends GStructureViewer
       @Override
       public void actionPerformed(ActionEvent actionEvent)
       {
-        chainColour_actionPerformed(actionEvent);
+        chainColour_actionPerformed();
       }
     });
 
@@ -706,7 +672,7 @@ public abstract class StructureViewerBase extends GStructureViewer
       @Override
       public void actionPerformed(ActionEvent actionEvent)
       {
-        chargeColour_actionPerformed(actionEvent);
+        chargeColour_actionPerformed();
       }
     });
 
@@ -717,11 +683,11 @@ public abstract class StructureViewerBase extends GStructureViewer
 
     if (_colourwith == null)
     {
-      _colourwith = new Vector<AlignmentPanel>();
+      _colourwith = new Vector<>();
     }
     if (_alignwith == null)
     {
-      _alignwith = new Vector<AlignmentPanel>();
+      _alignwith = new Vector<>();
     }
 
     ViewSelectionMenu seqColourBy = new ViewSelectionMenu(
@@ -738,7 +704,7 @@ public abstract class StructureViewerBase extends GStructureViewer
                 else
                 {
                   // update the Chimera display now.
-                  seqColour_actionPerformed(null);
+                  seqColour_actionPerformed();
                 }
               }
             });
@@ -782,24 +748,13 @@ public abstract class StructureViewerBase extends GStructureViewer
     buildColourMenu();
   }
 
-  @Override
-  public void setJalviewColourScheme(ColourSchemeI cs)
-  {
-    getBinding().setJalviewColourScheme(cs);
-  }
-
   /**
    * Sends commands to the structure viewer to superimpose structures based on
    * currently associated alignments. May optionally return an error message for
    * the operation.
    */
   @Override
-  protected String alignStructs_actionPerformed(ActionEvent actionEvent)
-  {
-    return alignStructs_withAllAlignPanels();
-  }
-
-  protected String alignStructs_withAllAlignPanels()
+  protected String alignStructsWithAllAlignPanels()
   {
     if (getAlignmentPanel() == null)
     {
@@ -814,19 +769,8 @@ public abstract class StructureViewerBase extends GStructureViewer
     String reply = null;
     try
     {
-      AlignmentI[] als = new Alignment[_alignwith.size()];
-      HiddenColumns[] alc = new HiddenColumns[_alignwith.size()];
-      int[] alm = new int[_alignwith.size()];
-      int a = 0;
-
-      for (AlignmentPanel ap : _alignwith)
-      {
-        als[a] = ap.av.getAlignment();
-        alm[a] = -1;
-        alc[a++] = ap.av.getAlignment().getHiddenColumns();
-      }
-      reply = getBinding().superposeStructures(als, alm, alc);
-      if (reply != null)
+      reply = getBinding().superposeStructures(_alignwith);
+      if (reply != null && !reply.isEmpty())
       {
         String text = MessageManager
                 .formatMessage("error.superposition_failed", reply);
@@ -835,9 +779,9 @@ public abstract class StructureViewerBase extends GStructureViewer
     } catch (Exception e)
     {
       StringBuffer sp = new StringBuffer();
-      for (AlignmentPanel ap : _alignwith)
+      for (AlignmentViewPanel alignPanel : _alignwith)
       {
-        sp.append("'" + ap.alignFrame.getTitle() + "' ");
+        sp.append("'" + alignPanel.getViewName() + "' ");
       }
       Cache.log.info("Couldn't align structures with the " + sp.toString()
               + "associated alignment panels.", e);
@@ -846,7 +790,7 @@ public abstract class StructureViewerBase extends GStructureViewer
   }
 
   @Override
-  public void background_actionPerformed(ActionEvent actionEvent)
+  public void background_actionPerformed()
   {
     Color col = JColorChooser.showDialog(this,
             MessageManager.getString("label.select_background_colour"),
@@ -858,7 +802,7 @@ public abstract class StructureViewerBase extends GStructureViewer
   }
 
