/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id: IFDocumentHandler.java 1356646 2012-07-03 09:46:41Z mehdi $ */

package org.apache.fop.render.intermediate;

import java.awt.Dimension;
import java.util.Locale;

import javax.xml.transform.Result;

import org.apache.fop.accessibility.StructureTreeEventHandler;
import org.apache.fop.fonts.FontInfo;

Interface used to paint whole documents layouted by Apache FOP.

Call sequence:

startDocument()
  [setDocumentLocale()]
  startDocumentHeader()
  [handleExtension()]*
  endDocumentHeader()
  [
  startPageSequence()
    [
    startPage()
      startPageHeader()
        [handleExtension()]*
      endPageHeader()
      startPageContent()
        (#box)+
      endPageContent()
      startPageTrailer()
        (addTarget())*
      endPageTrailer()
    endPage()
    ]*
  endPageSequence()
  ]*
  startDocumentTrailer()
  [handleExtension()]*
  endDocumentTrailer()
endDocument()
#box:
startBox() (#pageContent)+ endBox() |
startViewport() (#pageContext)+ endViewport()
#pageContent:
(
  setFont() |
  drawText() |
  drawRect() |
  drawImage() |
  TODO etc. etc. |
  handleExtensionObject()
)

/**
 * Interface used to paint whole documents layouted by Apache FOP.
 * <p>
 * Call sequence:
 * <p>
 * <pre>
 * startDocument()
 *   [setDocumentLocale()]
 *   startDocumentHeader()
 *   [handleExtension()]*
 *   endDocumentHeader()
 *   [
 *   startPageSequence()
 *     [
 *     startPage()
 *       startPageHeader()
 *         [handleExtension()]*
 *       endPageHeader()
 *       startPageContent()
 *         (#box)+
 *       endPageContent()
 *       startPageTrailer()
 *         (addTarget())*
 *       endPageTrailer()
 *     endPage()
 *     ]*
 *   endPageSequence()
 *   ]*
 *   startDocumentTrailer()
 *   [handleExtension()]*
 *   endDocumentTrailer()
 * endDocument()
 *
 * #box:
 * startBox() (#pageContent)+ endBox() |
 * startViewport() (#pageContext)+ endViewport()
 *
 * #pageContent:
 * (
 *   setFont() |
 *   drawText() |
 *   drawRect() |
 *   drawImage() |
 *   TODO etc. etc. |
 *   handleExtensionObject()
 * )
 * </pre>
 */
public interface IFDocumentHandler {

    
Returns the associated intermediate format context object.
Returns:
the context object/**
     * Returns the associated intermediate format context object.
     * @return the context object
     */
    IFContext getContext();

    
Sets the JAXP Result object to receive the generated content.
Params:
result – the JAXP Result object to receive the generated content
Throws:
IFException – if an error occurs setting up the output/**
     * Sets the JAXP Result object to receive the generated content.
     * @param result the JAXP Result object to receive the generated content
     * @throws IFException if an error occurs setting up the output
     */
    void setResult(Result result) throws IFException;

    
Sets the font set to work with.
Params:
fontInfo – the font info object/**
     * Sets the font set to work with.
     * @param fontInfo the font info object
     */
    void setFontInfo(FontInfo fontInfo);

    
Returns the font set to work with.
Returns:
the font info object/**
     * Returns the font set to work with.
     * @return the font info object
     */
    FontInfo getFontInfo();

    
Sets the default font set (with no custom configuration).
Params:
fontInfo – the font info object to populate/**
     * Sets the default font set (with no custom configuration).
     * @param fontInfo the font info object to populate
     */
    void setDefaultFontInfo(FontInfo fontInfo);

    
Returns the configurator for this document handler, if any.
Returns:
the configurator or null if there's no configurator/**
     * Returns the configurator for this document handler, if any.
     * @return the configurator or null if there's no configurator
     */
    IFDocumentHandlerConfigurator getConfigurator();

    
Returns:
the structure tree builder/**
     * @return the structure tree builder
     */
    StructureTreeEventHandler getStructureTreeEventHandler();

    
Returns a document navigation handler if this feature is supported.
Returns:
the document navigation handler or null if not supported/**
     * Returns a document navigation handler if this feature is supported.
     * @return the document navigation handler or null if not supported
     */
    IFDocumentNavigationHandler getDocumentNavigationHandler();

    
Indicates whether the painter supports to handle the pages in mixed order rather than
ascending order.
Returns:
true if out-of-order handling is supported/**
     * Indicates whether the painter supports to handle the pages in mixed order rather than
     * ascending order.
     * @return true if out-of-order handling is supported
     */
    boolean supportsPagesOutOfOrder();

    
Returns the MIME type of the output format that is generated by this implementation.
Returns:
the MIME type/**
     * Returns the MIME type of the output format that is generated by this implementation.
     * @return the MIME type
     */
    String getMimeType();

    
Indicates the start of a document. This method may only be called once before any other
event method.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of a document. This method may only be called once before any other
     * event method.
     * @throws IFException if an error occurs while handling this event
     */
    void startDocument() throws IFException;

    
Indicates the end of a document. This method may only be called once after the whole
document has been handled. Implementations can release resources (close streams). It is
an error to call any event method after this method.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of a document. This method may only be called once after the whole
     * document has been handled. Implementations can release resources (close streams). It is
     * an error to call any event method after this method.
     * @throws IFException if an error occurs while handling this event
     */
    void endDocument() throws IFException;

