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 * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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 */

package javafx.scene.control.cell;

import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.scene.control.Label;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.control.TextField;
import javafx.util.Callback;
import javafx.util.StringConverter;
import javafx.util.converter.DefaultStringConverter;

/**
 * A class containing a {@link ListCell} implementation that draws a
 * {@link TextField} node inside the cell.
 *
 * <p>By default, the TextFieldListCell is rendered as a {@link Label} when not
 * being edited, and as a TextField when in editing mode. The TextField will, by
 * default, stretch to fill the entire list cell.
 *
 * @param <T> The type of the elements contained within the ListView.
 * @since JavaFX 2.2
 */
public class TextFieldListCell<T> extends ListCell<T> {

    /***************************************************************************
     *                                                                         *
     * Static cell factories                                                   *
     *                                                                         *
     **************************************************************************/

    /**
     * Provides a {@link TextField} that allows editing of the cell content when
     * the cell is double-clicked, or when {@link ListView#edit(int)} is called.
     * This method will only work on {@link ListView} instances which are of
     * type String.
     *
     * @return A {@link Callback} that can be inserted into the
     *      {@link ListView#cellFactoryProperty() cell factory property} of a
     *      ListView, that enables textual editing of the content.
     */
    public static Callback<ListView<String>, ListCell<String>> forListView() {
        return forListView(new DefaultStringConverter());
    }

    /**
     * Provides a {@link TextField} that allows editing of the cell content when
     * the cell is double-clicked, or when {@link ListView#edit(int)} is called.
     * This method will work on any ListView instance, regardless of its generic
     * type. However, to enable this, a {@link StringConverter} must be provided
     * that will convert the given String (from what the user typed in) into an
     * instance of type T. This item will then be passed along to the
     * {@link ListView#onEditCommitProperty()} callback.
     *
     * @param converter A {@link StringConverter} that can convert the given String
     *      (from what the user typed in) into an instance of type T.
     * @return A {@link Callback} that can be inserted into the
     *      {@link ListView#cellFactoryProperty() cell factory property} of a
     *      ListView, that enables textual editing of the content.
     */
    public static <T> Callback<ListView<T>, ListCell<T>> forListView(final StringConverter<T> converter) {
        return list -> new TextFieldListCell<T>(converter);
    }



    /***************************************************************************
     *                                                                         *
     * Fields                                                                  *
     *                                                                         *
     **************************************************************************/
    private TextField textField;



    /***************************************************************************
     *                                                                         *
     * Constructors                                                            *
     *                                                                         *
     **************************************************************************/

    /**
     * Creates a default TextFieldListCell with a null converter. Without a
     * {@link StringConverter} specified, this cell will not be able to accept
     * input from the TextField (as it will not know how to convert this back
     * to the domain object). It is therefore strongly encouraged to not use
     * this constructor unless you intend to set the converter separately.
     */
    public TextFieldListCell() {
        this(null);
    }

    /**
     * Creates a TextFieldListCell that provides a {@link TextField} when put
     * into editing mode that allows editing of the cell content. This method
     * will work on any ListView instance, regardless of its generic type.
     * However, to enable this, a {@link StringConverter} must be provided that
     * will convert the given String (from what the user typed in) into an
     * instance of type T. This item will then be passed along to the
     * {@link ListView#onEditCommitProperty()} callback.
     *
     * @param converter A {@link StringConverter converter} that can convert
     *      the given String (from what the user typed in) into an instance of
     *      type T.
     */
    public TextFieldListCell(StringConverter<T> converter) {
        this.getStyleClass().add("text-field-list-cell");
        setConverter(converter);
    }



    /***************************************************************************
     *                                                                         *
     * Properties                                                              *
     *                                                                         *
     **************************************************************************/

    // --- converter
    private ObjectProperty<StringConverter<T>> converter =
            new SimpleObjectProperty<StringConverter<T>>(this, "converter");

    /**
     * The {@link StringConverter} property.
     */
    public final ObjectProperty<StringConverter<T>> converterProperty() {
        return converter;
    }

    /**
     * Sets the {@link StringConverter} to be used in this cell.
     */
    public final void setConverter(StringConverter<T> value) {
        converterProperty().set(value);
    }

    /**
     * Returns the {@link StringConverter} used in this cell.
     */
    public final StringConverter<T> getConverter() {
        return converterProperty().get();
    }


    /***************************************************************************
     *                                                                         *
     * Public API                                                              *
     *                                                                         *
     **************************************************************************/

    /** {@inheritDoc} */
    @Override public void startEdit() {
        if (! isEditable() || ! getListView().isEditable()) {
            return;
        }
        super.startEdit();

        if (isEditing()) {
            if (textField == null) {
                textField = CellUtils.createTextField(this, getConverter());
            }

            CellUtils.startEdit(this, getConverter(), null, null, textField);
        }
    }

    /** {@inheritDoc} */
    @Override public void cancelEdit() {
        super.cancelEdit();
        CellUtils.cancelEdit(this, getConverter(), null);
    }

    /** {@inheritDoc} */
    @Override public void updateItem(T item, boolean empty) {
        super.updateItem(item, empty);
        CellUtils.updateItem(this, getConverter(), null, null, textField);
    }
}