Letting add class name in GWT CellList parent row element - gwt

CellList from GWT have 4 class names: keyboardSelectedItem, SelectedItem, EventItem and OddItem.
I just need to add another one.
I was thinking in overriding:
#Override
protected void renderRowValues(SafeHtmlBuilder sb, List<T> values, int start,
SelectionModel<? super T> selectionModel) { ... }
And adding another custom class just like :
classesBuilder.append(anotherClass);
Is this the best approach? another idea?

Related

Is there a PickList widget in GWT?

There is a PickList widget in PrimeFaces JSF component library?
Does GWT (or any other GWT component library) has such a widget?
Have a look at SmartGWT's featured example on Databound Dragging. You can also view its source. But since gwt does not have such widget, the best solution is to create your own custom component with the help of CellList.
I prefer to create my own PickList as it's easy and straightforward, below is what it looks like:
public abstract class PickList<T> extends Composite {
//The renderer provide the flexibility for client class customize the cell
public PickList(SafeHtmlRenderer<T> renderer) {
...
}
public void setCandidates(List<T> candidates, List<T> selected) {
//todo
}
public List<T> getSelectedValues() {
//todo
}
//Below two abstract method can facilitate getting values from view or rendering view from value
protected abstract T fromIdentity(String identity);
protected abstract String toIdentity(T value);
}

how to inject a uiBinder with #Inject (instead of GWT.create())?

Firstly, is doing such thing a good practice ?
I tried what seems to be the right way for me but wasn't successful :
public class FormViewImpl extends CompositeView implements HasUiHandlers<C>, FormView {
public interface SettlementInstructionsSearchFormViewUiBinder extends UiBinder<Widget, SettlementInstructionsSearchFormViewImpl> {}
#Inject
static FormViewImpl uiBinder;
#Inject
static Provider<DateEditorWidget> dateEditorProvider;
#UiField(provided = true)
MyComponent<String> myComp;
#UiField
DateEditorWidget effectiveDateFrom;
// .. other fields
#Inject
public FormViewImpl () {
myComp = new MyComponent<String>("lol");
if (uiBinder == null)
uiBinder = GWT.create(SettlementInstructionsSearchFormViewUiBinder.class);
initWidget(uiBinder.createAndBindUi(this));
}
#UiFactory
DateEditorWidget createDateEditor() {
return dateEditorProvider.get();
}
}
What other things than a class with no arguments is required ? In my company's project the same kind of code works at some other place. Sorry from the high level of noob here...
If you guys had any pointers it would be nice.
Thanks
Two issues:
First, two of your #Inject fields are static - have you done anything to make static fields be injected? Static fields don't get set when Gin (or Guice) creates new instances, those have to be set once and done. As they are static, they will never be garbage collected - this may be okay with you, or it might be a problem, and you should change them to instance fields. If you want to keep them static, then you must invoke requestStaticInjection in your module to ask Gin to initialize them when the ginjector is created.
Next, if you do choose to remove static, the uiBinder field must still be null in that constructor, because the fields can't have been injected yet! How do you set a field on an object that you haven't yet created? That's what you are expecting Gin to be able to do. Instead, consider passing that as an argument into the #Inject decorated constructor. You don't even need to save it as a field, since the widget will only use it the one time.
To have a class generated by GIN (doesn't matter if it is a uiBinder or not) it is not necessary for it to have a default constructor (i.e. the one without parameters). The class you want to inject must have the constructor annotated with #Inject:
#Inject
public InjectMeClass(Object a, Object b)
The other class which is injected, suppose it is a UiBinder, must have the injected fields annotated with #UiField(provided=true):
public class Injected extends Composite {
private static InjectedUiBinder uiBinder = GWT
.create(InjectedUiBinder.class);
interface InjectedUiBinder extends UiBinder<Widget, Injected> {
}
#UiField(provided=true)
InjectMeClass imc;
public Injected(final InjectMeClass imc) {
this.imc=imc;
initWidget(uiBinder.createAndBindUi(this));
}
So, back to your case:
#UiField(provided = true)
MyComponent<String> myComp;
#Inject
public FormViewImpl (MyComponent<String> myComp) {
this.myComp = myComp;
and for example:
public class MyComponent<T> extends Composite {
private T value;
#Inject
public MyComponent(T t) {
this.value = t;
...
}
...
}
In the GIN module you can have a provider:
#Provides
#Singleton
public MyComponent<String> createMyComponent() {
return new MyComponent<String>("lol");
}

How must one use a ListEditor as a child of another Editor?

