source: josm/trunk/src/org/openstreetmap/josm/gui/tagging/AutoCompletingTextField.java@ 2048

// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.gui.tagging;

import java.awt.Component;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.logging.Logger;

import javax.swing.ComboBoxEditor;
import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.PlainDocument;

import org.openstreetmap.josm.gui.tagging.ac.AutoCompletionList;

/**
 * AutoCompletingTextField is an text field with autocompletion behaviour. It
 * can be used as table cell editor in {@see JTable}s.
 * 
 * Autocompletion is controlled by a list of {@see AutoCompletionListItem}s
 * managed in a {@see AutoCompletionList}.
 * 
 *
 */
public class AutoCompletingTextField extends JTextField implements ComboBoxEditor {

    static private Logger logger = Logger.getLogger(AutoCompletingTextField.class.getName());

    /**
     * The document model for the editor
     */
    class AutoCompletionDocument extends PlainDocument {

        /**
         * inserts a string at a specific position
         * 
         */
        @Override
        public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {
            if (autoCompletionList == null) {
                super.insertString(offs, str, a);
                return;
            }

            // if the current offset isn't at the end of the document we don't autocomplete.
            // If a highlighted autocompleted suffix was present and we get here Swing has
            // already removed it from the document. getLength() therefore doesn't include the
            // autocompleted suffix.
            //
            if (offs < getLength()) {
                super.insertString(offs, str, a);
                return;
            }

            String currentText = getText(0, getLength());
            // if the text starts with a number we don't autocomplete
            //
            try {
                Long.parseLong(str);
                if (currentText.length() == 0) {
                    // we don't autocomplete on numbers
                    super.insertString(offs, str, a);
                    return;
                }
                Long.parseLong(currentText);
                super.insertString(offs, str, a);
                return;
            } catch(NumberFormatException e) {
                // either the new text or the current text isn't a number. We continue with
                // autocompletion
            }
            String prefix = currentText.substring(0, offs);
            autoCompletionList.applyFilter(prefix+str);
            if (autoCompletionList.getFilteredSize()>0) {
                // there are matches. Insert the new text and highlight the
                // auto completed suffix
                //
                String matchingString = autoCompletionList.getFilteredItem(0).getValue();
                remove(0,getLength());
                super.insertString(0,matchingString,a);

                // highlight from end to insert position
                //
                setCaretPosition(getLength());
                moveCaretPosition(offs + str.length());
            } else {
                // there are no matches. Insert the new text, do not highlight
                //
                String newText = prefix + str;
                remove(0,getLength());
                super.insertString(0,newText,a);
                setCaretPosition(getLength());

            }
        }
    }

    /** the auto completion list user input is matched against */
    protected AutoCompletionList autoCompletionList = null;

    /**
     * creates the default document model for this editor
     * 
     */
    @Override
    protected Document createDefaultModel() {
        return new AutoCompletionDocument();
    }

    protected void init() {
        addFocusListener(
                new FocusAdapter() {
                    @Override public void focusGained(FocusEvent e) {
                        selectAll();
                        applyFilter(getText());
                    }
                }
        );

        addKeyListener(
                new KeyAdapter() {

                    @Override
                    public void keyReleased(KeyEvent e) {
                        if (getText().equals("")) {
                            applyFilter("");
                        }
                    }
                }
        );
    }

    /**
     * constructor
     */
    public AutoCompletingTextField() {
        init();
    }

    public AutoCompletingTextField(int columns) {
        super(columns);
        init();
    }

    protected void applyFilter(String filter) {
        if (autoCompletionList != null) {
            autoCompletionList.applyFilter(filter);
        }
    }

    /**
     * 
     * @return the auto completion list; may be null, if no auto completion list is set
     */
    public AutoCompletionList getAutoCompletionList() {
        return autoCompletionList;
    }

    /**
     * sets the auto completion list
     * @param autoCompletionList the auto completion list; if null, auto completion is
     *   disabled
     */
    public void setAutoCompletionList(AutoCompletionList autoCompletionList) {
        this.autoCompletionList = autoCompletionList;
    }

    public Component getEditorComponent() {
        return this;
    }

    public Object getItem() {
        return getText();
    }

    public void setItem(Object anObject) {
        if (anObject == null) {
            setText("");
        } else {
            setText(anObject.toString());
        }

    }


}