I am building a preference page extending the FieldEditorPreferencePage class.
This is the code (some obvious code not displayed):
public class PreferencePage extends FieldEditorPreferencePage implements IWorkbenchPreferencePage {
public static final String PREF_KEY_1 = "checkBoxPref";
public static final String PREF_KEY_2 = "filePref";
private FileFieldEditor pathField;
private BooleanFieldEditor yesOrNoField;
private Composite pathFieldParent;
#Override
public void init(IWorkbench workbench) {
setPreferenceStore(new ScopedPreferenceStore(InstanceScope.INSTANCE, Activator.PLUGIN_ID));
}
#Override
protected void createFieldEditors() {
this.yesOrNoField = new BooleanFieldEditor(PREF_KEY_1, "Check this box!", getFieldEditorParent());
this.pathFieldParent = getFieldEditorParent();
this.pathField = new FileFieldEditor(PREF_KEY_2, "Path:", this.pathFieldParent);
addField(this.yesOrNoField);
addField(this.pathField);
boolean isChecked = getPreferenceStore().getBoolean(PREF_KEY_1);
updatePathFieldEnablement(! isChecked);
}
/**
* Updates the fields according to entered values
*/
private void updatePathFieldEnablement(boolean enabled) {
this.pathField.setEnabled(enabled, this.pathFieldParent);
}
#SuppressWarnings("boxing")
#Override
public void propertyChange(PropertyChangeEvent event) {
if (event.getProperty().equals(FieldEditor.VALUE) && event.getSource() == this.yesOrNoField) {
updatePathFieldEnablement(! (boolean) event.getNewValue());
}
super.propertyChange(event);
}
}
The propertyChange method is there to enable/disable the FileFieldEditor depending on the BooleanFieldEditor value.
It works OK if I change the BooleanFieldEditor valeu by checking or unchecking it, but the propertyChange is not called when I hit the "Restore default values" button.
Do someone see a reason for that?
OK, I think I've got my response.
I went further in my investigation and I got to this code which seems suspect to me:
In class BooleanFieldEditor :
#Override
protected void doLoadDefault() {
if (checkBox != null) {
boolean value = getPreferenceStore().getDefaultBoolean(getPreferenceName());
checkBox.setSelection(value);
wasSelected = value;
}
}
and in class StringFieldEditor
#Override
protected void doLoadDefault() {
if (textField != null) {
String value = getPreferenceStore().getDefaultString(
getPreferenceName());
textField.setText(value);
}
valueChanged();
}
We can see that the FileFieldEditor (that inherits from StringFieldEditor) launches an PropertyChangeEvent to its listeners (valueChanged();) but not the BooleanFieldEditor. I did not find any code indicating that BooleanFieldEditor are using another mechanism. I think this is a bug in jFace.
To get around this problem, I just had to override the FieldEditorPreferencePage#performDefaults method and the result's fine.
Related
I am trying to Update my Custom ListView which is fed by two String Arrays:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getStringArray(ARG_PARAM1);
mParam2 = getArguments().getStringArray(ARG_PARAM2);
}
setupListView();
}
private void setupListView() {
listItemList = new ArrayList();
if (mParam1 != null && mParam2 != null && mParam1.length == mParam2.length) {
for (int i = 0; i < mParam1.length; i++) {
listItemList.add(new MyListItem(mParam1[i], (mParam2[i]).substring(0, 75) + "..."));
}
} else {
listItemList.add(new MyListItem("Loading...", "Swipe Down for Update"));
}
mAdapter = new MyListAdapter(getActivity(), listItemList);
}
mParam1 and mParam2 are Values which are fetched by an XML parser (IntentService) class in the MainActivity which i can show if needed.
Now, if i am to fast, and the mPara1 and mPara2 is empty there won´t be any ListView shown. Now i want to solve this by some AsyncTask or IntentService whatever is useful. I tried AsyncTask, which didn´t work at all. I tried notifyDataSetChanged() which didn´t work too...