    
Params:
locale – Locale of the document./**
    * @param locale Locale of the document.
    */
    void setDocumentLocale(Locale locale);

    
Indicates the start of the document header. This method is called right after the startDocument() method. Extensions sent to this painter between startDocumentHeader() and endDocumentHeader() apply to the document as a whole (like document metadata). 
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of the document header. This method is called right after the
     * {@link #startDocument()} method. Extensions sent to this painter between
     * {@link #startDocumentHeader()} and {@link #endDocumentHeader()} apply to the document as
     * a whole (like document metadata).
     * @throws IFException if an error occurs while handling this event
     */
    void startDocumentHeader() throws IFException;

    
Indicates the end of the document header. This method is called before the first
page sequence.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of the document header. This method is called before the first
     * page sequence.
     * @throws IFException if an error occurs while handling this event
     */
    void endDocumentHeader() throws IFException;

    
Indicates the start of the document trailer. This method is called after the last page sequence. Extensions sent to the painter between startDocumentTrailer() and endDocumentTrailer() apply to the document as a whole and is used for document-level content that is only known after all pages have been rendered (like named destinations or the bookmark tree). 
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of the document trailer. This method is called after the last
     * page sequence. Extensions sent to the painter between
     * {@link #startDocumentTrailer()} and {@link #endDocumentTrailer()} apply to the document as
     * a whole and is used for document-level content that is only known after all pages have
     * been rendered (like named destinations or the bookmark tree).
     * @throws IFException if an error occurs while handling this event
     */
    void startDocumentTrailer() throws IFException;

    
Indicates the end of the document trailer. This method is called right before the endDocument() method. 
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of the document trailer. This method is called right before the
     * {@link #endDocument()} method.
     * @throws IFException if an error occurs while handling this event
     */
    void endDocumentTrailer() throws IFException;

    
Indicates the start of a new page sequence.
Params:
id – the page sequence's identifier (or null if none is available)
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of a new page sequence.
     * @param id the page sequence's identifier (or null if none is available)
     * @throws IFException if an error occurs while handling this event
     */
    void startPageSequence(String id) throws IFException;
    
Indicates the end of a page sequence.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of a page sequence.
     * @throws IFException if an error occurs while handling this event
     */
    void endPageSequence() throws IFException;

    
Indicates the start of a new page.
Params:
index – the index of the page (0-based)
name – the page name (usually the formatted page number)
pageMasterName – the name of the simple-page-master that generated this page
size – the size of the page (equivalent to the MediaBox in PDF)
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of a new page.
     * @param index the index of the page (0-based)
     * @param name the page name (usually the formatted page number)
     * @param pageMasterName the name of the simple-page-master that generated this page
     * @param size the size of the page (equivalent to the MediaBox in PDF)
     * @throws IFException if an error occurs while handling this event
     */
    void startPage(int index, String name, String pageMasterName, Dimension size)
        throws IFException;

    
Indicates the end of a page
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of a page
     * @throws IFException if an error occurs while handling this event
     */
    void endPage() throws IFException;

    
Indicates the start of the page header.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of the page header.
     * @throws IFException if an error occurs while handling this event
     */
    void startPageHeader() throws IFException;

    
Indicates the end of the page header.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of the page header.
     * @throws IFException if an error occurs while handling this event
     */
    void endPageHeader() throws IFException;

    
Indicates the start of the page content. The method returns an IFPainter interface which is used to paint the page contents. 
Throws:
IFException – if an error occurs while handling this event
Returns:
the IFPainter for the page content/**
     * Indicates the start of the page content. The method returns an {@link IFPainter} interface
     * which is used to paint the page contents.
     * @throws IFException if an error occurs while handling this event
     * @return the IFPainter for the page content
     */
    IFPainter startPageContent() throws IFException;

    
Indicates the end of the page content. Calls to the IFPainter returned by the respective startPageContent() method are illegal. 
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of the page content. Calls to the {@link IFPainter} returned by the
     * respective {@link #startPageContent()} method are illegal.
     * @throws IFException if an error occurs while handling this event
     */
    void endPageContent() throws IFException;

    
Indicates the start of the page trailer. The page trailer is used for writing down page
elements which are only know after handling the page itself (like PDF targets).
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the start of the page trailer. The page trailer is used for writing down page
     * elements which are only know after handling the page itself (like PDF targets).
     * @throws IFException if an error occurs while handling this event
     */
    void startPageTrailer() throws IFException;

    
Indicates the end of the page trailer.
Throws:
IFException – if an error occurs while handling this event/**
     * Indicates the end of the page trailer.
     * @throws IFException if an error occurs while handling this event
     */
    void endPageTrailer() throws IFException;

    
Handles an extension object. This can be a DOM document or any arbitrary
object. If an implementation doesn't know how to handle a particular extension it is simply
ignored.
Params:
extension – the extension object
Throws:
IFException – if an error occurs while handling this event/**
     * Handles an extension object. This can be a DOM document or any arbitrary
     * object. If an implementation doesn't know how to handle a particular extension it is simply
     * ignored.
     * @param extension the extension object
     * @throws IFException if an error occurs while handling this event
     */
    void handleExtensionObject(Object extension) throws IFException;

}