Class LocationTextExtractionStrategy

java.lang.Object
com.itextpdf.text.pdf.parser.LocationTextExtractionStrategy
All Implemented Interfaces:
RenderListener, TextExtractionStrategy
public class LocationTextExtractionStrategy extends Object implements TextExtractionStrategy
Development preview - this class (and all of the parser classes) are still experiencing heavy development, and are subject to change both behavior and interface.
A text extraction renderer that keeps track of relative position of text on page The resultant text will be relatively consistent with the physical layout that most PDF files have on screen.
This renderer keeps track of the orientation and distance (both perpendicular and parallel) to the unit vector of the orientation. Text is ordered by orientation, then perpendicular, then parallel distance. Text with the same perpendicular distance, but different parallel distance is treated as being on the same line.
This renderer also uses a simple strategy based on the font metrics to determine if a blank space should be inserted into the output.
Since:
5.0.2

  • Field Details

  • Constructor Details

    • LocationTextExtractionStrategy

      public LocationTextExtractionStrategy()
      Creates a new text extraction renderer.

    • LocationTextExtractionStrategy

      public LocationTextExtractionStrategy(LocationTextExtractionStrategy.TextChunkLocationStrategy strat)
      Creates a new text extraction renderer, with a custom strategy for creating new TextChunkLocation objects based on the input of the TextRenderInfo.
      Parameters:
      strat - the custom strategy

  • Method Details

    • beginTextBlock

      public void beginTextBlock()
      Description copied from interface: RenderListener
      Called when a new text block is beginning (i.e. BT)
      Specified by:
      beginTextBlock in interface RenderListener
      See Also:

    • endTextBlock

      public void endTextBlock()
      Description copied from interface: RenderListener
      Called when a text block has ended (i.e. ET)
      Specified by:
      endTextBlock in interface RenderListener
      See Also:

    • startsWithSpace

      private boolean startsWithSpace(String str)
      Parameters:
      str -
      Returns:
      true if the string starts with a space character, false if the string is empty or starts with a non-space character

    • endsWithSpace

      private boolean endsWithSpace(String str)
      Parameters:
      str -
      Returns:
      true if the string ends with a space character, false if the string is empty or ends with a non-space character

    • filterTextChunks

      private List<LocationTextExtractionStrategy.TextChunk> filterTextChunks(List<LocationTextExtractionStrategy.TextChunk> textChunks, LocationTextExtractionStrategy.TextChunkFilter filter)
      Filters the provided list with the provided filter
      Parameters:
      textChunks - a list of all TextChunks that this strategy found during processing
      filter - the filter to apply. If null, filtering will be skipped.
      Returns:
      the filtered list
      Since:
      5.3.3

    • isChunkAtWordBoundary

      protected boolean isChunkAtWordBoundary(LocationTextExtractionStrategy.TextChunk chunk, LocationTextExtractionStrategy.TextChunk previousChunk)
      Determines if a space character should be inserted between a previous chunk and the current chunk. This method is exposed as a callback so subclasses can fine time the algorithm for determining whether a space should be inserted or not. By default, this method will insert a space if the there is a gap of more than half the font space character width between the end of the previous chunk and the beginning of the current chunk. It will also indicate that a space is needed if the starting point of the new chunk appears *before* the end of the previous chunk (i.e. overlapping text).
      Parameters:
      chunk - the new chunk being evaluated
      previousChunk - the chunk that appeared immediately before the current chunk
      Returns:
      true if the two chunks represent different words (i.e. should have a space between them). False otherwise.

    • getResultantText

      public String getResultantText(LocationTextExtractionStrategy.TextChunkFilter chunkFilter)
      Gets text that meets the specified filter If multiple text extractions will be performed for the same page (i.e. for different physical regions of the page), filtering at this level is more efficient than filtering using FilteredRenderListener - but not nearly as powerful because most of the RenderInfo state is not captured in LocationTextExtractionStrategy.TextChunk
      Parameters:
      chunkFilter - the filter to to apply
      Returns:
      the text results so far, filtered using the specified filter

    • getResultantText

      public String getResultantText()
      Returns the result so far.
      Specified by:
      getResultantText in interface TextExtractionStrategy
      Returns:
      a String with the resulting text.

    • dumpState

      private void dumpState()
      Used for debugging only

    • renderText

      public void renderText(TextRenderInfo renderInfo)
      Description copied from interface: RenderListener
      Called when text should be rendered
      Specified by:
      renderText in interface RenderListener
      Parameters:
      renderInfo - information specifying what to render
      See Also:

    • compareInts

      private static int compareInts(int int1, int int2)
      Parameters:
      int1 -
      int2 -
      Returns:
      comparison of the two integers

    • renderImage

      public void renderImage(ImageRenderInfo renderInfo)
      no-op method - this renderer isn't interested in image events
      Specified by:
      renderImage in interface RenderListener
      Parameters:
      renderInfo - information specifying what to render
      Since:
      5.0.1
      See Also: