API Reference 0.3.24dart_web_toolkit_uiRootPanel

RootPanel class

The panel to which all other widgets must ultimately be added. RootPanels are never created directly. Rather, they are accessed via RootPanel#get().

class RootPanel extends AbsolutePanel {

 /**
  * The singleton command used to detach widgets.
  */
 static AttachCommand _maybeDetachCommand = new MaybeDetachExceptionCommand();
 static Map<String, RootPanel> _rootPanels = new Map<String, RootPanel>();
 static Set<Widget> _widgetsToDetach = new Set<Widget>();

 static String DEFAULT_ID = "__id__";

 /**
  * Marks a widget as detached and removes it from the detach list.
  *
  * If an element belonging to a widget originally passed to
  * [#detachOnWindowClose(Widget)] has been removed from the document,
  * calling this method will cause it to be marked as detached immediately.
  * Failure to do so will keep the widget from being garbage collected until
  * the page is unloaded.
  *
  * This method may only be called per widget, and only for widgets that were
  * originally passed to [#detachOnWindowClose(Widget)].
  */
 static void detachNow(Widget widget) {
   assert (_widgetsToDetach.contains(widget)); // : "detachNow() called on a widget not currently in the detach list";

   try {
     widget.onDetach();
   } finally {
     _widgetsToDetach.remove(widget);
   }
 }

 /**
  * Adds a widget to the detach list. This is the list of widgets to be
  * detached when the page unloads.
  *
  * <p>
  * This method must be called for all widgets that have no parent widgets.
  * These are most commonly {@link RootPanel RootPanels}, but can also be any
  * widget used to wrap an existing element on the page. Failing to do this may
  * cause these widgets to leak memory. This method is called automatically by
  * widgets' wrap methods (e.g.
  * {@link Button#wrap(com.google.gwt.dom.client.Element)}).
  * </p>
  *
  * <p>
  * This method may <em>not</em> be called on any widget whose element is
  * contained in another widget. This is to ensure that the DOM and Widget
  * hierarchies cannot get into an inconsistent state.
  * </p>
  *
  * @param widget the widget to be cleaned up when the page closes
  * @see #detachNow(Widget)
  */
 static void detachOnWindowClose(Widget widget) {
   assert (!_widgetsToDetach.contains(widget)); // : "detachOnUnload() called twice for the same widget";
   assert (!_isElementChildOfWidget(widget.getElement())); // : "A widget that has an existing parent widget may not be added to the detach list";

   _widgetsToDetach.add(widget);
 }

 /**
  * Gets the root panel associated with a given browser element. For this to
  * work, the HTML document into which the application is loaded must have
  * specified an element with the given id.
  *
  * @param id the id of the element to be wrapped with a root panel (
  *          <code>null</code> specifies the default instance, which wraps the
  *          &lt;body&gt; element)
  * @return the root panel, or <code>null</code> if no such element was found
  */
 static RootPanel get([String id = null]) {
   // Find the element that this RootPanel will wrap.
   dart_html.Element elem = null;
   if (id != null) {
     // Return null if the id is specified, but no element is found.
     if (null == (elem = dart_html.document.getElementById(id))) {
       return null;
     }
   }

   if (id == null) {
     id = DEFAULT_ID;
   }

   // See if this RootPanel is already created.
   RootPanel rp = _rootPanels[id];
   if (rp != null) {
     // If the element associated with an existing RootPanel has been replaced
     // for any reason, return a new RootPanel rather than the existing one (
     // see issue 1937).
     if ((elem == null) || (rp.getElement() == elem)) {
       // There's already an existing RootPanel for this element. Return it.
       return rp;
     }
   }

   // Note that the code in this if block only happens once -
   // on the first RootPanel.get(String) or RootPanel.get()
   // call.
   if (_rootPanels.length == 0) {
     _hookWindowClosing();

     // If we're in a RTL locale, set the RTL directionality
     // on the entire document.
     if (LocaleInfo.getCurrentLocale().isRTL()) {
       BidiUtils.setDirectionOnElement(getRootElement(), Direction.RTL);
     }
   }

   // Create the panel and put it in the map.
   if (elem == null) {
     // 'null' means use document's body element.
     rp = new DefaultRootPanel();
   } else {
     // Otherwise, wrap the existing element.
     rp = new RootPanel(elem);
   }

   _rootPanels[id] = rp;
   detachOnWindowClose(rp);
   return rp;
 }

 /**
  * Convenience method for getting the document's body element.
  *
  * @return the document's body element
  */
 static dart_html.Element getBodyElement() {
   return dart_html.document.body;
 }

 /**
  * Determines whether the given widget is in the detach list.
  *
  * @param widget the widget to be checked
  * @return <code>true</code> if the widget is in the detach list
  */
 static bool isInDetachList(Widget widget) {
   return _widgetsToDetach.contains(widget);
 }

 /**
  * Convenience method for getting the document's root (<html>) element.
  *
  * @return the document's root element
  */
 static dart_html.Element getRootElement() {
   return dart_html.document.documentElement;
 }

 /*
  * Checks to see whether the given element has any parent element that
  * belongs to a widget. This is not terribly efficient, and is thus only used
  * in an assertion.
  */
 static bool _isElementChildOfWidget(dart_html.Element element) {
   // Walk up the DOM hierarchy, looking for any widget with an event listener
   // set. Though it is not dependable in the general case that a widget will
   // have set its element's event listener at all times, it *is* dependable
   // if the widget is attached. Which it will be in this case.
   element = element.parent;
   dart_html.BodyElement body = dart_html.document.body;
   while ((element != null) && (body != element)) {
     if (IEvent.getEventListener(element) != null) {
       return true;
     }
     element = element.parent;
   }
   return false;
 }

 // Package-protected for use by unit tests. Do not call this method directly.
 static void detachWidgets() {
   // When the window is closing, detach all widgets that need to be
   // cleaned up. This will cause all of their event listeners
   // to be unhooked, which will avoid potential memory leaks.
   try {
     AttachDetachException.tryCommand(_widgetsToDetach.iterator, _maybeDetachCommand);
   } finally {
     _widgetsToDetach.clear();

