uk.ac.starlink.array
Class Requirements

java.lang.Object
  extended by 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 Summary
Requirements()
          Constructs a Requirements object with no specifications.
Requirements(AccessMode mode)
          Constructs a Requirements object specifying a given access mode.
 
Method Summary
 Object clone()
          Provides a snapshot of this object; modifying the returned object will not affect the object from which it was cloned.
 BadHandler getBadHandler()
          Gets this object's required bad value handler.
 AccessMode getMode()
          Gets an object indicating the use to which the required array will be put.
 Order getOrder()
          Gets this object's required pixel ordering scheme.
 boolean getRandom()
          Gets a flag indicating whether random access is required.
 Type getType()
          Gets this object's required data type.
 NDShape getWindow()
          Gets this object's required window; the shape it must have.
 Requirements setBadHandler(BadHandler handler)
          Sets this object's required bad value handler.
 Requirements setBadValue(Number badValue)
          Sets this object's required bad value handler to be one with a given bad value.
 Requirements setMode(AccessMode mode)
          Sets an object indicating the use to which the required array will be put.
 Requirements setOrder(Order order)
          Sets this object's required pixel ordering scheme.
 Requirements setRandom(boolean random)
          Sets a flag indicating whether random access is required.
 Requirements setShape(OrderedNDShape oshape)
          Sets this object's required ordered shape (pixel sequence).
 Requirements setType(Type type)
          Sets this object's required data type.
 Requirements setWindow(NDShape window)
          Sets this object's required window; the shape it must have.
 String toString()
           
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

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 Detail

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


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