bundles/org.eclipse.team.cvs.ui/src/org/eclipse/team/internal/ccvs/ui/HistoryTableProvider.java - platform/eclipse.platform.team - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2011 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Olexiy Buyanskyy <olexiyb@gmail.com> - Bug 76386 - [History View] CVS Resource History shows revisions from all branches
  *******************************************************************************/
 package org.eclipse.team.internal.ccvs.ui;

 import java.util.Date;

 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.viewers.*;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.widgets.*;
 import org.eclipse.team.internal.ccvs.core.*;
 import org.eclipse.team.internal.ccvs.core.syncinfo.ResourceSyncInfo;

 import com.ibm.icu.text.DateFormat;

 /**
  * This class provides the table and it's required components for a file's revision
  * history
  */
 public class HistoryTableProvider {

 	private ICVSFile currentFile;
 	private String currentRevision;
 	private TableViewer viewer;
 	private Font currentRevisionFont;

 	/**
 	 * Constructor for HistoryTableProvider.
 	 */
 	public HistoryTableProvider() {
 		super();
 	}

 	//column constants
 	private static final int COL_REVISION = 0;
 	private static final int COL_BRANCHES = 1;
 	private static final int COL_TAGS = 2;
 	private static final int COL_DATE = 3;
 	private static final int COL_AUTHOR = 4;
 	private static final int COL_COMMENT = 5;

 	/**
 	 * The history label provider.
 	 */
 	class HistoryLabelProvider extends LabelProvider implements ITableLabelProvider, IColorProvider, IFontProvider {
 		private DateFormat dateFormat;
 		@Override
 		public Image getColumnImage(Object element, int columnIndex) {
 			return null;
 		}
 		@Override
 		public String getColumnText(Object element, int columnIndex) {
 			ILogEntry entry = adaptToLogEntry(element);
 			if (entry == null) return ""; //$NON-NLS-1$
 			switch (columnIndex) {
 				case COL_REVISION:
 					String revision = entry.getRevision();
 					String currentRevision = getCurrentRevision();
 					if (currentRevision != null && currentRevision.equals(revision)) {
 						revision = NLS.bind(CVSUIMessages.currentRevision, new String[] { revision });
 					}
 					return revision;
 				case COL_BRANCHES:
 					CVSTag[] branches = entry.getBranches();
 					StringBuffer result = new StringBuffer();
 					for (int i = 0; i < branches.length; i++) {
 						result.append(branches[i].getName());
 						if (i < branches.length - 1) {
 							result.append(", "); //$NON-NLS-1$
 						}
 					}
 					return result.toString();
 				case COL_TAGS:
 					CVSTag[] tags = entry.getTags();
 					result = new StringBuffer();
 					for (int i = 0; i < tags.length; i++) {
 						result.append(tags[i].getName());
 						if (i < tags.length - 1) {
 							result.append(", "); //$NON-NLS-1$
 						}
 					}
 					return result.toString();
 				case COL_DATE:
 					Date date = entry.getDate();
 					if (date == null) return CVSUIMessages.notAvailable;
 					return getDateFormat().format(date);
 				case COL_AUTHOR:
 					return entry.getAuthor();
 				case COL_COMMENT:
 					String comment = entry.getComment();
 					int index = comment.indexOf("\n"); //$NON-NLS-1$
 					switch (index) {
 						case -1:
 							return comment;
 						case 0:
 							return CVSUIMessages.HistoryView_______4;
 						default:
 							return NLS.bind(CVSUIMessages.CVSCompareRevisionsInput_truncate, new String[] { comment.substring(0, index) });
 					}
 			}
 			return ""; //$NON-NLS-1$
 		}

 		private synchronized DateFormat getDateFormat() {
 			if (dateFormat == null)
 				dateFormat = DateFormat.getInstance();
 			return dateFormat;
 		}

 		@Override
 		public Color getForeground(Object element) {
 			ILogEntry entry = adaptToLogEntry(element);
 			if (entry.isDeletion())  {
 				return Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW);
 			} else  {
 				return null;
 			}
 		}

