be.ac.ua.comp.scarletnebula.gui.BetterTextField.java Source code

Introduction

Here is the source code for be.ac.ua.comp.scarletnebula.gui.BetterTextField.java

Source

/*
 * Copyright (C) 2011  Ives van der Flaas
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package be.ac.ua.comp.scarletnebula.gui;

import java.awt.Color;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.JTextField;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import be.ac.ua.comp.scarletnebula.misc.Colors;

/**
 * A derivative of a JTextField that provides extra functionality such as easy
 * placeholders.
 * 
 * @author ives
 */
public class BetterTextField extends JTextField {
    private static final long serialVersionUID = 1L;
    private boolean originalPlaceholderText = true;
    private boolean placeholderDisplayed = false;
    private static Log log = LogFactory.getLog(BetterTextField.class);

    /**
     * @see JTextField
     */
    public BetterTextField(final int columns) {
        super(columns);
    }

    /**
     * @see JTextField
     */
    public BetterTextField() {
        super();
    }

    /**
     * Enables the JTextField to have a placeholder and sets the initial text to
     * placeholder. Call this somewhere before showing the textfield.
     * 
     * Concretly this placeholder will take the shape of gray text that will
     * appear when the field contains no text and is not focussed and that will
     * disappear when the field receives focus.
     * 
     * @param placeholder
     */
    public void setPlaceHolder(final String placeholder) {
        setText(placeholder);
        final Color originalTextColor = getForeground();
        setForeground(Colors.Gray.color());
        placeholderDisplayed = true;

        addFocusListener(new FocusListener() {
            @Override
            public void focusLost(final FocusEvent e) {
                if (getText().length() == 0) {
                    setForeground(Colors.Gray.alpha(1.0f));
                    setText(placeholder);
                    placeholderDisplayed = true;
                    originalPlaceholderText = true;
                }
            }

            @Override
            public void focusGained(final FocusEvent e) {
                log.info("Focus gained");
                if (originalPlaceholderText) {
                    log.info("Original text");
                    originalPlaceholderText = false;
                    setForeground(originalTextColor);
                    setText("");
                    placeholderDisplayed = false;
                }
            }
        });
    }

    /**
     * @return The field's content if there is any, the empty string if the
     *         BetterTextField has a placeholder displayed.
     */
    @Override
    public String getText() {
        String result = null;

        if (placeholderDisplayed) {
            result = "";
        } else {
            result = super.getText();
        }

        return result;
    }
}