     // Clear the RootPanel cache, since we've "detached" all RootPanels at
     // this point. This would be pointless, since it only happens on unload,
     // but it is very helpful for unit tests, because it allows
     // RootPanel.get() to work properly even after a synthesized "unload".
     _rootPanels.clear();
   }
 }

 static void _hookWindowClosing() {
   // Catch the window closing event.
   dart_html.window.onUnload.listen((dart_html.Event event) {
     detachWidgets();
   });
 }

 RootPanel(dart_html.Element elem) : super(elem) {
   onAttach();
 }
}

Extends

UiObject > Widget > Panel > ComplexPanel > AbsolutePanel > RootPanel

Subclasses

DefaultRootPanel

Static Properties

String DEFAULT_ID #

static String DEFAULT_ID = "__id__"

Static Methods

void detachNow(Widget widget) #

Marks a widget as detached and removes it from the detach list.

If an element belonging to a widget originally passed to #detachOnWindowClose(Widget) has been removed from the document, calling this method will cause it to be marked as detached immediately. Failure to do so will keep the widget from being garbage collected until the page is unloaded.

This method may only be called per widget, and only for widgets that were originally passed to #detachOnWindowClose(Widget).

static void detachNow(Widget widget) {
 assert (_widgetsToDetach.contains(widget)); // : "detachNow() called on a widget not currently in the detach list";

 try {
   widget.onDetach();
 } finally {
   _widgetsToDetach.remove(widget);
 }
}

void detachOnWindowClose(Widget widget) #

Adds a widget to the detach list. This is the list of widgets to be detached when the page unloads.

This method must be called for all widgets that have no parent widgets. These are most commonly {@link RootPanel RootPanels}, but can also be any widget used to wrap an existing element on the page. Failing to do this may cause these widgets to leak memory. This method is called automatically by widgets' wrap methods (e.g. {@link Button#wrap(com.google.gwt.dom.client.Element)}).

This method may not be called on any widget whose element is contained in another widget. This is to ensure that the DOM and Widget hierarchies cannot get into an inconsistent state.

@param widget the widget to be cleaned up when the page closes @see #detachNow(Widget)

static void detachOnWindowClose(Widget widget) {
 assert (!_widgetsToDetach.contains(widget)); // : "detachOnUnload() called twice for the same widget";
 assert (!_isElementChildOfWidget(widget.getElement())); // : "A widget that has an existing parent widget may not be added to the detach list";

 _widgetsToDetach.add(widget);
}

RootPanel get([String id = null]) #

Gets the root panel associated with a given browser element. For this to work, the HTML document into which the application is loaded must have specified an element with the given id.

@param id the id of the element to be wrapped with a root panel (

     <code>null</code> specifies the default instance, which wraps the
     &lt;body&gt; element)

@return the root panel, or <code>null</code> if no such element was found

static RootPanel get([String id = null]) {
 // Find the element that this RootPanel will wrap.
 dart_html.Element elem = null;
 if (id != null) {
   // Return null if the id is specified, but no element is found.
   if (null == (elem = dart_html.document.getElementById(id))) {
     return null;
   }
 }

 if (id == null) {
   id = DEFAULT_ID;
 }

 // See if this RootPanel is already created.
 RootPanel rp = _rootPanels[id];
 if (rp != null) {
   // If the element associated with an existing RootPanel has been replaced
   // for any reason, return a new RootPanel rather than the existing one (
   // see issue 1937).
   if ((elem == null) || (rp.getElement() == elem)) {
     // There's already an existing RootPanel for this element. Return it.
     return rp;
   }
 }

 // Note that the code in this if block only happens once -
 // on the first RootPanel.get(String) or RootPanel.get()
 // call.
 if (_rootPanels.length == 0) {
   _hookWindowClosing();

   // If we're in a RTL locale, set the RTL directionality
   // on the entire document.
   if (LocaleInfo.getCurrentLocale().isRTL()) {
     BidiUtils.setDirectionOnElement(getRootElement(), Direction.RTL);
   }
 }

 // Create the panel and put it in the map.
 if (elem == null) {
   // 'null' means use document's body element.
   rp = new DefaultRootPanel();
 } else {
   // Otherwise, wrap the existing element.
   rp = new RootPanel(elem);
 }

 _rootPanels[id] = rp;
 detachOnWindowClose(rp);
 return rp;
}

Element getBodyElement() #

Convenience method for getting the document's body element.

@return the document's body element

static dart_html.Element getBodyElement() {
 return dart_html.document.body;
}

bool isInDetachList(Widget widget) #

Determines whether the given widget is in the detach list.

@param widget the widget to be checked @return <code>true</code> if the widget is in the detach list

static bool isInDetachList(Widget widget) {
 return _widgetsToDetach.contains(widget);
}

Element getRootElement() #

Convenience method for getting the document's root (<html>) element.

@return the document's root element

static dart_html.Element getRootElement() {
 return dart_html.document.documentElement;
}

void detachWidgets() #

static void detachWidgets() {
 // When the window is closing, detach all widgets that need to be
 // cleaned up. This will cause all of their event listeners
 // to be unhooked, which will avoid potential memory leaks.
 try {
   AttachDetachException.tryCommand(_widgetsToDetach.iterator, _maybeDetachCommand);
 } finally {
   _widgetsToDetach.clear();

   // Clear the RootPanel cache, since we've "detached" all RootPanels at
   // this point. This would be pointless, since it only happens on unload,
   // but it is very helpful for unit tests, because it allows
   // RootPanel.get() to work properly even after a synthesized "unload".
   _rootPanels.clear();
 }
}

Constructors

new RootPanel(Element elem) #

Creates an empty absolute panel or with the given element. This is protected so that it can be used by RootPanel or a subclass that wants to substitute another element. The element is presumed to be a <div>.

docs inherited from AbsolutePanel
RootPanel(dart_html.Element elem) : super(elem) {
 onAttach();
}

Properties

int eventsToSink #

inherited from Widget

A set og events that should be sunk when the widget is attached to the DOM. (We delay the sinking of events to improve startup performance.) When the widget is attached, this is set is empty

Package protected to allow Composite to see it.

int eventsToSink = 0

String get title #

inherited from UiObject

Gets the title associated with this object. The title is the 'tool-tip' displayed to users when they hover over the object.

