/*******************************************************************************
 * Copyright (c) 2000, 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module org.eclipse.ui.forms.widgets.ScrolledPageBook;

import org.eclipse.ui.forms.widgets.SharedScrolledComposite;
import org.eclipse.ui.forms.widgets.LayoutComposite;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.ui.internal.forms.widgets.WrappedPageBook;

import java.lang.all;
import java.util.Set;

/**
 * ScrolledPageBook is a class that is capable of stacking several composites
 * (pages), while showing one at a time. The content is scrolled if there is
 * not enough space to fit it in the client area.
 *
 * @since 3.0
 */
public class ScrolledPageBook : SharedScrolledComposite {
    private WrappedPageBook pageBook;
    private Hashtable pages;
    private Composite emptyPage;
    private Control currentPage;
    /**
     * Creates a new instance in the provided parent
     *
     * @param parent
     */
    public this(Composite parent) {
        this(parent, SWT.H_SCROLL | SWT.V_SCROLL);
    }
    /**
     * Creates a new instance in the provided parent and with the provided
     * style.
     *
     * @param parent
     *            the control parent
     * @param style
     *            the style to use
     */
    public this(Composite parent, int style) {
        super(parent, style);
        pageBook = new WrappedPageBook(this, SWT.NULL);
        setContent(pageBook);
        pages = new Hashtable();
        setExpandHorizontal(true);
        setExpandVertical(true);
        this.addListener(SWT.Traverse, dgListener( (Event e) {
            switch (e.detail) {
                case SWT.TRAVERSE_ESCAPE :
                case SWT.TRAVERSE_RETURN :
                case SWT.TRAVERSE_TAB_NEXT :
                case SWT.TRAVERSE_TAB_PREVIOUS :
                    e.doit = true;
                    break;
                default:
            }
        }));
    }
    /**
     * Removes the default size of the composite, allowing the control to
     * shrink to the trim.
     *
     * @param wHint
     *            the width hint
     * @param hHint
     *            the height hint
     * @param changed
     *            if <code>true</code>, do not use cached values
     */
    public Point computeSize(int wHint, int hHint, bool changed) {
        Rectangle trim = computeTrim(0, 0, 10, 10);
        return new Point(trim.width, trim.height);
    }
    /**
     * Tests if the page under the provided key is currently in the book.
     *
     * @param key
     *            the page key
     * @return <code>true</code> if page exists, <code>false</code>
     *         otherwise.
     */
    public bool hasPage(Object key) {
        return pages.containsKey(key);
    }
    /**
     * Creates a new page for the provided key. Use the returned composite to
     * create children in it.
     *
     * @param key
     *            the page key
     * @return the newly created page composite
     */
    public Composite createPage(Object key) {
        Composite page = createPage();
        pages.put(key, page);
        return page;
    }
    /**
     * Returns the page book container.
     *
     * @return the page book container
     */
    public Composite getContainer() {
        return pageBook;
    }
    /**
     * Registers a page under the privided key to be managed by the page book.
     * The page must be a direct child of the page book container.
     *
     * @param key
     *            the page key
     * @param page
     *            the page composite to register
     * @see #createPage(Object)
     * @see #getContainer
     */
    public void registerPage(Object key, Control page) {
        pages.put(key, page);
    }
    /**
     * Removes the page under the provided key from the page book. Does nothing
     * if page with that key does not exist.
     *
     * @param key
     *            the page key.
     */
    public void removePage(Object key) {
        removePage(key, true);
    }
    /**
     * Removes the page under the provided key from the page book. Does nothing
     * if page with that key does not exist.
     *
     * @param key
     *            the page key.
     * @param showEmptyPage
     *            if <code>true</code>, shows the empty page
     *            after page removal.
     */
    public void removePage(Object key, bool showEmptyPage_) {
        Control page = cast(Control) pages.get(key);
        if (page !is null) {
            pages.remove(key);
            page.dispose();
            if (showEmptyPage_)
                showEmptyPage();
        }
    }
    /**
     * Shows the page with the provided key and hides the page previously
     * showing. Does nothing if the page with that key does not exist.
     *
     * @param key
     *            the page key
     */
    public void showPage(Object key) {
        Control page = cast(Control) pages.get(key);
        if (page !is null) {
            pageBook.showPage(page);
            if (currentPage !is null && currentPage !is page) {
                // switching pages - force layout
                if (null !is cast(Composite)page )
                    (cast(Composite) page).layout(false);
            }
            currentPage = page;
        } else {
            showEmptyPage();
        }
        reflow(true);
    }
    /**
     * Shows a page with no children to be used if the desire is to not show
     * any registered page.
     */
    public void showEmptyPage() {
        if (emptyPage is null) {
            emptyPage = createPage();
            emptyPage.setLayout(new GridLayout());
        }
        pageBook.showPage(emptyPage);
        currentPage = emptyPage;
        reflow(true);
    }
    /**
     * Sets focus on the current page if shown.
     */
    public bool setFocus() {
        if (currentPage !is null)
            return currentPage.setFocus();
        return super.setFocus();
    }
    /**
     * Returns the page currently showing.
     *
     * @return the current page
     */
    public Control getCurrentPage() {
        return currentPage;
    }
    private Composite createPage() {
        Composite page = new LayoutComposite(pageBook, SWT.NULL);
        page.setBackground(getBackground());
        page.setForeground(getForeground());
        page.setMenu(pageBook.getMenu());
        return page;
    }
}