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package javafx.scene.control;

import java.lang.ref.WeakReference;
import java.util.List;

import javafx.beans.NamedArg;

This class is used to represent a single row/column/cell in a TableView.
This is used throughout the TableView API to represent which rows/columns/cells
are currently selected, focused, being edited, etc. Note that this class is
immutable once it is created.
Because the TableView can have different selection modes, the row and column properties in TablePosition can be 'disabled' to represent an entire row or column. This is done by setting the unrequired property to -1 or null. 
Type parameters:
<S> – The type of the items contained within the TableView (i.e. the same
     generic type as the S in TableView<S>).
<T> – The type of the items contained within the TableColumn.
See Also:
TableView
TableColumn
Since:
JavaFX 2.0/**
 * This class is used to represent a single row/column/cell in a TableView.
 * This is used throughout the TableView API to represent which rows/columns/cells
 * are currently selected, focused, being edited, etc. Note that this class is
 * immutable once it is created.
 *
 * <p>Because the TableView can have different
 * {@link SelectionMode selection modes}, the row and column properties in
 * TablePosition can be 'disabled' to represent an entire row or column. This is
 * done by setting the unrequired property to -1 or null.
 *
 * @param <S> The type of the items contained within the TableView (i.e. the same
 *      generic type as the S in TableView&lt;S&gt;).
 * @param <T> The type of the items contained within the TableColumn.
 * @see TableView
 * @see TableColumn
 * @since JavaFX 2.0
 */
public class TablePosition<S,T> extends TablePositionBase<TableColumn<S,T>> {

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

    
Constructs a TablePosition instance to represent the given row/column
position in the given TableView instance. Both the TableView and
TableColumn are referenced weakly in this class, so it is possible that
they will be null when their respective getters are called.
Params:
tableView – The TableView that this position is related to.
row – The row that this TablePosition is representing.
tableColumn – The TableColumn instance that this TablePosition represents./**
     * Constructs a TablePosition instance to represent the given row/column
     * position in the given TableView instance. Both the TableView and
     * TableColumn are referenced weakly in this class, so it is possible that
     * they will be null when their respective getters are called.
     *
     * @param tableView The TableView that this position is related to.
     * @param row The row that this TablePosition is representing.
     * @param tableColumn The TableColumn instance that this TablePosition represents.
     */
    public TablePosition(@NamedArg("tableView") TableView<S> tableView, @NamedArg("row") int row, @NamedArg("tableColumn") TableColumn<S,T> tableColumn) {
        super(row, tableColumn);
        this.controlRef = new WeakReference<>(tableView);

        List<S> items = tableView.getItems();
        this.itemRef = new WeakReference<>(
                items != null && row >= 0 && row < items.size() ? items.get(row) : null);

        nonFixedColumnIndex = tableView == null || tableColumn == null ? -1 : tableView.getVisibleLeafIndex(tableColumn);
    }



    
                                                                        *
Instance Variables                                                      *
                                                                        *
/***************************************************************************
     *                                                                         *
     * Instance Variables                                                      *
     *                                                                         *
     **************************************************************************/

    private final WeakReference<TableView<S>> controlRef;
    private final WeakReference<S> itemRef;
    int fixedColumnIndex = -1;
    private final int nonFixedColumnIndex;

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

    
The column index that this TablePosition represents in the TableView. It
is -1 if the TableView or TableColumn instances are null at the time the class
is instantiated (i.e. it is computed at construction).
/**
     * The column index that this TablePosition represents in the TableView. It
     * is -1 if the TableView or TableColumn instances are null at the time the class
     * is instantiated (i.e. it is computed at construction).
     */
    @Override public int getColumn() {
        if (fixedColumnIndex > -1) {
            return fixedColumnIndex;
        }

        return nonFixedColumnIndex;
    }

    
The TableView that this TablePosition is related to.
Returns:
the TableView/**
     * The TableView that this TablePosition is related to.
     * @return the TableView
     */
    public final TableView<S> getTableView() {
        return controlRef.get();
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override public final TableColumn<S,T> getTableColumn() {
        // Forcing the return type to be TableColumn<S,T>, not TableColumnBase<S,T>
        return super.getTableColumn();
    }

    
Returns the item that backs the TablePositionBase.getRow() row}, at the point in time when this TablePosition was created. /**
     * Returns the item that backs the {@link #getRow()} row}, at the point
     * in time when this TablePosition was created.
     */
    final S getItem() {
        return itemRef == null ? null : itemRef.get();
    }

    
Returns a string representation of this TablePosition object. 
Returns:
a string representation of this TablePosition object./**
     * Returns a string representation of this {@code TablePosition} object.
     * @return a string representation of this {@code TablePosition} object.
     */
    @Override public String toString() {
        return "TablePosition [ row: " + getRow() + ", column: " + getTableColumn() + ", "
                + "tableView: " + getTableView() + " ]";
    }
}