ca.odell.glazedlists.swt.DefaultEventListViewer Maven / Gradle / Ivy
/* Glazed Lists (c) 2003-2012 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists.swt;
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.event.ListEvent;
import ca.odell.glazedlists.event.ListEventListener;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.List;
/**
* A view helper that displays an {@link EventList} in a {@link List}.
*
* This class is not thread safe. It must be used exclusively with the SWT
* event handler thread.
*
* @author Kevin Maltby
* @author Holger Brands
*/
public class DefaultEventListViewer implements ListEventListener {
/** indicator to dispose source list */
private boolean disposeSource;
/** the SWT List */
private List list;
/** the proxy moves events to the SWT user interface thread */
protected EventList source;
/** the formatter for list elements */
private ItemFormat itemFormat;
/** For selection management */
private SelectionManager selection;
/**
* Creates a new List that displays and responds to changes in the source list.
* List elements will simply be displayed as the result of calling
* toString() on the contents of the source list.
*
* @param source the EventList that provides the elements
* @param list the list
*/
public DefaultEventListViewer(EventList source, List list) {
this(source, list, new DefaultItemFormat());
}
/**
* Creates a new List that displays and responds to changes in the source list.
* List elements are formatted using the provided {@link ItemFormat}.
*
* @param source the EventList that provides the elements
* @param list the list
* @param itemFormat an {@link ItemFormat} for formatting the displayed values
*
* @see ItemFormat
* @see GlazedListsSWT#beanItemFormat(String)
*/
public DefaultEventListViewer(EventList source, List list, ItemFormat itemFormat) {
this(source, list, itemFormat, false);
}
/**
* Creates a new List that displays and responds to changes in the source list.
* List elements are formatted using the provided {@link ItemFormat}.
*
* @param source the EventList that provides the elements
* @param list the list
* @param itemFormat an optional {@link ItemFormat} for formatting the displayed values
* @param diposeSource true if the source list should be disposed when disposing
* this model, false otherwise
*
* @see ItemFormat
* @see GlazedListsSWT#beanItemFormat(String)
*/
protected DefaultEventListViewer(EventList source, List list, ItemFormat itemFormat, boolean disposeSource) {
this.disposeSource = disposeSource;
// lock the source list for reading since we want to prevent writes
// from occurring until we fully initialize this EventListViewer
source.getReadWriteLock().readLock().lock();
try {
this.source = source;
this.list = list;
this.itemFormat = itemFormat;
// Enable the selection lists
selection = new SelectionManager(this.source, new SelectableList());
// setup initial values
for(int i = 0, n = this.source.size(); i < n; i++) {
addRow(i, this.source.get(i));
}
// listen for changes
this.source.addListEventListener(this);
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Gets the List's {@link ItemFormat}.
*/
public ItemFormat getItemFormat() {
return itemFormat;
}
/**
* Gets the List being managed by this {@link DefaultEventListViewer}.
*/
public List getList() {
return list;
}
/**
* Provides access to an {@link EventList} that contains items from the
* viewed Table that are not currently selected.
*/
public EventList getDeselected() {
source.getReadWriteLock().readLock().lock();
try {
return selection.getSelectionList().getDeselected();
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Gets an {@link EventList} that contains only deselected values and
* modifies the selection state on mutation.
*
* Adding an item to this list deselects it and removing an item selects it.
* If an item not in the source list is added an
* {@link IllegalArgumentException} is thrown
*/
public EventList getTogglingDeselected() {
source.getReadWriteLock().readLock().lock();
try {
return selection.getSelectionList().getTogglingDeselected();
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Provides access to an {@link EventList} that contains items from the
* viewed Table that are currently selected.
*/
public EventList getSelected() {
source.getReadWriteLock().readLock().lock();
try {
return selection.getSelectionList().getSelected();
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Gets an {@link EventList} that contains only selected
* values and modifies the selection state on mutation.
*
* Adding an item to this list selects it and removing an item deselects it.
* If an item not in the source list is added an
* {@link IllegalArgumentException} is thrown.
*/
public EventList getTogglingSelected() {
source.getReadWriteLock().readLock().lock();
try {
return selection.getSelectionList().getTogglingSelected();
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Adds the value at the specified row.
*/
private void addRow(int row, E value) {
list.add(itemFormat.format(value), row);
}
/**
* Updates the value at the specified row.
*/
private void updateRow(int row, E value) {
list.setItem(row, itemFormat.format(value));
}
/**
* Removes the value at the specified row.
*/
private void deleteRow(int row) {
list.remove(row);
}
/**
* When the source list is changed, this forwards the change to the
* displayed List.
*/
public void listChanged(ListEvent listChanges) {
int firstModified = source.size();
// Apply the list changes
while (listChanges.next()) {
int changeIndex = listChanges.getIndex();
int changeType = listChanges.getType();
if (changeType == ListEvent.INSERT) {
addRow(changeIndex, source.get(changeIndex));
firstModified = Math.min(changeIndex, firstModified);
} else if (changeType == ListEvent.UPDATE) {
updateRow(changeIndex, source.get(changeIndex));
} else if (changeType == ListEvent.DELETE) {
deleteRow(changeIndex);
firstModified = Math.min(changeIndex, firstModified);
}
}
// Reapply selection to the List
selection.fireSelectionChanged(firstModified, source.size() - 1);
}
/**
* Inverts the current selection.
*/
public void invertSelection() {
selection.getSelectionList().invertSelection();
}
/**
* To use common selectable widget logic in a widget unaware fashion.
*/
private final class SelectableList implements Selectable {
/** {@inheritDoc} */
public void addSelectionListener(SelectionListener listener) {
list.addSelectionListener(listener);
}
/** {@inheritDoc} */
public void removeSelectionListener(SelectionListener listener) {
list.removeSelectionListener(listener);
}
/** {@inheritDoc} */
public int getSelectionIndex() {
return list.getSelectionIndex();
}
/** {@inheritDoc} */
public int[] getSelectionIndices() {
return list.getSelectionIndices();
}
/** {@inheritDoc} */
public int getStyle() {
return list.getStyle();
}
/** {@inheritDoc} */
public void select(int index) {
list.select(index);
}
/** {@inheritDoc} */
public void deselect(int index) {
list.deselect(index);
}
}
/**
* Releases the resources consumed by this {@link DefaultEventListViewer} so that it
* may eventually be garbage collected.
*
* An {@link DefaultEventListViewer} will be garbage collected without a call to
* {@link #dispose()}, but not before its source {@link EventList} is garbage
* collected. By calling {@link #dispose()}, you allow the {@link DefaultEventListViewer}
* to be garbage collected before its source {@link EventList}. This is
* necessary for situations where an {@link DefaultEventListViewer} is short-lived but
* its source {@link EventList} is long-lived.
*
*
Warning: It is an error
* to call any method on a {@link DefaultEventListViewer} after it has been disposed.
*/
public void dispose() {
selection.dispose();
source.removeListEventListener(this);
if (disposeSource) source.dispose();
}
}