/*******************************************************************************
 * Copyright (c) 2000, 2018 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
 *     Jacek Pospychala <jacek.pospychala@pl.ibm.com> - bugs 202583, 207466, 207344
 *     Remy Chi Jian Suen <remy.suen@gmail.com> - bug 272985
 *     Arnaud Mergey - <a_mergey@yahoo.fr>
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 485843
 *******************************************************************************/
package org.eclipse.ui.internal.views.log;

import com.ibm.icu.text.DateFormat;
import java.io.*;
import java.text.Collator;
import java.util.*;
import java.util.List;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.jface.dialogs.*;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.viewers.*;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.accessibility.AccessibleAdapter;
import org.eclipse.swt.accessibility.AccessibleEvent;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.*;

/**
 * Displays details about Log Entry. Event information is split in three
 * sections: details, stack trace and session. Details contain event date,
 * message and severity. Stack trace is displayed if an exception is bound to
 * event. Stack trace entries can be filtered.
 */
public class EventDetailsDialog extends TrayDialog {

	public static final String FILTER_ENABLED = "detailsStackFilterEnabled"; //$NON-NLS-1$
	public static final String FILTER_LIST = "detailsStackFilterList"; //$NON-NLS-1$

	private LogView logView;
	private IMemento memento;

	private AbstractEntry entry;
	private AbstractEntry parentEntry; // parent of the entry
	private AbstractEntry[] entryChildren; // children of the entry

	private LogViewLabelProvider labelProvider;
	private TreeViewer provider;

	private static int COPY_ID = 22;

	private int childIndex = 0;
	private boolean isOpen;
	private boolean isLastChild;
	private boolean isAtEndOfLog;

	private Label plugInIdLabel;
	private Label severityImageLabel;
	private Label severityLabel;
	private Label dateLabel;
	private Text msgText;
	private Text stackTraceText;
	private Text sessionDataText;
	// private Clipboard clipboard;
	private Button copyButton;
	private Button backButton;
	private Button nextButton;
	private SashForm sashForm;

	// sorting
	private Comparator comparator = null;
	Collator collator;

	// patterns for filtering stack traces
	private String[] stackFilterPatterns = null;

	// location configuration
	private Point dialogLocation;
	private Point dialogSize;
	private int[] sashWeights;

	private DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT);

	/**
	 *
	 * @param parentShell
	 *            shell in which dialog is displayed
	 * @param selection
	 *            entry initially selected and to be displayed
	 * @param provider
	 *            viewer
	 * @param comparator
	 *            comparator used to order all entries
	 */
	protected EventDetailsDialog(Shell parentShell, LogView logView, IAdaptable selection, ISelectionProvider provider,
			Comparator comparator, IMemento memento) {
		super(parentShell);
		this.logView = logView;
		this.provider = (TreeViewer) provider;
		labelProvider = (LogViewLabelProvider) this.provider.getLabelProvider();
		labelProvider.connect(this);
		this.entry = (AbstractEntry) selection;
		this.comparator = comparator;
		this.memento = memento;
		setShellStyle(SWT.MODELESS | SWT.MIN | SWT.MAX | SWT.RESIZE | SWT.CLOSE | SWT.BORDER | SWT.TITLE);
		// clipboard = new Clipboard(parentShell.getDisplay());
		initialize();
		collator = Collator.getInstance();
		readConfiguration();
		isLastChild = false;
		isAtEndOfLog = false;
		stackFilterPatterns = getFilters();
	}

	@Override
	protected void configureShell(Shell newShell) {
		super.configureShell(newShell);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(newShell, IHelpContextIds.LOG_EVENTDETAILS);
	}

	private void initialize() {
		parentEntry = (AbstractEntry) entry.getParent(entry);
		if (isChild(entry)) {
			setEntryChildren(parentEntry);
		} else {
			setEntryChildren();
		}
		resetChildIndex();
		isLastChild = false;
		isAtEndOfLog = false;
	}

	private void resetChildIndex() {
		if (entryChildren == null)
			return;

