org.eclipse.swt.snippets.Snippet179.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet179.java

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/*******************************************************************************
 * Copyright (c) 2000, 2018 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;

/*
 * Text example snippet: verify input (format for date)
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import java.util.*;

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

public class Snippet179 {

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Snippet 179");
        shell.setLayout(new GridLayout());
        final Text text = new Text(shell, SWT.BORDER);
        text.setText("YYYY/MM/DD");
        final Calendar calendar = Calendar.getInstance();
        text.addListener(SWT.Verify, new Listener() {
            boolean ignore;

            @Override
            public void handleEvent(Event e) {
                if (ignore)
                    return;
                e.doit = false;
                StringBuilder buffer = new StringBuilder(e.text);
                char[] chars = new char[buffer.length()];
                buffer.getChars(0, chars.length, chars, 0);
                if (e.character == '\b') {
                    for (int i = e.start; i < e.end; i++) {
                        switch (i) {
                        case 0: /* [Y]YYY */
                        case 1: /* Y[Y]YY */
                        case 2: /* YY[Y]Y */
                        case 3: /* YYY[Y] */ {
                            buffer.append('Y');
                            break;
                        }
                        case 5: /* [M]M*/
                        case 6: /* M[M] */ {
                            buffer.append('M');
                            break;
                        }
                        case 8: /* [D]D */
                        case 9: /* D[D] */ {
                            buffer.append('D');
                            break;
                        }
                        case 4: /* YYYY[/]MM */
                        case 7: /* MM[/]DD */ {
                            buffer.append('/');
                            break;
                        }
                        default:
                            return;
                        }
                    }
                    text.setSelection(e.start, e.start + buffer.length());
                    ignore = true;
                    text.insert(buffer.toString());
                    ignore = false;
                    text.setSelection(e.start, e.start);
                    return;
                }

                int start = e.start;
                if (start > 9)
                    return;
                int index = 0;
                for (int i = 0; i < chars.length; i++) {
                    if (start + index == 4 || start + index == 7) {
                        if (chars[i] == '/') {
                            index++;
                            continue;
                        }
                        buffer.insert(index++, '/');
                    }
                    if (chars[i] < '0' || '9' < chars[i])
                        return;
                    if (start + index == 5 && '1' < chars[i])
                        return; /* [M]M */
                    if (start + index == 8 && '3' < chars[i])
                        return; /* [D]D */
                    index++;
                }
                String newText = buffer.toString();
                int length = newText.length();
                StringBuilder date = new StringBuilder(text.getText());
                date.replace(e.start, e.start + length, newText);
                calendar.set(Calendar.YEAR, 1901);
                calendar.set(Calendar.MONTH, Calendar.JANUARY);
                calendar.set(Calendar.DATE, 1);
                String yyyy = date.substring(0, 4);
                if (yyyy.indexOf('Y') == -1) {
                    int year = Integer.parseInt(yyyy);
                    calendar.set(Calendar.YEAR, year);
                }
                String mm = date.substring(5, 7);
                if (mm.indexOf('M') == -1) {
                    int month = Integer.parseInt(mm) - 1;
                    int maxMonth = calendar.getActualMaximum(Calendar.MONTH);
                    if (0 > month || month > maxMonth)
                        return;
                    calendar.set(Calendar.MONTH, month);
                }
                String dd = date.substring(8, 10);
                if (dd.indexOf('D') == -1) {
                    int day = Integer.parseInt(dd);
                    int maxDay = calendar.getActualMaximum(Calendar.DATE);
                    if (1 > day || day > maxDay)
                        return;
                    calendar.set(Calendar.DATE, day);
                } else {
                    if (calendar.get(Calendar.MONTH) == Calendar.FEBRUARY) {
                        char firstChar = date.charAt(8);
                        if (firstChar != 'D' && '2' < firstChar)
                            return;
                    }
                }
                text.setSelection(e.start, e.start + length);
                ignore = true;
                text.insert(newText);
                ignore = false;
            }
        });
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}