com.google.gwt.lang

Class Array

java.lang.Object

com.google.gwt.lang.Array

public final class Array
extends Object

This is a magic class the compiler uses as a base class for injected array classes.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	queryId A representation of the necessary cast target for objects stored into this array.

Constructor Summary

Constructors

Constructor and Description
Array()

Method Summary

Modifier and Type	Method and Description
static <T> T[]	clone(T[] array) Creates a copy of the specified array.
static <T> T[]	cloneSubrange(T[] array, int fromIndex, int toIndex) Creates a copy of a subrange of the specified array.
static <T> T[]	createFrom(T[] array) Creates a new array of the exact same type and length as a given array.
static <T> T[]	createFrom(T[] array, int length) Creates an empty array of the exact same type as a given array, with the specified length.
static Array	initDim(Class<?> arrayClass, JavaScriptObject castableTypeMap, int queryId, int length, int seedType) Creates an array like "new T[a][b][c][][]" by passing in a native JSON array, [a, b, c].
static Array	initDims(Class<?>[] arrayClasses, JavaScriptObject[] castableTypeMapExprs, int[] queryIdExprs, int[] dimExprs, int count, int seedType) Creates an array like "new T[a][b][c][][]" by passing in a native JSON array, [a, b, c].
static Array	initValues(Class<?> arrayClass, JavaScriptObject castableTypeMap, int queryId, Array array) Creates an array like "new T[][]{a,b,c,d}" by passing in a native JSON array, [a, b, c, d].
static Object	setCheck(Array array, int index, Object value) Performs an array assignment, after validating the type of the value being stored.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, toString

Field Detail

queryId

protected int queryId

A representation of the necessary cast target for objects stored into this array.

See Also:

setCheck(com.google.gwt.lang.Array, int, java.lang.Object)

Constructor Detail

Array

public Array()

Method Detail

clone

public static <T> T[] clone(T[] array)

Creates a copy of the specified array.

cloneSubrange

public static <T> T[] cloneSubrange(T[] array,
                                    int fromIndex,
                                    int toIndex)

Creates a copy of a subrange of the specified array.

createFrom

public static <T> T[] createFrom(T[] array)

Creates a new array of the exact same type and length as a given array.

createFrom

public static <T> T[] createFrom(T[] array,
                                 int length)

Creates an empty array of the exact same type as a given array, with the specified length.

initDim

public static Array initDim(Class<?> arrayClass,
                            JavaScriptObject castableTypeMap,
                            int queryId,
                            int length,
                            int seedType)

Creates an array like "new T[a][b][c][][]" by passing in a native JSON array, [a, b, c].

Parameters:

arrayClass - the class of the array

castableTypeMap - the map of types to which this array can be casted, in the form of a JSON map object

queryId - the queryId of the array

length - the length of the array

seedType - the primitive type of the array; 0: null; 1: zero; 2: false; 3: long

Returns:

the new array

initDims

public static Array initDims(Class<?>[] arrayClasses,
                             JavaScriptObject[] castableTypeMapExprs,
                             int[] queryIdExprs,
                             int[] dimExprs,
                             int count,
                             int seedType)

Creates an array like "new T[a][b][c][][]" by passing in a native JSON array, [a, b, c].

Parameters:

arrayClasses - the class of each dimension of the array

castableTypeMapExprs - the JSON castableTypeMap of each dimension, from highest to lowest

queryIdExprs - the queryId of each dimension, from highest to lowest

dimExprs - the length of each dimension, from highest to lower

seedType - the primitive type of the array; 0: null; 1: zero; 2: false; 3: long

Returns:

the new array

initValues

public static Array initValues(Class<?> arrayClass,
                               JavaScriptObject castableTypeMap,
                               int queryId,
                               Array array)

Creates an array like "new T[][]{a,b,c,d}" by passing in a native JSON array, [a, b, c, d].

Parameters:

arrayClass - the class of the array

castableTypeMap - the map of types to which this array can be casted, in the form of a JSON map object

queryId - the queryId of the array

array - the JSON array that will be transformed into a GWT array

Returns:

values; having wrapped it for GWT

setCheck

public static Object setCheck(Array array,
                              int index,
                              Object value)

Performs an array assignment, after validating the type of the value being stored. The form of the type check depends on the value of queryId, as follows:

If the queryId is > 0, this indicates a normal cast check should be performed, using the queryId as the cast destination type. JavaScriptObjects cannot be stored in this case.

If the queryId == 0, this is the cast target for the Object type, in which case all types can be stored, including JavaScriptObject.

If the queryId == -1, this indicates that only JavaScriptObjects can be stored (-1 is the cast target for JavaScriptObject, by convention).

If the queryId is < -1, this indicates that both JavaScriptObjects, and Java types can be stored. In the case of Java types, the inverse of the queryId is used for castability testing. This case is provided to support arrays declared with an interface type, which has dual implementations (i.e. interface types which have both Java and JavaScriptObject implementations).

Note, by convention, a queryId of 1 is reserved for String, which is a final class, and can't implement an interface, and thus, it's inverse, -1, can safely be interpreted as a special case, as stated above.

Attempting to store an object that cannot satisfy the castability check throws an ArrayStoreException.