/*

* Copyright (c) 2009,2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package javax.microedition.lcdui;

import java.util.Timer;

import java.util.TimerTask;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.internal.extension.Style;

import org.eclipse.swt.internal.extension.LabelExtension;

import org.eclipse.swt.layout.*;

import org.eclipse.swt.widgets.*;

/**

 * The <code>Alert</code> class is basically a message dialog which shows

 * information (in form of text and image) to the user. It's highly customizable

 * and it can be:

 * <li>timed - when it waits for a predefined period of time and dismisses

 *             itself automatically </li>

 * <li>modal - user has to choose a command and dismiss the dialog

 *             explicitly</li>

 */

public class Alert extends Screen

{

    /**

     * Timeout constant used for modal Alerts.

     *

     * @value for FOREVER is -2.

     */

    public static final int FOREVER = -2;

    /**

     * The default command triggered when dismissing an Alert.

     */

    public static final Command DISMISS_COMMAND =

        new Command("", Command.OK, 0);

    /**

     * Default command listener.

     */

    private AlertCommandListener implicitListener = new AlertCommandListener();

    /**

     * Alert Timer.

     */

    private Timer timer = new Timer();

    /**

     * Alert Timer Task.

     */

    private AlertTimerTask timerTask;

    /**

     * Stores next Displayable to switch to.

     */

    private Displayable nextDisplayable;

    private int timeout;

    private String text;

    private Image image;

    private AlertType type;

    private Gauge indicator;

    private boolean textScrolling;

    // eSWT widgets

    private ScrolledTextComposite eswtScrolledText;

    private LabelExtension eswtImgLabel;

    private ProgressBar eswtProgressBar;

    private FormData eswtProgbarLD;

    private Shell topShell;

    private ResizeListener resizeListener = new ResizeListener();

    private KeyListener keyListener = new KeyListener();

    /**

     * Create a new empty Alert with the specified title.

     *

     * @param aTitle the title string

     */

    public Alert(String aTitle)

    {

        this(aTitle, null, null, null);

    }

    /**

     * Create a new Alert with the specified title, text, image, and alert type.

     *

     * @param title the title string

     * @param text the text string

     * @param image the image

     * @param type the alert type

     */

    public Alert(String title, String text, Image image, AlertType type)

    {

        super(title);

        construct();

        this.type = type;

        setImage(image);

        setString(text);

        setTimeout(getDefaultTimeout());

        super.addCommand(DISMISS_COMMAND);

        super.setCommandListener(implicitListener);

    }

    /**

     * Constructs custom eSWT shell for alert dialog.

     *

     * @return custom eSWT dialog shell

     */

    Shell eswtConstructShell(int style)

    {

        topShell = super.eswtConstructShell(style);

        Shell dialogShell = new Shell(topShell, style | SWT.DIALOG_TRIM | SWT.RESIZE);

        return dialogShell;

    }

    /**

     * Creates content Composite.

     */

    Composite eswtConstructContent(int style)

    {

        Composite comp = super.eswtConstructContent(SWT.VERTICAL);

        FormLayout layout = new FormLayout();

        layout.marginBottom = Style.pixelMetric(Style.QSTYLE_PM_LAYOUTBOTTOMMARGIN);

        layout.marginTop = Style.pixelMetric(Style.QSTYLE_PM_LAYOUTTOPMARGIN);

        layout.marginLeft = Style.pixelMetric(Style.QSTYLE_PM_LAYOUTLEFTMARGIN);

        layout.marginRight = Style.pixelMetric(Style.QSTYLE_PM_LAYOUTRIGHTMARGIN);

        layout.spacing = Style.pixelMetric(Style.QSTYLE_PM_LAYOUTVERTICALSPACING);

        comp.setLayout(layout);

        eswtScrolledText = new ScrolledTextComposite(comp, comp

                .getVerticalBar());

        eswtImgLabel = new LabelExtension(comp, SWT.NONE);

        FormData imageLD = new FormData();

        imageLD.right = new FormAttachment(100);

        imageLD.top = new FormAttachment(0);

        eswtImgLabel.setLayoutData(imageLD);

        FormData scrolledTextLD = new FormData();

        scrolledTextLD.left = new FormAttachment(0);

        scrolledTextLD.top = new FormAttachment(0);

        scrolledTextLD.right = new FormAttachment(eswtImgLabel);

        eswtScrolledText.setLayoutData(scrolledTextLD);

        eswtProgbarLD = new FormData();

        eswtProgbarLD.left = new FormAttachment(0);

        eswtProgbarLD.right = new FormAttachment(100);

        eswtProgbarLD.bottom = new FormAttachment(100);

        eswtUpdateProgressbar(comp, false, false);

        return comp;

