/*******************************************************************************
 * Copyright (c) 2000, 2016 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
 * 	   Lars Vogel <Lars.Vogel@vogella.com> - Bug 472690
 *******************************************************************************/
package org.eclipse.jface.dialogs;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;

/**
 * A dialog for showing messages to the user.
 * <p>
 * This concrete dialog class can be instantiated as is, or further subclassed
 * as required.
 * </p>
 * <p>
 * <strong>Note:</strong> This class does not use button IDs from
 * IDialogConstants. Instead, the ID is the index of the button in the supplied
 * array.
 * </p>
 */
public class MessageDialog extends IconAndMessageDialog {
    /**
	 * Constant for no image (value 0).
	 *
	 * @see #MessageDialog(Shell, String, Image, String, int, int, String...)
	 */
    public static final int NONE = 0;

    /**
	 * Constant for the error image, or a simple dialog with the error image and
	 * a single OK button (value 1).
	 *
	 * @see #MessageDialog(Shell, String, Image, String, int, int, String...)
	 * @see #open(int, Shell, String, String, int)
	 */
    public static final int ERROR = 1;

    /**
	 * Constant for the info image, or a simple dialog with the info image and a
	 * single OK button (value 2).
	 *
	 * @see #MessageDialog(Shell, String, Image, String, int, int, String...)
	 * @see #open(int, Shell, String, String, int)
	 */
    public static final int INFORMATION = 2;

    /**
	 * Constant for the question image, or a simple dialog with the question
	 * image and Yes/No buttons (value 3).
	 *
	 * @see #MessageDialog(Shell, String, Image, String, int, int, String...)
	 * @see #open(int, Shell, String, String, int)
	 */
    public static final int QUESTION = 3;

    /**
	 * Constant for the warning image, or a simple dialog with the warning image
	 * and a single OK button (value 4).
	 *
	 * @see #MessageDialog(Shell, String, Image, String, int, int, String...)
	 * @see #open(int, Shell, String, String, int)
	 */
    public static final int WARNING = 4;

    /**
     * Constant for a simple dialog with the question image and OK/Cancel buttons (value 5).
     *
     * @see #open(int, Shell, String, String, int)
     * @since 3.5
     */
    public static final int CONFIRM = 5;

    /**
     * Constant for a simple dialog with the question image and Yes/No/Cancel buttons (value 6).
     *
     * @see #open(int, Shell, String, String, int)
     * @since 3.5
     */
    public static final int QUESTION_WITH_CANCEL = 6;

    /**
     * Labels for buttons in the button bar (localized strings).
     */
    private String[] buttonLabels;

    /**
     * The buttons. Parallels <code>buttonLabels</code>.
     */
    private Button[] buttons;

    /**
     * Index into <code>buttonLabels</code> of the default button.
     */
    private int defaultButtonIndex;

    /**
     * Dialog title (a localized string).
     */
    private String title;

    /**
     * Dialog title image.
     */
    private Image titleImage;

    /**
     * Image, or <code>null</code> if none.
     */
    private Image image = null;

    /**
     * The custom dialog area.
     */
    private Control customArea;

	/**
	 * Create a message dialog. Note that the dialog will have no visual
	 * representation (no widgets) until it is told to open.
	 * <p>
	 * The labels of the buttons to appear in the button bar are supplied in this
	 * constructor as an array. The <code>open</code> method will return the index
	 * of the label in this array corresponding to the button that was pressed to
	 * close the dialog.
	 * </p>
	 * <p>
	 * <strong>Note:</strong> If the dialog was dismissed without pressing a button
	 * (ESC key, close box, etc.) then {@link SWT#DEFAULT} is returned. Note that
	 * the <code>open</code> method blocks.
	 * </p>
	 *
	 * As of 3.11 you can also use the other constructor which is based on varargs
	 *
	 * @param parentShell        the parent shell, or <code>null</code> to create a
	 *                           top-level shell
	 * @param dialogTitle        the dialog title, or <code>null</code> if none
	 * @param dialogTitleImage   the dialog title image, or <code>null</code> if
	 *                           none
	 * @param dialogMessage      the dialog message
	 * @param dialogImageType    one of the following values:
	 *                           <ul>
	 *                           <li><code>MessageDialog.NONE</code> for a dialog
	 *                           with no image</li>
	 *                           <li><code>MessageDialog.ERROR</code> for a dialog
	 *                           with an error image</li>
	 *                           <li><code>MessageDialog.INFORMATION</code> for a
	 *                           dialog with an information image</li>
	 *                           <li><code>MessageDialog.QUESTION </code> for a
	 *                           dialog with a question image</li>
	 *                           <li><code>MessageDialog.WARNING</code> for a dialog
	 *                           with a warning image</li>
	 *                           </ul>
	 * @param dialogButtonLabels an array of labels for the buttons in the button
	 *                           bar
	 * @param defaultIndex       the index in the button label array of the default
	 *                           button
	 *
	 */
	public MessageDialog(Shell parentShell, String dialogTitle, Image dialogTitleImage, String dialogMessage,
			int dialogImageType, String[] dialogButtonLabels, int defaultIndex) {
		super(parentShell);
		init(dialogTitle, dialogTitleImage, dialogMessage, dialogImageType, defaultIndex, dialogButtonLabels);
	}

