org.apache.wicket.markup.html.navigation.paging
Class PagingNavigation

java.lang.Object
  org.apache.wicket.Component
      org.apache.wicket.MarkupContainer
          org.apache.wicket.markup.html.WebMarkupContainer
              org.apache.wicket.markup.repeater.AbstractRepeater
                  org.apache.wicket.markup.html.list.Loop
                      org.apache.wicket.markup.html.navigation.paging.PagingNavigation

All Implemented Interfaces:

Serializable, Iterable<Component>, IEventSink, IEventSource, IConverterLocator, IHeaderContributor, IRequestableComponent, IHierarchical<Component>, IClusterable

Direct Known Subclasses:

AjaxPagingNavigation

public class PagingNavigation
extends Loop

A navigation for a PageableListView that holds links to other pages of the PageableListView.

For each row (one page of the list of pages) a PagingNavigationLinkwill be added that contains a Label with the page number of that link (1..n).

 
        <td wicket:id="navigation">
                <a wicket:id="pageLink" href="SearchCDPage.html">
                        <span wicket:id="pageNumber">1</span>
                </a>
        </td>
 
 

thus renders like:

        1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
 

Override method populateItem to customize the rendering of the navigation. For instance:

 protected void populateItem(LoopItem loopItem)
 {
        final int page = loopItem.getIteration();
        final PagingNavigationLink link = new PagingNavigationLink("pageLink", pageableListView, page);
        if (page > 0)
        {
                loopItem.add(new Label("separator", "|"));
        }
        else
        {
                loopItem.add(new Label("separator", ""));
        }
        link.add(new Label("pageNumber", String.valueOf(page + 1)));
        link.add(new Label("pageLabel", "page"));
        loopItem.add(link);
 }
 

With:

 <span wicket:id="navigation">
        <span wicket:id="separator"></span>
        <a wicket:id="pageLink" href="#">
                <span wicket:id="pageLabel"></span><span wicket:id="pageNumber"></span>
        </a>
 </span>
 

renders like:

 page1 | page2 | page3 | page4 | page5 | page6 | page7 | page8 | page9
 

Assuming a PageableListView with 1000 entries and not more than 10 lines shall be printed per page, the navigation bar would have 100 entries. Because this is not feasible PagingNavigation's navigation bar is pageable as well.

The page links displayed are automatically adjusted based on the number of page links to be displayed and a margin. The margin makes sure that the page link pointing to the current page is not at the left or right end of the page links currently printed and thus providing a better user experience.

Use setMargin() and setViewSize() to adjust the navigation's bar view size and margin.

Please

Author:

Jonathan Locke, Eelco Hillenius, Juergen Donnerstag

See Also:

for a ready made component which already includes links to the first, previous, next and last page., Serialized Form

Field Summary

protected IPagingLabelProvider	labelProvider The label provider for the text that the links should be displaying.
protected IPageable	pageable The PageableListView this navigation is navigating.

Fields inherited from class org.apache.wicket.Component

ENABLE, FLAG_INITIALIZED, FLAG_REMOVING_FROM_HIERARCHY, FLAG_RESERVED1, FLAG_RESERVED2, FLAG_RESERVED3, FLAG_RESERVED4, FLAG_RESERVED5, FLAG_RESERVED8, PARENT_PATH, PATH_SEPARATOR, RENDER

Constructor Summary

PagingNavigation(String id, IPageable pageable)
Constructor.

PagingNavigation(String id, IPageable pageable, IPagingLabelProvider labelProvider)
Constructor.

Method Summary

long	getMargin() Gets the margin, default value is half the view size, unless explicitly set.
String	getSeparator() Gets the seperator.
protected long	getStartIndex() Allow subclasses replacing populateItem to calculate the current page number
int	getViewSize() Gets the view size (is fixed by user).
protected AbstractLink	newPagingNavigationLink(String id, IPageable pageable, long pageIndex) Factory method for creating page number links.
protected void	onConfigure() Called once per request on components before they are about to be rendered.
protected void	populateItem(LoopItem loopItem) Populate the current cell with a page link (PagingNavigationLink) enclosing the page number the link is pointing to.
protected void	renderItem(LoopItem loopItem) Renders the page link.
void	setMargin(int margin) Sets the margin.
void	setSeparator(String separator) Sets the seperator.
void	setViewSize(int size) view size of the navigation bar.

Methods inherited from class org.apache.wicket.markup.html.list.Loop

getIterations, newItem, onPopulate, renderChild, renderIterator

Methods inherited from class org.apache.wicket.markup.repeater.AbstractRepeater

getMarkup, onBeforeRender, onRender

Methods inherited from class org.apache.wicket.markup.html.WebMarkupContainer

getWebApplication, getWebPage, getWebRequest, getWebResponse, getWebSession

Methods inherited from class org.apache.wicket.MarkupContainer

add, addOrReplace, autoAdd, contains, get, get, getAssociatedMarkup, getAssociatedMarkupStream, getMarkupType, internalAdd, internalInitialize, iterator, iterator, onAfterRenderChildren, onComponentTagBody, remove, remove, removeAll, renderAll, renderAssociatedMarkup, renderNext, replace, setDefaultModel, size, swap, toString, toString, visitChildren, visitChildren, visitChildren, visitChildren