I am using GWT 2.5.0
My intent was to create an editor hierarchy which binds to a ParentBean object. The ParentBean contains a List<Group>, and the Group bean has a List<ChildBean> and List<Group>. From the Editor tutorials I have found, it seemed simple enough to create an editor which contains a ListEditor as one of its sub-editors. But the parent editor never seems to properly initialize the sub ListEditor.
Here is an explanation of how I attempted to do this.
From the code below, I created a ParentBeanEditor which is composed of one other editor, GroupListEditor.
The GroupListEditor implements IsEditor<ListEditor<Group, GroupEditor>>.
Then, the GroupEditor contains a GroupListEditor subeditor and a ChildBeanEditor.
I initialized the ParentBeanEditor with a ParentBean which contained a list of Group objects, but no GroupEditor was ever constructed for any of the Group objects. I put break points in the EditorSource<GroupEditor>.create(int) method to verify that GroupEditors were being created for each Group in the ParentBean, but the break point was never hit (the ListEditor was not constructing editors).
I expected that the GroupListEditor would be initialized since it was a subeditor of ParentBeanEditor. Neither the list nor the editor chain was set in the GroupListEditor. I tried to set the list of the GroupListEditor subeditor directly in ParentBeanEditor by having it extend ValueAwareEditor<ParentBean>. Doing this, the break point I mentioned above was hit, and the GroupListEditor tried to attach a GroupEditor to the editor chain. But the editor chain was never set, and a NPE is thrown in ListEditorWrapper line 95.
Example
Here is the example where the GroupListEditor is not initializing as expected. The EditorChain is never set, and this results in a NPE being thrown in ListEditorWrapper line 95.
Data Model
public interface ParentBean {
...
List<Group> getGroups();
}
public interface Group {
...
List<ChildBean> getChildBeans();
List<Group> getGroups();
}
public interface ChildBean {
// ChildType is an enum
ChildType getChildType();
}
Editors
The ParentBean Editor
public class ParentBeanEditor extends Composite implements ValueAwareEditor<ParentBean> {
interface ParentBeanEditorUiBinder extends UiBinder<Widget, ParentBeanEditor> {
}
private static ParentBeanEditorUiBinder BINDER = GWT.create(ParentBeanEditorUiBinder.class);
#Path("groups")
#UiField
GroupListEditor groupsEditor;
public ParentBeanEditor() {
initWidget(BINDER.createAndBindUi(this));
}
#Override
public void setDelegate(EditorDelegate<ParentBean> delegate) {}
#Override
public void flush() {}
#Override
public void onPropertyChange(String... paths) {}
#Override
public void setValue(ParentBean value) {
groupsEditor.asEditor().setValue(value.getGroups());
}
}
GroupListEditor
public class GroupListEditor extends Composite implements IsEditor<ListEditor<Group, GroupEditor>>{
interface GroupListEditorUiBinder extends UiBinder<VerticalLayoutContainer, TemplateGroupListEditor> {
}
private static GroupListEditorUiBinder BINDER = GWT.create(GroupListEditorUiBinder.class);
private class GroupEditorSource extends EditorSource<GroupEditor> {
private final GroupListEditor GroupListEditor;
public GroupEditorSource(GroupListEditor GroupListEditor) {
this.GroupListEditor = GroupListEditor;
}
#Override
public GroupEditor create(int index) {
GroupEditor subEditor = new GroupEditor();
GroupListEditor.getGroupsContainer().insert(subEditor, index);
return subEditor;
}
#Override
public void dispose(GroupEditor subEditor){
subEditor.removeFromParent();
}
#Override
public void setIndex(GroupEditor editor, int index){
GroupListEditor.getGroupsContainer().insert(editor, index);
}
}
private final ListEditor<Group, GroupEditor> editor = ListEditor.of(new GroupEditorSource(this));
#UiField
VerticalLayoutContainer groupsContainer;
public GroupListEditor() {
initWidget(BINDER.createAndBindUi(this));
}
public InsertResizeContainer getGroupsContainer() {
return groupsContainer;
}
#Override
public ListEditor<Group, GroupEditor> asEditor() {
return editor;
}
}
GroupEditor
public class GroupEditor extends Composite implements ValueAwareEditor<Group> {
interface GroupEditorUiBinder extends UiBinder<Widget, GroupEditor> {}
private static GroupEditorUiBinder BINDER = GWT.create(GroupEditorUiBinder.class);
#Ignore
#UiField
FieldSet groupField;
#UiField
#Path("childBeans")
ChildBeanListEditor childBeansEditor;
#UiField
#Path("groups")
GroupListEditor groupsEditor;
public GroupEditor() {
initWidget(BINDER.createAndBindUi(this));
}
#Override
public void setDelegate(EditorDelegate<Group> delegate) {}
#Override
public void flush() { }
#Override
public void onPropertyChange(String... paths) {}
#Override
public void setValue(Group value) {
// When the value is set, update the FieldSet header text
groupField.setHeadingText(value.getLabel());