		LogEntry thisEntry = (LogEntry) entry;

		for (int i = 0; i < entryChildren.length; i++) {
			if (entryChildren[i] instanceof LogEntry) {

				LogEntry logEntry = (LogEntry) entryChildren[i];

				if (logEntry == thisEntry) {
					childIndex = i;
					return;
				}
			}
		}

		childIndex = 0;
	}

	private boolean isChild(AbstractEntry entry) {
		return entry.getParent(entry) != null;
	}

	public boolean isOpen() {
		return isOpen;
	}

	@Override
	public int open() {
		isOpen = true;
		if (sashWeights == null) {
			int a, b, c;
			int height = getSashForm().getClientArea().height;
			if (height < 250) {
				a = b = c = height / 3;
			} else {
				a = 100; // Details section needs about 100
				c = 100; // Text area gets 100
				b = height - a - c; // Stack trace should take up majority of room
			}
			sashWeights = new int[] { a, b, c };
		}
		getSashForm().setWeights(sashWeights);
		return super.open();
	}

	@Override
	public boolean close() {
		// if (clipboard != null) {
		// clipboard.dispose();
		// clipboard = null;
		// }
		storeSettings();
		isOpen = false;
		labelProvider.disconnect(this);
		return super.close();
	}

	@Override
	public void create() {
		super.create();

		// dialog location
		if (dialogLocation != null)
			getShell().setLocation(dialogLocation);

		// dialog size
		if (dialogSize != null)
			getShell().setSize(dialogSize);
		else
			getShell().setSize(500, 550);

		applyDialogFont(buttonBar);
		getButton(IDialogConstants.OK_ID).setFocus();
	}

	@Override
	protected void buttonPressed(int buttonId) {
		if (IDialogConstants.OK_ID == buttonId)
			okPressed();
		else if (IDialogConstants.CANCEL_ID == buttonId)
			cancelPressed();
		else if (IDialogConstants.BACK_ID == buttonId)
			backPressed();
		else if (IDialogConstants.NEXT_ID == buttonId)
			nextPressed();
		else if (COPY_ID == buttonId)
			copyPressed();
	}

	protected void backPressed() {
		if (childIndex > 0) {
			if (isLastChild && (isChild(entry))) {
				setEntryChildren(parentEntry);
				isLastChild = false;
			}
			childIndex--;
			entry = entryChildren[childIndex];
		} else {
			if (parentEntry instanceof LogEntry) {
				entry = parentEntry;
				if (isChild(entry)) {
					setEntryChildren((AbstractEntry) entry.getParent(entry));
				} else {
					setEntryChildren();
				}
				resetChildIndex();
			}
		}
		setEntrySelectionInTable();
	}

	protected void nextPressed() {
		if (childIndex < entryChildren.length - 1) {
			childIndex++;
			entry = entryChildren[childIndex];
			isLastChild = childIndex == entryChildren.length - 1;
		} else if (isChild(entry) && isLastChild && !isAtEndOfLog) {
			findNextSelectedChild(entry);
		} else { // at end of list but can branch into child elements - bug 58083
			setEntryChildren(entry);
			isAtEndOfLog = entryChildren.length == 0;
			isLastChild = entryChildren.length == 0;
			if (entryChildren.length > 0) {
				entry = entryChildren[0];
			}
		}
		setEntrySelectionInTable();
	}

	protected void copyPressed() {
		try (StringWriter writer = new StringWriter(); PrintWriter pwriter = new PrintWriter(writer)) {
			entry.write(pwriter);
			pwriter.flush();
			String textVersion = writer.toString();
			// set the clipboard contents
			// clipboard.setContents(new Object[] { textVersion }, new
			// Transfer[] { TextTransfer.getInstance() });
		} catch (IOException e) {
			// do nothing
		}
	}

	public void setComparator(Comparator comparator) {
		this.comparator = comparator;
		updateProperties();
	}

