extract tableHeader from PreventDraggingJTableHeader.java

src/main/java/net/sf/jabref/gui/maintable/MainTableHeaderRenderer.java

@@ -0,0 +1,50 @@
+/*  Copyright (C) 2016 JabRef contributors.
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+package net.sf.jabref.gui.maintable;
+
+import javax.swing.*;
+import javax.swing.table.TableCellRenderer;
+import java.awt.*;
+
+public class MainTableHeaderRenderer implements TableCellRenderer {
+
+    private final TableCellRenderer delegate;
+
+    public MainTableHeaderRenderer(TableCellRenderer delegate) {
+        this.delegate = delegate;
+    }
+
+    @Override
+    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
+            boolean hasFocus, int row, int column) {
+        // delegate to previously used TableCellRenderer which styles the component
+        Component resultFromDelegate = delegate.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
+
+        // Changing style is only possible if both value and resultFromDelegate are JLabels
+        if ((value instanceof JLabel) && (resultFromDelegate instanceof JLabel)) {
+            String text = ((JLabel) value).getText();
+            Icon icon = ((JLabel) value).getIcon();
+            if (icon == null) {
+                ((JLabel) resultFromDelegate).setText(text);
+            } else {
+                ((JLabel) resultFromDelegate).setIcon(icon);
+                ((JLabel) resultFromDelegate).setText(null);
+            }
+        }
+
+        return resultFromDelegate;
+    }
+}

src/main/java/net/sf/jabref/gui/maintable/PreventDraggingJTableHeader.java

@@ -1,4 +1,4 @@
-/*  Copyright (C) 2003-2015 JabRef contributors.
+/*  Copyright (C) 2003-2016 JabRef contributors.
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
@@ -17,9 +17,7 @@
 
 import javax.swing.*;
 import javax.swing.table.JTableHeader;
-import javax.swing.table.TableCellRenderer;
 import javax.swing.table.TableColumn;
-import java.awt.*;
 import java.awt.event.MouseEvent;
 import java.util.Collections;
 import java.util.Enumeration;
@@ -36,25 +34,21 @@
  * @author Fabian Bieker
  * @since 12/2008
  */
-class PreventDraggingJTableHeader extends JTableHeader implements TableCellRenderer {
+class PreventDraggingJTableHeader extends JTableHeader {
 
     private final MainTableFormat tableFormat;
 
-    private final TableCellRenderer delegate;
-
     public PreventDraggingJTableHeader(JTable table, MainTableFormat tableFormat) {
         super(table.getColumnModel());
         this.setTable(table);
         this.tableFormat = tableFormat;
-        this.delegate = table.getTableHeader().getDefaultRenderer();
         setupTableHeaderIcons();
     }
 
     private void setupTableHeaderIcons() {
 
         Enumeration<TableColumn> columns = columnModel.getColumns();
         for (TableColumn column : Collections.list(columns)) {
-            column.setHeaderRenderer(this);
             MainTableColumn mainTableColumn = tableFormat.getTableColumn(column.getModelIndex());
             column.setHeaderValue(mainTableColumn.getHeaderLabel());
         }
@@ -76,16 +70,15 @@ public String getToolTipText(MouseEvent event) {
     public void setDraggedColumn(TableColumn column) {
 
         if ((column != null) && (column.getModelIndex() == 0)) {
-                return;
+            return;
         }
         super.setDraggedColumn(column);
     }
 
     /**
      * Overridden to prevent dragging of an other column before the first column ("#").
      */
-    @Override
-    public TableColumn getDraggedColumn() {
+    @Override public TableColumn getDraggedColumn() {
         TableColumn column = super.getDraggedColumn();
         if (column != null) {
             PreventDraggingJTableHeader.preventDragBeforeNumberColumn(this.getTable(), column.getModelIndex());
@@ -94,28 +87,6 @@ public TableColumn getDraggedColumn() {
         return column;
     }
 
-    @Override
-    public Component getTableCellRendererComponent(JTable table, Object value,
-            boolean isSelected, boolean hasFocus, int row, int column) {
-
-        // delegate to previously used TableCellRenderer which styles the component
-        Component resultFromDelegate = delegate.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
-
-        // Changing style is only possible if both value and resultFromDelegate are JLabels
-        if ((value instanceof JLabel) && (resultFromDelegate instanceof JLabel)) {
-            String text = ((JLabel) value).getText();
-            Icon icon = ((JLabel) value).getIcon();
-            if (icon == null) {
-                ((JLabel) resultFromDelegate).setText(text);
-            } else {
-                ((JLabel) resultFromDelegate).setIcon(icon);
-                ((JLabel) resultFromDelegate).setText(null);
-            }
-        }
-
-        return resultFromDelegate;
-    }
-
     /**
      * Transform model index <code>modelIndex</code> to a view based index and
      * prevent dragging before model index <code>toIndex</code> (inclusive).