de.codesourcery.eve.skills.ui.utils.IntTextFieldValidator.java Source code

Introduction

Here is the source code for de.codesourcery.eve.skills.ui.utils.IntTextFieldValidator.java

Source

/**
 * Copyright 2004-2009 Tobias Gierke <tobias.gierke@code-sourcery.de>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package de.codesourcery.eve.skills.ui.utils;

import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
import javax.swing.text.JTextComponent;

import org.apache.commons.lang.StringUtils;

public class IntTextFieldValidator {
    private final JTextComponent comp;
    private final boolean checkRange;
    private final int minValue;
    private final int maxValue;

    private final DocumentFilter filter = new DocumentFilter() {

        private final StringBuffer myBuffer = new StringBuffer();

        @Override
        public void insertString(FilterBypass fb, int offset, String string, AttributeSet attr)
                throws BadLocationException {
            if (isInteger(string)) {

                if (checkRange) {
                    myBuffer.setLength(0);
                    myBuffer.append(comp.getText());
                    myBuffer.insert(offset, string);
                    if (!isWithinRange(myBuffer.toString())) {
                        return;
                    }
                }
                super.insertString(fb, offset, string, attr);
            }
        }

        @Override
        public void remove(FilterBypass fb, int offset, int length) throws BadLocationException {
            if (checkRange) {
                myBuffer.setLength(0);
                myBuffer.append(comp.getText());
                myBuffer.delete(offset, offset + length);
                if (!isInteger(myBuffer.toString()) || !isWithinRange(myBuffer.toString())) {
                    return;
                }
            }
            super.remove(fb, offset, length);
        }

        @Override
        public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet attrs)
                throws BadLocationException {
            if (isInteger(text)) {
                if (checkRange) {
                    myBuffer.setLength(0);
                    myBuffer.append(comp.getText());
                    myBuffer.replace(offset, offset + length, text);
                    if (!isWithinRange(myBuffer.toString())) {
                        return;
                    }
                }
                super.replace(fb, offset, length, text, attrs);
            }
        }

    };

    public IntTextFieldValidator(final JTextComponent comp, int minValue, int maxValue) {
        if (comp == null) {
            throw new IllegalArgumentException("component cannot be NULL");
        }
        this.comp = comp;
        this.checkRange = true;
        this.minValue = minValue;
        this.maxValue = maxValue;
        attachFilter(comp);

    }

    public IntTextFieldValidator(final JTextComponent comp) {
        if (comp == null) {
            throw new IllegalArgumentException("component cannot be NULL");
        }
        this.checkRange = false;
        this.comp = comp;
        this.minValue = 0;
        this.maxValue = 0;
        attachFilter(comp);
    }

    protected void attachFilter(JTextComponent comp) {

        // Casting is bad although seems to be 
        // the 'official way' as it's in the Swing tutorials as well....
        final AbstractDocument doc = (AbstractDocument) comp.getDocument();

        final String val = comp.getText();
        if (!isInteger(val) || !isWithinRange(val)) {
            comp.setText(Integer.toString(minValue));
        }
        doc.setDocumentFilter(filter);
    }

    protected boolean isWithinRange(String s) {
        final int val = Integer.parseInt(s);
        return minValue <= val && val <= maxValue;
    }

    protected static boolean isInteger(String s) {
        if (StringUtils.isBlank(s)) {
            return false;
        }
        for (char c : s.toCharArray()) {
            if (!Character.isDigit(c) && c != '-') {
                return false;
            }
        }
        return true;
    }
}