	private void setComparator(byte sortType, final int sortOrder) {
		if (sortType == LogView.DATE) {
			comparator = (e1, e2) -> {
				Date date1 = ((LogEntry) e1).getDate();
				Date date2 = ((LogEntry) e2).getDate();
				if (sortOrder == LogView.ASCENDING)
					return date1.getTime() < date2.getTime() ? LogView.DESCENDING : LogView.ASCENDING;
				return date1.getTime() > date2.getTime() ? LogView.DESCENDING : LogView.ASCENDING;
			};
		} else if (sortType == LogView.PLUGIN) {
			comparator = (e1, e2) -> {
				LogEntry entry1 = (LogEntry) e1;
				LogEntry entry2 = (LogEntry) e2;
				return collator.compare(entry1.getPluginId(), entry2.getPluginId()) * sortOrder;
			};
		} else {
			comparator = (e1, e2) -> {
				LogEntry entry1 = (LogEntry) e1;
				LogEntry entry2 = (LogEntry) e2;
				return collator.compare(entry1.getMessage(), entry2.getMessage()) * sortOrder;
			};
		}
	}

	public void resetSelection(IAdaptable selectedEntry, byte sortType, int sortOrder) {
		setComparator(sortType, sortOrder);
		resetSelection(selectedEntry);
	}

	public void resetSelection(IAdaptable selectedEntry) {
		if (entry.equals(selectedEntry)) {
			updateProperties();
			return;
		}
		if (selectedEntry instanceof AbstractEntry) {
			entry = (AbstractEntry) selectedEntry;
			initialize();
			updateProperties();
		}
	}

	public void resetButtons() {
		backButton.setEnabled(false);
		nextButton.setEnabled(false);
	}

	private void setEntrySelectionInTable() {
		ISelection selection = new StructuredSelection(entry);
		provider.setSelection(selection);
	}

	public void updateProperties() {
		if (isChild(entry)) {
			parentEntry = (AbstractEntry) entry.getParent(entry);
			setEntryChildren(parentEntry);
			resetChildIndex();
			if (childIndex == entryChildren.length - 1)
				isLastChild = true;
		}

		if (entry instanceof LogEntry) {
			LogEntry logEntry = (LogEntry) entry;

			String strDate = dateFormat.format(logEntry.getDate());
			dateLabel.setText(strDate);
			plugInIdLabel.setText(logEntry.getPluginId());
			severityImageLabel.setImage(labelProvider.getColumnImage(entry, 0));
			severityLabel.setText(logEntry.getSeverityText());
			msgText.setText(logEntry.getMessage() != null ? logEntry.getMessage() : ""); //$NON-NLS-1$
			String stack = logEntry.getStack();

			if (stack != null) {
				stack = filterStack(stack);
				stackTraceText.setText(stack);
			} else {
				stackTraceText.setText(Messages.get().EventDetailsDialog_noStack);
			}

			if (logEntry.getSession() != null) {
				String session = logEntry.getSession().getSessionData();
				if (session != null) {
					sessionDataText.setText(session);
				}
			}

		} else {
			dateLabel.setText(""); //$NON-NLS-1$
			severityImageLabel.setImage(null);
			severityLabel.setText(""); //$NON-NLS-1$
			msgText.setText(""); //$NON-NLS-1$
			stackTraceText.setText(""); //$NON-NLS-1$
			sessionDataText.setText(""); //$NON-NLS-1$
		}

		updateButtons();
	}

	private void updateButtons() {
		boolean isAtEnd = childIndex == entryChildren.length - 1;
		if (isChild(entry)) {
			boolean canGoToParent = (entry.getParent(entry) instanceof LogEntry);
			backButton.setEnabled((childIndex > 0) || canGoToParent);
			nextButton.setEnabled(nextChildExists(entry, parentEntry, entryChildren) || entry.hasChildren()
					|| !isLastChild || !isAtEnd);
		} else {
			backButton.setEnabled(childIndex != 0);
			nextButton.setEnabled(!isAtEnd || entry.hasChildren());
		}
	}

	private void findNextSelectedChild(AbstractEntry originalEntry) {
		if (isChild(parentEntry)) {
			// we're at the end of the child list; find next parent
			// to select. If the parent is a child at the end of the child
			// list, find its next parent entry to select, etc.