Now, how could i solve this....
Using AsyncTask i have the problem that i don´t know how to passt the two Arrays to publishProgress() correctly
THis is how my AsyncTask looks like:
class UpdateListView extends AsyncTask<Void, String, Void> {
private MyListAdapter adapter;
private ArrayList listItemList;
#Override
protected void onPreExecute() {
adapter = (MyListAdapter) mListView.getAdapter();
}
#Override
protected Void doInBackground(Void... params) {
for (String item1 : mParam1) {
publishProgress(item1);
}
return null;
}
#Override
protected void onProgressUpdate(String... values) {
adapter.add(new MyListItem(values[0], values[1]));
}
#Override
protected void onPostExecute(Void result) {
Log.d("onPostExecute", "Added successfully");
}
}
Okay solved it...My Fragments are running in same Activity where the Data is loaded in, so i just created getter and setter in MainActivity and access them in the needed Fragment via
String[] titles =(MainActivity) getActivity()).getTitlesArray();
String[] text=(MainActivity) getActivity()).getTextArray();
Whatever i do trying setting Bundle with
bundle.putStringArray(TITLES,titles);
doesn´t work. Should work using parceable/serializable class but didn´t try...
I am creating an Eclipse RCP application with multiple views. One of my views is a multi-page editor view. Each of those pages has a a master/details block. I need to register all of those TableViewers as selection providers for my other view to listen to.
After much research online, I came across this article about multiple selection providers in a single view. I followed the instructions to create this selection provider for multiple viewers.
class MyMultipleSelectionProvider implements ISelectionProvider {
private final ListenerList selectionListeners = new ListenerList();
private ISelectionProvider delegate;
private final ISelectionChangedListener selectionListener = new ISelectionChangedListener() {
#Override
public void selectionChanged(final SelectionChangedEvent event) {
if (event.getSelectionProvider() == AdaptabilityProfileSelectionProvider.this.delegate) {
fireSelectionChanged( event.getSelection() );
}
}
};
/**
* Sets a new selection provider to delegate to. Selection listeners
* registered with the previous delegate are removed before.
*
* #param newDelegate new selection provider
*/
public void setSelectionProviderDelegate(final ISelectionProvider newDelegate) {
if (this.delegate == newDelegate) {
return;
}
if (this.delegate != null) {
this.delegate.removeSelectionChangedListener(this.selectionListener);
}
this.delegate = newDelegate;
if (newDelegate != null) {
newDelegate.addSelectionChangedListener(this.selectionListener);
fireSelectionChanged(newDelegate.getSelection());
}
}
#Override
public void addSelectionChangedListener(final ISelectionChangedListener listener) {
this.selectionListeners.add(listener);
}
#Override
public ISelection getSelection() {
return this.delegate == null ? null : this.delegate.getSelection();
}
#Override
public void removeSelectionChangedListener(final ISelectionChangedListener listener) {
this.selectionListeners.remove(listener);
}
#Override
public void setSelection(final ISelection selection) {
if (this.delegate != null) {
this.delegate.setSelection(selection);
}
}
protected void fireSelectionChanged(final ISelection selection) {
fireSelectionChanged(this.selectionListeners, selection);
}
private void fireSelectionChanged(final ListenerList list, final ISelection selection) {
final SelectionChangedEvent event = new SelectionChangedEvent(this.delegate, selection);
final Object[] listeners = list.getListeners();
for (int i = 0; i < listeners.length; i++) {
final ISelectionChangedListener listener = (ISelectionChangedListener) listeners[i];
listener.selectionChanged(event);
}
}
}
I added a focusListener on all of the edior's viewers so they become the delegate:
tree.addFocusListener(new FocusAdapter() {
#Override
public void focusGained(final FocusEvent e) {
editor.getSelectionProvider().setSelectionProviderDelegate(MyEditorPage.this.treeViewer);
}
});
And I registered this as the selection provider for my editor:
site.setSelectionProvider( this.selectionProvider );
Then, within my view that needs to hear about the selection, I registered a selection listener for this editor:
getSite().getPage().addSelectionListener(MyEditor.ID, this.selectionListener);
When I run the application, I see that the delegate is being changed and the selection events are being fired. However, the listener list is empty.
