Class Requirements

java.lang.Object
uk.ac.starlink.array.Requirements
All Implemented Interfaces:
Cloneable

public class Requirements extends Object implements Cloneable
Specifies a set of requirements for an array object. A Requirements object may be passed to a constructor or factory method which returns an array object to indicate some required characteristics of the returned array. In general, any fields which are filled in constitute a requirement for the given attribute, while a null (or false) value indicates that the given attribute is not required; if the method/constructor in question cannot comply it should throw an exception rather than return an object lacking any of the requirements.

The attributes which may be stipulated are as follows:

type
Numerical data type
window
Shape of the array to be returned (as a window on the underlying array)
order
Pixel ordering scheme
badHandler
Bad value handler
random
Random access required flag
mode
Access mode
The mode requirement is slightly different from the others; it is examined by some methods to determine the use to which the resulting array object will be put, and controls whether data is copied from a source into it on return, or copied out of it to a sink at close time.

The attribute setter methods are declared to return the Requirements object itself for convenience so that settings may be chained.

Version:
$Id$
Author:
Mark Taylor (Starlink)
  • Constructor Details

    • Requirements

      public Requirements()
      Constructs a Requirements object with no specifications.
    • Requirements

      public Requirements(AccessMode mode)
      Constructs a Requirements object specifying a given access mode.
  • Method Details

    • getType

      public Type getType()
      Gets this object's required data type.
      Returns:
      this object's required data type
    • setType

      public Requirements setType(Type type)
      Sets this object's required data type. If the BadHandler is set to an incompatible type, this method will clear the BadHandler field (set it to null).
      Parameters:
      type - the required data type
      Returns:
      this object
    • getWindow

      public NDShape getWindow()
      Gets this object's required window; the shape it must have.
      Returns:
      this object's required window
    • setWindow

      public Requirements setWindow(NDShape window)
      Sets this object's required window; the shape it must have.
      Parameters:
      window - the required window
      Returns:
      this object
    • getOrder

      public Order getOrder()
      Gets this object's required pixel ordering scheme.
      Returns:
      this object's required ordering
    • setOrder

      public Requirements setOrder(Order order)
      Sets this object's required pixel ordering scheme.
      Parameters:
      order - the required ordering
      Returns:
      this object
    • setShape

      public Requirements setShape(OrderedNDShape oshape)
      Sets this object's required ordered shape (pixel sequence). This is simply a shortcut way of calling setWindow and setOrder in one go.
      Parameters:
      oshape - the ordered shape (or equivalently, pixel sequence) required
      Returns:
      this object
    • getBadHandler

      public BadHandler getBadHandler()
      Gets this object's required bad value handler.
      Returns:
      this object's required bad value handler
    • setBadHandler

      public Requirements setBadHandler(BadHandler handler)
      Sets this object's required bad value handler. This must only be set if the Type is already set, and the types must match (handler.getType()==this.getType()).
      Parameters:
      handler - the required handler
      Returns:
      this object
      Throws:
      IllegalStateException - if no type has been set
      IllegalArgumentException - if the type of handler does not match the type of this object
    • setBadValue

      public Requirements setBadValue(Number badValue)
      Sets this object's required bad value handler to be one with a given bad value. This convenience method does almost exactly the same as
          setBadHandler(BadHandler.getHandler(getType(),badValue))
       
      It may only be called if the type has already been set.
      Parameters:
      badValue - the bad value which the required bad value handler must use
      Returns:
      this object
      Throws:
      IllegalStateException - if no type has been set
      IllegalArgumentException - if the type of badValue does not match the reqired type of this object
    • getRandom

      public boolean getRandom()
      Gets a flag indicating whether random access is required.
      Returns:
      true if random access is required
    • setRandom

      public Requirements setRandom(boolean random)
      Sets a flag indicating whether random access is required.
      Parameters:
      random - whether random access will be required
    • getMode

      public AccessMode getMode()
      Gets an object indicating the use to which the required array will be put.
      Returns:
      the access mode required
    • setMode

      public Requirements setMode(AccessMode mode)
      Sets an object indicating the use to which the required array will be put.
      Parameters:
      mode - the required access mode
      Returns:
      this object
    • clone

      public Object clone()
      Provides a snapshot of this object; modifying the returned object will not affect the object from which it was cloned.
      Overrides:
      clone in class Object
    • toString

      public String toString()
      Overrides:
      toString in class Object