 		@Override
 		public Color getBackground(Object element) {
 			return null;
 		}

 		@Override
 		public Font getFont(Object element) {
 			ILogEntry entry = adaptToLogEntry(element);
 			if (entry == null)
 				return null;
 			String revision = entry.getRevision();
 			String currentRevision = getCurrentRevision();
 			if (currentRevision != null && currentRevision.equals(revision)) {
 				if (currentRevisionFont == null) {
 					Font defaultFont = JFaceResources.getDefaultFont();
 					FontData[] data = defaultFont.getFontData();
 					for (int i = 0; i < data.length; i++) {
 						data[i].setStyle(SWT.BOLD);
 					}
 					currentRevisionFont = new Font(viewer.getTable().getDisplay(), data);
 				}
 				return currentRevisionFont;
 			}
 			return null;
 		}
 	}

 	/**
 	 * The history sorter
 	 */
 	class HistoryComparator extends ViewerComparator {
 		private boolean reversed = false;
 		private int columnNumber;

 		private VersionCollator versionCollator = new VersionCollator();

 		// column headings:	"Revision" "Branches" "Tags" "Date" "Author" "Comment"
 		private int[][] SORT_ORDERS_BY_COLUMN = {
 			{COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_TAGS, COL_BRANCHES},	/* revision */
 			{COL_BRANCHES, COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_TAGS},	/* tags */
 			{COL_TAGS, COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_BRANCHES},	/* tags */
 			{COL_DATE, COL_REVISION, COL_AUTHOR, COL_COMMENT, COL_TAGS, COL_BRANCHES},	/* date */
 			{COL_AUTHOR, COL_REVISION, COL_DATE, COL_COMMENT, COL_TAGS, COL_BRANCHES},	/* author */
 			{COL_COMMENT, COL_REVISION, COL_DATE, COL_AUTHOR, COL_TAGS, COL_BRANCHES}		/* comment */
 		};

 		/**
 		 * The constructor.
 		 */
 		public HistoryComparator(int columnNumber) {
 			this.columnNumber = columnNumber;
 		}
 		/**
 		 * Compares two log entries, sorting first by the main column of this sorter,
 		 * then by subsequent columns, depending on the column sort order.
 		 */
 		@Override
 		public int compare(Viewer viewer, Object o1, Object o2) {
 			ILogEntry e1 = adaptToLogEntry(o1);
 			ILogEntry e2 = adaptToLogEntry(o2);
 			int result = 0;
 			if (e1 == null || e2 == null) {
 				result = super.compare(viewer, o1, o2);
 			} else {
 				int[] columnSortOrder = SORT_ORDERS_BY_COLUMN[columnNumber];
 				for (int i = 0; i < columnSortOrder.length; ++i) {
 					result = compareColumnValue(columnSortOrder[i], e1, e2);
 					if (result != 0)
 						break;
 				}
 			}
 			if (reversed)
 				result = -result;
 			return result;
 		}
 		/**
 		 * Compares two markers, based only on the value of the specified column.
 		 */
 		int compareColumnValue(int columnNumber, ILogEntry e1, ILogEntry e2) {
 			switch (columnNumber) {
 				case COL_REVISION: /* revision */
 					return versionCollator.compare(e1.getRevision(), e2.getRevision());
 				case COL_BRANCHES: /* branches */
 					CVSTag[] branches1 = e1.getBranches();
 					CVSTag[] branches2 = e2.getBranches();
 					if (branches2.length == 0) {
 						return -1;
 					}
 					if (branches1.length == 0) {
 						return 1;
 					}
 					return getComparator().compare(branches1[0].getName(), branches2[0].getName());
 				case COL_TAGS: /* tags */
 					CVSTag[] tags1 = e1.getTags();
 					CVSTag[] tags2 = e2.getTags();
 					if (tags2.length == 0) {
 						return -1;
 					}
 					if (tags1.length == 0) {
 						return 1;
 					}
 					return getComparator().compare(tags1[0].getName(), tags2[0].getName());
 				case COL_DATE: /* date */
 					Date date1 = e1.getDate();
 					Date date2 = e2.getDate();
 					return date1.compareTo(date2);
 				case COL_AUTHOR: /* author */
 					return getComparator().compare(e1.getAuthor(), e2.getAuthor());
 				case COL_COMMENT: /* comment */
 					return getComparator().compare(e1.getComment(), e2.getComment());
 				default:
 					return 0;
 			}
 		}
 		/**
 		 * Returns the number of the column by which this is sorting.
 		 */
 		public int getColumnNumber() {
 			return columnNumber;
 		}
 		/**
 		 * Returns true for descending, or false
 		 * for ascending sorting order.
 		 */
 		public boolean isReversed() {
 			return reversed;
 		}
 		/**
 		 * Sets the sorting order.
 		 */
 		public void setReversed(boolean newReversed) {
 			reversed = newReversed;
 		}
 	}