I am never calling addSelectionChangeListener() directly. I was under the impression that that was what the selection service is for. Am I wrong? Should I be calling it? If so, when? If not, who is supposed to be adding the listener, and why isn't it happening?
If your code is based on FormEditor (or MultiPageEditorPart) then the selection provider is set to MultiPageSelectionProvider at the end of the init method. This may be overriding your site.setSelectionProvider call.
Using:
#Override
public void init(IEditorSite site, IEditorInput input)
throws PartInitException {
super.init(site, input);
site.setSelectionProvider(this.selectionProvider);
}
should make sure your provider is the one used.
I want to create a Cell factory that returns a TableCell that behaves exactly like TextFieldTableCell, with the following difference: When it loses focus, it commits the changes.
My code is very simple:
public final class TextFieldCellFactory<S, T> implements Callback<TableColumn<S, T>, TableCell<S, T>> {
#Override
public TableCell<S, T> call(TableColumn<S, T> p) {
class EditingCell extends TextFieldTableCell {
public EditingCell() {
super();
setConverter(new DefaultStringConverter());
focusedProperty().addListener(new ChangeListener() {
#Override
public void changed(ObservableValue observable, Object oldValue, Object newValue) {
System.out.println("changed!");
System.out.println("getText() = " + getText());
System.out.println("textProperty() = " + textProperty().get());
System.out.println("getItem = " + getItem());
}
});
}
#Override
public void startEdit() {
super.startEdit();
}
#Override
public void cancelEdit() {
super.cancelEdit();
}
}
return new EditingCell();
}
}
As you see I add a change listener in the focusedProperty. The problem is that the change method is not called (nothing is printed).
How can I get the desired behaviour? Thank you.
Basically, you have to register the listener with the textField's (not the cell's) focusedProperty. As the textfield is a private field of super, it's not directly accessible - you have to look it up once after it was added to the cell. That's when an edit was started for the first time:
private TextField myTextField;
#Override
public void startEdit() {
super.startEdit();
if (isEditing() && myTextField == null) {
// most simple case, assuming that there is no graphic other than the field
// TBD: implement the general case: walk the tree and find the field
myTextField = (TextField) getGraphic();
myTextField.focusedProperty().addListener((e, old, nvalue) -> {
if (!nvalue) {
T edited = getConverter().fromString(myTextField.getText());
commitEdit(edited);
}
});
}
}
Some notes:
this is a workaround around an open issue (vote for it!)
since jdk8, it's not entirely functional: won't commit if you click somewhere else inside the table
a recent answer uses a binding approach which might or not be fully functional (didn't test)
I have implemented a GEF editor for a graph-like EMF model, with a remove command for a certain type of node in the graph. I think I've done all the necessary steps in order to make this set up work (vainolo's blog has been a great help).
However, when I'm deleting a model element, the view doesn't get refreshed, i.e., the figure for the model element isn't removed from the editor view, and I have no idea why. I'd be extremely grateful if somebody could have a look at my sources and point me to any problems (and possibly solutions :)). Many thanks in advance!
Below are what I think are the important classes for this issue. Please do let me know should I add further code/edit the code, etc. (I've left out code that I thought doesn't help, e.g., getters and setters, class variables). Thanks!
