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java.lang.Objectorg.eclipse.emf.edit.provider.ItemProvider
This item provider implementation is a convenient reusable base that can be used for an item provider that isn't an adapter for an EMF object. This default implemention is highly functional and is plastic enough for a wide variety of uses (as will be illustrated in the examples to come). The plasticity is the reason for providing a huge number of constructors.
The children
list is implemented using ItemProvider.ItemProviderNotifyingArrayList
.
As a result, any modification of the collection (using the stanandard List
interface)
will automatically fire the correct call to each INotifyChangedListener
in the changeNotifier
.
Furthermore, IUpdateableItemParent.setParent
is called to update parent
for the objects that are added to or removed from the list,
but optionally, i.e., only if the interface is implemented---the adapterFactory
is used if it isn't null.
There is also a text
and an image
,
which can be set via setText
and setImage
to cause appropriate domain event notifications to be fired.
The set methods use the stateless adapter signature for uniformity and to support
IUpdateableItemText.setText(Object, String)
.
This class is useful as a convenient wrapper object to act as the input to a view, e.g.,
viewer.setInput(new ItemProvider(text, image, collection));lets you take a mixed collection of model objects and item providers, and show it as the elements of a structured view, i.e., as the visible roots of the view. Although a structured viewer
viewer.setInput(new ItemProvider(Collections.singleton(object)));will leave the pane title blank and show the object as the root of the structured view.
One could use more of these item providers to build up a scaffolding within views.
Consider the following block of code
which has access to a collection of INotifyChangedListener
s.
// final Collection listeners = ...; // final StructuredContentViewer contentViewer = ...; // // These create the items and build up the structure. // final ItemProvider child11 = new ItemProvider(listeners, "Child 1"); final ItemProvider child12 = new ItemProvider(listeners, "Child 2"); final ItemProvider parent1 = new ItemProvider(listeners, "Parent 1", Arrays.asList(new Object [] {child11, child12})); final ItemProvider child21 = new ItemProvider(listeners, "Child 1"); final ItemProvider child22 = new ItemProvider(listeners, "Child 2"); final ItemProvider parent2 = new ItemProvider(listeners, "Parent 2", Arrays.asList(new Object [] {child21, child22})); final ItemProvider grandParent = new ItemProvider(listeners, "Grand Parent", Arrays.asList(new Object [] {parent1, parent2})); // Set the items into the visible roots of the structured content viewer. // contentViewer.setInput(new ItemProvider("Pane Tile", Collections.singleton(grandParent))); // Create some delayed actions that modify the item structure. // if (contentViewer.isControlOkToUse()) { contentViewer.getControl().getDisplay().asyncExec (new Runnable() { public void run() { // Use standard list modification that has the effect of producing a domain event notification. // parent1.getChildren().removeAll(Arrays.asList(new Object [] {child11, child12})); contentViewer.getControl().getDisplay().asyncExec (new Runnable() { public void run() { // This also as the effect of producing a correct a domain event notification. // parent2.setText("Parent 2!"); } }); } }); }The structure will be displayed within the contentViewer and will then change a little bit later; the flickering should be noticeable if the viewer is set to auto expand.
Another common pattern of usage will be to inject scaffolding within an EMF structure. In the following example, a new factory is defined to replace the adapters for Company and Department so as to inject an item that acts as the child of the Company and the parent of each Department. (Normally, this would not be done with all these inner classes.)
ItemProviderAdapterFactory myItemProviderAdapterFactory = new ItemProviderAdapterFactory() { public Adapter createCompanyAdapter() { // This returns a new instance each time. // The instance stores an injected child that in turn will have this original object's children as its children. // return new CompanyItemProvider(this) { // Keep track of the new child added below company. // ItemProvider injectedChild; public Collection getChildren(final Object object) { // Create one on demand. // if (injectedChild == null) { injectedChild = (new ItemProvider("Injected Child") { public Collection getChildren(Object o) { // Return the department of the company. // Note that we ignore o in favour of object. // return ((Company)object).getDepartment(); } public boolean hasChildren(Object o) { // You have to make sure you override this method to match the above. // return !((Company)object).getDepartment().isEmpty(); } }); } return Collections.singleton(injectedChild); } public boolean hasChildren(Object object) { // You have to make sure you override this method to match the above. // return true; } public void notifyChanged(Notification msg) { // If the departments are affected... // Company company = (Company)msg.getNotifier(); if (msg.getStructuralFeature() == company.ePackageCompany().getCompany_Deparment()) { // If there's a child around to care... // if (injectedChild != null) { // Fire the domain event as if it came from the child. // // EATM TODO fireNotifyChanged(injectedChild, msg.getEventType(), msg.getStructuralFeature(), msg.getOldValue(), msg.getNewValue(), msg.getPostition()); } } else { // Behave as normal. // super.notifyChanged(msg); } } }; } public Adapter createDepartmentAdapter() { // This is still stateless. // if (departmentItemProvider == null) { departmentItemProvider = new DepartmentItemProvider(this) { public Object getParent(Object object) { // Use the stateful adapter of the containing parent to determine the injected item. // Company company = ((Department)object).getCompany(); ITreeItemContentProvider companyAdapter = (ITreeItemContentProvider)this.adapterFactory.adapt(company, ITreeItemContentProvider.class); if (companyAdapter != null) { // Get the first child of the company's adapter. // return companyAdapter.getChildren(company).iterator().next(); } else { return null; } } }; } // Return the single factory instance. // return departmentItemProvider; } };