			entry = parentEntry;
			setEntryChildren((AbstractEntry) parentEntry.getParent(parentEntry));
			parentEntry = (AbstractEntry) parentEntry.getParent(parentEntry);
			resetChildIndex();
			isLastChild = childIndex == entryChildren.length - 1;
			if (isLastChild) {
				findNextSelectedChild(originalEntry);
			} else {
				nextPressed();
			}
		} else if (parentEntry instanceof LogEntry) {
			entry = parentEntry;
			setEntryChildren();
			resetChildIndex();
			isLastChild = childIndex == entryChildren.length - 1;
			if (isLastChild) {
				if (isChild(entry)) {
					findNextSelectedChild(originalEntry);
				} else {
					entry = originalEntry;
					isAtEndOfLog = true;
					nextPressed();
				}
			} else {
				nextPressed();
			}
		} else {
			entry = originalEntry;
			isAtEndOfLog = true;
			nextPressed();
		}
	}

	private boolean nextChildExists(AbstractEntry originalEntry, AbstractEntry originalParent,
			AbstractEntry[] originalEntries) {
		if (isChild(parentEntry)) {
			// we're at the end of the child list; find next parent
			// to select. If the parent is a child at the end of the child
			// list, find its next parent entry to select, etc.

			entry = parentEntry;
			parentEntry = (AbstractEntry) entry.getParent(entry);
			setEntryChildren(parentEntry);
			resetChildIndex();
			if (childIndex == entryChildren.length - 1) {
				return nextChildExists(originalEntry, originalParent, originalEntries);
			}
			entry = originalEntry;
			parentEntry = originalParent;
			entryChildren = originalEntries;
			resetChildIndex();
			return true;
		} else if (parentEntry instanceof LogEntry) {
			entry = parentEntry;
			setEntryChildren();
			childIndex = -1;
			resetChildIndex();
			if ((childIndex != -1) && (childIndex < entryChildren.length - 1)) {
				entry = originalEntry;
				parentEntry = originalParent;
				entryChildren = originalEntries;
				resetChildIndex();
				return true;
			}
		}
		entry = originalEntry;
		parentEntry = originalParent;
		entryChildren = originalEntries;
		resetChildIndex();
		return false;

	}

	/**
	 * Sets entry children (Prev-Next navigable) to top-level elements
	 */
	private void setEntryChildren() {
		AbstractEntry[] children = getElements();

		if (comparator != null)
			Arrays.sort(children, comparator);
		entryChildren = new AbstractEntry[children.length];

		System.arraycopy(children, 0, entryChildren, 0, children.length);
	}

	/**
	 * Sets entry children (Prev-Next navigable) to children of given entry
	 */
	private void setEntryChildren(AbstractEntry entry) {
		Object[] children = entry.getChildren(entry);

		if (comparator != null)
			Arrays.sort(children, comparator);

		List<AbstractEntry> result = new ArrayList<>();
		for (Object element : children) {
			if (element instanceof AbstractEntry) {
				result.add((AbstractEntry) element);
			}
		}

		entryChildren = result.toArray(new AbstractEntry[result.size()]);
	}

	public SashForm getSashForm() {
		return sashForm;
	}

	@Override
	protected Control createDialogArea(Composite parent) {
		Composite container = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.numColumns = 1;
		container.setLayout(layout);
		GridData gd = new GridData(GridData.FILL_BOTH);
		container.setLayoutData(gd);

		createSashForm(container);
		createDetailsSection(getSashForm());
		createStackSection(getSashForm());
		createSessionSection(getSashForm());

