We Keep Coding

What parent to set when calling FieldEditor#setEnabled?

I am building a preference page in Eclipse by extending the FieldEditorPreferencePage class. this page contains 2 fields : 1 BooleanFieldEditor (checkbox) and 1 FileFieldEditor. I would like to disable/enable the file field following the checkbox value.
I went up to something like this (some obvious code is 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
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);
}
}
My question is about this second parameter in FieldEditor#setEnabled. This parameter is the parent composite of the FieldEditor's controls ("Used to create the controls if required" says the javadoc) . At first, I set the value with the return of getFieldEditorParent but then I got an exception "Different parent". So I ended storing it (cf. this.pathFieldParent) and give it back to setEnabled and it works (or it seems to work).
But I am not sure I am doing well, especially because I had to create a member in my class that means nothing to it (and I would have to create many of them if I had many fields to enable/disable).
Do you think I am doing well or is there a better way to provide this parent ? And could you explain to me why *setEnabled" needs it ?
Thanks.

You are using the default FLAT layout for the preference page. When this layout is used each call to getFieldEditorParent generates a new Composite so you have to make just one call and remember the correct parent. Using the GRID layout getFieldEditorParent always returns the same parent. This is the actual code:
protected Composite getFieldEditorParent() {
if (style == FLAT) {
// Create a new parent for each field editor
Composite parent = new Composite(fieldEditorParent, SWT.NULL);
parent.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
return parent;
}
// Just return the parent
return fieldEditorParent;
}
setEnabled does sometimes create a new Label control so it needs to know the correct parent Composite.

Wicket - AjaxEventBehavior not rendered properly

Look at the following snippet.
add(new AjaxEventBehavior("onclick") {
private boolean toggle = false;
#Override
protected void onEvent(AjaxRequestTarget target)
{
log.debug("onEvent: " + toggle);
if (toggle)
{
toggle = false;
target.prependJavaScript("toogle(true)");
}
else
{
toggle = true;
target.prependJavaScript("toogle(false)");
}
}
});
But after the page rendering [no errors, warnings], I could see no event associated to the DOM [verified by means of firebug]. Even the debug log was never printed.
Is there any option in wicket to verify the behavior is added or not?

You should iterate trougth Behaviors added to this component to verify your one is added:
for (Behavior behavior : component.getBehaviors()) {
if(AjaxEventBehavior.class.equals(behavior.getClass())) {
// it works
}
}

The behavior won't contribute its JavaScript if the component it is attached on is either invisible or disabled.
BTW both of your prependJavaScript() calls use the same content toggle(true).

You should (almost) never have HTML ids in your markup:
For Wicket these ids take precedence over generated unique markup ids. If the id is present multiple times on the page (e.g. if you use a component multiple times), all Ajax handlers will attach to the first markup tag with that id.

GWT-Platform revealing presenters together

Hey so I am just learning the gwtp framework and I have come across a bit of a dilemma. I have a LayoutPresenter at the top level that has a main content slot and menu content slot and I am trying to find a way to bind my presenters for each slot together if possible so when the main content is revealed it will automatically show the correct side menu. Currently I have a static boolean in the Menu's Presenter that get updated onReveal and onHide. I can then check if the menu is visible when the main content is revealed and if not I reveal it.
public class MenuPresenter extends Presenter<MenuPresenter.MyView, MenuPresenter.MyProxy> {
private static boolean hidden = true;
...
#Override
protected void revealInParent() {
RevealContentEvent.fire(this, LayoutPresenter.SIDE, this);
}
#Override
protected void onReveal(){
super.onReveal();
hidden = false;
}
#Override
protected void onHide(){
super.onHide();
hidden = true;
}
public static boolean isHidden(){
return hidden;
}
}
Then in The main content Presenter:
public class ContentPresenter extends
Presenter<ContentPresenter.MyView, ContentPresenter.MyProxy> {
...
private final DispatchAsync dispather;
private final PlaceManager placeManager;
#Inject
public PhoneCallPresenter(final EventBus eventBus, final MyView view, final MyProxy proxy, final DispatchAsync dispatcher, final PlaceManager placeManager) {
super(eventBus, view, proxy);
this.dispather = dispatcher;
this.placeManager = placeManager;
}
#Override
protected void revealInParent() {
RevealContentEvent.fire(this, LayoutPresenter.CONTENT, this);
}
#Override
protected void onReveal() {
super.onReveal();
if (MenuPresenter.isHidden()){
placeManager.revealPlace(new PlaceRequest(NameTokens.menu));
}
}
}