	/**
	 * Create a message dialog. Note that the dialog will have no visual
	 * representation (no widgets) until it is told to open.
	 * <p>
	 * The labels of the buttons to appear in the button bar are supplied in this
	 * constructor as a varargs of Strings. The <code>open</code> method will return
	 * the index of the label in this array corresponding to the button that was
	 * pressed to close the dialog.
	 * </p>
	 * <p>
	 * <strong>Note:</strong> If the dialog was dismissed without pressing a button
	 * (ESC key, close box, etc.) then {@link SWT#DEFAULT} is returned. Note that
	 * the <code>open</code> method blocks.
	 * </p>
	 *
	 * @param parentShell        the parent shell, or <code>null</code> to create a
	 *                           top-level shell
	 * @param dialogTitle        the dialog title, or <code>null</code> if none
	 * @param dialogTitleImage   the dialog title image, or <code>null</code> if
	 *                           none
	 * @param dialogMessage      the dialog message
	 * @param dialogImageType    one of the following values:
	 *                           <ul>
	 *                           <li><code>MessageDialog.NONE</code> for a dialog
	 *                           with no image</li>
	 *                           <li><code>MessageDialog.ERROR</code> for a dialog
	 *                           with an error image</li>
	 *                           <li><code>MessageDialog.INFORMATION</code> for a
	 *                           dialog with an information image</li>
	 *                           <li><code>MessageDialog.QUESTION </code> for a
	 *                           dialog with a question image</li>
	 *                           <li><code>MessageDialog.WARNING</code> for a dialog
	 *                           with a warning image</li>
	 *                           </ul>
	 * @param defaultIndex       the index in the button label array of the default
	 *                           button
	 *
	 * @param dialogButtonLabels varargs of Strings for the button labels in the
	 *                           button bar
	 *
	 * @since 3.12
	 */
	public MessageDialog(Shell parentShell, String dialogTitle, Image dialogTitleImage, String dialogMessage,
			int dialogImageType, int defaultIndex, String... dialogButtonLabels) {
		super(parentShell);
		init(dialogTitle, dialogTitleImage, dialogMessage, dialogImageType, defaultIndex, dialogButtonLabels);
	}

	private void init(String dialogTitle, Image dialogTitleImage, String dialogMessage, int dialogImageType,
			int defaultIndex, String... dialogButtonLabels) {
		this.title = dialogTitle;
        this.titleImage = dialogTitleImage;
        this.message = dialogMessage;

        switch (dialogImageType) {
        case ERROR: {
            this.image = getErrorImage();
            break;
        }
        case INFORMATION: {
            this.image = getInfoImage();
            break;
        }
        case QUESTION:
        case QUESTION_WITH_CANCEL:
        case CONFIRM: {
            this.image = getQuestionImage();
            break;
        }
        case WARNING: {
            this.image = getWarningImage();
            break;
        }
        }
        this.buttonLabels = dialogButtonLabels;
        this.defaultButtonIndex = defaultIndex;
	}

    @Override
	protected void buttonPressed(int buttonId) {
        setReturnCode(buttonId);
        close();
    }

    @Override
	protected void configureShell(Shell shell) {
        super.configureShell(shell);
        if (title != null) {
			shell.setText(title);
		}
        if (titleImage != null) {
			shell.setImage(titleImage);
		}
    }

    @Override
	protected void createButtonsForButtonBar(Composite parent) {
        buttons = new Button[buttonLabels.length];
        for (int i = 0; i < buttonLabels.length; i++) {
            String label = buttonLabels[i];
			Button button = createButton(parent, i, label, defaultButtonIndex == i);
            buttons[i] = button;
        }
    }

	/**
	 * Creates and returns the contents of an area of the dialog which appears below
	 * the message and above the button bar.
	 * <p>
	 * The default implementation of this framework method returns
	 * <code>null</code>. Subclasses may override.
	 * </p>
	 *
	 * @param parent parent composite to contain the custom area
	 * @return the custom area control, or <code>null</code>
	 */
    protected Control createCustomArea(Composite parent) {
        return null;
    }

