Package org.apache.fop.layoutmgr

Class PageProvider

java.lang.Object
org.apache.fop.layoutmgr.PageProvider
All Implemented Interfaces:
Constants
public class PageProvider extends Object implements Constants

This class delivers Page instances. It also caches them as necessary.

Additional functionality makes sure that surplus instances that are requested by the page breaker are properly discarded, especially in situations where hard breaks cause blank pages. The reason for that: The page breaker sometimes needs to preallocate additional pages since it doesn't know exactly until the end how many pages it really needs.

  • Field Details

    • RELTO_PAGE_SEQUENCE

      public static final int RELTO_PAGE_SEQUENCE
      Indices are evaluated relative to the first page in the page-sequence.
      See Also:

    • RELTO_CURRENT_ELEMENT_LIST

      public static final int RELTO_CURRENT_ELEMENT_LIST
      Indices are evaluated relative to the first page in the current element list.
      See Also:

    • skipPagePositionOnly

      protected boolean skipPagePositionOnly

  • Constructor Details

    • PageProvider

      public PageProvider(AreaTreeHandler ath, PageSequence ps)
      Main constructor.
      Parameters:
      ath - the area tree handler
      ps - The page-sequence the provider operates on

  • Method Details

    • initialize

      public void initialize()

    • setStartOfNextElementList

      public void setStartOfNextElementList(int startPage, int startColumn, boolean spanAll)
      The page breaker notifies the provider about the page number an element list starts on so it can later retrieve PageViewports relative to this first page.
      Parameters:
      startPage - the number of the first page for the element list.
      startColumn - the starting column number for the element list.
      spanAll - true if the current element list is for a column-spanning section

    • setLastPageIndex

      public void setLastPageIndex(int index)
      Sets the index of the last page. This is done as soon as the position of the last page is known or assumed.
      Parameters:
      index - the index relative to the first page in the page-sequence

    • getAvailableBPD

      public int getAvailableBPD(int index)
      Returns the available BPD for the part/page indicated by the index parameter. The index is the part/page relative to the start of the current element list. This method takes multiple columns into account.
      Parameters:
      index - zero-based index of the requested part/page
      Returns:
      the available BPD

    • compareIPDs

      public int compareIPDs(int index)
      Compares the IPD of the given part with the following one.
      Parameters:
      index - index of the current part
      Returns:
      a negative integer, zero or a positive integer as the current IPD is less than, equal to or greater than the IPD of the following part

    • getStartingPartIndexForLastPage

      public int getStartingPartIndexForLastPage(int partCount)
      Returns the part index (0<x<partCount) which denotes the first part on the last page generated by the current element list.
      Parameters:
      partCount - Number of parts determined by the breaking algorithm
      Returns:
      the requested part index

    • getPage

      public Page getPage(boolean isBlank, int index, int relativeTo)
      Returns a Page.
      Parameters:
      isBlank - true if this page is supposed to be blank.
      index - Index of the page (see relativeTo)
      relativeTo - Defines which value the index parameter should be evaluated relative to. (One of PageProvider.RELTO_*)
      Returns:
      the requested Page

    • getPage

      protected Page getPage(boolean isBlank, int index)
      Returns a Page.
      Parameters:
      isBlank - true if the Page should be a blank one
      index - the Page's index
      Returns:
      a Page instance

    • discardCacheStartingWith

      protected void discardCacheStartingWith(int index)

    • getIndexOfCachedLastPage

      public int getIndexOfCachedLastPage()

    • getLastPageIndex

      public int getLastPageIndex()

    • getLastPageIPD

      public int getLastPageIPD()

    • getCurrentIPD

      public int getCurrentIPD()

    • getNextIPD

      public int getNextIPD()

    • getCurrentColumnCount

      public int getCurrentColumnCount()