Geek asks and answers

Wicket container that is hidden when all its child components are hidden

I have a block level element, a container that should be hidden when all of its Wicket children (buttons) are hidden. In other words, if any child button is visible, the container should be visible.

Previously, one of the buttons was always visible if there were any buttons, so I used this button to control the visibility <wicket:enclosure>, processing all this exclusively on the HTML side.

Now the specifications have changed so that the buttons can be hidden / visible independently, so a simple application will no longer work (I think).

I worked on this:

HTML:

<wicket:container wicket:id="downloadButtons">
     <wicket:message key="download.foo.bar"/>:
     <input type="button" wicket:id="excelDownloadButton" wicket:message="value:download.excel"/>
     <input type="button" wicket:id="textDownloadButton" wicket:message="value:download.text"/>
     <!-- etc ... -->
</wicket:container>

Java:

WebMarkupContainer container = new WebMarkupContainer("downloadButtons");

// ... add buttons to container ...

boolean showContainer = false;
Iterator<? extends Component> it = container.iterator();
while (it.hasNext()) {
    if (it.next().isVisible()) {
        showContainer = true;
        break;
    }
}
addOrReplace(container.setVisible(showContainer));

Java , , , , . ? - "" ( ), ?

( 1.4, .)

+5
3

, , IComponentConfigurationBehavior ( 1.4.16), , onConfigure()

class AutoHidingBehavior extends AbstractBehavior {

    @Override
    public void bind(Component component) {
        if (! (component instanceof MarkupContainer) ) {
            throw new IllegalArgumentException("This behavior can only be used with markup containers");
        }
    }

    @Override
    public void onConfigure(Component component) {
        MarkupContainer container = (MarkupContainer) component;
        boolean hasVisibleChildren = false;
        for (Iterator<? extends Component> iter = container.iterator(); iter.hasNext(); ) {
            if ( iter.next().isVisible() ) {
                hasVisibleChildren = true;
                break;
            }
        }
        container.setVisible(hasVisibleChildren);
    }

}
+10

isVisible, true, - ( , ). , "" , , , , "". .

EnclosureContainer -.

: isVisible...

[...] , :

  • , ,

  • /. if isVisible() true , , false,

+4

You can also use the visitor.

In my case, I have a container with links in Panel. The code:

public abstract class MyPanel extends Panel
{
   private final WebMarkupContainer webMarkupContainer;

   public MyPanel(String id)
   {
      super(id);

      webMarkupContainer = new WebMarkupContainer("customContainer")
      {
         @Override
         protected void onBeforeRender()
         {
            super.onBeforeRender();
            boolean visible = Boolean.TRUE.equals(checkVisibleLinks());
            setVisible(visible);
         }
      };

      AjaxLink myLink = new AjaxLink("myLink")
      {
         @Override
         public void onClick(AjaxRequestTarget target)
         {
            //some action
         }

      };

      webMarkupContainer.add(myLink);
   }

   private Boolean checkVisibleLinks()
   {
      return webMarkupContainer.visitChildren(AbstractLink.class, new IVisitor<AbstractLink, Boolean>()
      {
         @Override
         public void component(AbstractLink link, IVisit<Boolean> visit)
         {
            if (link.isVisible())
            {
               visit.dontGoDeeper();
               visit.stop(true);
            }
         }
      });
   }

}
0
source

More articles:


All Articles