    001/* ===========================================================
    002 * Orson Charts : a 3D chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
    006 *
    007 * http://www.object-refinery.com/orsoncharts/index.html
    008 *
    009 * This program is free software: you can redistribute it and/or modify
    010 * it under the terms of the GNU General Public License as published by
    011 * the Free Software Foundation, either version 3 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This program is distributed in the hope that it will be useful,
    015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
    016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    017 * GNU General Public License for more details.
    018 *
    019 * You should have received a copy of the GNU General Public License
    020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    021 *
    022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    023 * Other names may be trademarks of their respective owners.]
    024 *
    025 * If you do not wish to be bound by the terms of the GPL, an alternative
    026 * commercial license can be purchased.  For details, please see visit the
    027 * Orson Charts home page:
    028 *
    029 * http://www.object-refinery.com/orsoncharts/index.html
    030 *
    031 */
    032
    033package com.orsoncharts.table;
    034
    035import java.awt.Graphics2D;
    036import java.awt.geom.Dimension2D;
    037import java.awt.geom.Rectangle2D;
    038import java.util.List;
    039import java.util.Map;
    040import com.orsoncharts.util.RefPt2D;
    041
    042/**
    043 * An element (typically a single cell) in a table.  This interface defines
    044 * methods for determining the preferred size of the element, for laying out
    045 * the element (including sub-elements if there are any), and drawing the
    046 * element within specified bounds.  Various kinds of table elements will be
    047 * used to construct interesting tables.
    048 * <br><br>
    049 * It is important that these methods are implemented in a stateless manner.
    050 * There is some redundancy in calculation between the layout and drawing
    051 * methods in order to preserve the statelessness, but it is important to
    052 * ensure that table elements can be rendered to multiple targets
    053 * simultaneously.
    054 *
    055 */
    056public interface TableElement {
    057
    058    /**
    059     * A property key for the class of a table element.
    060     *
    061     * @since 1.3
    062     */
    063    final String CLASS = "class";
    064
    065    /**
    066     * Calculates the preferred size for the element, with reference to the
    067     * specified bounds.  The preferred size can exceed the bounds, but the
    068     * bounds might influence how sub-elements are sized and/or positioned.
    069     * For example, in a {@link FlowElement}, the width of the bounds will
    070     * determine when the flow layout wraps.
    071     *
    072     * @param g2  the graphics target ({@code null} not permitted).
    073     * @param bounds  the bounds ({@code null} not permitted).
    074     *
    075     * @return The preferred size (never {@code null}).
    076     */
    077    Dimension2D preferredSize(Graphics2D g2, Rectangle2D bounds);
    078
    079    /**
    080     * Returns the preferred size of the element, subject to the supplied
    081     * constraints.
    082     *
    083     * @param g2  the graphics target ({@code null} not permitted).
    084     * @param bounds  the bounds ({@code null} not permitted).
    085     * @param constraints  the constraints ({@code null} permitted).
    086     *
    087     * @return The preferred size.
    088     */
    089    Dimension2D preferredSize(Graphics2D g2, Rectangle2D bounds,
    090            Map<String, Object> constraints);
    091
    092    /**
    093     * Returns the reference point used to align the element with the bounding
    094     * rectangle within which it is drawn.
    095     *
    096     * @return The anchor point (never {@code null}).
    097     */
    098    RefPt2D getRefPoint();
    099
    100    /**
    101     * Performs a layout of this table element, returning a list of bounding
    102     * rectangles for the element and its subelements.  This method is
    103     * typically called by the {@link #draw(java.awt.Graphics2D,
    104     * java.awt.geom.Rectangle2D)} method.
    105     *
    106     * @param g2  the graphics target ({@code null} not permitted).
    107     * @param bounds  the bounds ({@code null} not permitted).
    108     * @param constraints  the constraints (if any).
    109     *
    110     * @return A list of bounding rectangles.
    111     */
    112    List<Rectangle2D> layoutElements(Graphics2D g2, Rectangle2D bounds,
    113            Map<String, Object> constraints);
    114
    115    /**
    116     * Draws the element within the specified bounds.
    117     *
    118     * @param g2  the graphics target ({@code null} not permitted).
    119     * @param bounds  the bounds ({@code null} not permitted).
    120     */
    121    void draw(Graphics2D g2, Rectangle2D bounds);
    122
    123    /**
    124     * Draws the element within the specified bounds.  The
    125     * {@code onDrawHandler} provides (optional) access to all elements
    126     * before and after they are rendered.
    127     *
    128     * @param g2  the graphics target ({@code null} not permitted).
    129     * @param bounds  the bounds ({@code null} not permitted).
    130     * @param onDrawHandler  an object that will receive notification before
    131     *     and after the element is drawn ({@code null} permitted).
    132     *
    133     * @since 1.3
    134     */
    135    void draw(Graphics2D g2, Rectangle2D bounds,
    136            TableElementOnDraw onDrawHandler);
    137
    138    /**
    139     * Returns the value of the property with the specified key, or
    140     * {@code null}.
    141     *
    142     * @param key  the key ({@code null} not permitted).
    143     *
    144     * @return The property value or {@code null}.
    145     *
    146     * @since 1.3
    147     */
    148    Object getProperty(String key);
    149
    150    /**
    151     * Sets the value of the property with the specified key.
    152     *
    153     * @param key  the key ({@code null} not permitted).
    154     * @param value  the value ({@code null} permitted).
    155     *
    156     * @since 1.3
    157     */
    158    void setProperty(String key, Object value);
    159
    160    /**
    161     * Receives a {@link TableElementVisitor}.  The visitor will have its
    162     * {@code visit(TableElement)} method called for each child element
    163     * of this table element (if it has children) and then for this element.
    164     *
    165     * @param visitor  the visitor ({@code null} not permitted).
    166     *
    167     * @since 1.2
    168     */
    169    void receive(TableElementVisitor visitor);
    170
    171}