DiagramEditPart
public class DiagramEditPart extends AbstractGraphicalEditPart {
public DiagramEditPart(Diagram model) {
this.setModel(model);
adapter = new DiagramAdapter();
}
#Override protected IFigure createFigure() {
Figure figure = new FreeformLayer();
return figure;
}
#Override protected void createEditPolicies() {
installEditPolicy(EditPolicy.LAYOUT_ROLE, new DiagramXYLayoutPolicy());
}
#Override protected List<EObject> getModelChildren() {
List<EObject> allModelObjects = new ArrayList<EObject>();
if (((Diagram) getModel()).getMyNodes() != null)
allModelObjects.addAll(((Diagram) getModel()).getMyNodes());
return allModelObjects;
}
#Override public void activate() {
if(!isActive()) {
((Diagram) getModel()).eAdapters().add(adapter);
}
super.activate();
}
#Override public void deactivate() {
if(isActive()) {
((Diagram) getModel()).eAdapters().remove(adapter);
}
super.deactivate();
}
public class DiagramAdapter implements Adapter {
#Override public void notifyChanged(Notification notification) {
switch (notification.getEventType()) {
case Notification.REMOVE: refreshChildren();
break;
default:
break;
}
}
#Override public Notifier getTarget() {
return (Diagram) getModel();
}
#Override public void setTarget(Notifier newTarget) {
// Do nothing.
}
#Override public boolean isAdapterForType(Object type) {
return type.equals(Diagram.class);
}
}
}
MyNodeEditPart
public class MyNodeEditPart extends AbstractGraphicalEditPart {
public MyNodeEditPart(MyNode model) {
this.setModel(model);
adapter = new MyNodeAdapter();
}
#Override protected IFigure createFigure() {
return new MyNodeFigure();
}
#Override protected void createEditPolicies() {
installEditPolicy(EditPolicy.COMPONENT_ROLE, new MyNodeComponentEditPolicy());
}
#Override protected void refreshVisuals() {
MyNodeFigure figure = (MyNodeFigure) getFigure();
DiagramEditPart parent = (DiagramEditPart) getParent();
Dimension labelSize = figure.getLabel().getPreferredSize();
Rectangle layout = new Rectangle((getParent().getChildren().indexOf(this) * 50),
(getParent().getChildren().indexOf(this) * 50), (labelSize.width + 20),
(labelSize.height + 20));
parent.setLayoutConstraint(this, figure, layout);
}
public List<Edge> getModelSourceConnections() {
if ((MyNode) getModel() != null && ((MyNode) getModel()).getDiagram() != null) {
ArrayList<Edge> sourceConnections = new ArrayList<Edge>();
for (Edge edge : ((MyNode) getModel()).getDiagram().getOutEdges(((MyNode) getModel()).getId())) {
sourceConnections.add(edge);
}
return sourceConnections;
}
return null;
}
// + the same method for targetconnections
#Override public void activate() {
if (!isActive()) {
((MyNode) getModel()).eAdapters().add(adapter);
}
super.activate();
}
#Override public void deactivate() {
if (isActive()) {
((MyNode) getModel()).eAdapters().remove(adapter);
}
super.deactivate();
}
public class MyNodeAdapter implements Adapter {
#Override
public void notifyChanged(Notification notification) {
refreshVisuals();
}
#Override
public Notifier getTarget() {
return (MyNode) getModel();
}
#Override
public void setTarget(Notifier newTarget) {
// Do nothing
}
#Override
public boolean isAdapterForType(Object type) {
return type.equals(MyNode.class);
}
}
}
MyNodeComponentEditPolicy
public class MyNodeComponentEditPolicy extends ComponentEditPolicy {
#Override
protected Command createDeleteCommand(GroupRequest deleteRequest) {
DeleteMyNodeCommand nodeDeleteCommand = new DeleteMyNodeCommand((MyNode) getHost().getModel());
return nodeDeleteCommand;
}
}
DeleteMyNodeCommand
public class DeleteMyNodeCommand extends Command {
public DeleteMyNodeCommand(MyNode model) {
this.node = model;
this.graph = node.getDiagram();
}
#Override public void execute() {
getMyNode().setDiagram(null);
System.out.println("Is the model still present in the graph? " + getGraph().getMyNodes().contains(getMyNode()));
// Returns false, i.e., graph doesn't contain model object at this point!
