com.google.gwt.user.client.ui

Class Hyperlink

java.lang.Object

com.google.gwt.user.client.ui.UIObject

com.google.gwt.user.client.ui.Widget

com.google.gwt.user.client.ui.Hyperlink

All Implemented Interfaces:

HasClickHandlers, HasAttachHandlers, HasHandlers, HasDirectionEstimator, HasSafeHtml, EventListener, HasDirectionalSafeHtml, HasDirectionalText, HasHTML, HasText, HasVisibility, IsWidget, SourcesClickEvents

Direct Known Subclasses:

InlineHyperlink

public class Hyperlink
extends Widget
implements HasHTML, SourcesClickEvents, HasClickHandlers, HasDirectionEstimator, HasDirectionalSafeHtml

A widget that serves as an "internal" hyperlink. That is, it is a link to another state of the running application. When clicked, it will create a new history frame using History.newItem(java.lang.String), but without reloading the page.

If you want an HTML hyperlink (<a> tag) without interacting with the history system, use Anchor instead.

Being a true hyperlink, it is also possible for the user to "right-click, open link in new window", which will cause the application to be loaded in a new window at the state specified by the hyperlink.

Built-in Bidi Text Support

This widget is capable of automatically adjusting its direction according to its content. This feature is controlled by setDirectionEstimator(boolean) or passing a DirectionEstimator parameter to the constructor, and is off by default.

CSS Style Rules

• .gwt-Hyperlink { }

Example

public class HistoryExample implements EntryPoint, ValueChangeHandler<String> {

  private Label lbl = new Label();

  public void onModuleLoad() {
    // Create three hyperlinks that change the application's history.
    Hyperlink link0 = new Hyperlink("link to foo", "foo");
    Hyperlink link1 = new Hyperlink("link to bar", "bar");
    Hyperlink link2 = new Hyperlink("link to baz", "baz");

    // If the application starts with no history token, redirect to a new
    // 'baz' state.
    String initToken = History.getToken();
    if (initToken.length() == 0) {
      History.newItem("baz");
    }

    // Add widgets to the root panel.
    VerticalPanel panel = new VerticalPanel();
    panel.add(lbl);
    panel.add(link0);
    panel.add(link1);
    panel.add(link2);
    RootPanel.get().add(panel);

    // Add history listener
    History.addValueChangeHandler(this);

    // Now that we've setup our listener, fire the initial history state.
    History.fireCurrentHistoryState();
  }

  public void onValueChange(ValueChangeEvent<String> event) {
    // This method is called whenever the application's history changes. Set
    // the label to reflect the current history token.
    lbl.setText("The current history token is: " + event.getValue());
  }
}

See Also:

Anchor

Nested Class Summary

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Field Summary

Fields

Modifier and Type	Field and Description
static DirectionEstimator	DEFAULT_DIRECTION_ESTIMATOR
protected DirectionalTextHelper	directionalTextHelper

Fields inherited from class com.google.gwt.user.client.ui.Widget

eventsToSink

Fields inherited from class com.google.gwt.user.client.ui.UIObject

DEBUG_ID_PREFIX, MISSING_ELEMENT_ERROR, SETELEMENT_TWICE_ERROR

Constructor Summary

Constructors

Modifier	Constructor and Description
	Hyperlink() Creates an empty hyperlink.
protected	Hyperlink(Element elem)
	Hyperlink(SafeHtml html, DirectionEstimator directionEstimator, java.lang.String targetHistoryToken) Creates a hyperlink with its html and target history token specified.
	Hyperlink(SafeHtml html, HasDirection.Direction dir, java.lang.String targetHistoryToken) Creates a hyperlink with its html and target history token specified.
	Hyperlink(SafeHtml html, java.lang.String targetHistoryToken) Creates a hyperlink with its html and target history token specified.
	Hyperlink(java.lang.String text, boolean asHTML, java.lang.String targetHistoryToken) Creates a hyperlink with its text and target history token specified.
	Hyperlink(java.lang.String text, DirectionEstimator directionEstimator, java.lang.String targetHistoryToken) Creates a hyperlink with its text and target history token specified.
	Hyperlink(java.lang.String text, HasDirection.Direction dir, java.lang.String targetHistoryToken) Creates a hyperlink with its text and target history token specified.
	Hyperlink(java.lang.String text, java.lang.String targetHistoryToken) Creates a hyperlink with its text and target history token specified.