As far as I understood the question, you want to have different side-menus for different main contents.
In this case there are two solutions:
Treat the menu as a normal Presenter (you will probably have multiple of them for each main content type). You just need to annotate the corresponding MenuPresenter with the same history token as your main content Presenter. So for the above example you would have a PhoneCallMenuPresenter that is annotated with the same history token as your PhoneCallPresenter. When you navigate to /phonecall (or whatever your history token is), both PhoneCallPresenter and PhoneCallMenuPresenter will be revealed automatically . (you don't have to do anything).
In case you want to have only one MenuPresenter and put the logic what to display in the Presenter itself, I would recommend to use a PresenterWidget instead of a normal Presenter. The MenuPresenterWidget will be injected into the LayoutPresenter and will be added to the LayoutPresenter.SIDE slot. You can define a setter for the MenuPresenterWidget to specify which main content is currently displayed (the setter will be called from the LayoutPresenter or you can override the onReset() method and check the current place request and decide what to display in the menu.
For solution 1 you have to have one MenuPresenter for each main content Presenter and potentially many code lines will be redundant (you could create a base MenuPresenter and derive from it). So in case you have a lot of business logic in the side-menu which is quite different from main content to main content, I would go with solution 1. In case you only display different links the overhead of creating a MenuPresenter per main content Presenter might be to high and I would go with solution 2 and create only one MenuPresenterWidget for all main content types and always show it.

GWT SuggestBox: How do I force the SuggestBox to select the first item in the suggestion list?

I have a textbox and one suggestbox. I attach a value change and key up handler to the text box such that whatever the user types (or pastes) into the text box is echo-ed inside the suggestbox. I can get the suggestbox to display the suggestion list by calling showSuggestionList on each value change and key up event.
Now, how do I get the suggestbox to automatically choose the first item in the suggestion list?
One of the methods I tried is to programatically simulate key presses, i.e
suggestBox.setFocus(true);
NativeEvent enterEvent = Document.get().createKeyPressEvent(false, false, false, false, KeyCodes.KEY_ENTER);
DomEvent.fireNativeEvent(enterEvent, suggestBox);
textBox.setFocus(true);
This doesn't work at all. The enter key isn't simulated. Another possible solution is to extend SuggestionBox.SuggestionDisplay, but I'm not too sure how to that. Any pointers appreciated.
Update: I'm still working on this and trying various methods.
Here, I tried to implement my own SuggestionDisplay by subclassing DefaultSuggestionDisplay and overriding getCurrentSelection() to make accessible from my class. This doesn't work either. Null is returned.
private class CustomSuggestionDisplay extends DefaultSuggestionDisplay {
#Override
protected Suggestion getCurrentSelection() {
return super.getCurrentSelection();
}
}
suggestBox.setAutoSelectEnabled(true);
textBox.addKeyUpHandler(new KeyUpHandler() {
public void onKeyUp(KeyUpEvent event) {
suggestBox.setValue(textBox.getText(), true);
suggestBox.showSuggestionList();
if (suggestBox.isSuggestionListShowing()) {
String s = ((CustomSuggestionDisplay) suggestBox.getSuggestionDisplay()).getCurrentSelection().getDisplayString();
Window.alert(s);
}
}
});
Here, I tried to attach a value change handler to the SuggestBox, and casting the event type to SuggestOracle.Suggestion. Again, null is returned.
suggestBox.addValueChangeHandler(new ValueChangeHandler<String>() {
public void onValueChange(ValueChangeEvent<String> event) {
String s = ((SuggestOracle.Suggestion) event).getDisplayString();
Window.alert(s);
}
});

Use suggesBox.setAutoSelectEnabled(true)
Here more info about the SuggestBox of GWT:

You could try using addSelectionHandler in conjunction with setAutoSelectEnabled to receive an event whenever a suggestion is selected. You could also have your Oracle send a message when it suggests something, or your Display send a message when it displays a list:
public class AutomaticallySelectingSuggestionDisplay extends SuggestBox.DefaultSuggestionDisplay {
#Override
protected void showSuggestions(SuggestBox box, Collection<? extends SuggestOracle.Suggestion> suggestions, boolean isDisplayHtml, boolean isAutoSelectEnabled, SuggestBox.SuggestionCallback callback) {
super.showSuggestions(box, suggestions, isDisplayHtml, isAutoSelectEnabled, callback);
fireValueChangeEventWithFirstSuggestion(suggestions);
}
}
This idea feels a little muddled to me, so I hope you can find a solution just using event handlers.