groupsEditor.asEditor().setValue(value.getGroups());
childBeansEditor.asEditor().setValue(value.getChildBeans());
}
}
The ChildBeanListEditor will be using the polymorphic editor methodology mention here. Meaning that a specific leafeditor is attached to the editor chain based off the value of the ChildBean.getType() enum. However, I am not showing that code since I am unable to get the GroupListEditor to properly initialize.
Two concerns about your code:
Why is ParentBeanEditor.setValue feeding data to its child? It appears from this that this was a way to work around the fact that the GroupListEditor was not getting data. This should not be necessary, and may be causing your NPE by wiring up a subeditor before it is time.
Then, assuming this, it seems to follow that the GroupListEditor isn't getting data or a chain. The lack of these suggests that the Editor Framework isn't aware of it. All the basic wiring looks correct, except for one thing: Where is your EditorDriver?
If you are trying to use the editor framework by just invoking parentBeanEditor.setValue and do not have a driver, you are missing most of the key features of this tool. You should be able to ask the driver to do this work for you, and not not to call your own setValue methods throughout the tree.
A quick test - try breaking something in such a way that shouldn't compile. This would include changing the #Path annotation to something like #Path("doesnt.exist"), and trying to run the app. You should get a rebind error, as there is no such path. If you do not get this, you definitely need to be creating and user a driver.
First, try driver itself:
It isn't quite clear from your code what kind of models you are using, so I'll assume that the SimpleBeanEditorDriver will suffice for you - the other main option is the RequestFactoryEditorDriver, but it isn't actually necessary to use the RequestFactoryEditorDriver even if you use RequestFactory.
The Driver is generic on two things: The bean type you intend to edit, and the editor type that will be responsible for it. It uses these generic arguments to traverse both objects and generate code required to bind the data. Yours will likely look like this:
public interface Driver extends
SimpleBeanEditorDriver<ParentBean, ParentBeanEditor> { }
We declare these just like UiBinder interfaces - just enough details to let the code generator look around and wire up essentials. Now that we have the type, we create an instance. This might be created in your view, but may still be owned and controlled by some presenter logic. Note that this is not like uibinder - we cannot keep a static instance, since each one is wired directly to a specific editor instance.
Two steps here - create the driver, and initialize it to a given editor instance (and all sub-editors, which will be automatic):
ParentBeanEditor editor = ...;
Driver driver = GWT.create(Driver.class);
driver.initialize(editor);
Next we bind data by passing it to the driver - it is its responsibility to pass sub-objects to each sub-editor's setValue method, as well as wiring up the editor chain required by the ListEditor.
driver.edit(parentInstance);
Now the user can view or edit the object, as your application requirement works. When editing is complete (say they click the Save button), we can flush all changes from the editors back into the instance (and note that we are still using the same driver instance, still holding that specific editor instance):
ParentBean instance = driver.flush();
Note that we also could have just invoked driver.flush() and reused the earlier reference to parentInstance - its the same thing.
Assuming this has all made sense so far, there is some cleanup that can be done - ParentBeanEditor isn't really using the ValueAwareEditor methods, so they can be removed:
public class ParentBeanEditor extends Composite implements Editor<ParentBean> {
interface ParentBeanEditorUiBinder extends UiBinder<Widget, ParentBeanEditor> {
}
private static ParentBeanEditorUiBinder BINDER = GWT.create(ParentBeanEditorUiBinder.class);
#Path("groups")
#UiField
GroupListEditor groupsEditor;
public ParentBeanEditor() {
initWidget(BINDER.createAndBindUi(this));
}
}
Observe that we still implement Editor<ParentBean> - this allows the driver generics to make sense, and declares that we have fields that might themselves be sub-editors to be wired up. Also: it turns out that the #Path annotation here is unnecessary - any field/method with the same name as the property (getGroups()/setGroups() ==> groups) or the name of the property plus 'Editor' (groupsEditor). If the editor contains a field that is an editor but doesn't map to a property in the bean, you'll get an error. If you actually did this on purpose (say, a text box for searching, not for data entry), you can tag it with #Ignore.

