org.eclipse.jface.layout.TreeColumnLayout.java Source code

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Here is the source code for org.eclipse.jface.layout.TreeColumnLayout.java

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/*******************************************************************************
 * Copyright (c) 2007, 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:
 *       Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 *                                               - fix for bug 178280, 183999, 184609
 *       Ruediger Herrmann <ruediger.herrmann@gmx.de> - fix for bug 395890
 *     IBM Corporation - API refactoring and general maintenance
 *******************************************************************************/

package org.eclipse.jface.layout;

import org.eclipse.jface.viewers.ColumnLayoutData;
import org.eclipse.jface.viewers.ColumnPixelData;
import org.eclipse.swt.events.TreeEvent;
import org.eclipse.swt.events.TreeListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Scrollable;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeColumn;
import org.eclipse.swt.widgets.Widget;

/**
 * The TreeColumnLayout is the {@link Layout} used to maintain {@link TreeColumn} sizes in a
 * {@link Tree}.
 *
 * <p>
 * <b>You can only add the {@link Layout} to a container whose <i>only</i>
 * child is the {@link Tree} control you want the {@link Layout} applied to.
 * Don't assign the layout directly the {@link Tree}</b>
 * </p>
 *
 * @since 3.3
 */
public class TreeColumnLayout extends AbstractColumnLayout {
    private boolean addListener = true;

    private static class TreeLayoutListener implements TreeListener {

        @Override
        public void treeCollapsed(TreeEvent e) {
            update((Tree) e.widget);
        }

        @Override
        public void treeExpanded(TreeEvent e) {
            update((Tree) e.widget);
        }

        private void update(final Tree tree) {
            tree.getDisplay().asyncExec(() -> {
                if (!tree.isDisposed()) {
                    tree.update();
                    tree.getParent().layout();
                }
            });
        }

    }

    private static final TreeLayoutListener listener = new TreeLayoutListener();

    /**
     * Creates a new tree column layout.
     */
    public TreeColumnLayout() {
    }

    /**
     * Creates a new tree column layout.
     *
     * @param adjustForScrollBar
     *            <code>true</code> if the layout should reserve space for the
     *            vertical scroll bar
     * @since 3.12
     */
    public TreeColumnLayout(boolean adjustForScrollBar) {
        super(adjustForScrollBar);
    }

    @Override
    protected void layout(Composite composite, boolean flushCache) {
        super.layout(composite, flushCache);
        if (addListener) {
            addListener = false;
            ((Tree) getControl(composite)).addTreeListener(listener);
        }
    }

    /**
     * {@inheritDoc}
     *
     * @since 3.5
     */
    @Override
    protected int getColumnCount(Scrollable tree) {
        return ((Tree) tree).getColumnCount();
    }

    /**
     * {@inheritDoc}
     *
     * @since 3.5
     */
    @Override
    protected void setColumnWidths(Scrollable tree, int[] widths) {
        TreeColumn[] columns = ((Tree) tree).getColumns();
        for (int i = 0; i < widths.length; i++) {
            columns[i].setWidth(widths[i]);
        }
    }

    /**
     * {@inheritDoc}
     *
     * @since 3.5
     */
    @Override
    protected ColumnLayoutData getLayoutData(Scrollable tableTree, int columnIndex) {
        TreeColumn column = ((Tree) tableTree).getColumn(columnIndex);
        return (ColumnLayoutData) column.getData(LAYOUT_DATA);
    }

    /**
     * {@inheritDoc}
     *
     * @since 3.5
     */
    @Override
    protected void updateColumnData(Widget column) {
        TreeColumn tColumn = (TreeColumn) column;
        Tree t = tColumn.getParent();

        if (!IS_GTK || t.getColumn(t.getColumnCount() - 1) != tColumn) {
            tColumn.setData(LAYOUT_DATA, new ColumnPixelData(tColumn.getWidth()));
            layout(t.getParent(), true);
        }
    }
}