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/*******************************************************************************

 * Copyright (c) 2003, 2007 IBM Corporation and others.

 * All rights reserved. This program and the accompanying materials

 * are made available under the terms of the Eclipse Public License v1.0

 * which accompanies this distribution, and is available at

 * http://www.eclipse.org/legal/epl-v10.html

 *

 * Contributors:

 *     IBM Corporation - initial API and implementation

 *******************************************************************************/

package org.eclipse.pde.internal.runtime.logview;

import java.io.*;

import java.lang.reflect.InvocationTargetException;

import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.jface.dialogs.*;

import org.eclipse.jface.operation.IRunnableWithProgress;

import org.eclipse.pde.internal.runtime.PDERuntimeMessages;

import org.eclipse.pde.internal.runtime.PDERuntimePlugin;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.layout.GridData;

import org.eclipse.swt.widgets.*;

/**

 * Displays the error log in non-Win32 platforms - see bug 55314.

 */

public final class OpenLogDialog extends TrayDialog {

    // input log file

    private File logFile;

    // location/size configuration

    private IDialogSettings dialogSettings;

    private Point dialogLocation;

    private Point dialogSize;

    private int DEFAULT_WIDTH = 750;

    private int DEFAULT_HEIGHT = 800;

    public OpenLogDialog(Shell parentShell, File logFile) {

        super(parentShell);

        this.logFile = logFile;

        setShellStyle(SWT.DIALOG_TRIM | SWT.RESIZE | SWT.MAX | SWT.MIN /*| SWT.MODELESS*/);

    }

    /*

     * (non-Javadoc) Method declared on Window.

     */

    protected void configureShell(Shell newShell) {

        super.configureShell(newShell);

        newShell.setText(PDERuntimeMessages.get().OpenLogDialog_title); 

        readConfiguration();

    }

    /*

     * (non-Javadoc) Method declared on Dialog.

     */

    protected void createButtonsForButtonBar(Composite parent) {

        createButton(parent, IDialogConstants.CLOSE_ID, IDialogConstants.get().CLOSE_LABEL,

                true);

    }

    public void create() {

        super.create();

        // dialog location

        if (dialogLocation != null)

            getShell().setLocation(dialogLocation);

        // dialog size

        if (dialogSize != null)

            getShell().setSize(dialogSize);

        else

            getShell().setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        getButton(IDialogConstants.CLOSE_ID).setFocus();

    }

    /*

     * (non-Javadoc) Method declared on Dialog.

     */

    protected Control createDialogArea(Composite parent) {

        Composite outer = (Composite) super.createDialogArea(parent);

        Text text = new Text(outer, SWT.MULTI | SWT.BORDER | SWT.READ_ONLY | SWT.V_SCROLL

                | SWT.NO_FOCUS | SWT.H_SCROLL);

        text.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND));

        GridData gridData = new GridData(GridData.HORIZONTAL_ALIGN_FILL

                | GridData.VERTICAL_ALIGN_FILL);

        gridData.grabExcessVerticalSpace = true;

        gridData.grabExcessHorizontalSpace = true;

        text.setLayoutData(gridData);

        text.setText(getLogSummary());

        return outer;

    }

    private String getLogSummary() {

        StringWriter out = new StringWriter();

        PrintWriter writer = new PrintWriter(out);

        if (logFile.length() > LogReader.MAX_FILE_LENGTH) {

            readLargeFileWithMonitor(writer);

        } else {

            readFileWithMonitor(writer);

        }

        writer.close();

        return out.toString();

    }

    /*

     * (non-Javadoc)

     * 

     * @see org.eclipse.jface.dialogs.Dialog#buttonPressed(int)

     */

    protected void buttonPressed(int buttonId) {

        if (buttonId == IDialogConstants.CLOSE_ID) {

            storeSettings();

            close();

        }

        super.buttonPressed(buttonId);

    }

    //--------------- 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 = PDERuntimePlugin.getDefault().getDialogSettings();

        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);

        } catch (NumberFormatException e) {

            dialogLocation = null;

            dialogSize = 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); //$NON-NLS-1$

    }

    // reading file within MAX_FILE_LENGTH size

    private void readFile(PrintWriter writer) throws FileNotFoundException, IOException {

        BufferedReader bReader = new BufferedReader(new FileReader(logFile));

        while (bReader.ready())

            writer.println(bReader.readLine());

    }

    // reading large files

    private void readLargeFile(PrintWriter writer) throws FileNotFoundException,

            IOException {

        RandomAccessFile random = null;

        boolean hasStarted = false;

        try {

            random = new RandomAccessFile(logFile, "r"); //$NON-NLS-1$

            random.seek(logFile.length() - LogReader.MAX_FILE_LENGTH);

            for (;;) {

                String line = random.readLine();

                if (line == null)

                    break;

                line = line.trim();

                if (line.length() == 0)

                    continue;

                if (!hasStarted

                        && (line.startsWith("!ENTRY") || line.startsWith("!SESSION"))) //$NON-NLS-1$ //$NON-NLS-2$

                    hasStarted = true;

                if (hasStarted)

                    writer.println(line);

                continue;

            }

        } finally {

            try {

                if (random != null)

                    random.close();

            } catch (IOException e1) {

            }

        }

    }

    private void readLargeFileWithMonitor(final PrintWriter writer) {

        IRunnableWithProgress runnable = new IRunnableWithProgress() {

            public void run(IProgressMonitor monitor) throws InvocationTargetException,

                    InterruptedException {

                monitor

                        .beginTask(

                                PDERuntimeMessages.get().OpenLogDialog_message, IProgressMonitor.UNKNOWN); 

                try {

                    readLargeFile(writer);

                } catch (IOException e) {

                    writer.println(PDERuntimeMessages.get().OpenLogDialog_cannotDisplay); 

                }

            }

        };

        ProgressMonitorDialog dialog = new ProgressMonitorDialog(getParentShell());

        try {

            dialog.run(true, true, runnable);

        } catch (InvocationTargetException e) {

        } catch (InterruptedException e) {

        }

    }

    private void readFileWithMonitor(final PrintWriter writer) {

        IRunnableWithProgress runnable = new IRunnableWithProgress() {

            public void run(IProgressMonitor monitor) throws InvocationTargetException,

                    InterruptedException {

                monitor

                        .beginTask(

                                PDERuntimeMessages.get().OpenLogDialog_message, IProgressMonitor.UNKNOWN); 

                try {

                    readFile(writer);

                } catch (IOException e) {

                    writer.println(PDERuntimeMessages.get().OpenLogDialog_cannotDisplay); 

                }

            }

        };

        ProgressMonitorDialog dialog = new ProgressMonitorDialog(getParentShell());

        try {

            dialog.run(true, true, runnable);

        } catch (InvocationTargetException e) {

        } catch (InterruptedException e) {

        }

    }

}