Eclipse JDT
Release 3.1

org.eclipse.jdt.core
Interface IJavaElementDelta


public interface IJavaElementDelta

A Java element delta describes changes in Java element between two discrete points in time. Given a delta, clients can access the element that has changed, and any children that have changed.

Deltas have a different status depending on the kind of change they represent. The list below summarizes each status (as returned by getKind) and its meaning (see individual constants for a more detailled description):

Move operations are indicated by other change flags, layered on top of the change flags described above. If element A is moved to become B, the delta for the change in A will have status REMOVED, with change flag F_MOVED_TO. In this case, getMovedToElement on delta A will return the handle for B. The delta for B will have status ADDED, with change flag F_MOVED_FROM, and getMovedFromElement on delta B will return the handle for A. (Note, the handle to A in this case represents an element that no longer exists).

Note that the move change flags only describe the changes to a single element, they do not imply anything about the parent or children of the element.

The F_ADDED_TO_CLASSPATH, F_REMOVED_FROM_CLASSPATH and F_CLASSPATH_REORDER flags are triggered by changes to a project's classpath. They do not mean that the underlying resource was added, removed or changed. For example, if a project P already contains a folder src, then adding a classpath entry with the 'P/src' path to the project's classpath will result in an IJavaElementDelta with the F_ADDED_TO_CLASSPATH flag for the IPackageFragmentRoot P/src. On the contrary, if a resource is physically added, removed or changed and this resource corresponds to a classpath entry of the project, then an IJavaElementDelta with the ADDED, REMOVED, or CHANGED kind will be fired.

Note that when a source attachment path or a source attachment root path is changed, then the flags of the delta contain both F_SOURCEATTACHED and F_SOURCEDETTACHED.

No assumptions should be made on whether the java element delta tree is rooted at the IJavaModel level or not.

IJavaElementDelta object are not valid outside the dynamic scope of the notification.

This interface is not intended to be implemented by clients.


Field Summary
static int ADDED
          Status constant indicating that the element has been added.
static int CHANGED
          Status constant indicating that the element has been changed, as described by the change flags.
static int F_ADDED_TO_CLASSPATH
          Change flag indicating that a classpath entry corresponding to the element has been added to the project's classpath.
static int F_ARCHIVE_CONTENT_CHANGED
          Change flag indicating that the element's archive content on the classpath has changed.
static int F_CHILDREN
          Change flag indicating that there are changes to the children of the element.
static int F_CLASSPATH_CHANGED
          Change flag indicating that the raw classpath (or the output folder) of a project has changed.
static int F_CLASSPATH_REORDER
          Deprecated. Use F_REORDER instead.
static int F_CLOSED
          Change flag indicating that the underlying IProject has been closed.
static int F_CONTENT
          Change flag indicating that the content of the element has changed.
static int F_FINE_GRAINED
          Change flag indicating that this is a fine-grained delta, that is, an analysis down to the members level was done to determine if there were structural changes to members.
static int F_MODIFIERS
          Change flag indicating that the modifiers of the element have changed.
static int F_MOVED_FROM
          Change flag indicating that the element was moved from another location.
static int F_MOVED_TO
          Change flag indicating that the element was moved to another location.
static int F_OPENED
          Change flag indicating that the underlying IProject has been opened.
static int F_PRIMARY_RESOURCE
          Change flag indicating that the resource of a primary compilation unit has changed.
static int F_PRIMARY_WORKING_COPY
          Change flag indicating that a compilation unit has become a primary working copy, or that a primary working copy has reverted to a compilation unit.
static int F_REMOVED_FROM_CLASSPATH
          Change flag indicating that a classpath entry corresponding to the element has been removed from the project's classpath.
static int F_REORDER
          Change flag indicating that the element has changed position relatively to its siblings.
static int F_SOURCEATTACHED
          Change flag indicating that the source attachment path or the source attachment root path of a classpath entry corresponding to the element was added.
static int F_SOURCEDETACHED
          Change flag indicating that the source attachment path or the source attachment root path of a classpath entry corresponding to the element was removed.
static int F_SUPER_TYPES
          Change flag indicating that one of the supertypes of an IType has changed.
static int REMOVED
          Status constant indicating that the element has been removed.
 