		updateProperties();
		Dialog.applyDialogFont(container);
		return container;
	}

	private void createSashForm(Composite parent) {
		sashForm = new SashForm(parent, SWT.VERTICAL);
		GridLayout layout = new GridLayout();
		layout.marginHeight = layout.marginWidth = 0;
		sashForm.setLayout(layout);
		sashForm.setLayoutData(new GridData(GridData.FILL_BOTH));
		sashForm.setSashWidth(10);
	}

	private void createToolbarButtonBar(Composite parent) {
		Composite comp = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.marginWidth = layout.marginHeight = 0;
		// layout.numColumns = 1;
		comp.setLayout(layout);
		comp.setLayoutData(new GridData(GridData.FILL_VERTICAL));
		((GridData) comp.getLayoutData()).verticalAlignment = SWT.BOTTOM;

		Composite container = new Composite(comp, SWT.NONE);
		layout = new GridLayout();
		layout.marginWidth = 0;
		layout.marginHeight = 0;
		container.setLayout(layout);
		container.setLayoutData(new GridData(GridData.FILL_BOTH));

		backButton = createButton(container, IDialogConstants.BACK_ID, "", false); //$NON-NLS-1$
		GridData gd = new GridData(GridData.FILL_HORIZONTAL);
		backButton.setLayoutData(gd);
		backButton.setToolTipText(Messages.get().EventDetailsDialog_previous);
		backButton.setImage(SharedImages.getImage(SharedImages.DESC_PREV_EVENT));
		backButton.getAccessible().addAccessibleListener(new AccessibleAdapter() {
			@Override
			public void getName(AccessibleEvent e) {
				e.result = Messages.get().EventDetailsDialog_previous;
			}
		});

		copyButton = createButton(container, COPY_ID, "", false); //$NON-NLS-1$
		gd = new GridData();
		copyButton.setLayoutData(gd);
		copyButton.setImage(PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_TOOL_COPY));
		copyButton.setToolTipText(Messages.get().EventDetailsDialog_copy);
		copyButton.getAccessible().addAccessibleListener(new AccessibleAdapter() {
			@Override
			public void getName(AccessibleEvent e) {
				e.result = Messages.get().EventDetailsDialog_copy;
			}
		});
		copyButton.setEnabled(false);
		// There is no clipboard access in rap so button is disabled

		nextButton = createButton(container, IDialogConstants.NEXT_ID, "", false); //$NON-NLS-1$
		gd = new GridData();
		nextButton.setLayoutData(gd);
		nextButton.setToolTipText(Messages.get().EventDetailsDialog_next);
		nextButton.setImage(SharedImages.getImage(SharedImages.DESC_NEXT_EVENT));
		nextButton.getAccessible().addAccessibleListener(new AccessibleAdapter() {
			@Override
			public void getName(AccessibleEvent e) {
				e.result = Messages.get().EventDetailsDialog_next;
			}
		});

		Button button = new Button(container, SWT.NONE);
		button.setToolTipText(Messages.get().EventDetailsDialog_ShowFilterDialog);
		button.setImage(SharedImages.getImage(SharedImages.DESC_FILTER));
		gd = new GridData();
		gd.horizontalAlignment = SWT.RIGHT;
		button.setLayoutData(gd);
		button.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				FilterDialog dialog = new FilterDialog(getShell(), memento);
				dialog.create();
				dialog.getShell().setText(Messages.get().EventDetailsDialog_FilterDialog);
				if (dialog.open() == Window.OK) {
					// update filters and currently displayed stack trace
					stackFilterPatterns = getFilters();
					logView.reloadLog();
					initialize();
				}
				updateProperties();
			}
		});
		button.getAccessible().addAccessibleListener(new AccessibleAdapter() {
			@Override
			public void getName(AccessibleEvent e) {
				e.result = Messages.get().EventDetailsDialog_FilterDialog;
			}
		});

