Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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. */ package com.vaadin.client.widget.grid; import com.google.gwt.dom.client.TableCellElement; import com.vaadin.client.widgets.Grid; /** * A data class which contains information which identifies a cell in a * {@link Grid}. * <p> * Since this class follows the <code>Flyweight</code>-pattern any instance of * this object is subject to change without the user knowing it and so should * not be stored anywhere outside of the method providing these instances. * * @author Vaadin Ltd * @param <T> * the type of the row object containing this cell * @since 7.4 */ public class CellReference<T> { private int columnIndexDOM; private int columnIndex; private Grid.Column<?, T> column; private final RowReference<T> rowReference; public CellReference(RowReference<T> rowReference) { this.rowReference = rowReference; } /** * Sets the identifying information for this cell. * <p> * The difference between {@link #columnIndexDOM} and {@link #columnIndex} * comes from hidden columns. * * @param columnIndexDOM * the index of the column in the DOM * @param columnIndex * the index of the column * @param column * the column object */ public void set(int columnIndexDOM, int columnIndex, Grid.Column<?, T> column) { this.columnIndexDOM = columnIndexDOM; this.columnIndex = columnIndex; this.column = column; } /** * Gets the grid that contains the referenced cell. * * @return the grid that contains referenced cell */ public Grid<T> getGrid() { return rowReference.getGrid(); } /** * Gets the row index of the row. * * @return the index of the row */ public int getRowIndex() { return rowReference.getRowIndex(); } /** * Gets the row data object. * * @return the row object */ public T getRow() { return rowReference.getRow(); } /** * Gets the index of the column. * <p> * <em>NOTE:</em> The index includes hidden columns in the count, unlike * {@link #getColumnIndexDOM()}. * * @return the index of the column */ public int getColumnIndex() { return columnIndex; } /** * Gets the index of the cell in the DOM. The difference to * {@link #getColumnIndex()} is caused by hidden columns. * * @since 7.5.0 * @return the index of the column in the DOM */ public int getColumnIndexDOM() { return columnIndexDOM; } /** * Gets the column objects. * * @return the column object */ public Grid.Column<?, T> getColumn() { return column; } /** * Gets the value of the cell. * * @return the value of the cell */ public Object getValue() { return getColumn().getValue(getRow()); } /** * Get the element of the cell. * * @return the element of the cell */ public TableCellElement getElement() { return rowReference.getElement().getCells().getItem(columnIndexDOM); } /** * Gets the RowReference for this CellReference. * * @return the row reference */ protected RowReference<T> getRowReference() { return rowReference; } }