Methods inherited from class org.apache.wicket.Component

add, addStateChange, afterRender, beforeRender, canCallListenerInterface, checkComponentTag, checkComponentTagAttribute, checkHierarchyChange, clearOriginalDestination, configure, continueToOriginalDestination, debug, detach, detachModel, detachModels, determineVisibility, error, exceptionMessage, fatal, findMarkupStream, findPage, findParent, findParentWithAssociatedMarkup, getAjaxRegionMarkupId, getApplication, getBehaviorById, getBehaviorId, getBehaviors, getBehaviors, getClassRelativePath, getConverter, getDefaultModel, getDefaultModelObject, getDefaultModelObjectAsString, getDefaultModelObjectAsString, getEscapeModelStrings, getFeedbackMessages, getFlag, getId, getInnermostModel, getInnermostModel, getLocale, getLocalizer, getMarkup, getMarkupAttributes, getMarkupId, getMarkupId, getMarkupIdFromMarkup, getMarkupIdImpl, getMarkupSourcingStrategy, getMetaData, getModelComparator, getOutputMarkupId, getOutputMarkupPlaceholderTag, getPage, getPageRelativePath, getParent, getPath, getRenderBodyOnly, getRequest, getRequestCycle, getRequestFlag, getResponse, getSession, getSizeInBytes, getStatelessHint, getString, getString, getString, getStyle, getVariation, hasBeenRendered, hasErrorMessage, hasFeedbackMessage, info, initModel, internalOnModelChanged, internalPrepareForRender, internalRenderComponent, isActionAuthorized, isAuto, isBehaviorAccepted, isEnableAllowed, isEnabled, isEnabledInHierarchy, isIgnoreAttributeModifier, isRenderAllowed, isRendering, isStateless, isVersioned, isVisibilityAllowed, isVisible, isVisibleInHierarchy, markRendering, modelChanged, modelChanging, newMarkupSourcingStrategy, onAfterRender, onComponentTag, onDetach, onEvent, onInitialize, onModelChanged, onModelChanging, onReAdd, onRemove, prepareForRender, redirectToInterceptPage, remove, remove, render, renderComponentTag, rendered, renderHead, renderHead, renderHead, renderPlaceholderTag, replaceComponentTagBody, replaceWith, sameInnermostModel, sameInnermostModel, send, setAuto, setDefaultModelObject, setEnabled, setEscapeModelStrings, setFlag, setIgnoreAttributeModifier, setMarkup, setMarkupId, setMarkupIdImpl, setMetaData, setOutputMarkupId, setOutputMarkupPlaceholderTag, setParent, setRenderBodyOnly, setRequestFlag, setResponsePage, setResponsePage, setResponsePage, setVersioned, setVisibilityAllowed, setVisible, success, urlFor, urlFor, urlFor, urlFor, urlFor, visitParents, visitParents, warn, wrap

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

pageable

protected IPageable pageable

The PageableListView this navigation is navigating.

labelProvider

protected IPagingLabelProvider labelProvider

The label provider for the text that the links should be displaying.

Constructor Detail

PagingNavigation

public PagingNavigation(String id,
                        IPageable pageable)

Constructor.

Parameters:

id - See Component

pageable - The underlying pageable component to navigate

PagingNavigation

public PagingNavigation(String id,
                        IPageable pageable,
                        IPagingLabelProvider labelProvider)

Constructor.

Parameters:

id - See Component

pageable - The underlying pageable component to navigate

labelProvider - The label provider for the text that the links should be displaying.

Method Detail

getMargin

public long getMargin()

Gets the margin, default value is half the view size, unless explicitly set.

Returns:

the margin

getSeparator

public String getSeparator()

Gets the seperator.

Returns:

the seperator

getViewSize

public int getViewSize()

Gets the view size (is fixed by user).

Returns:

view size

setViewSize

public void setViewSize(int size)

view size of the navigation bar.

Parameters:

size -

setMargin

public void setMargin(int margin)

Sets the margin.

Parameters:

margin - the margin

setSeparator

public void setSeparator(String separator)

Sets the seperator. Null meaning, no separator at all.

Parameters:

separator - the seperator

onConfigure

protected void onConfigure()

Description copied from class: Component

Called once per request on components before they are about to be rendered. This method should be used to configure such things as visibility and enabled flags.

Overrides must call super.onConfigure(), usually before any other code

NOTE: Component hierarchy should not be modified inside this method, instead it should be done in Component.onBeforeRender()

NOTE: Why this method is preferrable to directly overriding Component.isVisible() and Component.isEnabled()? Because those methods are called multiple times even for processing of a single request. If they contain expensive logic they can slow down the response time of the entire page. Further, overriding those methods directly on form components may lead to inconsistent or unexpected state depending on when those methods are called in the form processing workflow. It is a better practice to push changes to state rather than pull.

NOTE: If component's visibility or another property depends on another component you may call other.configure() followed by other.isVisible() as mentioned in Component.configure() javadoc.

NOTE: Why should Component.onBeforeRender() not be used for this? Because if a component's visibility is controlled inside Component.onBeforeRender(), once invisible the component will never become visible again.

Overrides:

onConfigure in class Component

getStartIndex

protected final long getStartIndex()

Allow subclasses replacing populateItem to calculate the current page number

Returns:

start index

populateItem

protected void populateItem(LoopItem loopItem)

Populate the current cell with a page link (PagingNavigationLink) enclosing the page number the link is pointing to. Subclasses may provide there own implementation adding more sophisticated page links.

Specified by:

populateItem in class Loop

Parameters:

loopItem - The iteration of the loop

See Also:

Loop.populateItem(org.apache.wicket.markup.html.list.LoopItem)

newPagingNavigationLink

protected AbstractLink newPagingNavigationLink(String id,
                                               IPageable pageable,
                                               long pageIndex)

Factory method for creating page number links.

Parameters:

id - the component id.

pageable - the pageable for the link

pageIndex - the page index the link points to

Returns:

the page navigation link.

renderItem

protected void renderItem(LoopItem loopItem)

Renders the page link. Add the separator if not the last page link

Overrides:

renderItem in class Loop

Parameters:

loopItem - The loop iteration

See Also:

Loop.renderItem(org.apache.wicket.markup.html.list.LoopItem)