/*******************************************************************************
* Copyright (c) 2006, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
* fix for bug 163317, 201905
* Ralf Ebert - bug 294738
*******************************************************************************/
package org.eclipse.jface.viewers;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.util.Policy;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.widgets.Widget;
/**
* Instances of this class represent a column of a {@link ColumnViewer}. Label
* providers and editing support can be configured for each column separately.
* Concrete subclasses of {@link ColumnViewer} should implement a matching
* concrete subclass of {@link ViewerColumn}.
*
* @since 3.3
*
*/
public abstract class ViewerColumn {
private CellLabelProvider labelProvider;
static String COLUMN_VIEWER_KEY = Policy.JFACE + ".columnViewer";//$NON-NLS-1$
private EditingSupport editingSupport;
private ILabelProviderListener listener;
private boolean listenerRegistered = false;
private ColumnViewer viewer;
/**
* Create a new instance of the receiver at columnIndex.
*
* @param viewer
* the viewer the column is part of
* @param columnOwner
* the widget owning the viewer in case the widget has no columns
* this could be the widget itself
*/
protected ViewerColumn(final ColumnViewer viewer, Widget columnOwner) {
this.viewer = viewer;
columnOwner.setData(ViewerColumn.COLUMN_VIEWER_KEY, this);
this.listener = new ILabelProviderListener() {
public void labelProviderChanged(LabelProviderChangedEvent event) {
viewer.handleLabelProviderChanged(event);
}
};
columnOwner.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
handleDispose(viewer);
}
});
}
/**
* Return the label provider for the receiver.
*
* @return ViewerLabelProvider
*/
/* package */CellLabelProvider getLabelProvider() {
return labelProvider;
}
/**
* Set the label provider for the column. Subclasses may extend but must
* call the super implementation.
*
* @param labelProvider
* the new {@link CellLabelProvider}
*/
public void setLabelProvider(CellLabelProvider labelProvider) {
setLabelProvider(labelProvider, true);
}
/**
* @param labelProvider
* @param registerListener
*/
/* package */void setLabelProvider(CellLabelProvider labelProvider,
boolean registerListener) {
if (listenerRegistered && this.labelProvider != null) {
this.labelProvider.removeListener(listener);
listenerRegistered = false;
if (registerListener) {
this.labelProvider.dispose(viewer, this);
}
}
this.labelProvider = labelProvider;
if (registerListener) {
this.labelProvider.initialize(viewer, this);
this.labelProvider.addListener(listener);
listenerRegistered = true;
}
}
/**
* Return the editing support for the receiver.
*
* @return {@link EditingSupport}
*/
/* package */EditingSupport getEditingSupport() {
return editingSupport;
}
/**
* Set the editing support. Subclasses may extend but must call the super
* implementation.
* <p>
* Users setting up an editable {@link TreeViewer} or {@link TableViewer} with more than 1 column <b>have</b>
* to pass the SWT.FULL_SELECTION style bit when creating the viewer
* </p>
* @param editingSupport
* The {@link EditingSupport} to set.
*/
public void setEditingSupport(EditingSupport editingSupport) {
this.editingSupport = editingSupport;
}
/**
* Refresh the cell for the given columnIndex. <strong>NOTE:</strong>the
* {@link ViewerCell} provided to this method is no longer valid after this
* method returns. Do not cache the cell for future use.
*
* @param cell
* {@link ViewerCell}
*/
/* package */void refresh(ViewerCell cell) {
CellLabelProvider labelProvider = getLabelProvider();
if (labelProvider == null) {
Assert.isTrue(false, "Column " + cell.getColumnIndex() + //$NON-NLS-1$
" has no label provider."); //$NON-NLS-1$
}
labelProvider.update(cell);
}
/**
* Disposes of the label provider (if set), unregisters the listener and
* nulls the references to the label provider and editing support. This
* method is called when the underlying widget is disposed. Subclasses may
* extend but must call the super implementation.
*/
protected void handleDispose() {
boolean disposeLabelProvider = listenerRegistered;
CellLabelProvider cellLabelProvider = labelProvider;
setLabelProvider(null, false);
if (disposeLabelProvider) {
cellLabelProvider.dispose(viewer, this);
}
editingSupport = null;
listener = null;
viewer = null;
}
private void handleDispose(ColumnViewer viewer) {
handleDispose();
viewer.clearLegacyEditingSetup();
}
/**
* Returns the viewer of this viewer column.
*
* @return Returns the viewer.
*
* @since 3.4
*/
public ColumnViewer getViewer() {
return viewer;
}
}