Method Summary

Modifier and Type	Method and Description
HandlerRegistration	addClickHandler(ClickHandler handler) Deprecated. Use FocusWidget.addClickHandler(com.google.gwt.event.dom.client.ClickHandler) instead and call History.newItem from the handler if you need to process the click before the history token is set.
void	addClickListener(ClickListener listener) Deprecated. Use FocusWidget.addClickHandler(com.google.gwt.event.dom.client.ClickHandler) instead and call History.newItem from the handler if you need to process the click before the history token is set.
DirectionEstimator	getDirectionEstimator() Returns the DirectionEstimator object.
java.lang.String	getHTML() Gets this object's contents as HTML.
java.lang.String	getTargetHistoryToken() Gets the history token referenced by this hyperlink.
java.lang.String	getText() Gets this object's text.
HasDirection.Direction	getTextDirection() Gets the direction of this object's text.
void	onBrowserEvent(Event event) Fired whenever a browser event is received.
protected void	onEnsureDebugId(java.lang.String baseID) Affected Elements: -wrapper = the div around the link.
void	removeClickListener(ClickListener listener) Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by an add*Handler method instead
void	setDirectionEstimator(boolean enabled) Toggles on / off direction estimation.
void	setDirectionEstimator(DirectionEstimator directionEstimator) Sets the DirectionEstimator object.
void	setHTML(SafeHtml html) Sets this object's contents via known-safe HTML.
void	setHTML(SafeHtml html, HasDirection.Direction dir) Sets this object's html, also declaring its direction.
void	setHTML(java.lang.String html) Sets this object's contents via HTML.
void	setTargetHistoryToken(java.lang.String targetHistoryToken) Sets the history token referenced by this hyperlink.
void	setText(java.lang.String text) Sets this object's text.
void	setText(java.lang.String text, HasDirection.Direction dir) Sets this object's text, also declaring its direction.

Methods inherited from class com.google.gwt.user.client.ui.Widget

addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, doAttachChildren, doDetachChildren, ensureHandlers, fireEvent, getHandlerCount, getHandlerManager, getLayoutData, getParent, isAttached, isOrWasAttached, onAttach, onDetach, onLoad, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents, unsinkEvents

Methods inherited from class com.google.gwt.user.client.ui.UIObject

addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.gwt.event.shared.HasHandlers

fireEvent

Field Detail

DEFAULT_DIRECTION_ESTIMATOR

public static final DirectionEstimator DEFAULT_DIRECTION_ESTIMATOR

directionalTextHelper

protected final DirectionalTextHelper directionalTextHelper

Constructor Detail

Hyperlink

public Hyperlink()

Creates an empty hyperlink.

Hyperlink

public Hyperlink(SafeHtml html,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its html and target history token specified.

Parameters:

html - the hyperlink's safe html

targetHistoryToken - the history token to which it will link

See Also:

setTargetHistoryToken(java.lang.String)

Hyperlink

public Hyperlink(SafeHtml html,
                 HasDirection.Direction dir,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its html and target history token specified.

Parameters:

html - the hyperlink's safe html

dir - the html's direction

targetHistoryToken - the history token to which it will link

See Also:

setTargetHistoryToken(java.lang.String)

Hyperlink

public Hyperlink(SafeHtml html,
                 DirectionEstimator directionEstimator,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its html and target history token specified.

Parameters:

html - the hyperlink's safe html

directionEstimator - A DirectionEstimator object used for automatic direction adjustment. For convenience, DEFAULT_DIRECTION_ESTIMATOR can be used.

targetHistoryToken - the history token to which it will link

See Also:

setTargetHistoryToken(java.lang.String)

Hyperlink

public Hyperlink(java.lang.String text,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its text and target history token specified.

Parameters:

text - the hyperlink's text

targetHistoryToken - the history token to which it will link, which may not be null (use Anchor instead if you don't need history processing)

Hyperlink

public Hyperlink(java.lang.String text,
                 HasDirection.Direction dir,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its text and target history token specified.

Parameters:

text - the hyperlink's text

dir - the text's direction

targetHistoryToken - the history token to which it will link, which may not be null (use Anchor instead if you don't need history processing)

Hyperlink

public Hyperlink(java.lang.String text,
                 DirectionEstimator directionEstimator,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its text and target history token specified.

Parameters:

text - the hyperlink's text

directionEstimator - A DirectionEstimator object used for automatic direction adjustment. For convenience, DEFAULT_DIRECTION_ESTIMATOR can be used.

targetHistoryToken - the history token to which it will link, which may not be null (use Anchor instead if you don't need history processing)

Hyperlink

public Hyperlink(java.lang.String text,
                 boolean asHTML,
                 java.lang.String targetHistoryToken)

Creates a hyperlink with its text and target history token specified.

Parameters:

text - the hyperlink's text

asHTML - true to treat the specified text as html

targetHistoryToken - the history token to which it will link

See Also:

setTargetHistoryToken(java.lang.String)

Hyperlink

protected Hyperlink(Element elem)

Method Detail

addClickHandler

@Deprecated
public HandlerRegistration addClickHandler(ClickHandler handler)

Deprecated. Use FocusWidget.addClickHandler(com.google.gwt.event.dom.client.ClickHandler) instead and call History.newItem from the handler if you need to process the click before the history token is set.

Description copied from interface: HasClickHandlers

Adds a ClickEvent handler.

Specified by:

addClickHandler in interface HasClickHandlers

Parameters:

handler - the click handler

Returns:

HandlerRegistration used to remove this handler

addClickListener

@Deprecated
public void addClickListener(ClickListener listener)

Deprecated. Use FocusWidget.addClickHandler(com.google.gwt.event.dom.client.ClickHandler) instead and call History.newItem from the handler if you need to process the click before the history token is set.