GWT CellTree Selection of Parent nodes

I'm trying to use the GWT CellTree to display a heterogeneous, hierarchical data model. I need to be able to a single selection, but be able to select Parent nodes as well as child nodes. For example, if you look at GWT's own example, you'll see that they only provide one selection model for the leave nodes.
I tried to extend their example by providing one selection model for all nodes. However, that seems impossible. So what I ended up with where 3 SelectionModels one for each node type (Composer, PlayList, Song).
What am I missing?
Thanks in advance.
In the getNodeInfo function of your TreeViewModel you have to pass the selectionModel to each new DefaultNodeInfo instance at each level.
return new DefaultNodeInfo<MyDTO>(dataProvider,new MyDTOCell(),selectionModel,null);
and then in the SelectionChangeEventHandler you have do something like this:
selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() {
#Override
public void onSelectionChange(SelectionChangeEvent event) {
Object object = selectionModel.getSelectedObject();
if (object instanceof MyRootDTO)
{
// DO SOMETHING with root level selected node
}
else if (object instanceof MySecondLevelDTO) {
// DO SOMETHING WITH 2. level selected node
}
// additional levels
});
Update:
In order to get around the typing problem, you can define an abstract base class which is extended by all your DTO's.
public abstract class BaseModel {
public static final ProvidesKey<BaseModel> KEY_PROVIDER = new ProvidesKey<BaseModel>() {
public Object getKey(BaseModel item) {
return item == null ? null : item.getId();
}
};
public abstract Object getId();
}
In your DTO's you extend the BaseModel and implement the abstract getId() method:
public class MyDTO extends BaseModel {
#Override
public Object getId() {
//return unique ID (i.e. MyDTO_1)
}
}

How can i add clickHandler to the <li> tag in GWT?

I want to add ClickHandler to the < li> tag
please help me ...
You could use a FocusWidget once you've got hold of the Element. There's a FocusWidget constructor taking a single Element. After that you can just call addClickHandler
You need to have the <li> tag as a widget that implements the HasClickHandler interface. Then you can instantiate a ClickHandler and add it to the <li> widget.
This is what I'm currently using. It works, but I'm not sure if it's the right approach.
public class ListItem extends HTMLPanel implements HasClickHandlers {
public ListItem(String html) {
super(html);
}
#Override
protected void setElement(Element elem) {
super.setElement(DOM.createElement("li"));
}
#Override
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
}
This allows using UiBinder to define a ListItem which can then contain arbitrary HTML (and be clickable).