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Class org.ifarchive.glk.OpaqueObject

java.lang.Object
   |
   +----org.ifarchive.glk.OpaqueObject

public class OpaqueObject

extends Object

This class contains general methods for handling any type of Glk object. Objects supported by the library have particular subclasses such as Window or Stream. You will only need to deal with OpaqueObject directly if the underlying Glk library contains object types not supported in this wrapper library.

clFileRef

Glk class number for file references

clSoundChannel

Glk class number for sound channels

clStream

Glk class number for streams

clWindow

Glk class number for windows

m_dispid

Reference to the underlying Glk object.

m_glkClass

The number of the Glk class to which this object belongs.

m_jrock

Rock given to this object if it was created within Java.

OpaqueObject(int, int)

Constructor.

castRock(Object)

Convert a Java rock to a Glk rock.

destroy()

Destroy this object and the underlying Glk object.

finalize()

If the Glk object is still in existence when this object is garbage-collected, destroy it.

getClassCount()

Count Glk classes.

getDispatchRock()

Get this object's dispatch rock.

getRock()

Return this object's rock.

iterate(int, OpaqueObject, Object[])

Generalised iterator.

setRegistry(ObjectRegistry)

Set an opaque object registry.

toString()

Text representation of this object.

 protected int m_dispid

Reference to the underlying Glk object. This is a unique integer; the C layer translates it to a pointer. If m_dispid is 0, the Glk object has been destroyed by the Glk library.

 protected Object m_jrock

Rock given to this object if it was created within Java. If this is null, the object was created by Glk, and its rock must be found by a glk_get_*_rock() call.

 protected int m_glkClass

The number of the Glk class to which this object belongs.

See Also:

clWindow, clStream, clFileRef, clSoundChannel

 public static final int clWindow

Glk class number for windows

 public static final int clStream

Glk class number for streams

 public static final int clFileRef

Glk class number for file references

 public static final int clSoundChannel

Glk class number for sound channels

 protected OpaqueObject(int glkClass,
                        int dispid)

Constructor.

Parameters:

glkClass - The Glk class this object is in.

dispid - The dispatch ID assigned to this object.

 public String toString()

Text representation of this object.

Returns:

A text string containing this object's Glk class, identity, and rock.

Overrides:

toString in class Object

 public static OpaqueObject iterate(int glkClass,
                                    OpaqueObject o,
                                    Object r[])

Generalised iterator. For a given object, find the next object of that class (ordering is arbitrary, but this will find all objects of the chosen class). If the parameter "o" is null, the first object of that class is returned.

Parameters:

glkClass - Glk class number of objects to iterate over

o - null, or an object of the correct class.

r - If not null, r[0] will be set to the returned object's rock.

Returns:

The next object, or null if there is no next object

 protected void finalize()

If the Glk object is still in existence when this object is garbage-collected, destroy it.

Overrides:

finalize in class Object

 protected void destroy()

Destroy this object and the underlying Glk object. This method must be overridden in subclasses since Glk has no way of destroying an object of unknown type.

 public Object getRock()

Return this object's rock. If the object was created by Glk, the rock will be of class Long. Otherwise it can be any class.

Returns:

The object's rock.

 protected static int castRock(Object object)

Convert a Java rock to a Glk rock.

Glk for Java allows a rock to be an object of any type, by storing the rock in the Java layer rather than the underlying Glk layer. However, if the object really is a number, then there's no harm it setting it at the Glk level as well as the Java level.

Parameters:

object - Any object.

Returns:

If object is a number, its integer value. Otherwise 0.

 public static int getClassCount()

Count Glk classes.

Returns:

The number of Glk object classes in the underlying Glk library.

 public Object getDispatchRock()

Get this object's dispatch rock. This will only have been set if an opaque object registry is in use.

Returns:

The dispatch rock.

 public static void setRegistry(ObjectRegistry r)

Set an opaque object registry. It will be called when opaque objects are created or destroyed.

Parameters:

r - An instance of your object registry.

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