Method Summary
 IJavaElementDelta[] getAddedChildren()
          Returns deltas for the children that have been added.
 IJavaElementDelta[] getAffectedChildren()
          Returns deltas for the affected (added, removed, or changed) children.
 IJavaElementDelta[] getChangedChildren()
          Returns deltas for the children which have changed.
 IJavaElement getElement()
          Returns the element that this delta describes a change to.
 int getFlags()
          Returns flags that describe how an element has changed.
 int getKind()
          Returns the kind of this delta - one of ADDED, REMOVED, or CHANGED.
 IJavaElement getMovedFromElement()
          Returns an element describing this element before it was moved to its current location, or null if the F_MOVED_FROM change flag is not set.
 IJavaElement getMovedToElement()
          Returns an element describing this element in its new location, or null if the F_MOVED_TO change flag is not set.
 IJavaElementDelta[] getRemovedChildren()
          Returns deltas for the children which have been removed.
 IResourceDelta[] getResourceDeltas()
          Returns the collection of resource deltas.
 

Field Detail

ADDED

public static final int ADDED
Status constant indicating that the element has been added. Note that an added java element delta has no children, as they are all implicitely added.

See Also:
Constant Field Values

REMOVED

public static final int REMOVED
Status constant indicating that the element has been removed. Note that a removed java element delta has no children, as they are all implicitely removed.

See Also:
Constant Field Values

CHANGED

public static final int CHANGED
Status constant indicating that the element has been changed, as described by the change flags.

See Also:
getFlags(), Constant Field Values

F_CONTENT

public static final int F_CONTENT
Change flag indicating that the content of the element has changed. This flag is only valid for elements which correspond to files.

See Also:
Constant Field Values

F_MODIFIERS

public static final int F_MODIFIERS
Change flag indicating that the modifiers of the element have changed. This flag is only valid if the element is an IMember.

See Also:
Constant Field Values

F_CHILDREN

public static final int F_CHILDREN
Change flag indicating that there are changes to the children of the element. This flag is only valid if the element is an IParent.

See Also:
Constant Field Values

F_MOVED_FROM

public static final int F_MOVED_FROM
Change flag indicating that the element was moved from another location. The location of the old element can be retrieved using getMovedFromElement.

See Also:
Constant Field Values

F_MOVED_TO

public static final int F_MOVED_TO
Change flag indicating that the element was moved to another location. The location of the new element can be retrieved using getMovedToElement.

See Also:
Constant Field Values

F_ADDED_TO_CLASSPATH

public static final int F_ADDED_TO_CLASSPATH
Change flag indicating that a classpath entry corresponding to the element has been added to the project's classpath. This flag is only valid if the element is an IPackageFragmentRoot.

See Also:
Constant Field Values

F_REMOVED_FROM_CLASSPATH

public static final int F_REMOVED_FROM_CLASSPATH
Change flag indicating that a classpath entry corresponding to the element has been removed from the project's classpath. This flag is only valid if the element is an IPackageFragmentRoot.

See Also:
Constant Field Values

F_CLASSPATH_REORDER

public static final int F_CLASSPATH_REORDER
Deprecated. Use F_REORDER instead.

Change flag indicating that a classpath entry corresponding to the element has changed position in the project's classpath. This flag is only valid if the element is an IPackageFragmentRoot.

See Also:
Constant Field Values

F_REORDER

public static final int F_REORDER
Change flag indicating that the element has changed position relatively to its siblings. If the element is an IPackageFragmentRoot, a classpath entry corresponding to the element has changed position in the project's classpath.

Since:
2.1
See Also:
Constant Field Values

F_OPENED

public static final int F_OPENED
Change flag indicating that the underlying IProject has been opened. This flag is only valid if the element is an IJavaProject.

See Also:
Constant Field Values

F_CLOSED

public static final int F_CLOSED
Change flag indicating that the underlying IProject has been closed. This flag is only valid if the element is an IJavaProject.

See Also:
Constant Field Values

F_SUPER_TYPES

public static final int F_SUPER_TYPES
Change flag indicating that one of the supertypes of an IType has changed.