   @Override
-  public void viewerColour_actionPerformed(ActionEvent actionEvent)
+  public void viewerColour_actionPerformed()
   {
     if (viewerColour.isSelected())
     {
@@ -868,27 +812,27 @@ public abstract class StructureViewerBase extends GStructureViewer
   }
 
   @Override
-  public void chainColour_actionPerformed(ActionEvent actionEvent)
+  public void chainColour_actionPerformed()
   {
     chainColour.setSelected(true);
     getBinding().colourByChain();
   }
 
   @Override
-  public void chargeColour_actionPerformed(ActionEvent actionEvent)
+  public void chargeColour_actionPerformed()
   {
     chargeColour.setSelected(true);
     getBinding().colourByCharge();
   }
 
   @Override
-  public void seqColour_actionPerformed(ActionEvent actionEvent)
+  public void seqColour_actionPerformed()
   {
     AAStructureBindingModel binding = getBinding();
     binding.setColourBySequence(seqColour.isSelected());
     if (_colourwith == null)
     {
-      _colourwith = new Vector<AlignmentPanel>();
+      _colourwith = new Vector<>();
     }
     if (binding.isColourBySequence())
     {
@@ -901,15 +845,16 @@ public abstract class StructureViewerBase extends GStructureViewer
         }
       }
       // Set the colour using the current view for the associated alignframe
-      for (AlignmentPanel ap : _colourwith)
+      for (AlignmentViewPanel alignPanel : _colourwith)
       {
-        binding.colourBySequence(ap);
+        binding.colourBySequence(alignPanel);
       }
+      seqColoursApplied = true;
     }
   }
 
   @Override
-  public void pdbFile_actionPerformed(ActionEvent actionEvent)
+  public void pdbFile_actionPerformed()
   {
     JalviewFileChooser chooser = new JalviewFileChooser(
             Cache.getProperty("LAST_DIRECTORY"));
@@ -960,7 +905,7 @@ public abstract class StructureViewerBase extends GStructureViewer
   }
 
   @Override
-  public void viewMapping_actionPerformed(ActionEvent actionEvent)
+  public void viewMapping_actionPerformed()
   {
     CutAndPasteTransfer cap = new CutAndPasteTransfer();
     try
@@ -984,6 +929,7 @@ public abstract class StructureViewerBase extends GStructureViewer
   /**
    * Configures the title and menu items of the viewer panel.
    */
+  @Override
   public void updateTitleAndMenus()
   {
     AAStructureBindingModel binding = getBinding();
@@ -1021,7 +967,188 @@ public abstract class StructureViewerBase extends GStructureViewer
 
