I would like to change the meta tag in gwt and I have found the metaElement class. But how can I use it?
That's how we do it for updating the description meta tag:
public void onModuleLoad() {
Button btn = new Button("update description");
btn.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
updateDescription();
}
});
RootPanel.get().add(btn);
}
private void updateDescription() {
NodeList<Element> tags = Document.get().getElementsByTagName("meta");
for (int i = 0; i < tags.getLength(); i++) {
MetaElement metaTag = ((MetaElement) tags.getItem(i));
if (metaTag.getName().equals("description")) {
metaTag.setContent("new description");
}
}
}
Iterate over Document.get().getElementsByTagName("meta"), search for your tag by matching the attribute. Then cast the Node to MetaElement.
Related
I've an combo box which is composed of a text field and a popup with a CellTable showing the suggestion items. The text field has a change handler that updates the CellTable's selection.
When typing a character and clicking an already selected suggestion, the first click is swallowed. The second click works and triggers the selection via the CellTable.addDomHandler(...).
Any idea why first click is swallowed?
Example code:
private static class SuggestFieldTextAndPopupSandbox extends SimplePanel {
private final TextField mText;
private CellTable<Handle<String>> mTable;
private SingleSelectionModel<Handle<String>> mTableSelection;
private SingleSelectionModel<Handle<String>> mSelection;
private ProvidesKey<Handle<String>> mKeyProvider = new SimpleKeyProvider<Handle<String>>();
private PopupPanel mPopup;
private List<Handle<String>> mData;
public SuggestFieldTextAndPopupSandbox() {
mData = Lists.newArrayList(new Handle<String>("AAA"), new Handle<String>("AAB"), new Handle<String>("ABB"));
mSelection = new SingleSelectionModel<Handle<String>>();
mText = new TextField();
mText.addKeyPressHandler(new KeyPressHandler() {
#Override
public void onKeyPress(KeyPressEvent pEvent) {
mPopup.showRelativeTo(mText);
}
});
mText.addBlurHandler(new BlurHandler() {
#Override
public void onBlur(BlurEvent pEvent) {
mTableSelection.setSelected(startsWith(mText.getValue()), true);
}
});
mText.addChangeHandler(new ChangeHandler() {
#Override
public void onChange(ChangeEvent pEvent) {
mText.setText(mText.getText().toUpperCase());
}
});
mTable = new CellTable<Handle<String>>(0, GWT.<TableResources>create(TableResources.class));
mTable.setTableLayoutFixed(false);
mTableSelection = new SingleSelectionModel<Handle<String>>(mKeyProvider);
mTable.setSelectionModel(mTableSelection);
mTable.addDomHandler(new ClickHandler() {
#Override
public void onClick(final ClickEvent pEvent) {
Scheduler.get().scheduleFinally(new ScheduledCommand() {
#Override
public void execute() {
mSelection.setSelected(mTableSelection.getSelectedObject(), true);
mText.setFocus(true);
mPopup.hide();
}
});
}
}, ClickEvent.getType());
mTable.addColumn(new TextColumn<Handle<String>>() {
#Override
public String getValue(Handle<String> pObject) {
return pObject.get();
}
});
mTable.setRowData(mData);
mPopup = new PopupPanel();
mPopup.setAutoHideEnabled(true);
mPopup.setWidget(mTable);
mPopup.setWidth("200px");
mPopup.setHeight("200px");
VerticalPanel p = new VerticalPanel();
p.add(mText);
setWidget(p);
}
private Handle<String> startsWith(final String pValue) {
final String val = nullToEmpty(pValue).toLowerCase();
int i = 0;
for (Handle<String> item : mData) {
String value = item.get();
if (value != null && value.toLowerCase().startsWith(val)) {
return item;
}
i++;
}
return null;
}
}
I reproduced your issue and here is the problem:
when you click on the suggestions the following is happening:
The text field is loosing focus which causes the corresponding ChangeEvent to be dealt with followed by the BlurEvent.
The click causes the popup to get the focus now which is why it is swallowed.
If you remove the ChangeHandler and the BlurHandler of the text field the issue disappears. But I think I found another solution
Try replacing the DOM handler of the mTable with a selection handler relative to the mTableSelection as follows:
mTableSelection.addSelectionChangeHandler(new Handler(){
#Override
public void onSelectionChange(SelectionChangeEvent event) {
Scheduler.get().scheduleFinally(new ScheduledCommand() {
#Override
public void execute() {
mSelection.setSelected(mTableSelection.getSelectedObject(), true);
mText.setFocus(true);
mPopup.hide();
}
});
}
});
Found a way how to properly solve this.