@return the object's title

String get title => getElement().title;

void set title(String value) #

inherited from UiObject

Sets the element's title.

void set title(String value) {
 getElement().title = value;
}

bool get visible #

inherited from UiObject

Determines whether or not this object is visible. Note that this does not necessarily take into account whether or not the receiver's parent is visible, or even if it is attached to the Document. The default implementation of this trait in UIObject is based on the value of a dom element's style object's display attribute.

@return <code>true</code> if the object is visible

bool get visible => isVisible(getElement());

void set visible(bool visible) #

inherited from UiObject

Sets whether this object is visible.

@param visible <code>true</code> to show the object, <code>false</code> to

     hide it
void set visible(bool visible) {
 setVisible(getElement(), visible);
}

Methods

void add(Widget w) #

inherited from AbsolutePanel

Adds a child widget.

How to Override this Method

There are several important things that must take place in the correct order to properly add or insert a Widget to a Panel. Not all of these steps will be relevant to every Panel, but all of the steps must be considered.

  1. Validate: Perform any sanity checks to ensure the Panel can accept a new Widget. Examples: checking for a valid index on insertion; checking that the Panel is not full if there is a max capacity.
  2. Adjust for Reinsertion: Some Panels need to handle the case where the Widget is already a child of this Panel. Example: when performing a reinsert, the index might need to be adjusted to account for the Widget's removal. See {@link ComplexPanel#adjustIndex(Widget, int)}.
  3. Detach Child: Remove the Widget from its existing parent, if any. Most Panels will simply call {@link Widget#removeFromParent()} on the Widget.
  4. Logical Attach: Any state variables of the Panel should be updated to reflect the addition of the new Widget. Example: the Widget is added to the Panel's {@link WidgetCollection} at the appropriate index.
  5. Physical Attach: The Widget's Element must be physically attached to the Panel's Element, either directly or indirectly.
  6. Adopt: Call {@link #adopt(Widget)} to finalize the add as the very last step.

@param child the widget to be added @throws UnsupportedOperationException if this method is not supported (most

      often this means that a specific overload must be called)

@see HasWidgets#add(Widget)

docs inherited from Panel
void add(Widget w) {
 super.addWidget(w, getElement());
}

HandlerRegistration addAttachHandler(AttachEventHandler handler) #

inherited from Widget

Adds an AttachEvent handler.

@param handler the handler @return the handler registration

HandlerRegistration addAttachHandler(AttachEventHandler handler) {
 return addHandler(handler, AttachEvent.TYPE);
}

HandlerRegistration addBitlessDomHandler(EventHandler handler, DomEventType type) #

inherited from Widget

For <a href= "http://code.google.com/p/google-web-toolkit/wiki/UnderstandingMemoryLeaks"

browsers which do not leak</a>, adds a native event handler to the widget.

Note that, unlike the {@link #addDomHandler(EventHandler, com.google.gwt.event.dom.client.DomEvent.Type)} implementation, there is no need to attach the widget to the DOM in order to cause the event handlers to be attached.

@param <H> the type of handler to add @param type the event key @param handler the handler @return {@link HandlerRegistration} used to remove the handler

HandlerRegistration addBitlessDomHandler(EventHandler handler, DomEventType type) {
 assert (handler != null);; // : "handler must not be null";
 assert (type != null); // : "type must not be null";
 sinkBitlessEvent(type.eventName);
 return ensureHandlers().addHandler(type, handler);
}

HandlerRegistration addDomHandler(EventHandler handler, DomEventType type) #

inherited from Widget

Adds a native event handler to the widget and sinks the corresponding native event. If you do not want to sink the native event, use the generic addHandler method instead.

@param <H> the type of handler to add @param type the event key @param handler the handler @return {@link HandlerRegistration} used to remove the handler

HandlerRegistration addDomHandler(EventHandler handler, DomEventType type) {
 assert (handler != null); // : "handler must not be null";
 assert (type != null); // : "type must not be null";
 int typeInt = IEvent.getTypeInt(type.eventName);
 if (typeInt == -1) {
   sinkBitlessEvent(type.eventName);
 } else {
   sinkEvents(typeInt);
 }
 return ensureHandlers().addHandler(type, handler);
}

HandlerRegistration addHandler(EventHandler handler, EventType<EventHandler> type) #

inherited from Widget

Adds this handler to the widget.

@param <H> the type of handler to add @param type the event type @param handler the handler @return {@link HandlerRegistration} used to remove the handler

HandlerRegistration addHandler(EventHandler handler, EventType<EventHandler> type) {
 return ensureHandlers().addHandler(type, handler);
}

void addInPosition(Widget w, int left, int top) #

inherited from AbsolutePanel

Adds a widget to the panel at the specified position. Setting a position of <code>(-1, -1)</code> will cause the child widget to be positioned statically.

@param w the widget to be added @param left the widget's left position @param top the widget's top position

void addInPosition(Widget w, int left, int top) {
 // In order to avoid the potential for a flicker effect, it is necessary
 // to set the position of the widget before adding it to the AbsolutePanel.
 // The Widget should be removed from its parent before any positional
 // changes are made to prevent flickering.
 w.removeFromParent();
 int beforeIndex = getWidgetCount();
 setWidgetPositionImpl(w, left, top);
 insertAt(w, beforeIndex);
 _verifyPositionNotStatic(w);
}

void addIsWidget(IsWidget child) #

inherited from Panel
void addIsWidget(IsWidget child) {
 this.add(Widget.asWidgetOrNull(child));
}

void addIsWidgetInPosition(IsWidget w, int left, int top) #

inherited from AbsolutePanel

Overloaded version for IsWidget.

