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Eclipse JDT 2.0 |
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Common protocol for Java elements that must be opened before they can be
navigated or modified. Opening a textual element (such as a compilation unit)
involves opening a buffer on its contents. While open, any changes to the buffer
can be reflected in the element's structure;
see isConsistent
and makeConsistent(IProgressMonitor)
.
To reduce complexity in clients, elements are automatically opened by the Java model as element properties are accessed. The Java model maintains an LRU cache of open elements, and automatically closes elements as they are swapped out of the cache to make room for other elements. Elements with unsaved changes are never removed from the cache, and thus, if the client maintains many open elements with unsaved changes, the LRU cache can grow in size (in this case the cache is not bounded). However, as elements are saved, the cache will shrink back to its original bounded size.
To open an element, all openable parent elements must be open.
The Java model automatically opens parent elements, as it automatically opens elements.
Opening an element may provide access to direct children and other descendants,
but does not automatically open any descendents which are themselves IOpenable
.
For example, opening a compilation unit provides access to all its constituent elements,
but opening a package fragment does not open all compilation units in the package fragment.
This interface is not intended to be implemented by clients.
Method Summary | |
void |
close()
Closes this element and its buffer (if any). |
IBuffer |
getBuffer()
Returns the buffer opened for this element, or null
if this element does not have a buffer. |
boolean |
hasUnsavedChanges()
Returns true if this element is open and:
its buffer has unsaved changes, or
one of its descendants has unsaved changes, or
a working copy has been created on one of this
element's children and has not yet destroyed
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boolean |
isConsistent()
Returns whether the element is consistent with its underlying resource or buffer. |
boolean |
isOpen()
Returns whether this openable is open. |
void |
makeConsistent(IProgressMonitor progress)
Makes this element consistent with its underlying resource or buffer by updating the element's structure and properties as necessary. |
void |
open(IProgressMonitor progress)
Opens this element and all parent elements that are not already open. |
void |
save(IProgressMonitor progress,
boolean force)
Saves any changes in this element's buffer to its underlying resource via a workspace resource operation. |
Method Detail |
public void close() throws JavaModelException
Note: although close
is exposed in the API, clients are
not expected to open and close elements - the Java model does this automatically
as elements are accessed.
JavaModelException
- if an error occurs closing this elementpublic IBuffer getBuffer() throws JavaModelException
null
if this element does not have a buffer.
null
if this element does not have a buffer
JavaModelException
- if this element does not exist or if an
exception occurs while accessing its corresponding resource.public boolean hasUnsavedChanges() throws JavaModelException
true
if this element is open and:
true
if this element is open and:
JavaModelException
- if this element does not exist or if an
exception occurs while accessing its corresponding resource.public boolean isConsistent() throws JavaModelException
NOTE: Child consistency is not considered. For example, a package fragment
responds true
when it knows about all of its
compilation units present in its underlying folder. However, one or more of
the compilation units could be inconsistent.
JavaModelException
- if this element does not exist or if an
exception occurs while accessing its corresponding resource.makeConsistent(org.eclipse.core.runtime.IProgressMonitor)
public boolean isOpen()
public void makeConsistent(IProgressMonitor progress) throws JavaModelException
progress
- the given progress monitor
JavaModelException
- if the element is unable to access the contents
of its underlying resource. Reasons include:
isConsistent()
public void open(IProgressMonitor progress) throws JavaModelException
Note: although open
is exposed in the API, clients are
not expected to open and close elements - the Java model does this automatically
as elements are accessed.
progress
- the given progress monitor
JavaModelException
- if an error occurs accessing the contents
of its underlying resource. Reasons include:
public void save(IProgressMonitor progress, boolean force) throws JavaModelException
The force
parameter controls how this method deals with
cases where the workbench is not completely in sync with the local file system.
If false
is specified, this method will only attempt
to overwrite a corresponding file in the local file system provided
it is in sync with the workbench. This option ensures there is no
unintended data loss; it is the recommended setting.
However, if true
is specified, an attempt will be made
to write a corresponding file in the local file system,
overwriting any existing one if need be.
In either case, if this method succeeds, the resource will be marked
as being local (even if it wasn't before).
As a result of this operation, the element is consistent with its underlying resource or buffer.
progress
- the given progress monitorforce
- it controls how this method deals with
cases where the workbench is not completely in sync with the local file system
JavaModelException
- if an error occurs accessing the contents
of its underlying resource. Reasons include:
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Eclipse JDT 2.0 |
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