    /**
     * This implementation of the <code>Dialog</code> framework method creates
     * and lays out a composite and calls <code>createMessageArea</code> and
     * <code>createCustomArea</code> to populate it. Subclasses should
     * override <code>createCustomArea</code> to add contents below the
     * message.
     */
    @Override
	protected Control createDialogArea(Composite parent) {
        // create message area
        createMessageArea(parent);
        // create the top level composite for the dialog area
        Composite composite = new Composite(parent, SWT.NONE);
        GridLayout layout = new GridLayout();
        layout.marginHeight = 0;
        layout.marginWidth = 0;
        composite.setLayout(layout);
        GridData data = new GridData(GridData.FILL_BOTH);
        data.horizontalSpan = 2;
        composite.setLayoutData(data);
        // allow subclasses to add custom controls
        customArea = createCustomArea(composite);
        //If it is null create a dummy label for spacing purposes
        if (customArea == null) {
			customArea = new Label(composite, SWT.NULL);
		}
        return composite;
    }

	/**
	 * Gets a button in this dialog's button bar.
	 *
	 * @param index the index of the button in the dialog's button bar
	 * @return a button in the dialog's button bar, or <code>null</code> if there's
	 *         no button with that index
	 */
    @Override
	protected Button getButton(int index) {
		if (buttons == null || index < 0 || index >= buttons.length) {
			return null;
		}
        return buttons[index];
    }

    /**
     * Returns the minimum message area width in pixels This determines the
     * minimum width of the dialog.
     * <p>
     * Subclasses may override.
     * </p>
     *
     * @return the minimum message area width (in pixels)
     */
    protected int getMinimumMessageWidth() {
        return convertHorizontalDLUsToPixels(IDialogConstants.MINIMUM_MESSAGE_AREA_WIDTH);
    }

    /**
     * Handle the shell close. Set the return code to <code>SWT.DEFAULT</code>
     * as there has been no explicit close by the user.
     *
     * @see org.eclipse.jface.window.Window#handleShellCloseEvent()
     */
    @Override
	protected void handleShellCloseEvent() {
        //Sets a return code of SWT.DEFAULT since none of the dialog buttons
        // were pressed to close the dialog.
        super.handleShellCloseEvent();
        setReturnCode(SWT.DEFAULT);
    }

	/**
	 * Convenience method to open a simple dialog as specified by the
	 * <code>kind</code> flag.
	 *
	 * @param kind    the kind of dialog to open, one of {@link #ERROR},
	 *                {@link #INFORMATION}, {@link #QUESTION}, {@link #WARNING},
	 *                {@link #CONFIRM}, or {@link #QUESTION_WITH_CANCEL}.
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 * @param style   {@link SWT#NONE} for a default dialog, or {@link SWT#SHEET}
	 *                for a dialog with sheet behavior
	 * @return <code>true</code> if the user presses the OK or Yes button,
	 *         <code>false</code> otherwise
	 * @since 3.5
	 */
	public static boolean open(int kind, Shell parent, String title, String message, int style) {
		MessageDialog dialog = new MessageDialog(parent, title, null, message, kind, 0, getButtonLabels(kind));
		style &= SWT.SHEET;
		dialog.setShellStyle(dialog.getShellStyle() | style);
		return dialog.open() == 0;
	}

	/**
	 * Method to open a simple dialog as specified by the <code>kind</code> flag.
	 *
	 * This method accepts varargs of String to set custom button labels.
	 *
	 * Use this method if you want to override the default labels.
	 *
	 * @param kind               the kind of dialog to open, one of {@link #ERROR},
	 *                           {@link #INFORMATION}, {@link #QUESTION},
	 *                           {@link #WARNING}, {@link #CONFIRM}, or
	 *                           {@link #QUESTION_WITH_CANCEL}.
	 * @param parent             the parent shell of the dialog, or
	 *                           <code>null</code> if none
	 * @param title              the dialog's title, or <code>null</code> if none
	 * @param message            the message
	 * @param style              {@link SWT#NONE} for a default dialog, or
	 *                           {@link SWT#SHEET} for a dialog with sheet behavior
	 * @param dialogButtonLabels varargs of Strings for the button labels in the
	 *                           button bar
	 * @return the index of the button that was pressed.
	 * @since 3.13
	 */
	public static int open(int kind, Shell parent, String title, String message, int style,
			String... dialogButtonLabels) {
		MessageDialog dialog = new MessageDialog(parent, title, null, message, kind, 0, dialogButtonLabels);
		style &= SWT.SHEET;
		dialog.setShellStyle(dialog.getShellStyle() | style);
		return dialog.open();
	}