 	protected ILogEntry adaptToLogEntry(Object element) {
 		// Get the log entry for the provided object
 		ILogEntry entry = null;
 		if (element instanceof ILogEntry) {
 			entry = (ILogEntry) element;
 		} else if (element instanceof IAdaptable) {
 			entry = ((IAdaptable)element).getAdapter(ILogEntry.class);
 		}
 		return entry;
 	}

 	/**
 	 * Create a TableViewer that can be used to display a list of ILogEntry instances.
 	 * Ths method provides the labels and sorter but does not provide a content provider
 	 *
 	 * @param parent
 	 * @return TableViewer
 	 */
 	public TableViewer createTable(Composite parent) {
 		Table table = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL | SWT.MULTI | SWT.FULL_SELECTION);
 		table.setHeaderVisible(true);
 		table.setLinesVisible(true);
 		GridData data = new GridData(GridData.FILL_BOTH);
 		table.setLayoutData(data);

 		TableLayout layout = new TableLayout();
 		table.setLayout(layout);

 		TableViewer viewer = new TableViewer(table);

 		createColumns(table, layout, viewer);

 		viewer.setLabelProvider(new HistoryLabelProvider());

 		// By default, reverse sort by revision.
 		HistoryComparator sorter = new HistoryComparator(COL_REVISION);
 		sorter.setReversed(true);
 		viewer.setComparator(sorter);

 		table.addDisposeListener(e -> {
 			if (currentRevisionFont != null) {
 				currentRevisionFont.dispose();
 			}
 		});

 		this.viewer = viewer;
 		return viewer;
 	}

 	/**
 	 * Create a CheckBoxTableViewer that can be used to display a list of ILogEntry instances.
 	 * Ths method provides the labels and sorter but does not provide a content provider
 	 *
 	 * @param parent
 	 * @return TableViewer
 	 */
 	public CheckboxTableViewer createCheckBoxTable(Composite parent) {
 		Table table = new Table(parent, SWT.CHECK | SWT.H_SCROLL | SWT.V_SCROLL | SWT.FULL_SELECTION);
 		table.setHeaderVisible(true);
 		table.setLinesVisible(true);
 		GridData data = new GridData(GridData.FILL_BOTH);
 		table.setLayoutData(data);

 		TableLayout layout = new TableLayout();
 		table.setLayout(layout);

 		CheckboxTableViewer viewer = new CheckboxTableViewer(table);

 		createColumns(table, layout, viewer);

 		viewer.setLabelProvider(new HistoryLabelProvider());

 		// By default, reverse sort by revision.
 		HistoryComparator sorter = new HistoryComparator(COL_REVISION);
 		sorter.setReversed(true);
 		viewer.setComparator(sorter);

 		table.addDisposeListener(e -> {
 			if (currentRevisionFont != null) {
 				currentRevisionFont.dispose();
 			}
 		});

 		this.viewer = viewer;
 		return viewer;
 	}

 	/**
 	 * Creates the columns for the history table.
 	 */
 	private void createColumns(Table table, TableLayout layout, TableViewer viewer) {
 		SelectionListener headerListener = getColumnListener(viewer);
 		// revision
 		TableColumn col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_revision);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(20, true));