Skipping the blur handler when user hovers the suggestion list area seemed to fix that issue, at least from the tests that were done didn't see any more issues.
This was necessary because just before the user clicks a suggestion item, the text is blurred and it fires a selection change. This in turn cancels the selection made when user clicks an item.
So I have implemented a very simple drag and drop file upload widget. Basically my widget is a vertical panel with a couple of labels and a button inside. The user can either drag file into vertical panel or click button and browse for file.
My problem is that when I drag a file into the vertical panel it fires the DragLeaveEvent every time I drag the item over the space that the labels or button occupies. I want it to know that the item is in the vertical panel even when it is on top of the label or button. Im sure I am missing something simple. I provide the drag functionality by adding these dom handlers to the vertical panel:
addDomHandler(new DragEnterHandler() {
#Override
public void onDragEnter(DragEnterEvent event) {
System.out.println("drag enter");
highlight(true);
}
}, DragEnterEvent.getType());
addDomHandler(new DragLeaveHandler() {
#Override
public void onDragLeave(DragLeaveEvent event) {
System.out.println("drag leave");
highlight(false);
}
}, DragLeaveEvent.getType());
addDomHandler(new DragOverHandler() {
#Override
public void onDragOver(DragOverEvent event) {
}
}, DragOverEvent.getType());
addDomHandler(new DropHandler() {
#Override
public void onDrop(DropEvent event) {
System.out.println("drop");
// stop default behaviour
event.preventDefault();
event.stopPropagation();
// starts the fetching, reading and callbacks
if (fileUploadHandler != null) {
handleFiles(event.getDataTransfer(), fileUploadHandler);
}
highlight(false);
}
}, DropEvent.getType());
Check that the event target is a child (or grand child) of your panel, or in this case maybe rather whether the event target is exactly your panel's element:
if (verticalPanel.getElement().isOrHasChild(Node.as(event.getNativeEvent().getEventTarget()))) {
// within the panel (possibly on a child)
}
if (verticalPanel.getElement() == Node.as(event.getNativeEvent().getEventTarget())) {
// targetting exactly the panel (e.g. leaving the panel, not one of its children)
}
Through lots of research I have come to the only solution I could find. I set highlight to true in the dragover handler instead of drag enter.
panel.addDomHandler(new DragEnterHandler() {
#Override
public void onDragEnter(DragEnterEvent event) {
}
}, DragEnterEvent.getType());
panel.addDomHandler(new DragLeaveHandler() {
#Override
public void onDragLeave(DragLeaveEvent event) {
highlight(false);
}
}, DragLeaveEvent.getType());
panel.addDomHandler(new DragOverHandler() {
#Override
public void onDragOver(DragOverEvent event) {
highlight(true);
}
}, DragOverEvent.getType());
panel.addDomHandler(new DropHandler() {
#Override
public void onDrop(DropEvent event) {
// stop default behaviour
event.preventDefault();
event.stopPropagation();
// starts the fetching, reading and callbacks
handleFiles(event.getDataTransfer());
highlight(false);
}
}, DropEvent.getType());
I copy pasted your code, but also added a:
RootPanel.get().addHandler(dropHandler, DropEvent.getType());
My drophandler looks like this:
DropHandler dropHandler = new DropHandler() {
#Override
public void onDrop(DropEvent event) {
handleFiles(event.getDataTransfer(), new FileUploadHandler() {
#Override
public TYPE specifyFileType() {
return TYPE.BINARY;
}
#Override
public void handleFileContent(String fileName, String fileContent) {
// do stuff with filename and content
}
#Override
public boolean checkFileName(String fileName) {
return true;
}
});
event.preventDefault();
event.stopPropagation();
}
};
and the file-upload interface:
public interface FileUploadHandler {
static public enum TYPE {
TEXT, BINARY, DATAURL
};
// check the filename and extension and return true if you are happy with
// proceeding
// returnning false will prevent the file from being read
boolean checkFileName(String fileName);
// tell the method to use to read this file
TYPE specifyFileType();
// do your stuff here, eg upload to a server
void handleFileContent(String fileName, String fileContent);
}
and the handle files func: (note you will have to change classpath to the FileUploadHandler-interface)
// native method to make use of the HTML5 file API functionality
private final native void handleFiles(JavaScriptObject dataTransfer, FileUploadHandler fileUploadHandler) /*-{
var files = dataTransfer.files;
var i;
var file;
var reader = new FileReader();
for (i = 0; i < files.length; i++) {
file = files[i];
if (fileUploadHandler.#<classpath_to>.FileUploadHandler::checkFileName(Ljava/lang/String;)(file.name)) {
var type = fileUploadHandler.#<classpath_to>.FileUploadHandler::specifyFileType()();
reader.onload = function(e) {
fileUploadHandler.#<classpath_to>.FileUploadHandler::handleFileContent(Ljava/lang/String;Ljava/lang/String;)(file.name, e.target.result);
}
if (type == "TEXT") {
reader.readAsText(file);
} else if (type == "BINARY") {
reader.readAsBinaryString(file);
} else if (type == "DATAURL") {
reader.readAsDataURL(file);
// not supported
} else if (type == "ARRAYBUFFER") {
reader.readAsArrayBuffer(file);
} else {
}
}
}
}-*/;
I have a CellList in GWT, i need to deselect the cell when one link is clicked without using the selectionchange handler.Can someone help in this situation.