}
#Override public void undo() {
getMyNode().setDiagram(getGraph());
}
}
EDIT
Re execc's comment: Yes, refreshChildren() is being called. I've tested this by overriding it and adding a simple System.err line, which is being displayed on the console on deletion of a node:
#Override
public void refreshChildren() {
super.refreshChildren();
System.err.println("refreshChildren() IS being called!");
}
EDIT 2
The funny (well...) thing is, when I close the editor and persist the model, then re-open the same file, the node isn't painted anymore, and is not present in the model. But what does this mean? Am I working on a stale model? Or is refreshing/getting the model children not working properly?
EDIT 3
I've just found a peculiar thing, which might explain the isues I have? In the getModelChildren() method I call allModelObjects.addAll(((Diagram) getModel()).getMyNodes());, and getMyNodes() returns an unmodifiable EList. I found out when I tried to do something along the lines of ((Diagram) getModel()).getMyNodes().remove(getMyNode()) in the delete command, and it threw an UnsupportedOperationException... Hm.
EDIT 4
Er, somebody kill me please?
I've double-checked whether I'm handling the same Diagram object at all times, and while doing this I stumbled across a very embarassing thing:
The getModelChildren() method in DiagramEditPart in the last version read approx. like this:
#Override protected List<EObject> getModelChildren() {
List<EObject> allModelObjects = new ArrayList<EObject>();
EList<MyNode> nodes = ((Diagram) getModel()).getMyNodes();
for (MyNode node : nodes) {
if (node.getDiagram() != null); // ### D'Uh! ###
allModelObjects.add(node);
}
return allModelObjects;
}
I'd like to apologize for stealing everyone's time! Your suggestions were very helpful, and indeed helped my to finally track down the bug!
I've also learned a number of lessons, amongst them: Always paste the original code, over-simplifaction may cloak your bugs! And I've learned a lot about EMF, Adapter, and GEF. Still:
There is one semi-colon too many in line 5 of the following part of the code, namely after the if statement: if (node.getDiagram() != null);:
1 #Override protected List<EObject> getModelChildren() {
2 List<EObject> allModelObjects = new ArrayList<EObject>();
3 EList<MyNode> nodes = ((Diagram) getModel()).getMyNodes();
4 for (MyNode node : nodes) {
5 if (node.getDiagram() != null);
6 allModelObjects.add(node);
7 }
8 return allModelObjects;
9 }
I'm trying to create a page which is very similar to the Google Form creation page.
This is how I am attempting to model it using the GWT MVP framework (Places and Activities), and Editors.
CreateFormActivity (Activity and presenter)
CreateFormView (interface for view, with nested Presenter interface)
CreateFormViewImpl (implements CreateFormView and Editor< FormProxy >
CreateFormViewImpl has the following sub-editors:
TextBox title
TextBox description
QuestionListEditor questionList
QuestionListEditor implements IsEditor< ListEditor< QuestionProxy, QuestionEditor>>
QuestionEditor implements Editor < QuestionProxy>
QuestionEditor has the following sub-editors:
TextBox questionTitle
TextBox helpText
ValueListBox questionType
An optional subeditor for each question type below.