@see #add(Widget,int,int)

void addIsWidgetInPosition(IsWidget w, int left, int top) {
 this.addInPosition(w.asWidget(),left,top);
}

void addStyleDependentName(String styleSuffix) #

inherited from UiObject

Adds a dependent style name by specifying the style name's suffix. The actual form of the style name that is added is:

getStylePrimaryName() + '-' + styleSuffix

@param styleSuffix the suffix of the dependent style to be added. @see #setStylePrimaryName(String) @see #removeStyleDependentName(String) @see #setStyleDependentName(String, boolean) @see #addStyleName(String)

void addStyleDependentName(String styleSuffix) {
 setStyleDependentName(styleSuffix, true);
}

void addStyleName(String style) #

inherited from UiObject

Adds a secondary or dependent style name to this object. A secondary style name is an additional style name that is, in HTML/CSS terms, included as a space-separated token in the value of the CSS <code>class</code> attribute for this object's root element.

The most important use for this method is to add a special kind of secondary style name called a dependent style name. To add a dependent style name, use {@link #addStyleDependentName(String)}, which will prefix the 'style' argument with the result of {@link #k()} (followed by a '-'). For example, suppose the primary style name is gwt-TextBox. If the following method is called as obj.setReadOnly(true):

public void setReadOnly(boolean readOnly) {
  isReadOnlyMode = readOnly;

// Create a dependent style name. String readOnlyStyle = "readonly";

if (readOnly) {

addStyleDependentName(readOnlyStyle);

} else {

removeStyleDependentName(readOnlyStyle);

} }</pre>

then both of the CSS style rules below will be applied:

// This rule is based on the primary style name and is always active. .gwt-TextBox { font-size: 12pt; }

// This rule is based on a dependent style name that is only active // when the widget has called addStyleName(getStylePrimaryName() + // "-readonly"). .gwt-TextBox-readonly { background-color: lightgrey; border: none; }</pre>

The code can also be simplified with {@link #setStyleDependentName(String, boolean)}:

public void setReadOnly(boolean readOnly) {
  isReadOnlyMode = readOnly;
  setStyleDependentName("readonly", readOnly);
}

Dependent style names are powerful because they are automatically updated whenever the primary style name changes. Continuing with the example above, if the primary style name changed due to the following call:

setStylePrimaryName("my-TextThingy");

then the object would be re-associated with following style rules, removing those that were shown above.

.my-TextThingy {
  font-size: 20pt;
}

.my-TextThingy-readonly { background-color: red; border: 2px solid yellow; }</pre>

Secondary style names that are not dependent style names are not automatically updated when the primary style name changes.

@param style the secondary style name to be added @see UIObject @see #removeStyleName(String)

void addStyleName(String style) {
 setStyleName(style, true);
}

void addWidget(Widget child, Element container) #

inherited from ComplexPanel

Adds a new child widget to the panel, attaching its Element to the specified container Element.

@param child the child widget to be added @param container the element within which the child will be contained

void addWidget(Widget child, dart_html.Element container) {
 // Detach new child.
 child.removeFromParent();

 // Logical attach.
 getChildren().add(child);

 // Physical attach.
 //Dom.appendChild(container, child.getElement());
 container.append(child.getElement());

 // Adopt.
 adopt(child);
}

int adjustIndex(Widget child, int beforeIndex) #

inherited from ComplexPanel

Adjusts beforeIndex to account for the possibility that the given widget is already a child of this panel.

@param child the widget that might be an existing child @param beforeIndex the index at which it will be added to this panel @return the modified index

int adjustIndex(Widget child, int beforeIndex) {
 checkIndexBoundsForInsertion(beforeIndex);

 // Check to see if this widget is already a direct child.
 if (child.getParent() == this) {
   // If the Widget's previous position was left of the desired new position
   // shift the desired position left to reflect the removal
   int idx = getWidgetIndex(child);
   if (idx < beforeIndex) {
     beforeIndex--;
   }
 }

 return beforeIndex;
}

void adopt(Widget child) #

inherited from Panel

Finalize the attachment of a Widget to this Panel. This method is the <b>last</b> step in adding or inserting a Widget into a Panel, and should be called after physical attachment in the DOM is complete. This Panel becomes the parent of the child Widget, and the child will now fire its {@link Widget#onAttach()} event if this Panel is currently attached.

@param child the widget to be adopted @see #add(Widget)

void adopt(Widget child) {
 assert (child.getParent() == null);
 child.setParent(this);
}

Widget asWidget() #

inherited from Widget

Returns the Widget aspect of the receiver.

Widget asWidget() {
 return this;
}

void checkIndexBoundsForAccess(int index) #

inherited from ComplexPanel

Checks that <code>index</code> is in the range [0, getWidgetCount()), which is the valid range on accessible indexes.

@param index the index being accessed

void checkIndexBoundsForAccess(int index) {
 if (index < 0 || index >= getWidgetCount()) {
   throw new Exception("Index Out Of Bounds Exception");
 }
}

void checkIndexBoundsForInsertion(int index) #

inherited from ComplexPanel

Checks that <code>index</code> is in the range 0, getWidgetCount(), which is the valid range for indexes on an insertion.

@param index the index where insertion will occur

void checkIndexBoundsForInsertion(int index) {
 if (index < 0 || index > getWidgetCount()) {
   throw new Exception("Index Out Of Bounds Exception");
 }
}

void clear() #

inherited from Panel

Removes all child widgets.

void clear() {
 Iterator<Widget> it = iterator();
 while (it.moveNext()) {
   it.current.removeFromParent();
 }
}

void clearAndSetStyleName(String style) #

inherited from UiObject

Clears all of the object's style names and sets it to the given style. You should normally use {@link #setStylePrimaryName(String)} unless you wish to explicitly remove all existing styles.

@param style the new style name @see #setStylePrimaryName(String)

void clearAndSetStyleName(String style) {
 setElementStyleName(getStyleElement(), style);
}

EventBus createEventBus() #

inherited from Widget

Creates the SimpleEventBus used by this Widget. You can override this method to create a custom EventBus.

@return the EventBus you want to use.

EventBus createEventBus() {
 return new SimpleEventBus();
}

void delegateEvent(Widget target, DwtEvent event) #

inherited from Widget

Fires an event on a child widget. Used to delegate the handling of an event from one widget to another.

