Package 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 detailed description):

  • ADDED - The element described by the delta has been added.
  • REMOVED - The element described by the delta has been removed.
  • CHANGED - The element described by the delta has been changed in some way. Specification of the type of change is provided by getFlags() which returns the following values:
    • F_ADDED_TO_CLASSPATH - 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.
    • F_ARCHIVE_CONTENT_CHANGED - The contents of an archive has changed in some way. This flag is only valid if the element is an IPackageFragmentRoot which is an archive.
    • F_CHILDREN - A child of the element has changed in some way. This flag is only valid if the element is an IParent.
    • F_CLASSPATH_REORDER - 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.
    • F_CLOSED - The underlying IProject has been closed. This flag is only valid if the element is an IJavaProject.
    • F_CONTENT - The contents of the element have been altered. This flag is only valid for elements which correspond to files.
    • F_FINE_GRAINED - The delta 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 of the element.
    • F_MODIFIERS - The modifiers on the element have changed in some way. This flag is only valid if the element is an IMember.
    • F_OPENED - The underlying IProject has been opened. This flag is only valid if the element is an IJavaProject.
    • F_REMOVED_FROM_CLASSPATH - 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.
    • F_SOURCEATTACHED - 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.
    • F_SOURCEDETACHED - 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.
    • F_SUPER_TYPES - One of the supertypes of an IType has changed.

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_SOURCEDETACHED.

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.

See Also:
Restriction:
This interface is not intended to be implemented by clients.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    ADDED
    Status constant indicating that the element has been added.
    static final int
    CHANGED
    Status constant indicating that the element has been changed, as described by the change flags.
    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.
    static final int
    F_ANNOTATIONS
    Change flag indicating that the annotations of the element have changed.
    static final int
    F_ARCHIVE_CONTENT_CHANGED
    Change flag indicating that the element's archive content on the classpath has changed.
    static final int
    F_AST_AFFECTED
    Change flag indicating that a reconcile operation has affected the compilation unit AST created in a previous reconcile operation.
    static final int
    F_CATEGORIES
    Change flag indicating that the categories of the element have changed.
    static final int
    F_CHILDREN
    Change flag indicating that there are changes to the children of the element.
    static final int
    F_CLASSPATH_ATTRIBUTES
    Change flag indicating that the attributes of the element have changed.
    static final int
    F_CLASSPATH_CHANGED
    Change flag indicating that the raw classpath (or the output folder) of a project has changed.
    static final int
    F_CLASSPATH_REORDER
    Deprecated.
    Use F_REORDER instead.
    static final int
    F_CLOSED
    Change flag indicating that the underlying IProject has been closed.
    static final int
    F_CONTENT
    Change flag indicating that the content of the element has changed.
    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.
    static final int
    F_MODIFIERS
    Change flag indicating that the modifiers of the element have changed.
    static final int
    F_MOVED_FROM
    Change flag indicating that the element was moved from another location.
    static final int
    F_MOVED_TO
    Change flag indicating that the element was moved to another location.
    static final int
    F_OPENED
    Change flag indicating that the underlying IProject has been opened.
    static final int
    F_PRIMARY_RESOURCE
    Change flag indicating that the resource of a primary compilation unit has changed.
    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.
    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.
    static final int
    F_REORDER
    Change flag indicating that the element has changed position relatively to its siblings.
    static final int
    F_RESOLVED_CLASSPATH_CHANGED
    Change flag indicating that the resolved classpath of a project has changed.
    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.
    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.
    static final int
    F_SUPER_TYPES
    Change flag indicating that one of the supertypes of an IType has changed.
    static final int
    REMOVED
    Status constant indicating that the element has been removed.

  • Method Summary

    Modifier and Type
    Method
    Description
    IJavaElementDelta[]
    getAddedChildren()
    Returns deltas for the children that have been added.
    IJavaElementDelta[]
    getAffectedChildren()
    Returns deltas for the affected (added, removed, or changed) children.
    IJavaElementDelta[]
    getAnnotationDeltas()
    Returns deltas for affected annotations (added, removed, or changed).
    IJavaElementDelta[]
    getChangedChildren()
    Returns deltas for the children which have changed.
    default IClasspathAttributeDelta[]
    getClasspathAttributeDeltas()
    Returns deltas for affected attributes (added, removed, or changed).
    CompilationUnit
    getCompilationUnitAST()
    Returns the compilation unit AST created by the last reconcile operation on this delta's element.
    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.
    org.eclipse.core.resources.IResourceDelta[]
    getResourceDeltas()
    Returns the collection of resource deltas.