 		// branches
 		col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_branches);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(20, true));

 		// tags
 		col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_tags);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(20, true));

 		// creation date
 		col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_date);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(20, true));

 		// author
 		col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_author);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(20, true));

 		//comment
 		col = new TableColumn(table, SWT.NONE);
 		col.setResizable(true);
 		col.setText(CVSUIMessages.HistoryView_comment);
 		col.addSelectionListener(headerListener);
 		layout.addColumnData(new ColumnWeightData(50, true));
 	}

 	/**
 	 * Adds the listener that sets the sorter.
 	 */
 	private SelectionListener getColumnListener(final TableViewer tableViewer) {
 		/**
 		 * This class handles selections of the column headers.
 		 * Selection of the column header will cause resorting
 		 * of the shown tasks using that column's sorter.
 		 * Repeated selection of the header will toggle
 		 * sorting order (ascending versus descending).
 		 */
 		return new SelectionAdapter() {
 			/**
 			 * Handles the case of user selecting the
 			 * header area.
 			 * <p>If the column has not been selected previously,
 			 * it will set the sorter of that column to be
 			 * the current tasklist sorter. Repeated
 			 * presses on the same column header will
 			 * toggle sorting order (ascending/descending).
 			 */
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				// column selected - need to sort
 				int column = tableViewer.getTable().indexOf((TableColumn) e.widget);
 				HistoryComparator oldSorter = (HistoryComparator)tableViewer.getComparator();
 				if (oldSorter != null && column == oldSorter.getColumnNumber()) {
 					oldSorter.setReversed(!oldSorter.isReversed());
 					tableViewer.refresh();
 				} else {
 					tableViewer.setComparator(new HistoryComparator(column));
 				}
 			}
 		};
 	}

 	public String getCurrentRevision() {
 		return currentRevision;
 	}

 	/**
 	 * Method getRevision.
 	 * @param currentEdition
 	 */
 	private String getRevision(ICVSFile currentEdition) throws CVSException {
 		if (currentEdition == null) return ""; //$NON-NLS-1$
 		ResourceSyncInfo info = currentEdition.getSyncInfo();
 		if (info == null) return ""; //$NON-NLS-1$
 		return info.getRevision();
 	}

 	public void setFile(ICVSFile file) throws CVSException {
 		this.currentFile = file;
 		this.currentRevision = getRevision(this.currentFile);
 	}

 	public ICVSFile getICVSFile() {
 		return this.currentFile;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2011 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Olexiy Buyanskyy <olexiyb@gmail.com> - Bug 76386 - [History View] CVS Resource History shows revisions from all branches
	*******************************************************************************/
	package org.eclipse.team.internal.ccvs.ui;

	import java.util.Date;

	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.viewers.*;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.*;
	import org.eclipse.swt.graphics.*;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.widgets.*;
	import org.eclipse.team.internal.ccvs.core.*;
	import org.eclipse.team.internal.ccvs.core.syncinfo.ResourceSyncInfo;

	import com.ibm.icu.text.DateFormat;

	/**
	* This class provides the table and it's required components for a file's revision
	* history
	*/
	public class HistoryTableProvider {

	private ICVSFile currentFile;
	private String currentRevision;
	private TableViewer viewer;
	private Font currentRevisionFont;

	/**
	* Constructor for HistoryTableProvider.
	*/
	public HistoryTableProvider() {
	super();
	}

	//column constants
	private static final int COL_REVISION = 0;
	private static final int COL_BRANCHES = 1;
	private static final int COL_TAGS = 2;
	private static final int COL_DATE = 3;
	private static final int COL_AUTHOR = 4;
	private static final int COL_COMMENT = 5;