Description copied from interface: SourcesClickEvents

Adds a listener interface to receive click events.

Specified by:

addClickListener in interface SourcesClickEvents

Parameters:

listener - the listener interface to add

getDirectionEstimator

public DirectionEstimator getDirectionEstimator()

Description copied from interface: HasDirectionEstimator

Returns the DirectionEstimator object.

Specified by:

getDirectionEstimator in interface HasDirectionEstimator

getHTML

public java.lang.String getHTML()

Description copied from interface: HasHTML

Gets this object's contents as HTML.

Specified by:

getHTML in interface HasHTML

Returns:

the object's HTML

getTargetHistoryToken

public java.lang.String getTargetHistoryToken()

Gets the history token referenced by this hyperlink.

Returns:

the target history token

See Also:

setTargetHistoryToken(java.lang.String)

getText

public java.lang.String getText()

Description copied from interface: HasText

Gets this object's text.

Specified by:

getText in interface HasText

Returns:

the object's text

getTextDirection

public HasDirection.Direction getTextDirection()

Description copied from interface: HasDirectionalText

Gets the direction of this object's text.

Specified by:

getTextDirection in interface HasDirectionalText

Returns:

the direction of this object's text

onBrowserEvent

public void onBrowserEvent(Event event)

Description copied from interface: EventListener

Fired whenever a browser event is received.

Specified by:

onBrowserEvent in interface EventListener

Overrides:

onBrowserEvent in class Widget

Parameters:

event - the event received

removeClickListener

@Deprecated
public void removeClickListener(ClickListener listener)

Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by an add*Handler method instead

Description copied from interface: SourcesClickEvents

Removes a previously added listener interface.

Specified by:

removeClickListener in interface SourcesClickEvents

Parameters:

listener - the listener interface to remove

setDirectionEstimator

public void setDirectionEstimator(boolean enabled)

Toggles on / off direction estimation.

See note at setDirectionEstimator(DirectionEstimator).

Specified by:

setDirectionEstimator in interface HasDirectionEstimator

Parameters:

enabled - Whether to enable direction estimation. If true, sets the DirectionEstimator object to a default DirectionEstimator.

setDirectionEstimator

public void setDirectionEstimator(DirectionEstimator directionEstimator)

Sets the DirectionEstimator object.

Note: DirectionEstimator should be set before the widget has any content; it's highly recommended to set it using a constructor. Reason: if the widget already has non-empty content, this will update its direction according to the new estimator's result. This may cause flicker, and thus should be avoided.

Specified by:

setDirectionEstimator in interface HasDirectionEstimator

Parameters:

directionEstimator - The DirectionEstimator to be set. null means turning off direction estimation.

setHTML

public void setHTML(SafeHtml html)

Description copied from interface: HasSafeHtml

Sets this object's contents via known-safe HTML.

The object will behave exactly the same as when a widget's HasHTML.setHTML(String) method is invoked; however the SafeHtml passed to this method observes the contract that it can be used in an HTML context without causing unsafe script execution. Thus, unlike HasHTML.setHTML(String), using this method cannot result in Cross-Site Scripting security vulnerabilities.

Specified by:

setHTML in interface HasSafeHtml

Parameters:

html - the object's new HTML, represented as a SafeHtml object

setHTML

public void setHTML(java.lang.String html)

Description copied from interface: HasHTML

Sets this object's contents via HTML. Use care when setting an object's HTML; it is an easy way to expose script-based security problems. Consider using HasText.setText(String) whenever possible.

Specified by:

setHTML in interface HasHTML

Parameters:

html - the object's new HTML

setHTML

public void setHTML(SafeHtml html,
                    HasDirection.Direction dir)

Description copied from interface: HasDirectionalSafeHtml

Sets this object's html, also declaring its direction.

Specified by:

setHTML in interface HasDirectionalSafeHtml

Parameters:

html - the object's new html

dir - the html's direction

setTargetHistoryToken

public void setTargetHistoryToken(java.lang.String targetHistoryToken)

Sets the history token referenced by this hyperlink. This is the history token that will be passed to History.newItem(java.lang.String) when this link is clicked.

Parameters:

targetHistoryToken - the new history token, which may not be null (use Anchor instead if you don't need history processing)

setText

public void setText(java.lang.String text)

Description copied from interface: HasText

Sets this object's text.

Specified by:

setText in interface HasText

Parameters:

text - the object's new text

setText

public void setText(java.lang.String text,
                    HasDirection.Direction dir)

Description copied from interface: HasDirectionalText

Sets this object's text, also declaring its direction.

Specified by:

setText in interface HasDirectionalText

Parameters:

text - the object's new text

dir - the text's direction

onEnsureDebugId

protected void onEnsureDebugId(java.lang.String baseID)

Affected Elements:

• -wrapper = the div around the link.

Overrides:

onEnsureDebugId in class UIObject

Parameters:

baseID - the base ID used by the main element

See Also:

UIObject.onEnsureDebugId(String)