Develop Reference

How to filter the inputs in Table with SWT.Virtual?

In my project, I have a TableViewer which needs to show around 3000 items and also filter them. Without SWT.VIRTUAL the table takes multiple seconds to display.
So, I implemented ILazyContentProvider and not using "ArrayContentProvider" but now I am facing issues in filtering the elements of TableViewer.
I am writing the below code for filtering but the select method is not running at all.
private static class DefaultFilterextends ViewerFilter {
private String searchText;
public void setSearchText(final String searchText) {
this.searchText = searchText;
}
#Override
public boolean select(Viewer viewer, Object parentElement, Object element) {
if (this.searchText == null) {
return true;
}
return (element.toString().contains(searchText) || element.toString().equals(searchText));
}
}
The below ContentProvider, I am writting
private class LazyContentProvider implements ILazyContentProvider {
private TableViewer viewer;
private List<String> elements;
public LazyContentProvider(TableViewer viewer) {
this.viewer = viewer;
}
#Override
public void dispose() {
}
#Override
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
this.elements = (List<String>) newInput;
}
#Override
public void updateElement(int index) {
viewer.replace(elements.get(index), index);
}
}
Can someone please guide me how can I do the filteration of elements in TableViewer with SWT.VIRTUAL?

TableViewer does not support filtering when SWT.VIRTUAL is used. Instead you must do the filtering in the content provider.
The content provider will need to maintain a filtered list of elements. For example:
public class LazyContentProvider implements ILazyContentProvider
{
private TableViewer viewer;
private List<String> allElements;
private List<String> filteredElements;
public LazyContentProvider()
{
//
}
#Override
public void dispose()
{
//
}
#SuppressWarnings("unchecked")
#Override
public void inputChanged(final Viewer viewer, final Object oldInput, final Object newInput)
{
this.viewer = (TableViewer)viewer;
allElements = (List<String>)newInput;
filteredElements = allElements;
}
#Override
public void updateElement(final int index)
{
viewer.replace(filteredElements.get(index), index);
}
public void filter(final String searchText)
{
filteredElements = allElements.stream().filter(element -> element.contains(searchText)).toList();
viewer.setItemCount(filteredElements.size());
viewer.refresh();
}
}
Here I have added a filteredElements list that contains just the current filtered elements, this is used in updateElement.
I added a filter method which updates the filtered elements list. It also tells the table viewer about the new item count and refreshes the table.
The .toList() method in the filter stream requires Java 16, for older versions of Java use .collect(Collectors.toList()).

GWT : Render a hyperlink in a TextColumn of a CellTable

First of all - I am a beginner with Java and GWT. I have a scripting language background so please be explicit.
I have a CellTable that is populated with data from a database( ServerKeyWord class gets the data ).
myCellTable.addColumn(new TextColumn<ServerKeyWord>() {
#Override
public String getValue(ServerKeyWord object) {
// TODO Auto-generated method stub
return object.getName();
}
});
The example from above works, but it only shows the data as a text. I need to make it a hyperlink, that when you click it, it opens a new tab to that location.
I've surfed the web and got to the conclusion that I need to override render.
public class HyperTextCell extends AbstractCell<ServerKeyWord> {
interface Template extends SafeHtmlTemplates {
#Template("<a target=\"_blank\" href=\"{0}\">{1}</a>")
SafeHtml hyperText(SafeUri link, String text);
}
private static Template template;
public static final int LINK_INDEX = 0, URL_INDEX = 1;
/**
* Construct a new linkCell.
*/
public HyperTextCell() {
if (template == null) {
template = GWT.create(Template.class);
}
}
#Override
public void render(Context context, ServerKeyWord value, SafeHtmlBuilder sb) {
if (value != null) {
// The template will sanitize the URI.
sb.append(template.hyperText(UriUtils.fromString(value.getName()), value.getName()));
}
}
}
Now ... How do I use the HyperTextCell class with the addColumn method as in the first code example?!
Thank you in advance!

HyperTextCell hyperTextCell = new HyperTextCell();
Column<ServerKeyWord, ServerKeyWord> hyperColumn = new Column<ServerKeyWord, ServerKeyWord>(
hyperTextCell) {
#Override
public ServerKeyWord getValue(ServerKeyWord keyWord) {
return keyWord;
}
};
myCellTable.addColumn(hyperColumn);

GWT GXT StoreFilterField event

I would like to search into my tree only if the user type 3 character at least.
How i can catch "doSelect" event to do this?
If i add a keylistener on the text field to check its value, the handler is invoked after the doSelect.
Can anyone help me?
This is an example...
filterText = new StoreFilterField<ModelData>() {
#Override
protected boolean doSelect(Store<ModelData> store,
ModelData parent, ModelData record, String property,
String filter) {
String name = record.get("name");
name = name.toLowerCase();
if (name.startsWith(filter.toLowerCase()))
return true;
else
return false;
}
};
KeyListener keyListener = new KeyListener() {
public void componentKeyUp(ComponentEvent event) {
loadingImage.setVisible(false);
if(filterText.isValid() && filterText.getRawValue().length()>=FILTER_MIN_SIZE) {
filterText.bind(store);
} else {
filterText.unbind(store);
}
}
};
filterText.setMinLength(FILTER_MIN_SIZE);
filterText.bind(store);