     if (!binding.isLoadingFromArchive())
     {
-      seqColour_actionPerformed(null);
+      seqColour_actionPerformed();
     }
   }
+
+  @Override
+  public String toString()
+  {
+    return getTitle();
+  }
+
+  @Override
+  public boolean hasMapping()
+  {
+    if (worker != null && (addingStructures || _started))
+    {
+      return false;
+    }
+    if (getBinding() == null)
+    {
+      if (_aps == null || _aps.size() == 0)
+      {
+        // viewer has been closed, but we did at some point run.
+        return true;
+      }
+      return false;
+    }
+    String[] pdbids = getBinding().getStructureFiles();
+    if (pdbids == null)
+    {
+      return false;
+    }
+    int p=0;
+    for (String pdbid:pdbids) {
+      StructureMapping sm[] = getBinding().getSsm().getMapping(pdbid);
+      if (sm!=null && sm.length>0 && sm[0]!=null) {
+        p++;
+      }
+    }
+    // only return true if there is a mapping for every structure file we have loaded
+    if (p == 0 || p != pdbids.length)
+    {
+      return false;
+    }
+    // and that coloring has been applied
+    return seqColoursApplied;
+  }
+
+  @Override
+  public void raiseViewer()
+  {
+    toFront();
+  }
+
+  @Override
+  public long startProgressBar(String msg)
+  {
+    // TODO would rather have startProgress/stopProgress as the
+    // IProgressIndicator interface
+    long tm = random.nextLong();
+    if (progressBar != null)
+    {
+      progressBar.setProgressBar(msg, tm);
+    }
+    return tm;
+  }
+
+  @Override
+  public void stopProgressBar(String msg, long handle)
+  {
+    if (progressBar != null)
+    {
+      progressBar.setProgressBar(msg, handle);
+    }
+  }
+
+  protected IProgressIndicator getProgressIndicator()
+  {
+    return progressBar;
+  }
+
+  protected void setProgressIndicator(IProgressIndicator pi)
+  {
+    progressBar = pi;
+  }
+
+  protected void setProgressMessage(String message, long id)
+  {
+    if (progressBar != null)
+    {
+      progressBar.setProgressBar(message, id);
+    }
+  }
+
+  @Override
+  public void showConsole(boolean show)
+  {
+    // default does nothing
+  }
+
+  /**
+   * Show only the selected chain(s) in the viewer
+   */
+  protected void showSelectedChains()
+  {
+    List<String> toshow = new ArrayList<>();
+    for (int i = 0; i < chainMenu.getItemCount(); i++)
+    {
+      if (chainMenu.getItem(i) instanceof JCheckBoxMenuItem)
+      {
+        JCheckBoxMenuItem item = (JCheckBoxMenuItem) chainMenu.getItem(i);
+        if (item.isSelected())
+        {
+          toshow.add(item.getText());
+        }
+      }
+    }
+    getBinding().showChains(toshow);
+  }
+
+  /**
+   * Tries to fetch a PDB file and save to a temporary local file. Returns the
+   * saved file path if successful, or null if not.
+   * 
+   * @param processingEntry
+   * @return
+   */
+  protected String fetchPdbFile(PDBEntry processingEntry)
+  {
+    String filePath = null;
+    Pdb pdbclient = new Pdb();
+    AlignmentI pdbseq = null;
+    String pdbid = processingEntry.getId();
+    long handle = System.currentTimeMillis()
+            + Thread.currentThread().hashCode();
+  
+    /*
+     * Write 'fetching PDB' progress on AlignFrame as we are not yet visible
+     */
+    String msg = MessageManager.formatMessage("status.fetching_pdb",
+            new Object[]
+            { pdbid });
+    getAlignmentPanel().alignFrame.setProgressBar(msg, handle);
+    // long hdl = startProgressBar(MessageManager.formatMessage(
+    // "status.fetching_pdb", new Object[]
+    // { pdbid }));
+    try
+    {
+      pdbseq = pdbclient.getSequenceRecords(pdbid);
+    } catch (Exception e)
+    {
+      System.err.println(
+              "Error retrieving PDB id " + pdbid + ": " + e.getMessage());
+    } finally
+    {
+      msg = pdbid + " " + MessageManager.getString("label.state_completed");
+      getAlignmentPanel().alignFrame.setProgressBar(msg, handle);
+      // stopProgressBar(msg, hdl);
+    }
+    /*
+     * If PDB data were saved and are not invalid (empty alignment), return the
+     * file path.
+     */
+    if (pdbseq != null && pdbseq.getHeight() > 0)
+    {
+      // just use the file name from the first sequence's first PDBEntry
+      filePath = new File(pdbseq.getSequenceAt(0).getAllPDBEntries()
+              .elementAt(0).getFile()).getAbsolutePath();
+      processingEntry.setFile(filePath);
+    }
+    return filePath;
+  }
+
+  /**
+   * If supported, saves the state of the structure viewer to a temporary file
+   * and returns the file, else returns null
+   * 
+   * @return
+   */
+  public File saveSession()
+  {
+    // TODO: a wait loop to ensure the file is written fully before returning?
+    return getBinding() == null ? null : getBinding().saveSession();
+  }
+
 }