CellList<MyClass> cellList;
SingleSelectionModel<MyClass> lSelectionModel;
final SingleSelectionModel<MyClass> lSelectionModel =
new SingleSelectionModel<MyClass>();
this.cellList.setSelectionModel(lSelectionModel);
public void setSelected(final MyClass pClass) {
Anchor lLink = new Anchor();
lLink.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent pEvent) {
//Here i need to deselect the cell(Myclass)
}
});
}
Thanks in advance,
Raj
Using a SingleSelectionModel, is as easy as:
lLink.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent pEvent) {
MyClass selected = lSelectionModel.getSelectedObject();
if (selected != null) {
lSelectionModel.setSelected(selected, false);
}
});
I'm working on a project with GWT 2.1 and mvp4g. In a view, I'm using
a CellList backed with a ListDataProvider. If I pass a List with data to the constructor
when instantiating the ListDataProvider, the CellList shows this data.
The problem is that afterthat, the CellList never gets redrawn
whenever I change the list within the ListDataProvider. I don't know what I am
doing wrong or if I missing something.
Here is the code:
The UIBinder xml file:
<g:DockLayoutPanel unit="PX">
<g:west size="300">
<g:VerticalPanel styleName='{style.leftPanel}' spacing="8">
<g:Label>Expositores</g:Label>
<g:ScrollPanel addStyleNames='{style.exhibitorList}' width="250px" height="600px">
<c:CellList ui:field="exhibitorList" />
</g:ScrollPanel>
<g:Button ui:field="editExhibitorButton" addStyleNames='{style.button}'>Editar</g:Button>
</g:VerticalPanel>
</g:west>
...
The View class:
public class ExhibitorsAdminView extends Composite implements
ExhibitorsAdminPresenter.IExhibitorsAdminView {
interface Binder extends UiBinder<Widget, ExhibitorsAdminView> {}
private static final Binder binder = GWT.create( Binder.class );
private static class ExhibitorCell extends AbstractCell<Exhibitor> {
#Override
public void render(Cell.Context context, Exhibitor exhibitor,
SafeHtmlBuilder sb) {
if (exhibitor != null) {
sb.appendEscaped(exhibitor.getName());
}
}
}
private ListDataProvider<Exhibitor> exhibitorsDataProvider;
private SingleSelectionModel<Exhibitor> exhibitorsSelectionModel;
#UiField( provided = true )
CellList<Exhibitor> exhibitorList;
#UiField
Button editExhibitorButton;
// #UiField(provided = true)
// CellTable<Object> moduleList = new CellTable<Object>();
public ExhibitorsAdminView() {
exhibitorsSelectionModel = new
SingleSelectionModel<Exhibitor>(Exhibitor.KEY_PROVIDER);
exhibitorList = new CellList<Exhibitor>(new ExhibitorCell(),
Exhibitor.KEY_PROVIDER);
exhibitorList.setSelectionModel(exhibitorsSelectionModel);
exhibitorsDataProvider = new
ListDataProvider<Exhibitor>(getExhibitors());
exhibitorsDataProvider.addDataDisplay(exhibitorList);
exhibitorList.setPageSize(exhibitorsDataProvider.getList().size());
initWidget( binder.createAndBindUi( this ) );
}
public SingleSelectionModel<Exhibitor> getExhibitorsSelectionModel()
{
return exhibitorsSelectionModel;
}
public ListDataProvider<Exhibitor> getExhibitorsDataProvider() {
return exhibitorsDataProvider;
}
private List<Exhibitor> getExhibitors() {
List<Exhibitor> exhibitors = new ArrayList<Exhibitor>();
for (int i = 0; i < 10; i++) {
exhibitors.add(new Exhibitor(i, "aaaaaaaaaaaaaaa"));
}
return exhibitors;
}
public HasClickHandlers getEditExhibitorButton() {
return editExhibitorButton;
}
}
The presenter class:
#Presenter(view = ExhibitorsAdminView.class)
public class ExhibitorsAdminPresenter extends
BasePresenter<ExhibitorsAdminPresenter.IExhibitorsAdminView,
ExhibitorsEventBus> {
public interface IExhibitorsAdminView {
SingleSelectionModel<Exhibitor> getExhibitorsSelectionModel();