		// set numColumns at the end, after all createButton() calls, which change this
		// value
		layout.numColumns = 2;
	}

	@Override
	protected void createButtonsForButtonBar(Composite parent) {
		// create OK button only by default
		createButton(parent, IDialogConstants.OK_ID, IDialogConstants.get().OK_LABEL, true);
	}

	private void createDetailsSection(Composite parent) {
		Composite container = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.marginWidth = layout.marginHeight = 0;
		layout.numColumns = 2;
		container.setLayout(layout);
		GridData data = new GridData(GridData.FILL_HORIZONTAL);
		data.heightHint = 200;
		container.setLayoutData(data);

		createTextSection(container);
		createToolbarButtonBar(container);
	}

	private void createTextSection(Composite parent) {
		Composite textContainer = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.numColumns = 3;
		layout.marginHeight = layout.marginWidth = 0;
		textContainer.setLayout(layout);
		textContainer.setLayoutData(new GridData(GridData.FILL_BOTH));

		Label label = new Label(textContainer, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_plugIn);
		plugInIdLabel = new Label(textContainer, SWT.NONE);
		GridData gd = new GridData(GridData.FILL_HORIZONTAL);
		gd.horizontalSpan = 2;
		plugInIdLabel.setLayoutData(gd);

		label = new Label(textContainer, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_severity);
		severityImageLabel = new Label(textContainer, SWT.NONE);
		severityLabel = new Label(textContainer, SWT.NONE);
		gd = new GridData(GridData.FILL_HORIZONTAL);
		severityLabel.setLayoutData(gd);

		label = new Label(textContainer, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_date);
		dateLabel = new Label(textContainer, SWT.NONE);
		gd = new GridData(GridData.FILL_HORIZONTAL);
		gd.horizontalSpan = 2;
		dateLabel.setLayoutData(gd);

		label = new Label(textContainer, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_message);
		gd = new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
		label.setLayoutData(gd);
		msgText = new Text(textContainer, SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER);
		msgText.setEditable(false);
		gd = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL);
		gd.horizontalSpan = 2;
		gd.grabExcessVerticalSpace = true;
		msgText.setLayoutData(gd);
	}

	private void createStackSection(Composite parent) {
		Composite container = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout(2, false);
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		container.setLayout(layout);
		GridData gd = new GridData(GridData.FILL_BOTH);
		gd.heightHint = 200;
		container.setLayoutData(gd);

		Label label = new Label(container, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_exception);
		gd = new GridData();
		gd.verticalAlignment = SWT.BOTTOM;
		label.setLayoutData(gd);

		stackTraceText = new Text(container, SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER);
		gd = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL);
		gd.grabExcessHorizontalSpace = true;
		gd.horizontalSpan = 2;
		stackTraceText.setLayoutData(gd);
		stackTraceText.setEditable(false);
	}

	private void createSessionSection(Composite parent) {
		Composite container = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		container.setLayout(layout);
		GridData gd = new GridData(GridData.FILL_HORIZONTAL);
		gd.heightHint = 100;
		container.setLayoutData(gd);

		Label label = new Label(container, SWT.NONE);
		label.setText(Messages.get().EventDetailsDialog_session);
		gd = new GridData(GridData.FILL_HORIZONTAL);
		label.setLayoutData(gd);
		sessionDataText = new Text(container, SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL);
		gd = new GridData(GridData.FILL_BOTH | GridData.GRAB_HORIZONTAL);
		gd.grabExcessHorizontalSpace = true;
		sessionDataText.setLayoutData(gd);
		sessionDataText.setEditable(false);
	}

	/**
	 * Loads filters from preferences.
	 * 
	 * @return filters from preferences or empty array
	 *
	 * @since 3.4
	 */
	private String[] getFilters() {

		Boolean filterEnabled = memento.getBoolean(FILTER_ENABLED);

		String filtersString = memento.getString(FILTER_LIST);

		if ((filterEnabled == null) || (filterEnabled.booleanValue() == false) || filtersString == null) {
			return new String[0];
		}