An editor for each question type:
TextQuestionEditor
ParagraphTextQuestionEditor
MultipleChoiceQuestionEditor
CheckboxesQuestionEditor
ListQuestionEditor
ScaleQuestionEditor
GridQuestionEditor
Specific Questions:
What is the correct way to add / remove questions from the form. (see follow up question)
How should I go about creating the Editor for each question type? I attempted to listen to the questionType value changes, I'm not sure what to do after. (answered by BobV)
Should each question-type-specific editor be wrapper with an optionalFieldEditor? Since only one of can be used at a time. (answered by BobV)
How to best manage creating/removing objects deep in the object hierarchy. Ex) Specifying answers for a question number 3 which is of type multiple choice question. (see follow up question)
Can OptionalFieldEditor editor be used to wrap a ListEditor? (answered by BobV)
Implementation based on Answer
The Question Editor
public class QuestionDataEditor extends Composite implements
CompositeEditor<QuestionDataProxy, QuestionDataProxy, Editor<QuestionDataProxy>>,
LeafValueEditor<QuestionDataProxy>, HasRequestContext<QuestionDataProxy> {
interface Binder extends UiBinder<Widget, QuestionDataEditor> {}
private CompositeEditor.EditorChain<QuestionDataProxy, Editor<QuestionDataProxy>> chain;
private QuestionBaseDataEditor subEditor = null;
private QuestionDataProxy currentValue = null;
#UiField
SimplePanel container;
#UiField(provided = true)
#Path("dataType")
ValueListBox<QuestionType> dataType = new ValueListBox<QuestionType>(new Renderer<QuestionType>() {
#Override
public String render(final QuestionType object) {
return object == null ? "" : object.toString();
}
#Override
public void render(final QuestionType object, final Appendable appendable) throws IOException {
if (object != null) {
appendable.append(object.toString());
}
}
});
private RequestContext ctx;
public QuestionDataEditor() {
initWidget(GWT.<Binder> create(Binder.class).createAndBindUi(this));
dataType.setValue(QuestionType.BooleanQuestionType, true);
dataType.setAcceptableValues(Arrays.asList(QuestionType.values()));
/*
* The type drop-down UI element is an implementation detail of the
* CompositeEditor. When a question type is selected, the editor will
* call EditorChain.attach() with an instance of a QuestionData subtype
* and the type-specific sub-Editor.
*/
dataType.addValueChangeHandler(new ValueChangeHandler<QuestionType>() {
#Override
public void onValueChange(final ValueChangeEvent<QuestionType> event) {
QuestionDataProxy value;
switch (event.getValue()) {
case MultiChoiceQuestionData:
value = ctx.create(QuestionMultiChoiceDataProxy.class);
setValue(value);
break;
case BooleanQuestionData:
default:
final QuestionNumberDataProxy value2 = ctx.create(BooleanQuestionDataProxy.class);
value2.setPrompt("this value doesn't show up");
setValue(value2);
break;
}
}
});
}
/*
* The only thing that calls createEditorForTraversal() is the PathCollector
* which is used by RequestFactoryEditorDriver.getPaths().
*
* My recommendation is to always return a trivial instance of your question
* type editor and know that you may have to amend the value returned by
* getPaths()
*/
#Override
public Editor<QuestionDataProxy> createEditorForTraversal() {
return new QuestionNumberDataEditor();
}
#Override
public void flush() {
//XXX this doesn't work, no data is returned
currentValue = chain.getValue(subEditor);
}
/**
* Returns an empty string because there is only ever one sub-editor used.
*/
#Override
public String getPathElement(final Editor<QuestionDataProxy> subEditor) {
return "";
}
#Override
public QuestionDataProxy getValue() {
return currentValue;
}
#Override
public void onPropertyChange(final String... paths) {
}
#Override
public void setDelegate(final EditorDelegate<QuestionDataProxy> delegate) {
}
#Override
public void setEditorChain(final EditorChain<QuestionDataProxy, Editor<QuestionDataProxy>> chain) {
this.chain = chain;
}
#Override
public void setRequestContext(final RequestContext ctx) {
this.ctx = ctx;
}
/*
* The implementation of CompositeEditor.setValue() just creates the
* type-specific sub-Editor and calls EditorChain.attach().
