Class Context

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.webkitgtk.jsc.Context

All Implemented Interfaces:

Proxy

@Generated("org.javagi.JavaGI")
public final class Context
extends GObject

JSCContext represents a JavaScript execution context, where all operations take place and where the values will be associated.

When a new context is created, a global object is allocated and the built-in JavaScript objects (Object, Function, String, Array) are populated. You can execute JavaScript in the context by using jsc_context_evaluate() or jsc_context_evaluate_with_source_uri(). It's also possible to register custom objects in the context with jsc_context_register_class().

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Context.Builder<B extends Context.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static class	Context.ContextClass

Nested classes/interfaces inherited from class GObject

GObject.NotifyCallback, GObject.ObjectClass

Constructor Summary

Constructors

Constructor	Description
Context()	Create a new Context.
Context(MemorySegment address)	Create a Context instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
protected Context	asParent()	Return this instance as if it were its parent type.
static Context.Builder<? extends Context.Builder>	builder()	A Context.Builder object constructs a Context with the specified properties.
CheckSyntaxResult	checkSyntax(String code, long length, CheckSyntaxMode mode, String uri, int lineNumber, @Nullable Out<Exception> exception)	Check the given code in this Context for syntax errors.
void	clearException()	Clear the uncaught exception in this Context if any.
Value	evaluate(String code, long length)	Evaluate code in context.
Value	evaluateInObject(String code, long length, @Nullable MemorySegment objectInstance, @Nullable Class objectClass, String uri, int lineNumber, Out<Value> object)	Evaluate code and create an new object where symbols defined in code will be added as properties, instead of being added to this Context global object.
Value	evaluateWithSourceUri(String code, long length, String uri, int lineNumber)	Evaluate code in this Context using uri as the source URI.
static @Nullable Context	getCurrent()	Get the JSCContext that is currently executing a function.
@Nullable Exception	getException()	Get the last unhandled exception thrown in this Context by API functions calls.
Value	getGlobalObject()	Get a JSCValue referencing the this Context global object
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
static @Nullable Type	getType()	Get the GType of the Context class.
Value	getValue(String name)	Get a property of this Context global object with name.
VirtualMachine	getVirtualMachine()	Get the JSCVirtualMachine where this Context was created.
void	popExceptionHandler()	Remove the last JSCExceptionHandler previously pushed to this Context with jsc_context_push_exception_handler().
void	pushExceptionHandler(@Nullable ExceptionHandler handler)	Push an exception handler in context. Whenever a JavaScript exception happens in the JSCContext, the given handler will be called.
Class	registerClass(String name, @Nullable Class parentClass, @Nullable ClassVTable vtable)	Register a custom class in this Context using the given name. If the new class inherits from another JSCClass, the parent should be passed as parentClass, otherwise null should be used.
void	setValue(String name, Value value)	Set a property of this Context global object with name and value.
void	throw_(String errorMessage)	Throw an exception to this Context using the given error message.
void	throwException(Exception exception)	Throw exception to context.
void	throwPrintf(String format, Object... varargs)	Throw an exception to this Context using the given formatted string as error message.
void	throwWithName(String errorName, String errorMessage)	Throw an exception to this Context using the given error name and message.
void	throwWithNamePrintf(String errorName, String format, Object... varargs)	Throw an exception to this Context using the given error name and the formatted string as error message.
static Context	withVirtualMachine(VirtualMachine vm)	Create a new JSCContext in virtualMachine.

Methods inherited from class GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newv, notify, notify, notifyByPspec, onNotify, ref, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, unref, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class TypeInstance

callParent, callParent, cast, getPrivate, readGClass, writeGClass

Methods inherited from class ProxyInstance

equals, handle, hashCode

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Context

public Context(MemorySegment address)

Create a Context instance for the provided memory address.

Parameters:

address - the memory address of the native object

Context

public Context()

Create a new Context.

Method Details

getType

public static @Nullable Type getType()

Get the GType of the Context class.

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected Context asParent()

Return this instance as if it were its parent type. Comparable to the Java super keyword, but ensures the parent typeclass is also used in native code.

Overrides:

asParent in class GObject

Returns:

the instance as if it were its parent type

withVirtualMachine

public static Context withVirtualMachine(VirtualMachine vm)

Create a new JSCContext in virtualMachine.

Parameters:

vm - a JSCVirtualMachine

Returns:

the newly created JSCContext.

getCurrent

public static @Nullable Context getCurrent()

Get the JSCContext that is currently executing a function. This should only be called within a function or method callback, otherwise null will be returned.

Returns:

the JSCContext that is currently executing.

checkSyntax

public CheckSyntaxResult checkSyntax(String code,
 long length,
 CheckSyntaxMode mode,
 String uri,
 int lineNumber,
 @Nullable Out<Exception> exception)

Check the given code in this Context for syntax errors. The lineNumber is the starting line number in uri; the value is one-based so the first line is 1. uri and lineNumber are only used to fill the exception. In case of errors exception will be set to a new JSCException with the details. You can pass null to exception to ignore the error details.

Parameters:

code - a JavaScript script to check

length - length of code, or -1 if code is a nul-terminated string

mode - a JSCCheckSyntaxMode

uri - the source URI

lineNumber - the starting line number

exception - return location for a JSCException, or null to ignore

Returns:

a JSCCheckSyntaxResult

clearException

public void clearException()

Clear the uncaught exception in this Context if any.

evaluate

public Value evaluate(String code,
 long length)

Evaluate code in context.

