Package org.fusesource.hawtjni.runtime
Class Callback
- java.lang.Object
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- org.fusesource.hawtjni.runtime.Callback
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public class Callback extends java.lang.Object
Instances of this class represent entry points into Java which can be invoked from operating system level callback routines.IMPORTANT: A callback is only valid when invoked on the thread which created it. The results are undefined (and typically bad) when a callback is passed out to the operating system (or other code) in such a way that the callback is called from a different thread.
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Field Summary
Fields Modifier and Type Field Description (package private) long
address
(package private) int
argCount
(package private) long
errorResult
(package private) boolean
isArrayBased
(package private) boolean
isStatic
(package private) java.lang.String
method
(package private) java.lang.Object
object
(package private) static java.lang.String
PTR_SIGNATURE
(package private) java.lang.String
signature
(package private) static java.lang.String
SIGNATURE_0
(package private) static java.lang.String
SIGNATURE_1
(package private) static java.lang.String
SIGNATURE_2
(package private) static java.lang.String
SIGNATURE_3
(package private) static java.lang.String
SIGNATURE_4
(package private) static java.lang.String
SIGNATURE_N
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Constructor Summary
Constructors Constructor Description Callback(java.lang.Object object, java.lang.String method, int argCount)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke and an argument count.Callback(java.lang.Object object, java.lang.String method, int argCount, boolean isArrayBased)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke, an argument count and a flag indicating whether or not the arguments will be passed in an array.Callback(java.lang.Object object, java.lang.String method, int argCount, boolean isArrayBased, long errorResult)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke, an argument count, a flag indicating whether or not the arguments will be passed in an array and a value to return when an exception happens.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description (package private) static long
bind(Callback callback, java.lang.Object object, java.lang.String method, java.lang.String signature, int argCount, boolean isStatic, boolean isArrayBased, long errorResult)
Allocates the native level resources associated with the callback.void
dispose()
Releases the native level resources associated with the callback, and removes all references between the callback and other objects.long
getAddress()
Returns the address of a block of machine code which will invoke the callback represented by the receiver.static boolean
getEnabled()
Returns whether or not callbacks which are triggered at the native level should cause the messages described by the matchingCallback
objects to be invoked.static int
getEntryCount()
Returns the number of times the system has been recursively entered through a callback.static java.lang.String
getPlatform()
Returns the SWT platform name.(package private) static java.lang.String
getSignature(int argCount)
static void
reset()
Immediately wipes out all native level state associated with all callbacks.static void
setEnabled(boolean enable)
Indicates whether or not callbacks which are triggered at the native level should cause the messages described by the matchingCallback
objects to be invoked.(package private) static void
unbind(Callback callback)
Releases the native level resources associated with the callback.
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Field Detail
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object
java.lang.Object object
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method
java.lang.String method
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signature
java.lang.String signature
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argCount
int argCount
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address
long address
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errorResult
long errorResult
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isStatic
boolean isStatic
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isArrayBased
boolean isArrayBased
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PTR_SIGNATURE
static final java.lang.String PTR_SIGNATURE
- See Also:
- Constant Field Values
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SIGNATURE_0
static final java.lang.String SIGNATURE_0
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SIGNATURE_1
static final java.lang.String SIGNATURE_1
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SIGNATURE_2
static final java.lang.String SIGNATURE_2
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SIGNATURE_3
static final java.lang.String SIGNATURE_3
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SIGNATURE_4
static final java.lang.String SIGNATURE_4
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SIGNATURE_N
static final java.lang.String SIGNATURE_N
- See Also:
- Constant Field Values
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Constructor Detail
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Callback
public Callback(java.lang.Object object, java.lang.String method, int argCount)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke and an argument count. Note that, if the object is an instance ofClass
it is assumed that the method is a static method on that class.- Parameters:
object
- the object to send the message tomethod
- the name of the method to invokeargCount
- the number of arguments that the method takes
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Callback
public Callback(java.lang.Object object, java.lang.String method, int argCount, boolean isArrayBased)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke, an argument count and a flag indicating whether or not the arguments will be passed in an array. Note that, if the object is an instance ofClass
it is assumed that the method is a static method on that class.- Parameters:
object
- the object to send the message tomethod
- the name of the method to invokeargCount
- the number of arguments that the method takesisArrayBased
-true
if the arguments should be passed in an array and false otherwise
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Callback
public Callback(java.lang.Object object, java.lang.String method, int argCount, boolean isArrayBased, long errorResult)
Constructs a new instance of this class given an object to send the message to, a string naming the method to invoke, an argument count, a flag indicating whether or not the arguments will be passed in an array and a value to return when an exception happens. Note that, if the object is an instance ofClass
it is assumed that the method is a static method on that class.- Parameters:
object
- the object to send the message tomethod
- the name of the method to invokeargCount
- the number of arguments that the method takesisArrayBased
-true
if the arguments should be passed in an array and false otherwiseerrorResult
- the return value if the java code throws an exception
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Method Detail
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bind
static long bind(Callback callback, java.lang.Object object, java.lang.String method, java.lang.String signature, int argCount, boolean isStatic, boolean isArrayBased, long errorResult)
Allocates the native level resources associated with the callback. This method is only invoked from within the constructor for the argument.- Parameters:
callback
- the callback to bindobject
- the callback's objectmethod
- the callback's methodsignature
- the callback's method signatureargCount
- the callback's method argument countisStatic
- whether the callback's method is staticisArrayBased
- whether the callback's method is array basederrorResult
- the callback's error result
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dispose
public void dispose()
Releases the native level resources associated with the callback, and removes all references between the callback and other objects. This helps to prevent (bad) application code from accidentally holding onto extraneous garbage.
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getAddress
public long getAddress()
Returns the address of a block of machine code which will invoke the callback represented by the receiver.- Returns:
- the callback address
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getPlatform
public static java.lang.String getPlatform()
Returns the SWT platform name.- Returns:
- the platform name of the currently running SWT
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getEntryCount
public static int getEntryCount()
Returns the number of times the system has been recursively entered through a callback.Note: This should not be called by application code.
- Returns:
- the entry count
- Since:
- 2.1
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getSignature
static java.lang.String getSignature(int argCount)
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setEnabled
public static final void setEnabled(boolean enable)
Indicates whether or not callbacks which are triggered at the native level should cause the messages described by the matchingCallback
objects to be invoked. This method is used to safely shut down SWT when it is run within environments which can generate spurious events.Note: This should not be called by application code.
- Parameters:
enable
- true if callbacks should be invoked
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getEnabled
public static final boolean getEnabled()
Returns whether or not callbacks which are triggered at the native level should cause the messages described by the matchingCallback
objects to be invoked. This method is used to safely shut down SWT when it is run within environments which can generate spurious events.Note: This should not be called by application code.
- Returns:
- true if callbacks should not be invoked
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reset
public static final void reset()
Immediately wipes out all native level state associated with all callbacks.WARNING: This operation is extremely dangerous, and should never be performed by application code.
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