See Also:
Constant Field Values

F_SOURCEATTACHED

public static final int F_SOURCEATTACHED
Change flag indicating that the source attachment path or the source attachment root path of a classpath entry corresponding to the element was added. This flag is only valid if the element is an IPackageFragmentRoot.

See Also:
Constant Field Values

F_SOURCEDETACHED

public static final int F_SOURCEDETACHED
Change flag indicating that the source attachment path or the source attachment root path of a classpath entry corresponding to the element was removed. This flag is only valid if the element is an IPackageFragmentRoot.

See Also:
Constant Field Values

F_FINE_GRAINED

public static final int F_FINE_GRAINED
Change flag indicating that this is a fine-grained delta, that is, an analysis down to the members level was done to determine if there were structural changes to members.

Clients can use this flag to find out if a compilation unit that have a F_CONTENT change should assume that there are no finer grained changes (F_FINE_GRAINED is set) or if finer grained changes were not considered (F_FINE_GRAINED is not set).

Since:
2.0
See Also:
Constant Field Values

F_ARCHIVE_CONTENT_CHANGED

public static final int F_ARCHIVE_CONTENT_CHANGED
Change flag indicating that the element's archive content on the classpath has changed. This flag is only valid if the element is an IPackageFragmentRoot which is an archive.

Since:
2.0
See Also:
IPackageFragmentRoot.isArchive(), Constant Field Values

F_PRIMARY_WORKING_COPY

public static final int F_PRIMARY_WORKING_COPY
Change flag indicating that a compilation unit has become a primary working copy, or that a primary working copy has reverted to a compilation unit. This flag is only valid if the element is an ICompilationUnit.

Since:
3.0
See Also:
Constant Field Values

F_CLASSPATH_CHANGED

public static final int F_CLASSPATH_CHANGED
Change flag indicating that the raw classpath (or the output folder) of a project has changed. This flag is only valid if the element is an IJavaProject.

Since:
3.0
See Also:
Constant Field Values

F_PRIMARY_RESOURCE

public static final int F_PRIMARY_RESOURCE
Change flag indicating that the resource of a primary compilation unit has changed. This flag is only valid if the element is a primary ICompilationUnit.

Since:
3.0
See Also:
Constant Field Values
Method Detail

getAddedChildren

public IJavaElementDelta[] getAddedChildren()
Returns deltas for the children that have been added.

Returns:
deltas for the children that have been added

getAffectedChildren

public IJavaElementDelta[] getAffectedChildren()
Returns deltas for the affected (added, removed, or changed) children.

Returns:
deltas for the affected (added, removed, or changed) children

getChangedChildren

public IJavaElementDelta[] getChangedChildren()
Returns deltas for the children which have changed.

Returns:
deltas for the children which have changed

getElement

public IJavaElement getElement()
Returns the element that this delta describes a change to.

Returns:
the element that this delta describes a change to

getFlags

public int getFlags()
Returns flags that describe how an element has changed. Such flags should be tested using the & operand. For example:
 if ((delta.getFlags() & IJavaElementDelta.F_CONTENT) != 0) {
 	// the delta indicates a content change
 }
 

Returns:
flags that describe how an element has changed

getKind

public int getKind()
Returns the kind of this delta - one of ADDED, REMOVED, or CHANGED.

Returns:
the kind of this delta

getMovedFromElement

public IJavaElement getMovedFromElement()
Returns an element describing this element before it was moved to its current location, or null if the F_MOVED_FROM change flag is not set.

Returns:
an element describing this element before it was moved to its current location, or null if the F_MOVED_FROM change flag is not set

getMovedToElement

public IJavaElement getMovedToElement()
Returns an element describing this element in its new location, or null if the F_MOVED_TO change flag is not set.

Returns:
an element describing this element in its new location, or null if the F_MOVED_TO change flag is not set

getRemovedChildren

public IJavaElementDelta[] getRemovedChildren()
Returns deltas for the children which have been removed.

Returns:
deltas for the children which have been removed

getResourceDeltas

public IResourceDelta[] getResourceDeltas()
Returns the collection of resource deltas.

Note that resource deltas, like Java element deltas, are generally only valid for the dynamic scope of an event notification. Clients must not hang on to these objects.

Returns:
the underlying resource deltas, or null if none

Eclipse JDT
Release 3.1

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