		StringTokenizer st = new StringTokenizer(filtersString, ";"); //$NON-NLS-1$
		List<String> filters = new ArrayList<>();
		while (st.hasMoreElements()) {
			String filter = st.nextToken();
			filters.add(filter);
		}

		return filters.toArray(new String[filters.size()]);
	}

	/**
	 * Filters stack trace. Every stack trace line is compared against all patterns.
	 * If line contains any of pattern strings, it's excluded from output.
	 *
	 * @returns filtered stack trace
	 * @since 3.4
	 */
	private String filterStack(String stack) {
		if (stackFilterPatterns.length == 0) {
			return stack;
		}

		StringTokenizer st = new StringTokenizer(stack, "\n"); //$NON-NLS-1$
		StringBuilder result = new StringBuilder();
		while (st.hasMoreTokens()) {
			String stackElement = st.nextToken();

			boolean filtered = false;
			int i = 0;
			while ((!filtered) && (i < stackFilterPatterns.length)) {
				filtered = stackElement.indexOf(stackFilterPatterns[i]) >= 0;
				i++;
			}

			if (!filtered) {
				result.append(stackElement).append("\n"); //$NON-NLS-1$
			}
		}

		return result.toString();
	}

	// --------------- configuration handling --------------

	/**
	 * Stores the current state in the dialog settings.
	 * 
	 * @since 2.0
	 */
	private void storeSettings() {
		writeConfiguration();
	}

	/**
	 * Returns the dialog settings object used to share state between several event
	 * detail dialogs.
	 *
	 * @return the dialog settings to be used
	 */
	private IDialogSettings getDialogSettings() {
		IDialogSettings settings = Activator.getDefault().getDialogSettings();
		IDialogSettings dialogSettings = settings.getSection(getClass().getName());
		if (dialogSettings == null)
			dialogSettings = settings.addNewSection(getClass().getName());
		return dialogSettings;
	}

	/**
	 * Initializes itself from the dialog settings with the same state as at the
	 * previous invocation.
	 */
	private void readConfiguration() {
		IDialogSettings s = getDialogSettings();
		try {
			int x = s.getInt("x"); //$NON-NLS-1$
			int y = s.getInt("y"); //$NON-NLS-1$
			dialogLocation = new Point(x, y);

			x = s.getInt("width"); //$NON-NLS-1$
			y = s.getInt("height"); //$NON-NLS-1$
			dialogSize = new Point(x, y);

			sashWeights = new int[3];
			sashWeights[0] = s.getInt("sashWidth1"); //$NON-NLS-1$
			sashWeights[1] = s.getInt("sashWidth2"); //$NON-NLS-1$
			sashWeights[2] = s.getInt("sashWidth3"); //$NON-NLS-1$
		} catch (NumberFormatException e) {
			dialogLocation = null;
			dialogSize = null;
			sashWeights = null;
		}
	}

	private void writeConfiguration() {
		IDialogSettings s = getDialogSettings();
		Point location = getShell().getLocation();
		s.put("x", location.x); //$NON-NLS-1$
		s.put("y", location.y); //$NON-NLS-1$

		Point size = getShell().getSize();
		s.put("width", size.x); //$NON-NLS-1$
		s.put("height", size.y); //$NON-NLS-1$

		sashWeights = getSashForm().getWeights();
		s.put("sashWidth1", sashWeights[0]); //$NON-NLS-1$
		s.put("sashWidth2", sashWeights[1]); //$NON-NLS-1$
		s.put("sashWidth3", sashWeights[2]); //$NON-NLS-1$
	}

	/**
	 * Utility method to get all top level elements of the Log View
	 * 
	 * @return top level elements of the Log View
	 */
	private AbstractEntry[] getElements() {
		return (AbstractEntry[]) ((ITreeContentProvider) provider.getContentProvider()).getElements(null);
	}
}