*/
#Override
public void setValue(final QuestionDataProxy value) {
// if (currentValue != null && value == null) {
chain.detach(subEditor);
// }
QuestionType type = null;
if (value instanceof QuestionMultiChoiceDataProxy) {
if (((QuestionMultiChoiceDataProxy) value).getCustomList() == null) {
((QuestionMultiChoiceDataProxy) value).setCustomList(new ArrayList<CustomListItemProxy>());
}
type = QuestionType.CustomList;
subEditor = new QuestionMultipleChoiceDataEditor();
} else {
type = QuestionType.BooleanQuestionType;
subEditor = new BooleanQuestionDataEditor();
}
subEditor.setRequestContext(ctx);
currentValue = value;
container.clear();
if (value != null) {
dataType.setValue(type, false);
container.add(subEditor);
chain.attach(value, subEditor);
}
}
}
Question Base Data Editor
public interface QuestionBaseDataEditor extends HasRequestContext<QuestionDataProxy>, IsWidget {
}
Example Subtype
public class BooleanQuestionDataEditor extends Composite implements QuestionBaseDataEditor {
interface Binder extends UiBinder<Widget, BooleanQuestionDataEditor> {}
#Path("prompt")
#UiField
TextBox prompt = new TextBox();
public QuestionNumberDataEditor() {
initWidget(GWT.<Binder> create(Binder.class).createAndBindUi(this));
}
#Override
public void setRequestContext(final RequestContext ctx) {
}
}
The only issue left is that QuestionData subtype specific data isn't being displayed, or flushed. I think it has to do with the Editor setup I'm using.
For example, The value for prompt in the BooleanQuestionDataEditor is neither set nor flushed, and is null in the rpc payload.
My guess is: Since the QuestionDataEditor implements LeafValueEditor, the driver will not visit the subeditor, even though it has been attached.
Big thanks to anyone who can help!!!
Fundamentally, you want a CompositeEditor to handle cases where objects are dynamically added or removed from the Editor hierarchy. The ListEditor and OptionalFieldEditor adaptors implement CompositeEditor.
If the information required for the different types of questions is fundamentally orthogonal, then multiple OptionalFieldEditor could be used with different fields, one for each question type. This will work when you have only a few question types, but won't really scale well in the future.
A different approach, that will scale better would be to use a custom implementation of a CompositeEditor + LeafValueEditor that handles a polymorphic QuestionData type hierarchy. The type drop-down UI element would become an implementation detail of the CompositeEditor. When a question type is selected, the editor will call EditorChain.attach() with an instance of a QuestionData subtype and the type-specific sub-Editor. The newly-created QuestionData instance should be retained to implement LeafValueEditor.getValue(). The implementation of CompositeEditor.setValue() just creates the type-specific sub-Editor and calls EditorChain.attach().
FWIW, OptionalFieldEditor can be used with ListEditor or any other editor type.
We implemented similar approach (see accepted answer) and it works for us like this.
Since driver is initially unaware of simple editor paths that might be used by sub-editors, every sub-editor has own driver:
public interface CreatesEditorDriver<T> {
RequestFactoryEditorDriver<T, ? extends Editor<T>> createDriver();
}
public interface RequestFactoryEditor<T> extends CreatesEditorDriver<T>, Editor<T> {
}
Then we use the following editor adapter that would allow any sub-editor that implements RequestFactoryEditor to be used. This is our workaround to support polimorphism in editors:
public static class DynamicEditor<T>
implements LeafValueEditor<T>, CompositeEditor<T, T, RequestFactoryEditor<T>>, HasRequestContext<T> {
private RequestFactoryEditorDriver<T, ? extends Editor<T>> subdriver;
private RequestFactoryEditor<T> subeditor;
private T value;
private EditorDelegate<T> delegate;
private RequestContext ctx;
public static <T> DynamicEditor<T> of(RequestFactoryEditor<T> subeditor) {
return new DynamicEditor<T>(subeditor);
}
protected DynamicEditor(RequestFactoryEditor<T> subeditor) {
this.subeditor = subeditor;
}
#Override
public void setValue(T value) {
this.value = value;
subdriver = null;
if (null != value) {