  • Field Details

    • ADDED

      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:

    • REMOVED

      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:

    • CHANGED

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

    • F_CONTENT

      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:

    • F_MODIFIERS

      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:

    • F_CHILDREN

      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:

    • F_MOVED_FROM

      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:

    • F_MOVED_TO

      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:

    • F_ADDED_TO_CLASSPATH

      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:

    • F_REMOVED_FROM_CLASSPATH

      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:

    • F_CLASSPATH_REORDER

      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:

    • F_REORDER

      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:

    • F_OPENED

      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:

    • F_CLOSED

      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:

    • F_SUPER_TYPES

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

    • F_SOURCEATTACHED

      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:

    • F_SOURCEDETACHED

      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:

    • F_FINE_GRAINED

      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:

    • F_ARCHIVE_CONTENT_CHANGED

      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:

    • F_PRIMARY_WORKING_COPY

      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:

    • F_CLASSPATH_CHANGED

      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. Also see F_RESOLVED_CLASSPATH_CHANGED, which indicates that there is a change to the resolved class path. The resolved classpath can change without the raw classpath changing (e.g. if a container resolves to a different set of classpath entries). And conversely, it is possible to construct a case where the raw classpath can change without the resolved classpath changing.
      Since:
      3.0
      See Also:

    • F_PRIMARY_RESOURCE

      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:

    • F_AST_AFFECTED

      static final int F_AST_AFFECTED
      Change flag indicating that a reconcile operation has affected the compilation unit AST created in a previous reconcile operation. Use getCompilationUnitAST() to retrieve the AST (if any is available). This flag is only valid if the element is an ICompilationUnit in working copy mode.
      Since:
      3.2
      See Also:

    • F_CATEGORIES

      static final int F_CATEGORIES
      Change flag indicating that the categories of the element have changed. This flag is only valid if the element is an IMember.
      Since:
      3.2
      See Also:

    • F_RESOLVED_CLASSPATH_CHANGED

      static final int F_RESOLVED_CLASSPATH_CHANGED
      Change flag indicating that the resolved classpath of a project has changed. This flag is only valid if the element is an IJavaProject. Also see F_CLASSPATH_CHANGED, which indicates that there is a change to the raw class path. The resolved classpath can change without the raw classpath changing (e.g. if a container resolves to a different set of classpath entries). And conversely, it is possible to construct a case where the raw classpath can change without the resolved classpath changing.
      Since:
      3.4
      See Also:

    • F_ANNOTATIONS

      static final int F_ANNOTATIONS
      Change flag indicating that the annotations of the element have changed. Use getAnnotationDeltas() to get the added/removed/changed annotations. This flag is only valid if the element is an IAnnotatable.
      Since:
      3.4
      See Also:

    • F_CLASSPATH_ATTRIBUTES

      static final int F_CLASSPATH_ATTRIBUTES
      Change flag indicating that the attributes of the element have changed. Use getClasspathAttributeDeltas() to get the added/removed/changed attributes.
      Since:
      3.33
      See Also:

  • Method Details

    • getAddedChildren

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

    • getAffectedChildren

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

    • getAnnotationDeltas

      IJavaElementDelta[] getAnnotationDeltas()
      Returns deltas for affected annotations (added, removed, or changed). Returns an empty array if no annotations was affected, or if this delta's element is not an IAnnotatable.
      Returns:
      deltas for affected annotations (added, removed, or changed)
      Since:
      3.4

    • getCompilationUnitAST

      CompilationUnit getCompilationUnitAST()
      Returns the compilation unit AST created by the last reconcile operation on this delta's element. This returns a non-null value if and only if:
      Returns:
      the AST created during the last reconcile operation
      Since:
      3.2
      See Also:

    • getChangedChildren

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

    • getElement

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

    • getFlags

      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

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

    • getMovedFromElement

      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

      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

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

    • getResourceDeltas

      org.eclipse.core.resources.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

    • getClasspathAttributeDeltas

      default IClasspathAttributeDelta[] getClasspathAttributeDeltas()
      Returns deltas for affected attributes (added, removed, or changed). Returns an empty array if no attribute was affected, or if this delta's element is not for an affected IClasspathEntry.
      Returns:
      deltas for affected attributes (added, removed, or changed)
      Since:
      3.33