	/**
	* The history label provider.
	*/
	class HistoryLabelProvider extends LabelProvider implements ITableLabelProvider, IColorProvider, IFontProvider {
	private DateFormat dateFormat;
	@Override
	public Image getColumnImage(Object element, int columnIndex) {
	return null;
	}
	@Override
	public String getColumnText(Object element, int columnIndex) {
	ILogEntry entry = adaptToLogEntry(element);
	if (entry == null) return ""; //$NON-NLS-1$
	switch (columnIndex) {
	case COL_REVISION:
	String revision = entry.getRevision();
	String currentRevision = getCurrentRevision();
	if (currentRevision != null && currentRevision.equals(revision)) {
	revision = NLS.bind(CVSUIMessages.currentRevision, new String[] { revision });
	}
	return revision;
	case COL_BRANCHES:
	CVSTag[] branches = entry.getBranches();
	StringBuffer result = new StringBuffer();
	for (int i = 0; i < branches.length; i++) {
	result.append(branches[i].getName());
	if (i < branches.length - 1) {
	result.append(", "); //$NON-NLS-1$
	}
	}
	return result.toString();
	case COL_TAGS:
	CVSTag[] tags = entry.getTags();
	result = new StringBuffer();
	for (int i = 0; i < tags.length; i++) {
	result.append(tags[i].getName());
	if (i < tags.length - 1) {
	result.append(", "); //$NON-NLS-1$
	}
	}
	return result.toString();
	case COL_DATE:
	Date date = entry.getDate();
	if (date == null) return CVSUIMessages.notAvailable;
	return getDateFormat().format(date);
	case COL_AUTHOR:
	return entry.getAuthor();
	case COL_COMMENT:
	String comment = entry.getComment();
	int index = comment.indexOf("\n"); //$NON-NLS-1$
	switch (index) {
	case -1:
	return comment;
	case 0:
	return CVSUIMessages.HistoryView_______4;
	default:
	return NLS.bind(CVSUIMessages.CVSCompareRevisionsInput_truncate, new String[] { comment.substring(0, index) });
	}
	}
	return ""; //$NON-NLS-1$
	}

	private synchronized DateFormat getDateFormat() {
	if (dateFormat == null)
	dateFormat = DateFormat.getInstance();
	return dateFormat;
	}

	@Override
	public Color getForeground(Object element) {
	ILogEntry entry = adaptToLogEntry(element);
	if (entry.isDeletion()) {
	return Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW);
	} else {
	return null;
	}
	}

	@Override
	public Color getBackground(Object element) {
	return null;
	}

	@Override
	public Font getFont(Object element) {
	ILogEntry entry = adaptToLogEntry(element);
	if (entry == null)
	return null;
	String revision = entry.getRevision();
	String currentRevision = getCurrentRevision();
	if (currentRevision != null && currentRevision.equals(revision)) {
	if (currentRevisionFont == null) {
	Font defaultFont = JFaceResources.getDefaultFont();
	FontData[] data = defaultFont.getFontData();
	for (int i = 0; i < data.length; i++) {
	data[i].setStyle(SWT.BOLD);
	}
	currentRevisionFont = new Font(viewer.getTable().getDisplay(), data);
	}
	return currentRevisionFont;
	}
	return null;
	}
	}

	/**
	* The history sorter
	*/
	class HistoryComparator extends ViewerComparator {
	private boolean reversed = false;
	private int columnNumber;

	private VersionCollator versionCollator = new VersionCollator();

	// column headings: "Revision" "Branches" "Tags" "Date" "Author" "Comment"
	private int[][] SORT_ORDERS_BY_COLUMN = {
	{COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_TAGS, COL_BRANCHES}, /* revision */
	{COL_BRANCHES, COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_TAGS}, /* tags */
	{COL_TAGS, COL_REVISION, COL_DATE, COL_AUTHOR, COL_COMMENT, COL_BRANCHES}, /* tags */
	{COL_DATE, COL_REVISION, COL_AUTHOR, COL_COMMENT, COL_TAGS, COL_BRANCHES}, /* date */
	{COL_AUTHOR, COL_REVISION, COL_DATE, COL_COMMENT, COL_TAGS, COL_BRANCHES}, /* author */
	{COL_COMMENT, COL_REVISION, COL_DATE, COL_AUTHOR, COL_TAGS, COL_BRANCHES} /* comment */
	};