@param event the event @param target fire the event on the given target

void delegateEvent(Widget target, DwtEvent event) {
 target.fireEvent(event);
}

void doAttachChildren() #

inherited from Panel

If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call {@link #onAttach()} for each of its child widgets.

@see #onAttach()

docs inherited from Widget
void doAttachChildren() {
 AttachDetachException.tryCommand(this.iterator(), AttachDetachException.attachCommand);
}

void doDetachChildren() #

inherited from Panel

If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call {@link #onDetach()} for each of its child widgets.

@see #onDetach()

docs inherited from Widget
void doDetachChildren() {
 AttachDetachException.tryCommand(this.iterator(), AttachDetachException.detachCommand);
}

void doLogicalClear() #

inherited from ComplexPanel
void doLogicalClear() {
 // TODO(jgw): When Layout work has landed, deprecate FlowPanel (the only
 // caller of this method in our code), and deprecate this method with an eye
 // to making it private down the road.

 // Only use one orphan command per panel to avoid object creation.
 if (_orphanCommand == null) {
   _orphanCommand = new OrpahExceptionCommand(this);
 }
 try {
   AttachDetachException.tryCommand(this.iterator(), _orphanCommand);
 } finally {
   _children = new WidgetCollection(this);
 }
}

EventBus ensureHandlers() #

inherited from Widget

Ensures the existence of the event bus.

@return the EventBus.

EventBus ensureHandlers() {
 return _eventBus == null ? _eventBus = createEventBus() : _eventBus;
}

double extractLengthValue(String s) #

inherited from UiObject

Intended to be used to pull the value out of a CSS length. If the value is "auto" or "inherit", 0 will be returned.

@param s The CSS length string to extract @return The leading numeric portion of <code>s</code>, or 0 if "auto" or

    "inherit" are passed in.
double extractLengthValue(String s) {
 if (s == "auto" || s == "inherit" || s == "") {
   return 0.0;
 } else {
   // numberRegex divides the string into a leading numeric portion
   // followed by an arbitrary portion.
   if(numberRegex.hasMatch(s)) {
     // Extract the leading numeric portion of string
     s = numberRegex.firstMatch(s)[0];
   }
   return double.parse(s);
 }
}

void fireEvent(DwtEvent event) #

inherited from Widget

Fires the given event to the handlers listening to the event's type.

Any exceptions thrown by handlers will be bundled into a UmbrellaException and then re-thrown after all handlers have completed. An exception thrown by a handler will not prevent other handlers from executing.

@param event the event

void fireEvent(DwtEvent event) {
//    if (_eventBus != null) {
//      _eventBus.fireEvent(event);
//    }
 if (_eventBus != null) {
   // If it not live we should revive it.
   if (!event.isLive()) {
     event.revive();
   }
   Object oldSource = event.getSource();
   event.overrideSource(getElement());
   try {

     // May throw an UmbrellaException.
     _eventBus.fireEventFromSource(event, getElement());
   } on UmbrellaException catch (e) {
     throw new UmbrellaException(e.causes);
   } finally {
     if (oldSource == null) {
       // This was my event, so I should kill it now that I'm done.
       event.kill();
     } else {
       // Restoring the source for the next handler to use.
       event.overrideSource(oldSource);
     }
   }
 }
}

int getAbsoluteLeft() #

inherited from UiObject

Gets the object's absolute left position in pixels, as measured from the browser window's client area.

@return the object's absolute left position

int getAbsoluteLeft() {
 return Dom.getAbsoluteLeft(getElement());
}

int getAbsoluteTop() #

inherited from UiObject

Gets the object's absolute top position in pixels, as measured from the browser window's client area.

@return the object's absolute top position

int getAbsoluteTop() {
 return Dom.getAbsoluteTop(getElement());
}

WidgetCollection getChildren() #

inherited from ComplexPanel

Gets the list of children contained in this panel.

@return a collection of child widgets

WidgetCollection getChildren() {
 return _children;
}

Element getElement() #

inherited from UiObject

Gets this object's browser element.

dart_html.Element getElement() {
 assert (_element != null); // : MISSING_ELEMENT_ERROR;
 return _element;
}

EventBus getEventBus() #

inherited from Widget

Return EventBus.

EventBus getEventBus() {
 return _eventBus;
}

Object getLayoutData() #

inherited from Widget

Gets the panel-defined layout data associated with this widget.

@return the widget's layout data @see #setLayoutData

Object getLayoutData() {
 return _layoutData;
}

int getOffsetHeight() #

inherited from UiObject

Gets the object's offset height in pixels. This is the total height of the object, including decorations such as border and padding, but not margin.

@return the object's offset height

int getOffsetHeight() {
 return getElement().offset.height; // Dom.getElementPropertyInt(getElement(), "offsetHeight");
}

int getOffsetWidth() #

inherited from UiObject

Gets the object's offset width in pixels. This is the total width of the object, including decorations such as border and padding, but not margin.

@return the object's offset width

int getOffsetWidth() {
 return getElement().offset.width; // Dom.getElementPropertyInt(getElement(), "offsetWidth");
}

Widget getParent() #

inherited from Widget

Gets this widget's parent panel.

@return the widget's parent panel

Widget getParent() {
 return _parent;
}

Element getStyleElement() #

inherited from UiObject

Template method that returns the element to which style names will be applied. By default it returns the root element, but this method may be overridden to apply styles to a child element.

@return the element to which style names will be applied

dart_html.Element getStyleElement() {
 return getElement();
}

String getStyleName() #

inherited from UiObject

Gets all of the object's style names, as a space-separated list. If you wish to retrieve only the primary style name, call {@link #getStylePrimaryName()}.

@return the objects's space-separated style names @see #getStylePrimaryName()

String getStyleName() {
 return getElementStyleName(getStyleElement());
}

String getStylePrimaryName() #

inherited from UiObject

Gets the primary style name associated with the object.

@return the object's primary style name @see #setStyleName(String) @see #addStyleName(String) @see #removeStyleName(String)

String getStylePrimaryName() {
 return getElementStylePrimaryName(getStyleElement());
}

Widget getWidgetAt(int index) #

inherited from ComplexPanel

Gets the child widget at the specified index.