RequestFactoryEditorDriver<T, ? extends Editor<T>> newSubdriver = subeditor.createDriver();
if (null != ctx) {
newSubdriver.edit(value, ctx);
} else {
newSubdriver.display(value);
}
subdriver = newSubdriver;
}
}
#Override
public T getValue() {
return value;
}
#Override
public void flush() {
if (null != subdriver) {
subdriver.flush();
}
}
#Override
public void onPropertyChange(String... paths) {
}
#Override
public void setDelegate(EditorDelegate<T> delegate) {
this.delegate = delegate;
}
#Override
public RequestFactoryEditor<T> createEditorForTraversal() {
return subeditor;
}
#Override
public String getPathElement(RequestFactoryEditor<T> subEditor) {
return delegate.getPath();
}
#Override
public void setEditorChain(EditorChain<T, RequestFactoryEditor<T>> chain) {
}
#Override
public void setRequestContext(RequestContext ctx) {
this.ctx = ctx;
}
}
Our example sub-editor:
public static class VirtualProductEditor implements RequestFactoryEditor<ProductProxy> {
interface Driver extends RequestFactoryEditorDriver<ProductProxy, VirtualProductEditor> {}
private static final Driver driver = GWT.create(Driver.class);
public Driver createDriver() {
driver.initialize(this);
return driver;
}
...
}
Our usage example:
#Path("")
DynamicEditor<ProductProxy> productDetailsEditor;
...
public void setProductType(ProductType type){
if (ProductType.VIRTUAL==type){
productDetailsEditor = DynamicEditor.of(new VirtualProductEditor());
} else if (ProductType.PHYSICAL==type){
productDetailsEditor = DynamicEditor.of(new PhysicalProductEditor());
}
}
Would be great to hear your comments.
Regarding your question why subtype specific data isn't displayed or flushed:
My scenario is a little bit different but I made the following observation:
GWT editor databinding does not work as one would expect with abstract editors in the editor hierarchy. The subEditor declared in your QuestionDataEditor is of type QuestionBaseDataEditor and this is fully abstract type (an interface). When looking for fields/sub editors to populate with data/flush GWT takes all the fields declared in this type. Since QuestionBaseDataEditor has no sub editors declared nothing is displayed/flushed. From debugging I found out that is happens due to GWT using a generated EditorDelegate for that abstract type rather than the EditorDelegate for the concrete subtype present at that moment.
In my case all the concrete sub editors had the same types of leaf value editors (I had two different concrete editors one to display and one to edit the same bean type) so I could do something like this to work around this limitation:
interface MyAbstractEditor1 extends Editor<MyBean>
{
LeafValueEditor<String> description();
}
// or as an alternative
abstract class MyAbstractEditor2 implements Editor<MyBean>
{
#UiField protected LeafValueEditor<String> name;
}
class MyConcreteEditor extends MyAbstractEditor2 implements MyAbstractEditor1
{
#UiField TextBox description;
public LeafValueEditor<String> description()
{
return description;
}
// super.name is bound to a TextBox using UiBinder :)
}
Now GWT finds the subeditors in the abstract base class and in both cases I get the corresponding fields name and description populated and flushed.
Unfortunately this approach is not suitable when the concrete subeditors have different values in your bean structure to edit :(
I think this is a bug of the editors framework GWT code generation, that can only be solved by the GWT development team.
Isn't the fundamental problem that the binding happens at compile time so will only bind to QuestionDataProxy so won't have sub-type specific bindings? The CompositeEditor javadoc says "An interface that indicates that a given Editor is composed of an unknown number of sub-Editors all of the same type" so that rules this usage out?
At my current job I'm pushing to avoid polymorphism altogether as the RDBMS doesn't support it either. Sadly we do have some at the moment so I'm experimenting with a dummy wrapper class that exposes all the sub-types with specific getters so the compiler has something to work on. Not pretty though.
Have you seen this post: http://markmail.org/message/u2cff3mfbiboeejr this seems along the right lines.
I'm a bit worried about code bloat though.
Hope that makes some sort of sense!