org.eclipse.jface.viewers.EditingSupport Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.jface Show documentation
This is org.eclipse.jface jar used by Scout SDK
The newest version!
/*******************************************************************************
 * Copyright (c) 2006, 2015 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  - initial API and implementation
 *     											   fix in bug 151295,167325,201905
 *******************************************************************************/

package org.eclipse.jface.viewers;

import org.eclipse.core.runtime.Assert;

/**
 * EditingSupport is the abstract superclass of the support for cell editing.
 *
 * @since 3.3
 *
 */
public abstract class EditingSupport {

	private ColumnViewer viewer;

	/**
	 * @param viewer
	 *            a new viewer
	 */
	public EditingSupport(ColumnViewer viewer) {
		Assert.isNotNull(viewer, "Viewer is not allowed to be null"); //$NON-NLS-1$
		this.viewer = viewer;
	}

	/**
	 * The editor to be shown
	 *
	 * @param element
	 *            the model element
	 * @return the CellEditor
	 */
	protected abstract CellEditor getCellEditor(Object element);

	/**
	 * Is the cell editable
	 *
	 * @param element
	 *            the model element
	 * @return true if editable
	 */
	protected abstract boolean canEdit(Object element);

	/**
	 * Get the value to set to the editor
	 *
	 * @param element
	 *            the model element
	 * @return the value shown
	 */
	protected abstract Object getValue(Object element);

	/**
	 * Sets the new value on the given element. Note that implementers need to
	 * ensure that getViewer().update(element, null) or similar
	 * methods are called, either directly or through some kind of listener
	 * mechanism on the implementer's model, to cause the new value to appear in
	 * the viewer.
	 *
	 * 
	 * Subclasses should overwrite.
	 * 
	 *
	 * @param element
	 *            the model element
	 * @param value
	 *            the new value
	 */
	protected abstract void setValue(Object element, Object value);

	/**
	 * @return the viewer this editing support works for
	 */
	public ColumnViewer getViewer() {
		return viewer;
	}

	/**
	 * Initialize the editor. Frameworks like Databinding can hook in here and provide
	 * a customized implementation. Standard customers should not overwrite this method but {@link #getValue(Object)}
	 *
	 * @param cellEditor
	 *            the cell editor
	 * @param cell
	 *            the cell the editor is working for
	 */
	protected void initializeCellEditorValue(CellEditor cellEditor, ViewerCell cell) {
		Object value = getValue(cell.getElement());
		cellEditor.setValue(value);
	}

	/**
	 * Save the value of the cell editor back to the model. Frameworks like Databinding can hook in here and provide
	 * a customized implementation. Standard customers should not overwrite this method but {@link #setValue(Object, Object)} 
	 * @param cellEditor
	 *            the cell-editor
	 * @param cell
	 * 			  the cell the editor is working for
	 */
	protected void saveCellEditorValue(CellEditor cellEditor, ViewerCell cell) {
		Object value = cellEditor.getValue();
		setValue(cell.getElement(), value);
	}

	boolean isLegacySupport() {
		return false;
	}
}