ListDataProvider<Exhibitor> getExhibitorsDataProvider();
HasClickHandlers getEditExhibitorButton();
}
private DispatchAsync dispatch = null;
#Inject
public ExhibitorsAdminPresenter(final DispatchAsync dispatch) {
this.dispatch = dispatch;
}
#Override
public void bind() {
getView().getExhibitorsSelectionModel().addSelectionChangeHandler(
new SelectionChangeEvent.Handler() {
public void onSelectionChange(SelectionChangeEvent event) {
Exhibitor selected =
getView().getExhibitorsSelectionModel().getSelectedObject();
if (selected != null) {
Window.alert("You selected: " + selected.getName());
}
}
});
getView().getEditExhibitorButton().addClickHandler(
new ClickHandler() {
public void onClick(ClickEvent event) {
}
});
}
public void onGoToExhibitorsAdmin() {
}
public void onLoadExhibitors() {
dispatch.execute(new GetExhibitors(), new
AsyncCallback<GetExhibitorsResult>() {
public void onSuccess(GetExhibitorsResult result) {
getView().getExhibitorsDataProvider().setList(
result.getExhibitors());
getView().getExhibitorsDataProvider().refresh();
}
public void onFailure(Throwable caught) {
GWT.log("error executing command ", caught);
}
});
}
}
Thanks.
I solved it. I'm sorry, it was an issue related with mvp4g. I was doing something wrong that was causing to have to different instances of the view where the CellList was placed. The update operations I was doing on the list of the ListDataProvider were being done on the view instance that wasn't being shown.
You have to manipulate the list by getting it first of your provider like provider.getList().add(...). See How to add or remove a single element from/to CellList? for a minimal example.
Just call exhibitorsDataProvider.refresh() after all operations with underlying list.
How to add an event handler on all div elements with GWT?
I tried the following code but the window alerts are not fired up (But "etvoila" class is set up):
private NodeList<Element> pageDIVElements;
public void initDiv() {
MyDIVEventHandler handler = new MyDIVEventHandler();
pageDIVElements = Document.get().getElementsByTagName("div");
for (int i = 0; i < pageDIVElements.getLength(); i++) {
Element elem = pageDIVElements.getItem(i);
elem.addClassName("etvoila");
com.google.gwt.user.client.Element castedElem = (com.google.gwt.user.client.Element) elem;
DOM.setEventListener(castedElem, handler);
}
class MyDIVEventHandler implements EventListener {
private Element divElement;
#Override
public void onBrowserEvent(Event event) {
Window.alert("Yeepee");
if (event.equals(Event.ONMOUSEOVER)) {
Window.alert("ONMOUSEOVER");
divElement = Element.as(((NativeEvent) event).getEventTarget());
divElement.setPropertyString("background-color", "#C6D4E6");
} else if (event.equals(Event.ONMOUSEOUT)) {
divElement = Element.as(((NativeEvent) event).getEventTarget());
divElement.setAttribute("background-color", "");
}else if (event.equals(Event.ONCLICK)) {
divElement = Element.as(((NativeEvent) event).getEventTarget());
divElement.setAttribute("background-color", "");
Window.alert("ONCLICK");
}
}
}
What is wrong in this method?
Looks like you negelected to sink the events that you want the listener to be notified of.
In this case for example I would add the following into initDiv to element or the relevant children.
DOM.sinkEvents(elem, Event.ONCLICK | Event.ONMOUSEOUT | Event.ONMOUSEOVER);
Similarly to this question, you can wrap it in a Label.
NodeList<Element> elems = Document.get().getElementsByTagName("div");
for (int i = 0; i < elems.getLength(); i++) {
Element elem = elems.get(i);
Label l = Label.wrap(elem);
l.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
Window.alert("yay!");
}
});
}