@param index the child widget's index @return the child widget

Widget getWidgetAt(int index) {
 return getChildren().get(index);
}

int getWidgetCount() #

inherited from ComplexPanel

Gets the number of child widgets in this panel.

@return the number of children

int getWidgetCount() {
 return getChildren().size();
}

int getWidgetIndex(Widget child) #

inherited from ComplexPanel

Gets the index of the specified child widget.

@param child the widget to be found @return the widget's index, or <code>-1</code> if it is not a child of this

    panel
int getWidgetIndex(Widget child) {
 return getChildren().indexOf(child);
}

int getWidgetIndexIsWidget(IsWidget child) #

inherited from ComplexPanel
int getWidgetIndexIsWidget(IsWidget child) {
 return getWidgetIndex(Widget.asWidgetOrNull(child));
}

int getWidgetLeft(Widget w) #

inherited from AbsolutePanel

Gets the position of the left outer border edge of the widget relative to the left outer border edge of the panel.

@param w the widget whose position is to be retrieved @return the widget's left position

int getWidgetLeft(Widget w) {
 _checkWidgetParent(w);
 return Dom.getAbsoluteLeft(w.getElement()) - Dom.getAbsoluteLeft(getElement());
}

int getWidgetTop(Widget w) #

inherited from AbsolutePanel

Gets the position of the top outer border edge of the widget relative to the top outer border edge of the panel.

@param w the widget whose position is to be retrieved @return the widget's top position

int getWidgetTop(Widget w) {
 _checkWidgetParent(w);
 return Dom.getAbsoluteTop(w.getElement()) - Dom.getAbsoluteTop(getElement());
}

void insert(Widget child, Element container, int beforeIndex, bool domInsert) #

inherited from ComplexPanel

Insert a new child Widget into this Panel at a specified index, attaching its Element to the specified container Element. The child Element will either be attached to the container at the same index, or simply appended to the container, depending on the value of <code>domInsert</code>.

@param child the child Widget to be added @param container the Element within which <code>child</code> will be

     contained

@param beforeIndex the index before which <code>child</code> will be

     inserted

@param domInsert if <code>true</code>, insert <code>child</code> into

     <code>container</code> at <code>beforeIndex</code>; otherwise
     append <code>child</code> to the end of <code>container</code>.
void insert(Widget child, dart_html.Element container, int beforeIndex,
   bool domInsert) {

 if (container == null) {
   throw new Exception("container may not be null");
 }

 // Validate index; adjust if the widget is already a child of this panel.
 beforeIndex = adjustIndex(child, beforeIndex);

 // Detach new child.
 child.removeFromParent();

 // Logical attach.
 getChildren().insert(child, beforeIndex);

 // Physical attach.
 if (domInsert) {
   //DOM.insertChild(container, child.getElement(), beforeIndex);
   Dom.insertChild(container, child.getElement(), beforeIndex);
//      dart_html.Element refChild = container.nodes[beforeIndex];
//      if (refChild != null) {
//        container.insertBefore(child.getElement(), refChild);
//      } else {
//        container.append(child.getElement());
//      }
 } else {
   //DOM.appendChild(container, child.getElement());
   container.append(child.getElement());
 }

 // Adopt.
 adopt(child);
}

void insertAt(Widget w, int beforeIndex) #

inherited from AbsolutePanel

Inserts a child widget before the specified index. If the widget is already a child of this panel, it will be moved to the specified index.

@param w the child widget to be inserted @param beforeIndex the index before which it will be inserted @throws IndexOutOfBoundsException if <code>beforeIndex</code> is out of

      range
docs inherited from InsertPanel
void insertAt(Widget w, int beforeIndex) {
 insert(w, getElement(), beforeIndex, true);
}

void insertIsWidget(IsWidget w, int beforeIndex) #

inherited from AbsolutePanel

Convenience overload to allow {@link IsWidget} to be used directly.

void insertIsWidget(IsWidget w, int beforeIndex) {
 insertAt(Widget.asWidgetOrNull(w), beforeIndex);
}

void insertPosition(Widget w, int left, int top, int beforeIndex) #

inherited from AbsolutePanel

Inserts a child widget at the specified position before the specified index. Setting a position of <code>(-1, -1)</code> will cause the child widget to be positioned statically. If the widget is already a child of this panel, it will be moved to the specified index.

@param w the child widget to be inserted @param left the widget's left position @param top the widget's top position @param beforeIndex the index before which it will be inserted @throws IndexOutOfBoundsException if <code>beforeIndex</code> is out of

      range
void insertPosition(Widget w, int left, int top, int beforeIndex) {
 // In order to avoid the potential for a flicker effect, it is necessary
 // to set the position of the widget before adding it to the AbsolutePanel.
 // The Widget should be removed from its parent before any positional
 // changes are made to prevent flickering.
 w.removeFromParent();
 setWidgetPositionImpl(w, left, top);
 insertAt(w, beforeIndex);
 _verifyPositionNotStatic(w);
}

bool isAttached() #

inherited from Widget

Returns whether or not the receiver is attached to the {@link com.google.gwt.dom.client.Document Document}'s {@link com.google.gwt.dom.client.BodyElement BodyElement}.

@return true if attached, false otherwise

bool isAttached() {
 return _attached;
}

bool isOrWasAttached() #

inherited from Widget

Has this widget ever been attached?

@return true if this widget ever been attached to the DOM, false otherwise

bool isOrWasAttached() {
 return eventsToSink == -1;
}

Iterator<Widget> iterator() #

inherited from ComplexPanel

Returns an Iterator that iterates over this Iterable object.

docs inherited from HasWidgets
Iterator<Widget> iterator() {
 return getChildren().iterator;
}

void onAttach() #

inherited from Widget

This method is called when a widget is attached to the browser's document. To receive notification after a Widget has been added to the document, override the {@link #onLoad} method or use {@link #addAttachHandler}.

It is strongly recommended that you override {@link #onLoad()} or {@link #doAttachChildren()} instead of this method to avoid inconsistencies between logical and physical attachment states.

