package org.rubypeople.rdt.internal.ui.util;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Set;
import java.util.Vector;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;
/**
* A composite widget which holds a list of elements for user selection.
* The elements are sorted alphabetically.
* Optionally, the elements can be filtered and duplicate entries can
* be hidden (folding).
*/
public class FilteredList extends Composite {
public interface FilterMatcher {
/**
* Sets the filter.
*
* @param pattern the filter pattern.
* @param ignoreCase a flag indicating whether pattern matching is case insensitive or not.
* @param ignoreWildCards a flag indicating whether wildcard characters are interpreted or not.
*/
void setFilter(String pattern, boolean ignoreCase, boolean ignoreWildCards);
/**
* Returns <code>true</code> if the object matches the pattern, <code>false</code> otherwise.
* <code>setFilter()</code> must have been called at least once prior to a call to this method.
*/
boolean match(Object element);
}
private class DefaultFilterMatcher implements FilterMatcher {
private StringMatcher fMatcher;
public void setFilter(String pattern, boolean ignoreCase, boolean ignoreWildCards) {
fMatcher= new StringMatcher(pattern + '*', ignoreCase, ignoreWildCards);
}
public boolean match(Object element) {
return fMatcher.match(fRenderer.getText(element));
}
}
private Table fList;
private ILabelProvider fRenderer;
private boolean fMatchEmtpyString= true;
private boolean fIgnoreCase;
private boolean fAllowDuplicates;
private String fFilter= ""; //$NON-NLS-1$
private TwoArrayQuickSorter fSorter;
private Object[] fElements= new Object[0];
private Label[] fLabels;
private Vector fImages= new Vector();
private int[] fFoldedIndices;
private int fFoldedCount;
private int[] fFilteredIndices;
private int fFilteredCount;
private FilterMatcher fFilterMatcher= new DefaultFilterMatcher();
private Comparator fComparator;
private static class Label {
public final String string;
public final Image image;
public Label(String string, Image image) {
this.string= string;
this.image= image;
}
public boolean equals(Label label) {
if (label == null)
return false;
return
string.equals(label.string) &&
image.equals(label.image);
}
}
private final class LabelComparator implements Comparator {
private boolean fIgnoreCase;
LabelComparator(boolean ignoreCase) {
fIgnoreCase= ignoreCase;
}
public int compare(Object left, Object right) {
Label leftLabel= (Label) left;
Label rightLabel= (Label) right;
int value;
if (fComparator == null) {
value= fIgnoreCase
? leftLabel.string.compareToIgnoreCase(rightLabel.string)
: leftLabel.string.compareTo(rightLabel.string);
} else {
value= fComparator.compare(leftLabel.string, rightLabel.string);
}
if (value != 0)
return value;
// images are allowed to be null
if (leftLabel.image == null) {
return (rightLabel.image == null) ? 0 : -1;
} else if (rightLabel.image == null) {
return +1;
} else {
return
fImages.indexOf(leftLabel.image) -
fImages.indexOf(rightLabel.image);
}
}
}
/**
* Constructs a new instance of a filtered list.
* @param parent the parent composite.
* @param style the widget style.
* @param renderer the label renderer.
* @param ignoreCase specifies whether sorting and folding is case sensitive.
* @param allowDuplicates specifies whether folding of duplicates is desired.
* @param matchEmptyString specifies whether empty filter strings should filter everything or nothing.
*/
public FilteredList(Composite parent, int style, ILabelProvider renderer,
boolean ignoreCase, boolean allowDuplicates, boolean matchEmptyString)
{
super(parent, SWT.NONE);
GridLayout layout= new GridLayout();
layout.marginHeight= 0;
layout.marginWidth= 0;
setLayout(layout);
fList= new Table(this, style);
fList.setLayoutData(new GridData(GridData.FILL_BOTH));
fList.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
fRenderer.dispose();
}
});
fRenderer= renderer;
fIgnoreCase= ignoreCase;
fSorter= new TwoArrayQuickSorter(new LabelComparator(ignoreCase));
fAllowDuplicates= allowDuplicates;
fMatchEmtpyString= matchEmptyString;
}
/**
* Sets the list of elements.
* @param elements the elements to be shown in the list.
*/
public void setElements(Object[] elements) {
if (elements == null) {
fElements= new Object[0];
} else {
// copy list for sorting
fElements= new Object[elements.length];
System.arraycopy(elements, 0, fElements, 0, elements.length);
}
int length= fElements.length;
// fill labels
fLabels= new Label[length];
Set imageSet= new HashSet();
for (int i= 0; i != length; i++) {
String text= fRenderer.getText(fElements[i]);
Image image= fRenderer.getImage(fElements[i]);
fLabels[i]= new Label(text, image);
imageSet.add(image);
}
fImages.clear();
fImages.addAll(imageSet);
fSorter.sort(fLabels, fElements);
fFilteredIndices= new int[length];
fFilteredCount= filter();
fFoldedIndices= new int[length];
fFoldedCount= fold();
updateList();
}
/**
* Tests if the list (before folding and filtering) is empty.
* @return returns <code>true</code> if the list is empty, <code>false</code> otherwise.
*/
public boolean isEmpty() {
return (fElements == null) || (fElements.length == 0);
}
/**
* Sets the filter matcher.
*/
public void setFilterMatcher(FilterMatcher filterMatcher) {
Assert.isNotNull(filterMatcher);
fFilterMatcher= filterMatcher;
}
/**
* Sets a custom comparator for sorting the list.