	static String[] getButtonLabels(int kind) {
		String[] dialogButtonLabels;
		switch (kind) {
		case ERROR:
		case INFORMATION:
		case WARNING: {
			dialogButtonLabels = new String[] { IDialogConstants.OK_LABEL };
			break;
		}
		case CONFIRM: {
			dialogButtonLabels = new String[] { IDialogConstants.OK_LABEL,
					IDialogConstants.CANCEL_LABEL };
			break;
		}
		case QUESTION: {
			dialogButtonLabels = new String[] { IDialogConstants.YES_LABEL,
					IDialogConstants.NO_LABEL };
			break;
		}
		case QUESTION_WITH_CANCEL: {
			dialogButtonLabels = new String[] { IDialogConstants.YES_LABEL,
                    IDialogConstants.NO_LABEL,
                    IDialogConstants.CANCEL_LABEL };
			break;
		}
		default: {
			throw new IllegalArgumentException("Illegal value for kind in MessageDialog.open()"); //$NON-NLS-1$
		}
		}
		return dialogButtonLabels;
	}

	/**
	 * Convenience method to open a simple confirm (OK/Cancel) dialog.
	 *
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 * @return <code>true</code> if the user presses the OK button,
	 *         <code>false</code> otherwise
	 */
    public static boolean openConfirm(Shell parent, String title, String message) {
        return open(CONFIRM, parent, title, message, SWT.NONE);
    }

	/**
	 * Convenience method to open a standard error dialog.
	 *
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 */
    public static void openError(Shell parent, String title, String message) {
        open(ERROR, parent, title, message, SWT.NONE);
    }

	/**
	 * Convenience method to open a standard information dialog.
	 *
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 */
	public static void openInformation(Shell parent, String title, String message) {
        open(INFORMATION, parent, title, message, SWT.NONE);
    }

	/**
	 * Convenience method to open a simple Yes/No question dialog.
	 *
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 * @return <code>true</code> if the user presses the Yes button,
	 *         <code>false</code> otherwise
	 */
	public static boolean openQuestion(Shell parent, String title, String message) {
        return open(QUESTION, parent, title, message, SWT.NONE);
    }

	/**
	 * Convenience method to open a standard warning dialog.
	 *
	 * @param parent  the parent shell of the dialog, or <code>null</code> if none
	 * @param title   the dialog's title, or <code>null</code> if none
	 * @param message the message
	 */
    public static void openWarning(Shell parent, String title, String message) {
        open(WARNING, parent, title, message, SWT.NONE);
    }

    @Override
	protected Button createButton(Composite parent, int id, String label, boolean defaultButton) {
        Button button = super.createButton(parent, id, label, defaultButton);
        //Be sure to set the focus if the custom area cannot so as not
        //to lose the defaultButton.
        if (defaultButton && !customShouldTakeFocus()) {
			button.setFocus();
		}
        return button;
    }

    /**
     * Return whether or not we should apply the workaround where we take focus
     * for the default button or if that should be determined by the dialog. By
     * default only return true if the custom area is a label or CLabel that
     * cannot take focus.
     *
     * @return boolean
     */
    protected boolean customShouldTakeFocus() {
        if (customArea instanceof Label) {
			return false;
		}
        if (customArea instanceof CLabel) {
			return (customArea.getStyle() & SWT.NO_FOCUS) > 0;
		}
        return true;
    }

    @Override
	public Image getImage() {
        return image;
    }

    /**
     * An accessor for the labels to use on the buttons.
     *
     * @return The button labels to used; never <code>null</code>.
     */
    protected String[] getButtonLabels() {
        return buttonLabels;
    }

    /**
     * An accessor for the index of the default button in the button array.
     *
     * @return The default button index.
     */
    protected int getDefaultButtonIndex() {
        return defaultButtonIndex;
    }

	/**
	 * A mutator for the array of buttons in the button bar.
	 *
	 * @param buttons The buttons in the button bar; must not be <code>null</code>.
	 */
	protected void setButtons(Button... buttons) {
        if (buttons == null) {
			throw new NullPointerException("The array of buttons cannot be null."); //$NON-NLS-1$
		}
        this.buttons = buttons;
    }

    /**
     * A mutator for the button labels.
     *
     * @param buttonLabels
     *            The button labels to use; must not be <code>null</code>.
     */
	protected void setButtonLabels(String... buttonLabels) {
        if (buttonLabels == null) {
			throw new NullPointerException("The array of button labels cannot be null."); //$NON-NLS-1$
		}
        this.buttonLabels = buttonLabels;
    }
}