Nested Class Summary | |
class |
ItemProvider.ItemProviderNotification
This class implements a Notification for an ItemProvider. |
class |
ItemProvider.ItemProviderNotifyingArrayList
This class overrides the "notify" methods to fire INotifyChangedListener calls
and it overrides the "inverse basic" methods to maintain referential integrity
by calling IUpdateableItemParent.setParent . |
Field Summary | |
protected AdapterFactory |
adapterFactory
This is the optional adapter factory that is used to get adapters for parent or child objects. |
protected IChangeNotifier |
changeNotifier
This is the optional collection used for changes to the text, parent, or children. |
protected ItemProvider.ItemProviderNotifyingArrayList |
children
This is the children returned by getChildren(Object) . |
protected Object |
image
This is the image returned by getImage(Object) . |
protected Object |
parent
This is the parent returned by getParent(Object) . |
protected String |
text
This is the text returned by getText(Object) . |
Constructor Summary | |
ItemProvider()
This creates an instance with an empty text that yields no children. |
|
ItemProvider(AdapterFactory adapterFactory)
This creates an instance with the given adapter factory and an empty text that yields no children. |
|
ItemProvider(AdapterFactory adapterFactory,
Collection children)
This creates an instance with the given adapter factory that yields the given children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text)
This creates an instance with the given adapter factor and text that yields no children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text,
Collection children)
This creates an instance with the given adapter factory and text that yields the given children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text,
Object image)
This creates an instance with the given adapter factory, text, and image that yields no children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text,
Object image,
Collection children)
This creates an instance with the given adapter factory, text and image that yields the given children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text,
Object image,
Object parent)
This creates an instance with the given adapter factory, text, image, and parent that yields no children. |
|
ItemProvider(AdapterFactory adapterFactory,
String text,
Object image,
Object parent,
Collection children)
This creates an instance with the given adapter factory, notifier, text, image, and parent that yields the given children. |
|
ItemProvider(Collection children)
This creates an instance with an empty text that yields the given children. |
|
ItemProvider(String text)
This creates an instance with the given text that yields the no children. |
|
ItemProvider(String text,
Collection children)
This creates an instance with the given text that yields the given children. |
|
ItemProvider(String text,
Object image)
This creates an instance with the given text and image that yields the no children. |
|
ItemProvider(String text,
Object image,
Collection children)
This creates an instance with the given text and image that yields the given children. |
|
ItemProvider(String text,
Object image,
Object parent)
This creates an instance with the given text, image, and parent that yields no children. |
|
ItemProvider(String text,
Object image,
Object parent,
Collection children)
This creates an instance with the given text, image, and parent that yields the given children. |
Method Summary | |
void |
addListener(INotifyChangedListener listener)
This adds another listener. |
Command |
createCommand(Object object,
EditingDomain editingDomain,
Class commandClass,
CommandParameter commandParameter)
This implements IEditingDomainItemProvider.createCommand() , returning the unexecutable
command. |
void |
dispose()
This is called to dispose the object. |
void |
fireNotifyChanged(Notification notification)
This calls notifyChanged for each listener. |
AdapterFactory |
getAdapterFactory()
This yields the optional adapter factory. |
EList |
getChildren()
This returns getChildren(this) . |
Collection |
getChildren(Object object)
This implements ITreeItemContentProvider.getChildren
return children .
|
EList |
getElements()
This returns getChildren() .
|
Collection |
getElements(Object object)
This implements IStructuredItemContentProvider.getElements
by returning getChildren(Object) .
|
Object |
getImage()
This delegates to getImage(this) . |
Object |
getImage(Object object)
This implements IItemLabelProvider.getImage
by returning image . |
Collection |
getNewChildDescriptors(Object object,
EditingDomain editingDomain,
Object sibling)
This implements IEditingDomainItemProvider.getNewChildDescriptors , returning an empty
list. |
Object |
getParent()
This returns getParent(this) . |
Object |
getParent(Object object)
This implements ITreeItemContentProvider.getParent
by returning parent . |
String |
getText()
This delegates to getText(this) . |
String |
getText(Object object)
This implements IItemLabelProvider.getText by returning text . |
String |
getUpdateableText(Object object)
This implements IUpdateableItemText.getUpdateableText ,
although the class doesn't declare that it implements this interface. |
boolean |
hasChildren()
This returns hasChildren(this) . |
boolean |
hasChildren(Object object)
This implements ITreeItemContentProvider.hasChildren
by simply testing whether children is empty.
|
void |
removeListener(INotifyChangedListener listener)
This removes a listener. |
void |
setAdapterFactory(AdapterFactory adapterFactory)
This sets the optional adapter factory. |
void |
setImage(Object image)
This delegates to setImage(this, image) . |
void |
setImage(Object object,
Object image)
This allows image to be set.