*/
public void setComparator(Comparator comparator) {
Assert.isNotNull(comparator);
fComparator= comparator;
}
/**
* Adds a selection listener to the list.
* @param listener the selection listener to be added.
*/
public void addSelectionListener(SelectionListener listener) {
fList.addSelectionListener(listener);
}
/**
* Removes a selection listener from the list.
* @param listener the selection listener to be removed.
*/
public void removeSelectionListener(SelectionListener listener) {
fList.removeSelectionListener(listener);
}
/**
* Sets the selection of the list.
* @param selection an array of indices specifying the selection.
*/
public void setSelection(int[] selection) {
fList.setSelection(selection);
}
/**
* Returns the selection of the list.
* @return returns an array of indices specifying the current selection.
*/
public int[] getSelectionIndices() {
return fList.getSelectionIndices();
}
/**
* Returns the selection of the list.
* This is a convenience function for <code>getSelectionIndices()</code>.
* @return returns the index of the selection, -1 for no selection.
*/
public int getSelectionIndex() {
return fList.getSelectionIndex();
}
/**
* Sets the selection of the list.
* @param elements the array of elements to be selected.
*/
public void setSelection(Object[] elements) {
if ((elements == null) || (fElements == null))
return;
// fill indices
int[] indices= new int[elements.length];
for (int i= 0; i != elements.length; i++) {
int j;
for (j= 0; j != fFoldedCount; j++) {
int max= (j == fFoldedCount - 1)
? fFilteredCount
: fFoldedIndices[j + 1];
int l;
for (l= fFoldedIndices[j]; l != max; l++) {
// found matching element?
if (fElements[fFilteredIndices[l]].equals(elements[i])) {
indices[i]= j;
break;
}
}
if (l != max)
break;
}
// not found
if (j == fFoldedCount)
indices[i] = 0;
}
fList.setSelection(indices);
}
/**
* Returns an array of the selected elements. The type of the elements
* returned in the list are the same as the ones passed with
* <code>setElements</code>. The array does not contain the rendered strings.
* @return returns the array of selected elements.
*/
public Object[] getSelection() {
if (fList.isDisposed() || (fList.getSelectionCount() == 0))
return new Object[0];
int[] indices= fList.getSelectionIndices();
Object[] elements= new Object[indices.length];
for (int i= 0; i != indices.length; i++)
elements[i]= fElements[fFilteredIndices[fFoldedIndices[indices[i]]]];
return elements;
}
/**
* Sets the filter pattern. Current only prefix filter patterns are supported.
* @param filter the filter pattern.
*/
public void setFilter(String filter) {
fFilter= (filter == null) ? "" : filter; //$NON-NLS-1$
fFilteredCount= filter();
fFoldedCount= fold();
updateList();
}
/**
* Returns the filter pattern.
* @return returns the filter pattern.
*/
public String getFilter() {
return fFilter;
}
/**
* Returns all elements which are folded together to one entry in the list.
* @param index the index selecting the entry in the list.
* @return returns an array of elements folded together, <code>null</code> if index is out of range.
*/
public Object[] getFoldedElements(int index) {
if ((index < 0) || (index >= fFoldedCount))
return null;
int start= fFoldedIndices[index];
int count= (index == fFoldedCount - 1)
? fFilteredCount - start
: fFoldedIndices[index + 1] - start;
Object[] elements= new Object[count];
for (int i= 0; i != count; i++)
elements[i]= fElements[fFilteredIndices[start + i]];
return elements;
}
/*
* Folds duplicate entries. Two elements are considered as a pair of
* duplicates if they coiincide in the rendered string and image.
* @return returns the number of elements after folding.
*/
private int fold() {
if (fAllowDuplicates) {
for (int i= 0; i != fFilteredCount; i++)
fFoldedIndices[i]= i; // identity mapping
return fFilteredCount;
}
int k= 0;
Label last= null;
for (int i= 0; i != fFilteredCount; i++) {
int j= fFilteredIndices[i];
Label current= fLabels[j];
if (! current.equals(last)) {
fFoldedIndices[k]= i;
k++;
last= current;
}
}
return k;
}
/*
* Filters the list with the filter pattern.
* @return returns the number of elements after filtering.
*/
private int filter() {
if (((fFilter == null) || (fFilter.length() == 0)) && !fMatchEmtpyString)
return 0;
fFilterMatcher.setFilter(fFilter.trim(), fIgnoreCase, false);
int k= 0;
for (int i= 0; i != fElements.length; i++) {
if (fFilterMatcher.match(fElements[i]))
fFilteredIndices[k++]= i;
}
return k;
}
/*
* Updates the list widget.
*/
private void updateList() {
if (fList.isDisposed())
return;
fList.setRedraw(false);
// resize table
int itemCount= fList.getItemCount();
if (fFoldedCount < itemCount)
fList.remove(0, itemCount - fFoldedCount - 1);
else if (fFoldedCount > itemCount)
for (int i= 0; i != fFoldedCount - itemCount; i++)
new TableItem(fList, SWT.NONE);
// fill table
TableItem[] items= fList.getItems();
for (int i= 0; i != fFoldedCount; i++) {
TableItem item= items[i];
Label label= fLabels[fFilteredIndices[fFoldedIndices[i]]];
item.setText(label.string);
item.setImage(label.image);
}
// select first item if any
if (fList.getItemCount() > 0)
fList.setSelection(0);
fList.setRedraw(true);
fList.notifyListeners(SWT.Selection, new Event());
}
}