This object allows the user to set a filter on one of the workspace trees, specifying a preset type, or a regular expression that a files must match to be in the tree. Note that all directories are included. This class includes the controls for editing the filter. The trick is that several instances of the Filter class can share the same internal data (termed a 'run' of filters), so that the filter set on the GatherPane and the EnrichPane are virtually the same.
*The regular expression typed uses '*' as a wildcard character (equivalent to '.*'), and does not use '.' to match any single character (use '?' instead).
* @author John Thompson, Greenstone Digital Library, University of Waikato * @version 2.3 */ public class Filter extends JPanel { /** The other filters in this run of filters, used to ensure they all show the same thing. */ private ArrayList others = null; /** Is this the first filter of this run of filters created (later filters will share the same information). */ private boolean first = true; /** Prevent any changes we make in the class from causing events which we then process causing events... */ private boolean ignore = false; /** A reference to ourselves so inner classes can refer to us. */ private Filter this_filter = null; /** The check box to enable/disable filter. */ private JCheckBox checkbox = null; /** The editable combobox where you either choose a predefined filter, or type a new pseudo-regular expression. */ private GComboBox combobox = null; /** The label shown on the filter controls. */ private JLabel label = null; /** A reference to the tree this filter is being applied to. */ private DragTree tree = null; /** The default size for the label. */ static final private Dimension SIZE = new Dimension(100,30); /** Preprogrammed default filters. */ static final private String DEFAULTS[] = {"^.*\\.html?$", "^.*\\.xml$", "^.*\\.txt$", "(^.*\\.jpe?g$)|(^.*\\.png$)|(^.*\\.gif$)|(^.*\\.bmp$)|(^.*\\.tiff?$)", "^.*\\.pdf$", "(^.*\\.docx?$)|(^.*\\.pptx?$)|(^.*\\.xlsx?$)|(^.*\\.od(t|s|p)$)"}; /** Constructor. * @param tree A reference to the JTree being affected. */ public Filter(DragTree tree) { this(tree, null); } /** Constructor. * @param tree A reference to the JTree being affected. * @param others An ArrayList of the other Filters already in this run. */ public Filter(DragTree tree, ArrayList others) { super(); this.setComponentOrientation(Dictionary.getOrientation()); if (others == null) { others = new ArrayList(); } this.others = others; this.others.add(this); this.this_filter = this; this.tree = tree; // Create components. combobox = new GComboBox(true); try { combobox.add(new Entry()); } catch (Exception error) { error.printStackTrace(); } for(int i = 0; i < DEFAULTS.length; i++) { try { Entry entry = new Entry(Dictionary.get("Filter." + i), Pattern.compile(DEFAULTS[i])); combobox.add(entry); } catch (Exception error) { error.printStackTrace(); } } label = new JLabel(Dictionary.get("Filter.Filter_Tree")); label.setComponentOrientation(Dictionary.getOrientation()); label.setComponentOrientation(org.greenstone.gatherer.Dictionary.getOrientation()); combobox.setToolTipText(Dictionary.get("Collection.Filter_Tooltip")); // Add listeners. combobox.addActionListener(new ComboBoxListener()); // Layout. label.setBorder(BorderFactory.createEmptyBorder(0,0,0,5)); setBorder(BorderFactory.createEmptyBorder(2,2,2,2)); setLayout(new BorderLayout()); add(label, BorderLayout.LINE_START); add(combobox, BorderLayout.CENTER); } /** Used to restore the filter state to enabled, the normal state during collection editing. * @param state The new state for the filter. true for enabled, false otherwise. */ public void setEnabled(boolean state) { ignore = true; combobox.setEnabled(state); ignore = false; } /** Set the combobox model for this filter. * @param model The new ComboBoxModel to use. */ public void setComboBoxModel(ComboBoxModel model) { combobox.setModel(model); } /** Ensure that a certain entry is selected from the combobox. * @param selection The Entry that should be selected. */ public void setComboBoxSelection(Entry selection) { ignore = true; combobox.setSelectedItem(selection); ignore = false; } /** Sets whether this combobox is editable or not * @param value true to make the control editable, false otherwise */ public void setEditable(boolean value) { combobox.setEditable(value); } /** Set to signify that this filter is the first in a new run of filters. * @param first true if this is the first filter in a run, false if it will just be added to the current run. */ public void setFirst(boolean first) { this.first = first; } /** Encode an expression in pseudo-regular expression into regular expression. * @param raw The pseudo-regular expression String which includes several characters which differ in meaning from regular expression queries. * @return A proper regular expression as a String. */ private String encode(String raw) { StringBuffer working = new StringBuffer(); for(int i = 0; i < raw.length(); i++) { char c = raw.charAt(i); switch(c) { case '.': working.append("\\."); break; case '*': working.append(".