    }

    int eswtGetPreferredContentHeight()

    {

        int ret = getContentComp().computeSize(SWT.DEFAULT, SWT.DEFAULT).y;

        // Point imgSize = (eswtImgLabel != null

        // ? eswtImgLabel.computeSize(SWT.DEFAULT, SWT.DEFAULT) : new Point(0, 0));

        // int ret = Math.max(

        // Math.min(

        // eswtScrolledText.computeSize(topShell.getClientArea().width - imgSize.x, SWT.DEFAULT).y,

        // topShell.getClientArea().height / 2),

        // imgSize.y);

        if(eswtProgressBar != null && eswtProgressBar.isVisible())

        {

            ret += eswtProgressBar.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;

        }

        return ret;

    }

    /**

     * Update ProgressBar widget.<br>

     * Try to reuse the old ProgressBar if possible, otherwise dispose it and

     * create a new one.

     *

     * @param parent

     * @param indeterminate

     * @param visible

     */

    void eswtUpdateProgressbar(Composite parent,

                               boolean indeterminate,

                               boolean visible)

    {

        // Only dispose old ProgressBar if it has wrong style

        if(eswtProgressBar != null)

        {

            boolean isIndeterminate =

                (eswtProgressBar.getStyle() & SWT.INDETERMINATE) != 0;

            if(indeterminate != isIndeterminate)

            {

                eswtProgressBar.setLayoutData(null);

                eswtProgressBar.dispose();

                eswtProgressBar = null;

            }

        }

        // create new ProgressBar

        if(eswtProgressBar == null)

        {

            int newStyle = indeterminate ? SWT.INDETERMINATE : SWT.NONE;

            eswtProgressBar = new ProgressBar(parent, newStyle);

            eswtProgressBar.setLayoutData(eswtProgbarLD);

            // update ScrolledText's layoutdata

            FormData imageLD = (FormData) eswtImgLabel.getLayoutData();

            imageLD.bottom = new FormAttachment(eswtProgressBar);

        }

        // set Progressbar visibility

        if(eswtProgressBar != null)

        {

            eswtProgbarLD.top = (visible ? null : new FormAttachment(100));

            eswtProgressBar.setVisible(visible);

        }

    }

    /**

     * Update ProgressBar values.

     *

     * @param minValue the minimum value

     * @param maxValue the maximum value

     * @param selValue the value

     */

    void eswtSetProgressbarValues(int minValue, int maxValue, int selValue)

    {

        if(eswtProgressBar != null)

        {

            eswtProgressBar.setMinimum(minValue);

            eswtProgressBar.setMaximum(maxValue);

            eswtProgressBar.setSelection(selValue);

        }

    }

    /* (non-Javadoc)

     * @see javax.microedition.lcdui.Displayable#handleShowEvent()

     */

    void eswtHandleShowCurrentEvent()

    {

        super.eswtHandleShowCurrentEvent();

        topShell.addListener(SWT.Resize, resizeListener);

        // add key filter for scrollable text composite

        org.eclipse.swt.widgets.Display.getCurrent().addFilter(

            SWT.KeyDown, keyListener);

        org.eclipse.swt.widgets.Display.getCurrent().addFilter(

            SWT.Traverse, keyListener);

        org.eclipse.swt.widgets.Display.getCurrent().addFilter(

            SWT.MouseUp, keyListener);

        resetTimerTask(true);

    }

    /* (non-Javadoc)

     * @see javax.microedition.lcdui.Displayable#handleHideEvent()

     */

    void eswtHandleHideCurrentEvent()

    {

        super.eswtHandleHideCurrentEvent();

        topShell.removeListener(SWT.Resize, resizeListener);

        nextDisplayable = null;

        resetTimerTask(false);

        // remove key filter for scrollable text composite

        org.eclipse.swt.widgets.Display.getCurrent().removeFilter(

            SWT.KeyDown, keyListener);

        org.eclipse.swt.widgets.Display.getCurrent().removeFilter(

            SWT.Traverse, keyListener);

        org.eclipse.swt.widgets.Display.getCurrent().removeFilter(

            SWT.MouseUp, keyListener);

    }

    /**

     * Set the next displayable to be shown.

     *

     * @param next next displayable

     */

    void setNextDisplayable(Displayable next)

    {

        nextDisplayable = next;

    }

    /**

     * Gets the default Alert image based on the type.

