/*
* This file is part of the aidGer project.
*
* Copyright (C) 2010-2013 The aidGer Team
*
* 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 de.aidger.view.utils;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.ComboBoxEditor;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
import javax.swing.text.PlainDocument;
/*
* This class is used for auto complete combo boxes.
*
*/
@SuppressWarnings("serial")
public class AutoCompletion extends PlainDocument {
JComboBox comboBox;
ComboBoxModel model;
JTextComponent editor;
// flag to indicate if setSelectedItem has been called
// subsequent calls to remove/insertString should be ignored
boolean selecting = false;
boolean hidePopupOnFocusLoss;
boolean hitBackspace = false;
boolean hitBackspaceOnSelection;
KeyListener editorKeyListener;
FocusListener editorFocusListener;
public AutoCompletion(final JComboBox comboBox) {
this.comboBox = comboBox;
model = comboBox.getModel();
comboBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (!selecting) {
highlightCompletedText(0);
}
}
});
comboBox.addPropertyChangeListener(new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
if (e.getPropertyName().equals("editor")) {
configureEditor((ComboBoxEditor) e.getNewValue());
}
if (e.getPropertyName().equals("model")) {
model = (ComboBoxModel) e.getNewValue();
}
}
});
editorKeyListener = new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
if (comboBox.isDisplayable()) {
comboBox.setPopupVisible(true);
}
hitBackspace = false;
switch (e.getKeyCode()) {
// determine if the pressed key is backspace (needed by the
// remove method)
case KeyEvent.VK_BACK_SPACE:
hitBackspace = true;
hitBackspaceOnSelection = editor.getSelectionStart() != editor
.getSelectionEnd();
break;
// ignore delete key
case KeyEvent.VK_DELETE:
e.consume();
comboBox.getToolkit().beep();
break;
}
}
};
// Bug 5100422 on Java 1.5: Editable JComboBox won't hide popup when
// tabbing out
hidePopupOnFocusLoss = System.getProperty("java.version").startsWith(
"1.5");
// Highlight whole text when gaining focus
editorFocusListener = new FocusAdapter() {
@Override
public void focusGained(FocusEvent e) {
highlightCompletedText(0);
}
@Override
public void focusLost(FocusEvent e) {
// Workaround for Bug 5100422 - Hide Popup on focus loss
if (hidePopupOnFocusLoss) {
comboBox.setPopupVisible(false);
}
}
};
configureEditor(comboBox.getEditor());
// Handle initially selected object
Object selected = comboBox.getSelectedItem();
if (selected != null) {
setText(selected.toString());
}
highlightCompletedText(0);
}
public static void enable(JComboBox comboBox) {
// has to be editable
comboBox.setEditable(true);
// change the editor's document
new AutoCompletion(comboBox);
}
void configureEditor(ComboBoxEditor newEditor) {
if (editor != null) {
editor.removeKeyListener(editorKeyListener);
editor.removeFocusListener(editorFocusListener);
}
if (newEditor != null) {
editor = (JTextComponent) newEditor.getEditorComponent();
editor.addKeyListener(editorKeyListener);
editor.addFocusListener(editorFocusListener);
editor.setDocument(this);
}
}
@Override
public void remove(int offs, int len) throws BadLocationException {
// return immediately when selecting an item
if (selecting) {
return;
}
if (hitBackspace) {
// user hit backspace => move the selection backwards
// old item keeps being selected
if (offs > 0) {
if (hitBackspaceOnSelection) {
offs--;
}
} else {
// User hit backspace with the cursor positioned on the start =>
// beep
comboBox.getToolkit().beep(); // when available use:
// UIManager.getLookAndFeel().provideErrorFeedback(comboBox);
}
highlightCompletedText(offs);
} else {
super.remove(offs, len);
}
}
@Override
public void insertString(int offs, String str, AttributeSet a)
throws BadLocationException {
// return immediately when selecting an item
if (selecting) {
return;
}
// insert the string into the document
super.insertString(offs, str, a);
// lookup and select a matching item
Object item = lookupItem(getText(0, getLength()));
if (item != null) {
setSelectedItem(item);
} else {
// keep old item selected if there is no match
item = comboBox.getSelectedItem();
// imitate no insert (later on offs will be incremented by
// str.length(): selection won't move forward)
offs = offs - str.length();
// provide feedback to the user that his input has been received but
// can not be accepted
comboBox.getToolkit().beep(); // when available use:
// UIManager.getLookAndFeel().provideErrorFeedback(comboBox);
}
setText(item.toString());
// select the completed part
highlightCompletedText(offs + str.length());
}
private void setText(String text) {
try {
// remove all text and insert the completed string
super.remove(0, getLength());
super.insertString(0, text, null);
} catch (BadLocationException e) {
throw new RuntimeException(e.toString());
}
}
private void highlightCompletedText(int start) {
editor.setCaretPosition(getLength());
editor.moveCaretPosition(start);
}
private void setSelectedItem(Object item) {
selecting = true;
model.setSelectedItem(item);
selecting = false;
}
private Object lookupItem(String pattern) {
Object selectedItem = model.getSelectedItem();
// only search for a different item if the currently selected does not
// match
if (selectedItem != null
&& startsWithIgnoreCase(selectedItem.toString(), pattern)) {
return selectedItem;
} else {
// iterate over all items
for (int i = 0, n = model.getSize(); i < n; i++) {
Object currentItem = model.getElementAt(i);
// current item starts with the pattern?
if (currentItem != null
&& startsWithIgnoreCase(currentItem.toString(), pattern)) {
return currentItem;
}
}
}
return null;
}
// checks if str1 starts with str2 - ignores case
private boolean startsWithIgnoreCase(String str1, String str2) {
return str1.toUpperCase().startsWith(str2.toUpperCase());
}
}