Class ContextualRule

java.lang.Object
com.itextpdf.io.font.otf.ContextualRule
Direct Known Subclasses:
ContextualPositionRule, ContextualSubstRule

public abstract class ContextualRule extends Object
  • Constructor Details

    • ContextualRule

      public ContextualRule()
  • Method Details

    • getContextLength

      public abstract int getContextLength()
      Gets the length of the context glyph sequence defined by this rule
      Returns:
      length of the context
    • isGlyphMatchesInput

      public abstract boolean isGlyphMatchesInput (int glyphId, int atIdx)
      Checks if glyph line element matches element from input sequence of the rule.

      NOTE: rules do not contain the first element of the input sequence, the first element is defined by rule position in substitution table. Therefore atIdx shall not be 0.
      Parameters:
      glyphId - glyph code id
      atIdx - index in the rule sequence. Shall be: 0 < atIdx < getContextLength()
      Returns:
      true if glyph matches element
    • getLookaheadContextLength

      public int getLookaheadContextLength()
      Gets the length of the lookahead context glyph sequence defined by this rule
      Returns:
      length of the lookahead context
    • getBacktrackContextLength

      public int getBacktrackContextLength()
      Gets the length of the backtrack context glyph sequence defined by this rule
      Returns:
      length of the backtrack context
    • isGlyphMatchesLookahead

      public boolean isGlyphMatchesLookahead (int glyphId, int atIdx)
      Checks if glyph line element matches element from lookahead sequence of the rule.
      Parameters:
      glyphId - glyph code id
      atIdx - index in rule sequence. Shall be: 0 <= atIdx < getLookaheadContextLength()
      Returns:
      true if glyph matches element from lookahead sequence
    • isGlyphMatchesBacktrack

      public boolean isGlyphMatchesBacktrack (int glyphId, int atIdx)
      Checks if glyph line element matches element from backtrack sequence of the rule.
      Parameters:
      glyphId - glyph code id
      atIdx - index in rule sequence. Shall be: 0 <= atIdx < getBacktrackContextLength()
      Returns:
      true if glyph matches element from backtrack sequence