(Appears to be GXT 2, let me know if you are actually using GXT 3)
StoreFilterField relies on the applyFilters method to actually apply all of these. It has a check already that the text has at least one character:
protected void applyFilters(Store<M> store) {
if (getRawValue().length() > 0) {
store.addFilter(filter);
store.applyFilters(property);
} else {
store.removeFilter(filter);
}
}
The easiest way I see to override this would be to subclass StoreFilterField and redefine this method:
filterText = new StoreFilterField<ModelData>() {
#Override
protected void applyFilters(Store<M> store) {
if (getRawValue().length() > 3) {
store.addFilter(filter);
store.applyFilters(getProperty());
} else {
store.removeFilter(filter);
}
}
}

GWT: handling event in composite cell

CompositeCell let us customize the content of a table cell's in GWT using Java. We can put almost any other group of widget within the table's cell and layout them as we want. Problem is that if we used the html tags to define the layout of the CompositeCell as yet another table (see CompositeCell anonymous class implementation bellow) we loose the event handling for the components of the cell :(.
Running the following code, when we click in the buttons of the cell will realize the popup in response of the event handling IF WE COMMENT the CompositeCell anonymous implementation.
I've been debugging CompositeCell.onBrowserEvent(Context, Element, C, NativeEvent, ValueUpdater) because i think that the definition of the cell layout using HTML table tags breaks the event chain within GWT widgets hierarchy but haven't been successful so far.
Remark: both commented and uncommented versions of the code realize the same GUI layout. This example just intent to show that we loose event handling when customizing cell's content.
public class ActionCellTest implements EntryPoint {
private static final String SERVER_ERROR = "An error occurred while " + "attempting to contact the server. Please check your network "
+ "connection and try again.";
private final GreetingServiceAsync greetingService = GWT.create(GreetingService.class);
public void onModuleLoad() {
CellTable<Person> table = new CellTable<ActionCellTest.Person>();
final List<HasCell<Person, ?>> cells = new LinkedList<HasCell<Person, ?>>();
cells.add(new HasCellImpl("first name", new ActionCell.Delegate<Person>() {
#Override
public void execute(Person object) {
Window.alert(object.getFirstName());
}
}));
cells.add(new HasCellImpl("last name", new ActionCell.Delegate<ActionCellTest.Person>() {
#Override
public void execute(Person object) {
Window.alert(object.getLastName());
}
}));
CompositeCell<Person> cell = new CompositeCell<Person>(cells) {
#Override
public void render(Context context, Person value, SafeHtmlBuilder sb) {
sb.appendHtmlConstant("<table><tbody><tr>");
for (HasCell<Person, ?> hasCell : cells) {
render(context, value, sb, hasCell);
}
sb.appendHtmlConstant("</tr></tbody></table>");
}
#Override
protected <X> void render(Context context, Person value, SafeHtmlBuilder sb, HasCell<Person, X> hasCell) {
Cell<X> cell = hasCell.getCell();
sb.appendHtmlConstant("<td>");
cell.render(context, hasCell.getValue(value), sb);
sb.appendHtmlConstant("</td>");
}
#Override
protected Element getContainerElement(Element parent) {
return parent.getFirstChildElement().getFirstChildElement().getFirstChildElement();
}
};
table.addColumn(new TextColumn<ActionCellTest.Person>() {
#Override
public String getValue(ActionCellTest.Person object) {
return object.getFirstName() + " " + object.getLastName();
}
}, "name");
table.addColumn(new Column<Person, Person>(cell) {
#Override
public Person getValue(ActionCellTest.Person object) {
return object;
}
}, "composite");
LinkedList<Person> data = new LinkedList<ActionCellTest.Person>();
data.add(new Person("Amy", "Reed"));
data.add(new Person("Tim", "Gardner"));
table.setRowData(data);
RootPanel.get().add(table);
}
private class HasCellImpl implements HasCell<Person, Person> {
private ActionCell<Person> fCell;
public HasCellImpl(String text, Delegate<Person> delegate) {
fCell = new ActionCell<Person>(text, delegate);
}
#Override
public Cell<Person> getCell() {
return fCell;
}
#Override
public FieldUpdater<Person, Person> getFieldUpdater() {
return null;
}
#Override
public Person getValue(Person object) {
return object;
}
}
private class Person {
private String fFirstName;
private String fLastName;
public Person(String first, String last) {
fFirstName = first;
fLastName = last;
}
public String getFirstName() {
return fFirstName;
}
public String getLastName() {
return fLastName;
}
}
}

This is a known issue which will be fixed in the upcoming GWT 2.5 (a matter of weeks): http://code.google.com/p/google-web-toolkit/issues/detail?id=5714
(in the mean time, you can run off trunk or try backporting the change)

RequestFactoryEditorDriver doesn't save full graph even though "with()" is called. Is circular reference an issue?

