HintTextField.java

/*
 * #%L
 * =====================================================
 *   _____                _     ____  _   _       _   _
 *  |_   _|_ __ _   _ ___| |_  / __ \| | | | ___ | | | |
 *    | | | '__| | | / __| __|/ / _` | |_| |/ __|| |_| |
 *    | | | |  | |_| \__ \ |_| | (_| |  _  |\__ \|  _  |
 *    |_| |_|   \__,_|___/\__|\ \__,_|_| |_||___/|_| |_|
 *                             \____/
 * 
 * =====================================================
 * 
 * Hochschule Hannover
 * (University of Applied Sciences and Arts, Hannover)
 * Faculty IV, Dept. of Computer Science
 * Ricklinger Stadtweg 118, 30459 Hannover, Germany
 * 
 * Email: trust@f4-i.fh-hannover.de
 * Website: http://trust.f4.hs-hannover.de/
 * 
 * This file is part of visitmeta-visualization, version 0.6.0,
 * implemented by the Trust@HsH research group at the Hochschule Hannover.
 * %%
 * Copyright (C) 2012 - 2016 Trust@HsH
 * %%
 * 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.
 * #L%
 */
package de.hshannover.f4.trust.visitmeta.gui.util;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.text.Format;

import javax.swing.JFormattedTextField;
import javax.swing.plaf.basic.BasicTextFieldUI;
import javax.swing.text.JTextComponent;

public class HintTextField extends JFormattedTextField {

	private static final long serialVersionUID = -3261867067230514829L;

	private String mHint;

	public HintTextField(String hint, Format format) {
		super(format);
		mHint = hint;
		setHint(mHint);
	}

	public void setHint(String hint) {
		setUI(new HintTextFieldUI(hint, true));
	}

	@Override
	public String getText() {
		String typed = super.getText();
		return typed.equals(mHint) ? "" : typed;
	}
}

class HintTextFieldUI extends BasicTextFieldUI implements FocusListener {

	private String mHint;
	private boolean mHideOnFocus;
	private Color mHintColor;

	public HintTextFieldUI(String hint) {
		this(hint, false);
	}

	public HintTextFieldUI(String hint, boolean hideOnFocus) {
		this(hint, hideOnFocus, null);
	}

	public HintTextFieldUI(String hint, boolean hideOnFocus, Color color) {
		mHint = hint;
		mHideOnFocus = hideOnFocus;
		mHintColor = color;
	}

	public Color getColor() {
		return mHintColor;
	}

	public void setColor(Color color) {
		mHintColor = color;
		repaint();
	}

	private void repaint() {
		if (getComponent() != null) {
			getComponent().repaint();
		}
	}

	public boolean isHideOnFocus() {
		return mHideOnFocus;
	}

	public void setHideOnFocus(boolean hideOnFocus) {
		mHideOnFocus = hideOnFocus;
		repaint();
	}

	public String getHint() {
		return mHint;
	}

	public void setHint(String hint) {
		mHint = hint;
		repaint();
	}

	@Override
	protected void paintSafely(Graphics g) {
		super.paintSafely(g);
		JTextComponent comp = getComponent();
		if (mHint != null && comp.getText().length() == 0 && (!(mHideOnFocus && comp.hasFocus()))) {
			if (mHintColor != null) {
				g.setColor(mHintColor);
			} else {
				g.setColor(Color.gray);
			}
			int padding = (comp.getHeight() - comp.getFont().getSize()) / 2;
			g.drawString(mHint, 5, comp.getHeight() - padding - 1);
		}
	}

	@Override
	public void focusGained(FocusEvent e) {
		if (mHideOnFocus) {
			repaint();
		}

	}

	@Override
	public void focusLost(FocusEvent e) {
		if (mHideOnFocus) {
			repaint();
		}
	}

	@Override
	protected void installListeners() {
		super.installListeners();
		getComponent().addFocusListener(this);
	}

	@Override
	protected void uninstallListeners() {
		super.uninstallListeners();
		getComponent().removeFocusListener(this);
	}
}