|
void |
setParent(Object parent)
This calls setParent(this, parent) . |
void |
setParent(Object object,
Object parent)
This implements IUpdateableItemParent.setParent
by delegating to setParent(Object) . |
void |
setText(Object object,
String text)
This implements IUpdateableItemText.setText ,
although the class doesn't declare that it implements this interface.
|
void |
setText(String text)
This delegates to setText(this, text) . |
String |
toString()
This returns the super result with the text appended to it. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
protected String text
getText(Object)
.
protected Object image
getImage(Object)
.
protected Object parent
getParent(Object)
.
protected ItemProvider.ItemProviderNotifyingArrayList children
getChildren(Object)
.
protected AdapterFactory adapterFactory
protected IChangeNotifier changeNotifier
Constructor Detail |
public ItemProvider()
public ItemProvider(Collection children)
public ItemProvider(String text)
public ItemProvider(String text, Collection children)
public ItemProvider(String text, Object image)
public ItemProvider(String text, Object image, Collection children)
public ItemProvider(String text, Object image, Object parent)
public ItemProvider(String text, Object image, Object parent, Collection children)
public ItemProvider(AdapterFactory adapterFactory)
public ItemProvider(AdapterFactory adapterFactory, String text)
public ItemProvider(AdapterFactory adapterFactory, String text, Object image)
public ItemProvider(AdapterFactory adapterFactory, String text, Object image, Object parent)
public ItemProvider(AdapterFactory adapterFactory, Collection children)
public ItemProvider(AdapterFactory adapterFactory, String text, Collection children)
public ItemProvider(AdapterFactory adapterFactory, String text, Object image, Collection children)
public ItemProvider(AdapterFactory adapterFactory, String text, Object image, Object parent, Collection children)
Method Detail |
public AdapterFactory getAdapterFactory()
public void setAdapterFactory(AdapterFactory adapterFactory)
public void addListener(INotifyChangedListener listener)
IChangeNotifier
addListener
in interface IChangeNotifier
public void removeListener(INotifyChangedListener listener)
IChangeNotifier
removeListener
in interface IChangeNotifier
public void fireNotifyChanged(Notification notification)
IChangeNotifier
notifyChanged
for each listener.
fireNotifyChanged
in interface IChangeNotifier
public Collection getElements(Object object)
IStructuredItemContentProvider.getElements
by returning getChildren(Object)
.
It seems that you almost always want getElements and getChildren to return the same thing, so this makes that easy.
getElements
in interface IStructuredItemContentProvider
public EList getElements()
getChildren()
.
It seems that you almost always want getElements and getChildren to return the same thing, so this makes that easy.
public Collection getChildren(Object object)
ITreeItemContentProvider.getChildren
return children
.
You can also choose to ignore the children
entirely and implement a virtual collection;
In this case, you must implement notification is some other way yourself,
and you should override hasChildren(Object)
appropriately.
getChildren
in interface ITreeItemContentProvider
public EList getChildren()
getChildren(this)
.
public boolean hasChildren(Object object)
ITreeItemContentProvider.hasChildren
by simply testing whether children
is empty.
This implementation will always be right,
however, for efficiency you may want to override it to return false for a leaf item, or true for an item that always has children.
hasChildren
in interface ITreeItemContentProvider
public boolean hasChildren()
hasChildren(this)
.
public Object getParent(Object object)
ITreeItemContentProvider.getParent
by returning parent
.
getParent
in interface ITreeItemContentProvider
public Object getParent()
getParent(this)
.
public void setParent(Object object, Object parent)
IUpdateableItemParent.setParent
by delegating to setParent(Object)
.
setParent
in interface IUpdateableItemParent
public void setParent(Object parent)
setParent(this, parent)
.
public Object getImage(Object object)
IItemLabelProvider.getImage
by returning image
.
getImage
in interface IItemLabelProvider
public Object getImage()
getImage(this)
.
public void setImage(Object object, Object image)
image
to be set.
If there is a domain notifier, it fires the appropriate domain event.
public void setImage(Object image)
setImage(this, image)
.
public String getText(Object object)
IItemLabelProvider.getText
by returning text
.
getText
in interface IItemLabelProvider
public String getText()
getText(this)
.
public String getUpdateableText(Object object)
IUpdateableItemText.getUpdateableText
,
although the class doesn't declare that it implements this interface.
public void setText(Object object, String text)
IUpdateableItemText.setText
,
although the class doesn't declare that it implements this interface.
If there is a domain notifier, it fires the appropriate domain event.
public void setText(String text)
setText(this, text)
.
public String toString()
text
appended to it.
public void dispose()
IDisposable
dispose
in interface IDisposable
public Collection getNewChildDescriptors(Object object, EditingDomain editingDomain, Object sibling)
IEditingDomainItemProvider.getNewChildDescriptors
, returning an empty
list.
public Command createCommand(Object object, EditingDomain editingDomain, Class commandClass, CommandParameter commandParameter)
IEditingDomainItemProvider.createCommand()
, returning the unexecutable
command.
|
Copyright 2001-2006 IBM Corporation and others. All Rights Reserved. |
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