	/**
	* The constructor.
	*/
	public HistoryComparator(int columnNumber) {
	this.columnNumber = columnNumber;
	}
	/**
	* Compares two log entries, sorting first by the main column of this sorter,
	* then by subsequent columns, depending on the column sort order.
	*/
	@Override
	public int compare(Viewer viewer, Object o1, Object o2) {
	ILogEntry e1 = adaptToLogEntry(o1);
	ILogEntry e2 = adaptToLogEntry(o2);
	int result = 0;
	if (e1 == null \|\| e2 == null) {
	result = super.compare(viewer, o1, o2);
	} else {
	int[] columnSortOrder = SORT_ORDERS_BY_COLUMN[columnNumber];
	for (int i = 0; i < columnSortOrder.length; ++i) {
	result = compareColumnValue(columnSortOrder[i], e1, e2);
	if (result != 0)
	break;
	}
	}
	if (reversed)
	result = -result;
	return result;
	}
	/**
	* Compares two markers, based only on the value of the specified column.
	*/
	int compareColumnValue(int columnNumber, ILogEntry e1, ILogEntry e2) {
	switch (columnNumber) {
	case COL_REVISION: /* revision */
	return versionCollator.compare(e1.getRevision(), e2.getRevision());
	case COL_BRANCHES: /* branches */
	CVSTag[] branches1 = e1.getBranches();
	CVSTag[] branches2 = e2.getBranches();
	if (branches2.length == 0) {
	return -1;
	}
	if (branches1.length == 0) {
	return 1;
	}
	return getComparator().compare(branches1[0].getName(), branches2[0].getName());
	case COL_TAGS: /* tags */
	CVSTag[] tags1 = e1.getTags();
	CVSTag[] tags2 = e2.getTags();
	if (tags2.length == 0) {
	return -1;
	}
	if (tags1.length == 0) {
	return 1;
	}
	return getComparator().compare(tags1[0].getName(), tags2[0].getName());
	case COL_DATE: /* date */
	Date date1 = e1.getDate();
	Date date2 = e2.getDate();
	return date1.compareTo(date2);
	case COL_AUTHOR: /* author */
	return getComparator().compare(e1.getAuthor(), e2.getAuthor());
	case COL_COMMENT: /* comment */
	return getComparator().compare(e1.getComment(), e2.getComment());
	default:
	return 0;
	}
	}
	/**
	* Returns the number of the column by which this is sorting.
	*/
	public int getColumnNumber() {
	return columnNumber;
	}
	/**
	* Returns true for descending, or false
	* for ascending sorting order.
	*/
	public boolean isReversed() {
	return reversed;
	}
	/**
	* Sets the sorting order.
	*/
	public void setReversed(boolean newReversed) {
	reversed = newReversed;
	}
	}

	protected ILogEntry adaptToLogEntry(Object element) {
	// Get the log entry for the provided object
	ILogEntry entry = null;
	if (element instanceof ILogEntry) {
	entry = (ILogEntry) element;
	} else if (element instanceof IAdaptable) {
	entry = ((IAdaptable)element).getAdapter(ILogEntry.class);
	}
	return entry;
	}

	/**
	* Create a TableViewer that can be used to display a list of ILogEntry instances.
	* Ths method provides the labels and sorter but does not provide a content provider
	*
	* @param parent
	* @return TableViewer
	*/
	public TableViewer createTable(Composite parent) {
	Table table = new Table(parent, SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.MULTI \| SWT.FULL_SELECTION);
	table.setHeaderVisible(true);
	table.setLinesVisible(true);
	GridData data = new GridData(GridData.FILL_BOTH);
	table.setLayoutData(data);

	TableLayout layout = new TableLayout();
	table.setLayout(layout);

	TableViewer viewer = new TableViewer(table);

	createColumns(table, layout, viewer);

	viewer.setLabelProvider(new HistoryLabelProvider());