Set focus on a component with Apache Wicket?

How do you set focus on a component with Apache Wicket? Searching leads to very little information, mostly on setting the default field. I do not want to set a default field, rather I am looking to set focus when, for example, a specific radio button is selected.

I suggest using the native org.apache.wicket.ajax.AjaxRequestTarget#focusComponent(). For example:
/**
* Sets the focus in the browser to the given component. The markup id must be set. If
* the component is null the focus will not be set to any component.
*
* #param component
* The component to get the focus or null.
*/
org.apache.wicket.ajax.AjaxRequestTarget#focusComponent(Component component)

Once you create your behavior to set the focus, you should be able to add it to the component on any event, just make sure that component is part of the AjaxRequestTarget. I don't see why this wouldn't work...
myRadioButton.add(new AjaxEventBehavior("onchange") {
#Override
protected void onEvent(AjaxRequestTarget target) {
myOtherComponent.add(new DefaultFocusBehavior());
target.addComponent(myForm);
}
});
Here's a link that shows how to create the default focus behavior if you do not have one already:
http://javathoughts.capesugarbird.com/2009/01/wicket-and-default-focus-behavior.html

If you only want to setFocus through javascript and don't want to reload a form or a component, you can use the following code:
import org.apache.wicket.Component;
public class JavascriptUtils {
private JavascriptUtils() {
}
public static String getFocusScript(Component component) {
return "document.getElementById('" + component.getMarkupId() + "').focus();";
}
}
And then in any Ajax Method you can use:
target.appendJavascript(JavascriptUtils.getFocusScript(componentToFocus));

For a pop-up like modalWindow my workaround solution was to use the attribute "autofocus" on the first input tag.
An easy solution is to add it to the html directly.
<input ..... autofocus>
Another solution is to add it to the modalWindow itself:
#Override
public void show(AjaxRequestTarget target) {
super.show(target);
setUpFocus();
}
protected void setUpFocus() {
DeepChildFirstVisitor visitor = new DeepChildFirstVisitor() {
#Override
public void component(Component component, IVisit<Void> iVisit) {
if (isAutofocusable(component)) {
component.add(new AttributeAppender("autofocus", ""));
iVisit.stop();
}
}
#Override
public boolean preCheck(Component component) {
return false;
}
};
this.visitChildren(FormComponent.class, visitor);
}
protected boolean isAutofocusable(Component component) {
if (component instanceof TextArea ||
component instanceof DropDownChoice ||
// component instanceof RadioChoice ||
component instanceof AjaxCheckBox ||
component instanceof AjaxButton ||
component instanceof TextField) {
return true;
}
return false;
}
RadioChoice is commented out because this solution is not working on that. For RadioChoice i would recommend to implement a FocusedRadioChoice:
public class FocusedRadioChoice<T> extends RadioChoice<T> {
//constructors...
#Override
protected IValueMap getAdditionalAttributes(int index, T choice) {
super.getAdditionalAttributes(0, choice);
AttributeMap am = new AttributeMap();
am.put("autofocus", "");
return am;
}
}

Is there a way to achieve the same without JavaScript?
(I am implementing a form with a feedback-Panel that only comes up when Javascript is turned off, so it would not make sense to depend on JavaScript there...,-)
I could only find answers which use JS .focs()... maybe Wicket 1.5 will provide a method Component.setFocus()...

If you happen to be using an Ajax button, you can simply call target.focusComponent(myComponent); in the button's onSubmit method.

#martin-g 's solution was the only solution that got it working for my scenario - a modal/pop up.
Note:
I think autofocus embedded explicitly in HTML only works on page load, not modal load so any efforts to skillfully set the autofocus attribute in the HTML of a modal just fail miserably - always.
Here I lay out the steps for setting the focus on an input field called 'myInput' using the full power of Wicket (no JS!):
In onInitialize:
// Make sure the field has an ID in markup
myInput.setOutoutMarkupId(true);
Provide an overridden show method where you call the focusComponent method:
public void show(AjaxRequestTarget target)
{
// Make sure you call the super method first!
super.show(target);
target.focusComponent(myInput);
}
This does require that your component is an attribute of your modal content class so that you can access it in the show method. To avoid creating a class attribute for your input component you could blend this solution with the solution from BlondCode by replacing that solution's
component.add(new AttributeAppender("autofocus", ""));
with
target.focusComponent(component);
This also works!