     *

     * @param type the alert type

     * @return the default image based on the type or null if the type is null

     */

    private static int getDefaultImageType(final AlertType type)

    {

        if(type == AlertType.ERROR)

        {

            return LabelExtension.STANDARDICON_ERROR;

        }

        else if(type == AlertType.WARNING)

        {

            return LabelExtension.STANDARDICON_WARNING;

        }

        else if(type == AlertType.INFO)

        {

            return LabelExtension.STANDARDICON_INFO;

        }

        else if(type == AlertType.CONFIRMATION)

        {

            return LabelExtension.STANDARDICON_CONFIRMATION;

        }

        else if(type == AlertType.ALARM)

        {

            return LabelExtension.STANDARDICON_ALARM;

        }

        else

        {

            return LabelExtension.STANDARDICON_ALARM;

        }

    }

    /**

     * Gets the default Alert text based on the type.

     *

     * @param type the alert type

     * @return the default text based on the type

     */

    private static String getDefaultText(final AlertType type)

    {

        if(type == AlertType.ERROR)

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_ERROR;

        }

        else if(type == AlertType.WARNING)

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_WARNING;

        }

        else if(type == AlertType.INFO)

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_INFO;

        }

        else if(type == AlertType.CONFIRMATION)

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_CONFIRMATION;

        }

        else if(type == AlertType.ALARM)

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_ALARM;

        }

        else

        {

            return MsgRepository.ALERT_DEFAULT_TEXT_ALERT;

        }

    }

    /**

     * Returns if the Alert is modal.

     */

    private boolean isModal()

    {

        return ((timeout == FOREVER)

                || (getNumCommands() > 1)

                || isTextScrolling());

    }

    /**

     * Set the time for the Alert to be shown.

     *

     * @param timeout the timeout value in milliseconds or FOREVER

     * @throws IllegalArgumentException if time is not positive nor FOREVER.

     */

    public void setTimeout(int timeout)

    {

        if(timeout > 0 || timeout == FOREVER)

        {

            this.timeout = timeout;

            setCommandsVisibility(isModal());

        }

        else

        {

            throw new IllegalArgumentException(

                MsgRepository.ALERT_EXCEPTION_INVALID_TIMEOUT);

        }

    }

    /**

     * Get the time the Alert is shown.

     *

     * @return timeout in milliseconds, or FOREVER

     */

    public int getTimeout()

    {

        if(isModal())

        {

            return FOREVER;

        }

        else

        {

            return timeout;

        }

    }

    /**

     * Get the default time for showing an Alert.

     *

     * @return default timeout in milliseconds

     */

    public int getDefaultTimeout()

    {

        return Config.ALERT_DEFAULT_TIMEOUT;

    }

    /**

     * Sets the type of the Alert.

     *

     * @param type an AlertType or null if it doesn't have a specific type

     */

    public void setType(AlertType type)

    {

        this.type = type;

        if(text == null)

        {

            // show default text

            setString(text);

        }

        if(image == null)

        {

            // show default image

            setImage(image);

        }

    }

    /**

     * Gets the type of the Alert.

     *

     * @return an AlertType or null if it doesn't have a specific type

     */

    public AlertType getType()

    {

        return type;

    }

    /**

     * Sets the image of this Alert.

     *

     * @param newImage an Image, or null if there is no image

     */

    public void setImage(Image newImage)

    {

        image = newImage;

        ESWTUIThreadRunner.syncExec(new Runnable()

        {

            public void run()

            {

                Image temp = (image != null) ? image : null;

                //Get the image size from QT Style for scaling

                int scaleToSize = Style.pixelMetric(Style.QSTYLE_PM_MESSAGEBOXICONSIZE);

                if(temp != null)

                {

                    //calculate the aspect ratio

                    float aspectRatio = (float)temp.getHeight()/temp.getWidth();

                    //check the image size

                    if((temp.getWidth() > scaleToSize) ||

                            (temp.getHeight() > scaleToSize))

                    {

                        // we need to scale down the image

                        if(temp.getWidth() > scaleToSize)

                        {

                            //Width is greater

                            Image wScaled = Image.createImage(temp,

                                                              scaleToSize,

                                                              (int)(scaleToSize*aspectRatio));

                            //now check the new dimension against height

                            if(wScaled.getHeight() > scaleToSize)

                            {

                                //scale the image again

                                Image whScaled = Image.createImage(temp,

                                                                   scaleToSize,

                                                                   scaleToSize);

                                eswtImgLabel.setImage(Image.getESWTImage(whScaled));

                            }

                            else

                            {

                                //height was ok after scaling on width

                                eswtImgLabel.setImage(Image.getESWTImage(wScaled));

                            }

                        }

                        else if(temp.getHeight() > scaleToSize)

                        {