org.eclipse.jface.viewers.ColumnLabelProvider.java Source code

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Here is the source code for org.eclipse.jface.viewers.ColumnLabelProvider.java

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/*******************************************************************************
 * Copyright (c) 2006, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.jface.viewers;

import java.util.Objects;
import java.util.function.Function;

import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;

/**
 * The ColumnLabelProvider is the label provider for viewers
 * that have column support such as {@link TreeViewer} and
 * {@link TableViewer}
 *
 * <p><b>This classes is intended to be subclassed</b></p>
 *
 * @since 3.3
 *
 */
public class ColumnLabelProvider extends CellLabelProvider
        implements IFontProvider, IColorProvider, ILabelProvider {

    @Override
    public void update(ViewerCell cell) {
        Object element = cell.getElement();
        cell.setText(getText(element));
        Image image = getImage(element);
        cell.setImage(image);
        cell.setBackground(getBackground(element));
        cell.setForeground(getForeground(element));
        cell.setFont(getFont(element));

    }

    @Override
    public Font getFont(Object element) {
        return null;
    }

    @Override
    public Color getBackground(Object element) {
        return null;
    }

    @Override
    public Color getForeground(Object element) {
        return null;
    }

    @Override
    public Image getImage(Object element) {
        return null;
    }

    @Override
    public String getText(Object element) {
        return element == null ? "" : element.toString();//$NON-NLS-1$
    }

    /**
     * Creates a {@link ColumnLabelProvider} which implements the {@link #getText}
     * method by calling the argument function.
     *
     * @param textFunction the function which returns the text
     * @return The new ColumnLabelProvider
     * @since 3.19
     */
    public static ColumnLabelProvider createTextProvider(Function<Object, String> textFunction) {
        Objects.requireNonNull(textFunction);
        return new ColumnLabelProvider() {
            @Override
            public String getText(Object e) {
                return textFunction.apply(e);
            }
        };
    }

    /**
     * Creates a {@link ColumnLabelProvider} which implements the {@link #getImage}
     * method by calling the argument function.
     *
     * @param imageFunction the function which returns the image
     * @return The new ColumnLabelProvider
     * @since 3.19
     */
    public static ColumnLabelProvider createImageProvider(Function<Object, Image> imageFunction) {
        Objects.requireNonNull(imageFunction);
        return new ColumnLabelProvider() {
            @Override
            public Image getImage(Object e) {
                return imageFunction.apply(e);
            }
        };
    }

    /**
     * Creates a {@link ColumnLabelProvider} which implements both the
     * {@link #getText} and {@link #getImage} methods by calling the argument
     * functions.
     *
     * @param textFunction  the function which returns the text
     * @param imageFunction the function which returns the image
     * @return The new ColumnLabelProvider
     * @since 3.19
     */
    public static ColumnLabelProvider createTextImageProvider(Function<Object, String> textFunction,
            Function<Object, Image> imageFunction) {
        Objects.requireNonNull(textFunction);
        Objects.requireNonNull(imageFunction);
        return new ColumnLabelProvider() {
            @Override
            public String getText(Object e) {
                return textFunction.apply(e);
            }

            @Override
            public Image getImage(Object e) {
                return imageFunction.apply(e);
            }
        };
    }

}