org.eclipse.swt.snippets.Snippet231.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet231.java

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/*******************************************************************************
 * Copyright (c) 2000, 2016 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.swt.snippets;

/*
 * Table example snippet: draw multiple lines of text in a table item
 *
 * For a detailed explanation of this snippet see
 * http://www.eclipse.org/articles/Article-CustomDrawingTableAndTreeItems/customDraw.htm#_example6
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 *
 * @since 3.2
 */

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class Snippet231 {

    public static void main(String[] args) {
        final int COLUMN_COUNT = 4;
        final int ITEM_COUNT = 8;
        final int TEXT_MARGIN = 3;
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Snippet 231");
        final Table table = new Table(shell, SWT.FULL_SELECTION);
        table.setHeaderVisible(true);
        table.setLinesVisible(true);
        for (int i = 0; i < COLUMN_COUNT; i++) {
            new TableColumn(table, SWT.NONE);
        }
        for (int i = 0; i < ITEM_COUNT; i++) {
            TableItem item = new TableItem(table, SWT.NONE);
            for (int j = 0; j < COLUMN_COUNT; j++) {
                String string = "item " + i + " col " + j;
                if ((i + j) % 3 == 1) {
                    string += "\nnew line1";
                }
                if ((i + j) % 3 == 2) {
                    string += "\nnew line1\nnew line2";
                }
                item.setText(j, string);
            }
        }

        /*
         * NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
         * Therefore, it is critical for performance that these methods be
         * as efficient as possible.
         */
        table.addListener(SWT.MeasureItem, event -> {
            TableItem item = (TableItem) event.item;
            String text = item.getText(event.index);
            Point size = event.gc.textExtent(text);
            event.width = size.x + 2 * TEXT_MARGIN;
            event.height = Math.max(event.height, size.y + TEXT_MARGIN);
        });
        table.addListener(SWT.EraseItem, event -> event.detail &= ~SWT.FOREGROUND);
        table.addListener(SWT.PaintItem, event -> {
            TableItem item = (TableItem) event.item;
            String text = item.getText(event.index);
            /* center column 1 vertically */
            int yOffset = 0;
            if (event.index == 1) {
                Point size = event.gc.textExtent(text);
                yOffset = Math.max(0, (event.height - size.y) / 2);
            }
            event.gc.drawText(text, event.x + TEXT_MARGIN, event.y + yOffset, true);
        });

        for (int i = 0; i < COLUMN_COUNT; i++) {
            table.getColumn(i).pack();
        }
        table.pack();
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}