001 // Copyright 2004, 2005 The Apache Software Foundation
002 //
003 // Licensed under the Apache License, Version 2.0 (the "License");
004 // you may not use this file except in compliance with the License.
005 // You may obtain a copy of the License at
006 //
007 // http://www.apache.org/licenses/LICENSE-2.0
008 //
009 // Unless required by applicable law or agreed to in writing, software
010 // distributed under the License is distributed on an "AS IS" BASIS,
011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012 // See the License for the specific language governing permissions and
013 // limitations under the License.
014
015 package org.apache.tapestry.contrib.table.components;
016
017 import org.apache.tapestry.IAsset;
018 import org.apache.tapestry.IMarkupWriter;
019 import org.apache.tapestry.IRender;
020 import org.apache.tapestry.IRequestCycle;
021 import org.apache.tapestry.contrib.table.model.ITableColumn;
022 import org.apache.tapestry.contrib.table.model.ITableColumnModel;
023
024 import java.util.Iterator;
025
026 /**
027 * A low level Table component that renders the column headers in the table.
028 * This component must be wrapped by
029 * {@link org.apache.tapestry.contrib.table.components.TableView}.
030 * <p>
031 * The component iterates over all column objects in the
032 * {@link org.apache.tapestry.contrib.table.model.ITableColumnModel}and renders
033 * a header for each one of them using the renderer provided by the
034 * getColumnRender() method in
035 * {@link org.apache.tapestry.contrib.table.model.ITableColumn}. The headers
036 * are wrapped in 'th' tags by default.
037 * <p>
038 * Please see the Component Reference for details on how to use this component. [
039 * <a
040 * href="../../../../../../../ComponentReference/contrib.TableColumns.html">Component
041 * Reference </a>]
042 *
043 * @author mindbridge
044 */
045 public abstract class TableColumns extends AbstractTableViewComponent
046 {
047
048 public static final String TABLE_COLUMN_ARROW_UP_ATTRIBUTE = "org.apache.tapestry.contrib.table.components.TableColumns.arrowUp";
049
050 public static final String TABLE_COLUMN_ARROW_DOWN_ATTRIBUTE = "org.apache.tapestry.contrib.table.components.TableColumns.arrowDown";
051
052 public static final String TABLE_COLUMN_CSS_CLASS_SUFFIX = "ColumnHeader";
053
054 // Transient
055 private ITableColumn m_objTableColumn = null;
056
057 public abstract IAsset getArrowDownAsset();
058
059 public abstract IAsset getArrowUpAsset();
060
061 public abstract void setColumn(ITableColumn column);
062
063 /**
064 * Returns the currently rendered table column. You can call this method to
065 * obtain the current column.
066 *
067 * @return ITableColumn the current table column
068 */
069 public ITableColumn getTableColumn()
070 {
071 return m_objTableColumn;
072 }
073
074 /**
075 * Sets the currently rendered table column. This method is for internal use
076 * only.
077 *
078 * @param tableColumn
079 * The current table column
080 */
081 public void setTableColumn(ITableColumn tableColumn)
082 {
083 m_objTableColumn = tableColumn;
084
085 if (isParameterBound("column"))
086 setColumn(tableColumn);
087 }
088
089 /**
090 * Get the list of all table columns to be displayed.
091 *
092 * @return an iterator of all table columns
093 */
094 public Iterator getTableColumnIterator()
095 {
096 ITableColumnModel objColumnModel = getTableModelSource() .getTableModel().getColumnModel();
097
098 return objColumnModel.getColumns();
099 }
100
101 /**
102 * Returns the renderer to be used to generate the header of the current
103 * column.
104 *
105 * @return the header renderer of the current column
106 */
107 public IRender getTableColumnRenderer()
108 {
109 return getTableColumn().getColumnRenderer(getPage().getRequestCycle(), getTableModelSource());
110 }
111
112 public abstract String getColumnClassParameter();
113
114 /**
115 * Returns the CSS class of the generated table cell. It uses the class
116 * parameter if it has been bound, or the default value of "[column
117 * name]ColumnHeader" otherwise.
118 *
119 * @return the CSS class of the cell
120 */
121 public String getColumnClass()
122 {
123 if (isParameterBound("class"))
124 return getColumnClassParameter();
125
126 return getTableColumn().getColumnName() + TABLE_COLUMN_CSS_CLASS_SUFFIX;
127 }
128
129 /**
130 * @see org.apache.tapestry.BaseComponent#renderComponent(IMarkupWriter,
131 * IRequestCycle)
132 */
133 protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
134 {
135 Object oldValueUp = cycle.getAttribute(TABLE_COLUMN_ARROW_UP_ATTRIBUTE);
136 Object oldValueDown = cycle.getAttribute(TABLE_COLUMN_ARROW_DOWN_ATTRIBUTE);
137
138 try
139 {
140 cycle.setAttribute(TABLE_COLUMN_ARROW_UP_ATTRIBUTE, getArrowUpAsset());
141 cycle.setAttribute(TABLE_COLUMN_ARROW_DOWN_ATTRIBUTE, getArrowDownAsset());
142
143 super.renderComponent(writer, cycle);
144 }
145 finally
146 {
147 cycle.setAttribute(TABLE_COLUMN_ARROW_UP_ATTRIBUTE, oldValueUp);
148 cycle.setAttribute(TABLE_COLUMN_ARROW_DOWN_ATTRIBUTE, oldValueDown);
149
150 // set the current column to null when the component is not active
151 m_objTableColumn = null;
152 }
153 }
154
155 }