Subclasses that override this method must call super.onAttach() to ensure that the Widget has been attached to its underlying Element.

@throws IllegalStateException if this widget is already attached @see #onLoad() @see #doAttachChildren()

void onAttach() {
 if (isAttached()) {
   throw new Exception("Should only call onAttach when the widget is detached from the browser's document");
 }

 _attached = true;

 // Event hookup code
 Dom.setEventListener(getElement(), this);
 int bitsToAdd = eventsToSink;
 eventsToSink = -1;
 if (bitsToAdd > 0) {
   sinkEvents(bitsToAdd);
 }
 doAttachChildren();

 // onLoad() gets called only *after* all of the children are attached and
 // the attached flag is set. This allows widgets to be notified when they
 // are fully attached, and panels when all of their children are attached.
 onLoad();
 AttachEvent.fire(this, true);
}

void onBrowserEvent(Event event) #

inherited from Widget

Fired whenever a browser event is received.

@param event the event received

TODO

void onBrowserEvent(dart_html.Event event) {
 switch (Dom.eventGetType(event)) {
   case IEvent.ONMOUSEOVER:
     // Only fire the mouse over event if it's coming from outside this
     // widget.
   case IEvent.ONMOUSEOUT:
     // Only fire the mouse over event if it's coming from outside this widget.
     // Only fire the mouse out event if it's leaving this widget.
     dart_html.Element related = (event as dart_html.MouseEvent).relatedTarget as dart_html.Element;
     if (related != null && Dom.isOrHasChild(getElement(), related)) {
       return;
     }
     break;
 }

 DomEvent.fireNativeEvent(event, this, this.getElement());
}

void onDetach() #

inherited from Widget

This method is called when a widget is detached from the browser's document. To receive notification before a Widget is removed from the document, override the {@link #onUnload} method or use {@link #addAttachHandler}.

It is strongly recommended that you override {@link #onUnload()} or {@link #doDetachChildren()} instead of this method to avoid inconsistencies between logical and physical attachment states.

Subclasses that override this method must call super.onDetach() to ensure that the Widget has been detached from the underlying Element. Failure to do so will result in application memory leaks due to circular references between DOM Elements and JavaScript objects.

@throws IllegalStateException if this widget is already detached @see #onUnload() @see #doDetachChildren()

void onDetach() {
 if (!isAttached()) {
   throw new Exception("Should only call onDetach when the widget is attached to the browser's document");
 }

 try {
   // onUnload() gets called *before* everything else (the opposite of
   // onLoad()).
   onUnload();
   AttachEvent.fire(this, false);
 } finally {
   // Put this in a finally, just in case onUnload throws an exception.
   try {
     doDetachChildren();
   } finally {
     // Put this in a finally, in case doDetachChildren throws an exception.
     Dom.setEventListener(getElement(), null);
     _attached = false;
   }
 }
}

void onLoad() #

inherited from Widget

This method is called immediately after a widget becomes attached to the browser's document.

void onLoad() {
}

void onUnload() #

inherited from Widget

This method is called immediately before a widget will be detached from the browser's document.

void onUnload() {
}

void orphan(Widget child) #

inherited from Panel

This method must be called as part of the remove method of any Panel. It ensures that the Widget's parent is cleared. This method should be called after verifying that the child Widget is an existing child of the Panel, but before physically removing the child Widget from the DOM. The child will now fire its {@link Widget#onDetach()} event if this Panel is currently attached.

Calls to {@link #orphan(Widget)} should be wrapped in a try/finally block to ensure that the widget is physically detached even if orphan throws an exception.

@param child the widget to be disowned @see #add(Widget)

void orphan(Widget child) {
 assert (child.getParent() == this);
 child.setParent(null);
}

bool remove(Widget w) #

inherited from AbsolutePanel

Overrides {@link ComplexPanel#remove(Widget)} to change the removed Widget's element back to static positioning.This is done so that any positioning changes to the widget that were done by the panel are undone when the widget is disowned from the panel.

bool remove(Widget w) {
 bool removed = super.remove(w);
 if (removed) {
   _changeToStaticPositioning(w.getElement());
 }
 return removed;
}

bool removeAt(int index) #

inherited from ComplexPanel

Removes the widget at the specified index.

@param index the index of the widget to be removed @return <code>false</code> if the widget is not present

bool removeAt(int index) {
 return remove(getWidgetAt(index));
}

void removeFromParent() #

inherited from Widget

Removes this widget from its parent widget, if one exists.

If it has no parent, this method does nothing. If it is a "root" widget (meaning it's been added to the detach list via {@link RootPanel#detachOnWindowClose(Widget)}), it will be removed from the detached immediately. This makes it possible for Composites and Panels to adopt root widgets.

@throws IllegalStateException if this widget's parent does not support

      removal (e.g. {@link Composite})
void removeFromParent() {
 if (_parent == null) {
   // If the widget had no parent, check to see if it was in the detach list
   // and remove it if necessary.
   if (RootPanel.isInDetachList(this)) {
     RootPanel.detachNow(this);
   }
 } else if (_parent is HasWidgets) {
   (_parent as HasWidgets).remove(this);
 } else if (_parent != null) {
   throw new Exception("This widget's parent does not implement HasWidgets");
 }
}

bool removeIsWidget(IsWidget child) #

inherited from Panel
bool removeIsWidget(IsWidget child) {
 return remove(Widget.asWidgetOrNull(child));
}

void removeStyleDependentName(String styleSuffix) #

inherited from UiObject

Removes a dependent style name by specifying the style name's suffix.

@param styleSuffix the suffix of the dependent style to be removed @see #setStylePrimaryName(Element, String) @see #addStyleDependentName(String) @see #setStyleDependentName(String, boolean)

void removeStyleDependentName(String styleSuffix) {
 setStyleDependentName(styleSuffix, false);
}

void removeStyleName(String style) #

inherited from UiObject

Removes a style name. This method is typically used to remove secondary style names, but it can be used to remove primary stylenames as well. That use is not recommended.

