Package org.apache.fop.fo.expr

Interface Function

All Known Implementing Classes:
AbsFunction, BodyStartFunction, FromNearestSpecifiedValueFunction, FromParentFunction, FromTableColumnFunction, FunctionBase, InheritedPropFunction, LabelEndFunction, MaxFunction, MinFunction, OCAColorFunction, ProportionalColumnWidthFunction
public interface Function
Interface for managing XSL-FO Functions

  • Method Details

    • getRequiredArgsCount

      int getRequiredArgsCount()
      Returns:
      the number of required (non-optional) arguments that must be specified in the argument list

    • getOptionalArgsCount

      int getOptionalArgsCount()
      Returns:
      the number of non-required (optional) arguments that may be specified in the argument list, which, if specified, must follow the required arguments

    • getOptionalArgDefault

      Property getOptionalArgDefault(int index, PropertyInfo pi) throws PropertyException
      Parameters:
      index - of optional argument
      pi - property information instance that applies to property being evaluated
      Returns:
      the default property value for the optional argument at INDEX, where INDEX is with respect to optional arguments; i.e., the first optional argument position is index 0; if no default for a given index, then null is returned
      Throws:
      PropertyException - if index is greater than or equal to optional args count

    • hasVariableArgs

      boolean hasVariableArgs()
      Determine if function allows variable arguments. If it does, then they must appear after required and optional arguments, and all optional arguments must be specified.
      Returns:
      true if function permits additional variable number of arguments after required and (completely specified) optional arguments

    • getPercentBase

      PercentBase getPercentBase()
      Returns:
      the basis for percentage calculations

    • eval

      Property eval(Property[] args, PropertyInfo pi) throws PropertyException
      Evaluate the function
      Parameters:
      args - an array of Properties that should be evaluated
      pi - property information instance that applies to property being evaluated
      Returns:
      the Property satisfying the function
      Throws:
      PropertyException - for problems when evaluating the function