/*
 * Copyright 2004 by Paulo Soares.
 *
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 *
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

package com.lowagie.text.pdf;

import java.util.ArrayList;
/**
 * An optional content group is a dictionary representing a collection of graphics
 * that can be made visible or invisible dynamically by users of viewer applications.
 * In iText they are referenced as layers.
 *
 * @author Paulo Soares (psoares@consiste.pt)
 */
public class PdfLayer extends PdfDictionary implements PdfOCG {
    protected PdfIndirectReference ref;
    protected ArrayList children;
    protected PdfLayer parent;
    protected String title;

    /**
     * Holds value of property on.
     */
    private boolean on = true;
    
    /**
     * Holds value of property onPanel.
     */
    private boolean onPanel = true;
    
    PdfLayer(String title) {
        this.title = title;
    }
    
    /**
     * Creates a title layer. A title layer is not really a layer but a collection of layers
     * under the same title heading.
     * @param title the title text
     * @param writer the <CODE>PdfWriter</CODE>
     * @return the title layer
     */    
    public static PdfLayer createTitle(String title, PdfWriter writer) {
        if (title == null)
            throw new NullPointerException("Title cannot be null.");
        PdfLayer layer = new PdfLayer(title);
        writer.registerLayer(layer);
        return layer;
    }
    /**
     * Creates a new layer.
     * @param name the name of the layer
     * @param writer the writer
     */    
    public PdfLayer(String name, PdfWriter writer) {
        super(PdfName.OCG);
        setName(name);
        ref = writer.getPdfIndirectReference();
        writer.registerLayer(this);
    }
    
    String getTitle() {
        return title;
    }
    
    /**
     * Adds a child layer. Nested layers can only have one parent.
     * @param child the child layer
     */    
    public void addChild(PdfLayer child) {
        if (child.parent != null)
            throw new IllegalArgumentException("The layer '" + ((PdfString)child.get(PdfName.NAME)).toUnicodeString() + "' already has a parent.");
        child.parent = this;
        if (children == null)
            children = new ArrayList();
        children.add(child);
    }

    
    /**
     * Gets the parent layer.
     * @return the parent layer or <CODE>null</CODE> if the layer has no parent
     */    
    public PdfLayer getParent() {
        return parent;
    }
    
    /**
     * Gets the children layers.
     * @return the children layers or <CODE>null</CODE> if the layer has no children
     */    
    public ArrayList getChildren() {
        return children;
    }
    
    /**
     * Gets the <CODE>PdfIndirectReference</CODE> that represents this layer.
     * @return the <CODE>PdfIndirectReference</CODE> that represents this layer
     */    
    public PdfIndirectReference getRef() {
        return ref;
    }
    
    /**
     * Sets the name of this layer.
     * @param name the name of this layer
     */    
    public void setName(String name) {
        put(PdfName.NAME, new PdfString(name, PdfObject.TEXT_UNICODE));
    }
    
    /**
     * Gets the dictionary representing the layer. It just returns <CODE>this</CODE>.
     * @return the dictionary representing the layer
     */    
    public PdfObject getPdfObject() {
        return this;
    }
    
    /**
     * Gets the initial visibility of the layer.
     * @return the initial visibility of the layer
     */
    public boolean isOn() {
        return this.on;
    }
    
    /**
     * Sets the initial visibility of the layer.
     * @param on the initial visibility of the layer
     */
    public void setOn(boolean on) {
        this.on = on;
    }
    
    private PdfDictionary getUsage() {
        PdfDictionary usage = (PdfDictionary)get(PdfName.USAGE);
        if (usage == null) {
            usage = new PdfDictionary();
            put(PdfName.USAGE, usage);
        }
        return usage;
    }
    