Parameters:

code - a JavaScript script to evaluate

length - length of code, or -1 if code is a nul-terminated string

Returns:

a JSCValue representing the last value generated by the script.

evaluateInObject

public Value evaluateInObject(String code,
 long length,
 @Nullable MemorySegment objectInstance,
 @Nullable Class objectClass,
 String uri,
 int lineNumber,
 Out<Value> object)

Evaluate code and create an new object where symbols defined in code will be added as properties, instead of being added to this Context global object. The new object is returned as object parameter. Similar to how jsc_value_new_object() works, if objectInstance is not null objectClass must be provided too. The lineNumber is the starting line number in uri; the value is one-based so the first line is 1. uri and lineNumber will be shown in exceptions and they don't affect the behavior of the script.

Parameters:

code - a JavaScript script to evaluate

length - length of code, or -1 if code is a nul-terminated string

objectInstance - an object instance

objectClass - a JSCClass or null to use the default

uri - the source URI

lineNumber - the starting line number

object - return location for a JSCValue.

Returns:

a JSCValue representing the last value generated by the script.

evaluateWithSourceUri

public Value evaluateWithSourceUri(String code,
 long length,
 String uri,
 int lineNumber)

Evaluate code in this Context using uri as the source URI. The lineNumber is the starting line number in uri; the value is one-based so the first line is 1. uri and lineNumber will be shown in exceptions and they don't affect the behavior of the script.

Parameters:

code - a JavaScript script to evaluate

length - length of code, or -1 if code is a nul-terminated string

uri - the source URI

lineNumber - the starting line number

Returns:

a JSCValue representing the last value generated by the script.

getException

public @Nullable Exception getException()

Get the last unhandled exception thrown in this Context by API functions calls.

Returns:

a JSCException or null if there isn't any unhandled exception in the JSCContext.

getGlobalObject

public Value getGlobalObject()

Get a JSCValue referencing the this Context global object

Returns:

a JSCValue

getValue

public Value getValue(String name)

Get a property of this Context global object with name.

Parameters:

name - the value name

Returns:

a JSCValue

getVirtualMachine

public VirtualMachine getVirtualMachine()

Get the JSCVirtualMachine where this Context was created.

Returns:

the JSCVirtualMachine where the JSCContext was created.

popExceptionHandler

public void popExceptionHandler()

Remove the last JSCExceptionHandler previously pushed to this Context with jsc_context_push_exception_handler().

pushExceptionHandler

public void pushExceptionHandler(@Nullable ExceptionHandler handler)

Push an exception handler in context. Whenever a JavaScript exception happens in the JSCContext, the given handler will be called. The default JSCExceptionHandler simply calls jsc_context_throw_exception() to throw the exception to the JSCContext. If you don't want to catch the exception, but only get notified about it, call jsc_context_throw_exception() in handler like the default one does. The last exception handler pushed is the only one used by the JSCContext, use jsc_context_pop_exception_handler() to remove it and set the previous one. When handler is removed from the context, destroyNotify is called with userData as parameter.

Parameters:

handler - a JSCExceptionHandler

registerClass

public Class registerClass(String name,
 @Nullable Class parentClass,
 @Nullable ClassVTable vtable)

Register a custom class in this Context using the given name. If the new class inherits from another JSCClass, the parent should be passed as parentClass, otherwise null should be used. The optional vtable parameter allows to provide a custom implementation for handling the class, for example, to handle external properties not added to the prototype. When an instance of the JSCClass is cleared in the context, destroyNotify is called with the instance as parameter.

Parameters:

name - the class name

parentClass - a JSCClass or null

vtable - an optional JSCClassVTable or null

Returns:

a JSCClass

setValue

public void setValue(String name,
 Value value)

Set a property of this Context global object with name and value.

Parameters:

name - the value name

value - a JSCValue

throw_

public void throw_(String errorMessage)

Throw an exception to this Context using the given error message. The created JSCException can be retrieved with jsc_context_get_exception().

Parameters:

errorMessage - an error message

throwException

public void throwException(Exception exception)

Throw exception to context.

Parameters:

exception - a JSCException

throwPrintf

public void throwPrintf(String format,
 Object... varargs)

Throw an exception to this Context using the given formatted string as error message. The created JSCException can be retrieved with jsc_context_get_exception().

Parameters:

format - the string format

varargs - the parameters to insert into the format string

throwWithName

public void throwWithName(String errorName,
 String errorMessage)

Throw an exception to this Context using the given error name and message. The created JSCException can be retrieved with jsc_context_get_exception().

Parameters:

errorName - the error name

errorMessage - an error message

throwWithNamePrintf

public void throwWithNamePrintf(String errorName,
 String format,
 Object... varargs)

Throw an exception to this Context using the given error name and the formatted string as error message. The created JSCException can be retrieved with jsc_context_get_exception().

Parameters:

errorName - the error name

format - the string format

varargs - the parameters to insert into the format string

builder

public static Context.Builder<? extends Context.Builder> builder()

A Context.Builder object constructs a Context with the specified properties. Use the various set...() methods to set properties, and finish construction with Context.Builder.build().

Returns:

the builder object