Could you guys please help me find where I made a mistake ?
I switched from SimpleBeanEditorDriver to RequestFactoryEditorDriver and my code no longer saves full graph even though with() method is called. But it correctly loads full graph in the constructor.
Could it be caused by circular reference between OrganizationProxy and PersonProxy ? I don't know what else to think :( It worked with SimpleBeanEditorDriver though.
Below is my client code. Let me know if you want me to add sources of proxies to this question (or you can see them here).
public class NewOrderView extends Composite
{
interface Binder extends UiBinder<Widget, NewOrderView> {}
private static Binder uiBinder = GWT.create(Binder.class);
interface Driver extends RequestFactoryEditorDriver<OrganizationProxy, OrganizationEditor> {}
Driver driver = GWT.create(Driver.class);
#UiField
Button save;
#UiField
OrganizationEditor orgEditor;
AdminRequestFactory requestFactory;
AdminRequestFactory.OrderRequestContext requestContext;
OrganizationProxy organization;
public NewOrderView()
{
initWidget(uiBinder.createAndBindUi(this));
requestFactory = createFactory();
requestContext = requestFactory.contextOrder();
driver.initialize(requestFactory, orgEditor);
String[] paths = driver.getPaths();
createFactory().contextOrder().findOrganizationById(1).with(paths).fire(new Receiver<OrganizationProxy>()
{
#Override
public void onSuccess(OrganizationProxy response)
{
if (response == null)
{
organization = requestContext.create(OrganizationProxy.class);
organization.setContactPerson(requestContext.create(PersonProxy.class));
} else
organization = requestContext.edit(response);
driver.edit(organization, requestContext);
}
#Override
public void onFailure(ServerFailure error)
{
createConfirmationDialogBox(error.getMessage()).center();
}
});
}
private static AdminRequestFactory createFactory()
{
AdminRequestFactory factory = GWT.create(AdminRequestFactory.class);
factory.initialize(new SimpleEventBus());
return factory;
}
#UiHandler("save")
void buttonClick(ClickEvent e)
{
e.stopPropagation();
save.setEnabled(false);
try
{
AdminRequestFactory.OrderRequestContext ctx = (AdminRequestFactory.OrderRequestContext) driver.flush();
if (!driver.hasErrors())
{
// Link to each other
PersonProxy contactPerson = organization.getContactPerson();
contactPerson.setOrganization(organization);
String[] paths = driver.getPaths();
ctx.saveOrganization(organization).with(paths).fire(new Receiver<Void>()
{
#Override
public void onSuccess(Void arg0)
{
createConfirmationDialogBox("Saved!").center();
}
#Override
public void onFailure(ServerFailure error)
{
createConfirmationDialogBox(error.getMessage()).center();
}
});
}
} finally
{
save.setEnabled(true);
}
}
}

with() is only used for retrieval of information, so your with() use with a void return type is useless (but harmless).
Whether a full graph is persisted is entirely up to your server-side code, which is intimately bound to your persistence API (JPA, JDO, etc.)
First, check that the Organization object you receive in your save() method on the server-side is correctly populated. If it's not the case, check your Locators (and/or static findXxx methods) ; otherwise, check your save() method's code.
Judging from the code above, I can't see a reason why it wouldn't work.

It took me some time to realize that the problem was the composite id of Person entity.
Below is the code snippet of PojoLocator that is used by my proxy entities.
public class PojoLocator extends Locator<DatastoreObject, Long>
{
#Override
public DatastoreObject find(Class<? extends DatastoreObject> clazz, Long id)
{
}
#Override
public Long getId(DatastoreObject domainObject)
{
}
}
In order to fetch child entity from DataStore you need to have id of a parent class. In order to achieve that I switched "ID class" for Locator<> to String which represents textual form of Objectify's Key<> class.
Here is how to looks now:
public class PojoLocator extends Locator<DatastoreObject, String>
{
#Override
public DatastoreObject find(Class<? extends DatastoreObject> clazz, String id)
{
Key<DatastoreObject> key = Key.create(id);
return ofy.load(key);
}
#Override
public String getId(DatastoreObject domainObject)
{
if (domainObject.getId() != null)
{
Key<DatastoreObject> key = ofy.fact().getKey(domainObject);
return key.getString();
} else
return null;
}
}
Please note that your implementation may slightly differ because I'm using Objectify4.