*"); break; case '?': working.append("."); break; default: working.append(Character.toLowerCase(c)); } } return working.toString(); } /** This method applies the given pattern to the tree registered as belonging to this filter.*/ private void setFilter(Pattern pattern) { // Show busy cursor. Gatherer.g_man.wait(true); FileSystemModel model = (FileSystemModel) tree.getModel(); // Apply filter if(pattern != null) { model.setFilter(pattern.pattern()); } else { model.setFilter(null); } // Ask tree to completely refresh tree.refresh(null); // Restore cursor Gatherer.g_man.wait(false); } /** Listens for changes in the combobox as when one is detected attempts to compile a regular expression from whatever text was entered. If successful, or if the item chosen was a predefined filter, it then applies the filter to the target tree. */ private class ComboBoxListener implements ActionListener { /** Called when a new item is selected from the filter combobox, we treat the new entry as a pseudo-regular expression, compile it and then apply it to the tree. * @param event An ActionEvent containing more information about the change performed. * @see org.greenstone.gatherer.gui.Filter.Entry */ public void actionPerformed(ActionEvent event) { try { Object temp = combobox.getSelectedItem(); Entry entry = null; if(temp instanceof String) { String temp_str = (String) temp; ///ystem.err.println("Filter = " + temp_str); // Ignore any string which matches a predefined filter if(temp_str.equals(Dictionary.get("Filter.All_Files"))) { } // HTM & HTML else if(temp_str.equals(Dictionary.get("Filter.0"))) { } // XML else if(temp_str.equals(Dictionary.get("Filter.1"))) { } // Text files else if(temp_str.equals(Dictionary.get("Filter.2"))) { } // Images else if(temp_str.equals(Dictionary.get("Filter.3"))) { } // PDF else if(temp_str.equals(Dictionary.get("Filter.4"))) { } // Office Docs else if(temp_str.equals(Dictionary.get("Filter.5"))) { } else { // Make sure the filter isn't already in the list boolean already_exists = false; for (int i = 0; i < combobox.getItemCount(); i++) { if (temp_str.equals(combobox.getItemAt(i).toString())) { already_exists = true; entry = (Entry) combobox.getItemAt(i); break; } } if (already_exists == false) { entry = new Entry(temp_str, Pattern.compile(encode(temp_str))); int position = combobox.getItemCount(); combobox.insertItemAt(entry, position); combobox.setSelectedIndex(position); } } } else { ///ystem.err.println("Custom Filter"); entry = (Entry) temp; } if(entry != null) { setFilter(entry.getPattern()); } // Else we ignore this event as being one of the painfully erroneous events we receive because we've been silly enough to have an editable combobox. } catch (PatternSyntaxException error) { if(first) { JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("Filter.Invalid_Pattern"), Dictionary.get("General.Error"), JOptionPane.ERROR_MESSAGE); } } } } /** An object that holds a filter entry. This is string used for the filter pattern and, if not custom built, its name. */ private class Entry implements Comparable { /** The compiled pattern created from a regular expression. */ private Pattern pattern = null; /** The name of this filter entry. */ private String name = null; /** Constructor. */ public Entry() { } /** Constructor. * @param name The name of this entry as a String. * @param pattern The compiled regular expression as a Pattern. */ public Entry(String name, Pattern pattern) { this.name = name; this.pattern = pattern; } /** Compare two Entrys for ordering. * @param object The other Entry to compare to, as an Object. * @return An int indicating the respective ordering, as defined in java.lang.String#compareTo */ public int compareTo(Object object) { return toString().compareTo(object.toString()); } /** Retrieve the pattern associated with this entry. * @return The Pattern. */ public Pattern getPattern() { return pattern; } /** Translate this entry into a textual representation. * @return A String containing the representation. */ public String toString() { String result = null; if (name != null) { result = name; } else if (pattern == null) { result = Dictionary.get("Filter.All_Files"); } else { result = pattern.pattern(); } return result; } } }