001: /*
002: * ============================================================================
003: * GNU Lesser General Public License
004: * ============================================================================
005: *
006: * JasperReports - Free Java report-generating library.
007: * Copyright (C) 2001-2006 JasperSoft Corporation http://www.jaspersoft.com
008: *
009: * This library is free software; you can redistribute it and/or
010: * modify it under the terms of the GNU Lesser General Public
011: * License as published by the Free Software Foundation; either
012: * version 2.1 of the License, or (at your option) any later version.
013: *
014: * This library 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 GNU
017: * Lesser General Public License for more details.
018: *
019: * You should have received a copy of the GNU Lesser General Public
020: * License along with this library; if not, write to the Free Software
021: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
022: *
023: * JasperSoft Corporation
024: * 303 Second Street, Suite 450 North
025: * San Francisco, CA 94107
026: * http://www.jaspersoft.com
027: */
028: package net.sf.jasperreports.crosstabs;
029:
030: import net.sf.jasperreports.engine.JRVariable;
031:
032: /**
033: * Base interface for crosstab row and column groups.
034: *
035: * @author Lucian Chirita (lucianc@users.sourceforge.net)
036: * @version $Id: JRCrosstabGroup.java 1229 2006-04-19 10:27:35Z teodord $
037: */
038: public interface JRCrosstabGroup {
039: /**
040: * Returns the name of the group.
041: *
042: * @return the name of the group
043: * @see #getVariable()
044: */
045: public String getName();
046:
047: /**
048: * Returns the position of the total row/column for this group.
049: * <p>
050: * A group can have a total row/column summing the values for all the
051: * entries in the group. E.g. if there is a Year group having Month as
052: * a subgroup, the total row/column for the Year group would sum the values
053: * for all the years and the total row/column for the Month group would sum
054: * the values for all the months of an year.
055: * <p>
056: * Possible values for this attribute are:
057: * <ul>
058: * <li>{@link net.sf.jasperreports.crosstabs.fill.calculation.BucketDefinition#TOTAL_POSITION_NONE Bucket.TOTAL_POSITION_NONE}
059: * - the group will not display a total row/column</li>
060: * <li>{@link net.sf.jasperreports.crosstabs.fill.calculation.BucketDefinition#TOTAL_POSITION_START Bucket.TOTAL_POSITION_START}
061: * - the group will display the total row/column before the group rows/columns</li>
062: * <li>{@link net.sf.jasperreports.crosstabs.fill.calculation.BucketDefinition#TOTAL_POSITION_END Bucket.TOTAL_POSITION_END}
063: * - the group will display the total row/column at the end of the group rows/columns</li>
064: *
065: * @return the position of the total row/column for this group
066: */
067: public byte getTotalPosition();
068:
069: /**
070: * Returns the bucketing information for this group.
071: * <p>
072: * The bucketing information consists of grouping expression and
073: * group ordering.
074: *
075: * @return the bucketing information for this group
076: */
077: public JRCrosstabBucket getBucket();
078:
079: /**
080: * Returns the group header cell.
081: * <p>
082: * The size of the header cell is computed based on the following rules
083: * (only the row header rules are listed, the ones for columns can be
084: * deducted by simmetrical duality):
085: * <ul>
086: * <li>the width of the header is given by {@link JRCrosstabRowGroup#getWidth() JRCrosstabRowGroup.getWidth()}</li>
087: * <li>the height of the last row group header is given by the height of the base cell</li>
088: * <li>the height of a non-last row group header is the sum of the next group header's height and
089: * the next group total header's height (0 if the next group doesn't have a total header)</li>
090: * </ul>
091: * <p>
092: * Should never return null, but empty cell contents instead.
093: *
094: * @return the group header cell
095: */
096: public JRCellContents getHeader();
097:
098: /**
099: * Returns the group total header cell.
100: * <p>
101: * The size of a row group total header is computed based on the following rules:
102: * <ul>
103: * <li>the width is the sum the widths of this and subsequent row groups</li>
104: * <li>the height is the height of the base cell for this total row</li>
105: * </ul>
106: * <p>
107: * Should never return null, but empty cell contents instead.
108: *
109: * @return the group total header cell
110: */
111: public JRCellContents getTotalHeader();
112:
113: /**
114: * Returns the variable associated to this group.
115: * <p>
116: * Each group in the crosstab has a variable that can be used
117: * inside the group header as the current group value.
118: * The variable has the same name as the group and the same type
119: * as the bucket expression of the group.
120: *
121: * @return the variable associated to this group
122: */
123: public JRVariable getVariable();
124:
125: /**
126: * Returns whether the group has a total row/column.
127: * <p>
128: * This method is currently equivalent to
129: * <code>getTotalPosition() != Bucket.TOTAL_POSITION_NONE</code> and is therefore
130: * redundant.
131: *
132: * @return whether the group has a total row/column
133: */
134: public boolean hasTotal();
135: }
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