    /**
     * Used by the creating application to store application-specific
     * data associated with this optional content group.
     * @param creator a text string specifying the application that created the group
     * @param subtype a string defining the type of content controlled by the group. Suggested
     * values include but are not limited to <B>Artwork</B>, for graphic-design or publishing
     * applications, and <B>Technical</B>, for technical designs such as building plans or
     * schematics
     */    
    public void setCreatorInfo(String creator, String subtype) {
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        dic.put(PdfName.CREATOR, new PdfString(creator, PdfObject.TEXT_UNICODE));
        dic.put(PdfName.SUBTYPE, new PdfName(subtype));
        usage.put(PdfName.CREATORINFO, dic);
    }
    
    /**
     * Specifies the language of the content controlled by this
     * optional content group
     * @param lang a language string which specifies a language and possibly a locale
     * (for example, <B>es-MX</B> represents Mexican Spanish)
     * @param preferred used by viewer applications when there is a partial match but no exact
     * match between the system language and the language strings in all usage dictionaries
     */    
    public void setLanguage(String lang, boolean preferred) {
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        dic.put(PdfName.LANG, new PdfString(lang, PdfObject.TEXT_UNICODE));
        if (preferred)
            dic.put(PdfName.PREFERRED, PdfName.ON);
        usage.put(PdfName.LANGUAGE, dic);
    }
    
    /**
     * Specifies the recommended state for content in this
     * group when the document (or part of it) is saved by a viewer application to a format
     * that does not support optional content (for example, an earlier version of
     * PDF or a raster image format).
     * @param export the export state
     */    
    public void setExport(boolean export) {
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        dic.put(PdfName.EXPORTSTATE, export ? PdfName.ON : PdfName.OFF);
        usage.put(PdfName.EXPORT, dic);
    }
    
    /**
     * Specifies a range of magnifications at which the content
     * in this optional content group is best viewed.
     * @param min the minimum recommended magnification factors at which the group
     * should be ON. A negative value will set the default to 0
     * @param max the maximum recommended magnification factor at which the group
     * should be ON. A negative value will set the largest possible magnification supported by the
     * viewer application
     */    
    public void setZoom(float min, float max) {
        if (min <= 0 && max < 0)
            return;
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        if (min > 0)
            dic.put(PdfName.MIN, new PdfNumber(min));
        if (max >= 0)
            dic.put(PdfName.MAX, new PdfNumber(max));
        usage.put(PdfName.ZOOM, dic);
    }

    /**
     * Specifies that the content in this group is intended for
     * use in printing
     * @param subtype a name specifying the kind of content controlled by the group;
     * for example, <B>Trapping</B>, <B>PrintersMarks</B> and <B>Watermark</B>
     * @param printstate indicates that the group should be
     * set to that state when the document is printed from a viewer application
     */    
    public void setPrint(String subtype, boolean printstate) {
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        dic.put(PdfName.SUBTYPE, new PdfName(subtype));
        dic.put(PdfName.PRINTSTATE, printstate ? PdfName.ON : PdfName.OFF);
        usage.put(PdfName.PRINT, dic);
    }

    /**
     * Indicates that the group should be set to that state when the
     * document is opened in a viewer application.
     * @param view the view state
     */    
    public void setView(boolean view) {
        PdfDictionary usage = getUsage();
        PdfDictionary dic = new PdfDictionary();
        dic.put(PdfName.VIEWSTATE, view ? PdfName.ON : PdfName.OFF);
        usage.put(PdfName.VIEW, dic);
    }
    
    /**
     * Gets the layer visibility in Acrobat's layer panel
     * @return the layer visibility in Acrobat's layer panel
     */
    public boolean isOnPanel() {
        return this.onPanel;
    }
    
    /**
     * Sets the visibility of the layer in Acrobat's layer panel. If <CODE>false</CODE>
     * the layer cannot be directly manipulated by the user. Note that any children layers will
     * also be absent from the panel.
     * @param onPanel the visibility of the layer in Acrobat's layer panel
     */
    public void setOnPanel(boolean onPanel) {
        this.onPanel = onPanel;
    }
    
}