	// By default, reverse sort by revision.
	HistoryComparator sorter = new HistoryComparator(COL_REVISION);
	sorter.setReversed(true);
	viewer.setComparator(sorter);

	table.addDisposeListener(e -> {
	if (currentRevisionFont != null) {
	currentRevisionFont.dispose();
	}
	});

	this.viewer = viewer;
	return viewer;
	}

	/**
	* Create a CheckBoxTableViewer that can be used to display a list of ILogEntry instances.
	* Ths method provides the labels and sorter but does not provide a content provider
	*
	* @param parent
	* @return TableViewer
	*/
	public CheckboxTableViewer createCheckBoxTable(Composite parent) {
	Table table = new Table(parent, SWT.CHECK \| SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.FULL_SELECTION);
	table.setHeaderVisible(true);
	table.setLinesVisible(true);
	GridData data = new GridData(GridData.FILL_BOTH);
	table.setLayoutData(data);

	TableLayout layout = new TableLayout();
	table.setLayout(layout);

	CheckboxTableViewer viewer = new CheckboxTableViewer(table);

	createColumns(table, layout, viewer);

	viewer.setLabelProvider(new HistoryLabelProvider());

	// By default, reverse sort by revision.
	HistoryComparator sorter = new HistoryComparator(COL_REVISION);
	sorter.setReversed(true);
	viewer.setComparator(sorter);

	table.addDisposeListener(e -> {
	if (currentRevisionFont != null) {
	currentRevisionFont.dispose();
	}
	});

	this.viewer = viewer;
	return viewer;
	}

	/**
	* Creates the columns for the history table.
	*/
	private void createColumns(Table table, TableLayout layout, TableViewer viewer) {
	SelectionListener headerListener = getColumnListener(viewer);
	// revision
	TableColumn col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_revision);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(20, true));

	// branches
	col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_branches);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(20, true));

	// tags
	col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_tags);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(20, true));

	// creation date
	col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_date);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(20, true));

	// author
	col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_author);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(20, true));

	//comment
	col = new TableColumn(table, SWT.NONE);
	col.setResizable(true);
	col.setText(CVSUIMessages.HistoryView_comment);
	col.addSelectionListener(headerListener);
	layout.addColumnData(new ColumnWeightData(50, true));
	}

	/**
	* Adds the listener that sets the sorter.
	*/
	private SelectionListener getColumnListener(final TableViewer tableViewer) {
	/**
	* This class handles selections of the column headers.
	* Selection of the column header will cause resorting
	* of the shown tasks using that column's sorter.
	* Repeated selection of the header will toggle
	* sorting order (ascending versus descending).
	*/
	return new SelectionAdapter() {
	/**
	* Handles the case of user selecting the
	* header area.
	* <p>If the column has not been selected previously,
	* it will set the sorter of that column to be
	* the current tasklist sorter. Repeated
	* presses on the same column header will
	* toggle sorting order (ascending/descending).
	*/
	@Override
	public void widgetSelected(SelectionEvent e) {
	// column selected - need to sort
	int column = tableViewer.getTable().indexOf((TableColumn) e.widget);
	HistoryComparator oldSorter = (HistoryComparator)tableViewer.getComparator();
	if (oldSorter != null && column == oldSorter.getColumnNumber()) {
	oldSorter.setReversed(!oldSorter.isReversed());
	tableViewer.refresh();
	} else {
	tableViewer.setComparator(new HistoryComparator(column));
	}
	}
	};
	}

	public String getCurrentRevision() {
	return currentRevision;
	}

	/**
	* Method getRevision.
	* @param currentEdition
	*/
	private String getRevision(ICVSFile currentEdition) throws CVSException {
	if (currentEdition == null) return ""; //$NON-NLS-1$
	ResourceSyncInfo info = currentEdition.getSyncInfo();
	if (info == null) return ""; //$NON-NLS-1$
	return info.getRevision();
	}

	public void setFile(ICVSFile file) throws CVSException {
	this.currentFile = file;
	this.currentRevision = getRevision(this.currentFile);
	}

	public ICVSFile getICVSFile() {
	return this.currentFile;
	}
	}