@param style the secondary style name to be removed @see #addStyleName(String) @see #setStyleName(String, boolean)

void removeStyleName(String style) {
 setStyleName(style, false);
}

void replaceElement(Element elem) #

inherited from Widget

Replaces this object's browser element.

This method exists only to support a specific use-case in Image, and should not be used by other classes.

@param elem the object's new element

void replaceElement(dart_html.Element elem) {
 if (isAttached()) {
   // Remove old event listener to avoid leaking. onDetach will not do this
   // for us, because it is only called when the widget itself is detached
   // from the document.
   Dom.setEventListener(getElement(), null);
 }

 super.replaceElement(elem);

 if (isAttached()) {
   // Hook the event listener back up on the new element. onAttach will not
   // do this for us, because it is only called when the widget itself is
   // attached to the document.
   Dom.setEventListener(getElement(), this);
 }
}

void setElement(Element elem) #

inherited from UiObject

Sets this object's browser element. UIObject subclasses must call this method before attempting to call any other methods, and it may only be called once.

@param elem the object's element

void setElement(dart_html.Element elem) {
 assert (_element == null);
 this._element = elem;
}

void setHeight(String height) #

inherited from UiObject

Sets the object's height. This height does not include decorations such as border, margin, and padding.

@param height the object's new height, in CSS units (e.g. "10px", "1em")

void setHeight(String height) {
 // This exists to deal with an inconsistency in IE's implementation where
 // it won't accept negative numbers in length measurements
 assert (extractLengthValue(height.trim().toLowerCase()) >= 0); // : "CSS heights should not be negative";
 Dom.setStyleAttribute(getElement(), "height", height);
}

void setLayoutData(Object value) #

inherited from Widget

Sets the panel-defined layout data associated with this widget. Only the panel that currently contains a widget should ever set this value. It serves as a place to store layout bookkeeping data associated with a widget.

@param layoutData the widget's layout data

void setLayoutData(Object value) {
 this._layoutData = value;
}

void setParent(Widget parent) #

inherited from Widget

Sets this widget's parent. This method should only be called by {@link Panel} and {@link Composite}.

@param parent the widget's new parent @throws IllegalStateException if <code>parent</code> is non-null and the

      widget already has a parent
void setParent(Widget parent) {
 Widget oldParent = this._parent;
 if (parent == null) {
   try {
     if (oldParent != null && oldParent.isAttached()) {
       onDetach();
       assert (!isAttached()); // : "Failure of " + this.getClass().getName() + " to call super.onDetach()";
     }
   } finally {
     // Put this in a finally in case onDetach throws an exception.
     this._parent = null;
   }
 } else {
   if (oldParent != null) {
     throw new Exception("Cannot set a new parent without first clearing the old parent");
   }
   this._parent = parent;
   if (parent.isAttached()) {
     onAttach();
     assert (isAttached()); // : "Failure of " + this.getClass().getName() + " to call super.onAttach()";
   }
 }
}

void setPixelSize(int width, int height) #

inherited from UiObject

Sets the object's size, in pixels, not including decorations such as border, margin, and padding.

@param width the object's new width, in pixels @param height the object's new height, in pixels

void setPixelSize(int width, int height) {
 if (width >= 0) {
   setWidth(width.toString() + "px");
 }
 if (height >= 0) {
   setHeight(height.toString() + "px");
 }
}

void setSize(String width, String height) #

inherited from UiObject

Sets the object's size. This size does not include decorations such as border, margin, and padding.

@param width the object's new width, in CSS units (e.g. "10px", "1em") @param height the object's new height, in CSS units (e.g. "10px", "1em")

void setSize(String width, String height) {
 setWidth(width);
 setHeight(height);
}

void setStyleDependentName(String styleSuffix, bool add) #

inherited from UiObject

Adds or removes a dependent style name by specifying the style name's suffix. The actual form of the style name that is added is:

getStylePrimaryName() + '-' + styleSuffix

@param styleSuffix the suffix of the dependent style to be added or removed @param add <code>true</code> to add the given style, <code>false</code> to

     remove it

@see #setStylePrimaryName(Element, String) @see #addStyleDependentName(String) @see #setStyleName(String, boolean) @see #removeStyleDependentName(String)

void setStyleDependentName(String styleSuffix, bool add) {
 setStyleName(getStylePrimaryName() + '-' + styleSuffix, add);
}

void setStyleName(String style, bool add) #

inherited from UiObject

Adds or removes a style name. This method is typically used to remove secondary style names, but it can be used to remove primary stylenames as well. That use is not recommended.

@param style the style name to be added or removed @param add <code>true</code> to add the given style, <code>false</code> to

     remove it

@see #addStyleName(String) @see #removeStyleName(String)

void setStyleName(String style, bool add) {
 manageElementStyleName(getStyleElement(), style, add);
}

void setStylePrimaryName(String style) #

inherited from UiObject

Sets the object's primary style name and updates all dependent style names.

@param style the new primary style name @see #addStyleName(String) @see #removeStyleName(String)

void setStylePrimaryName(String style) {
 setElementStylePrimaryName(getStyleElement(), style);
}

void setWidgetPosition(Widget w, int left, int top) #

inherited from AbsolutePanel

Sets the position of the specified child widget. Setting a position of <code>(-1, -1)</code> will cause the child widget to be positioned statically.

@param w the child widget to be positioned @param left the widget's left position @param top the widget's top position

void setWidgetPosition(Widget w, int left, int top) {
 _checkWidgetParent(w);
 setWidgetPositionImpl(w, left, top);
 _verifyPositionNotStatic(w);
}

void setWidgetPositionImpl(Widget w, int left, int top) #

inherited from AbsolutePanel
void setWidgetPositionImpl(Widget w, int left, int top) {
 dart_html.Element h = w.getElement();
 if (left == -1 && top == -1) {
   _changeToStaticPositioning(h);
 } else {
   h.style.position = "absolute";
   h.style.left = left.toString() + "px";
   h.style.top = top.toString() + "px";
 }
}

void setWidth(String width) #

inherited from UiObject

Sets the object's width. This width does not include decorations such as border, margin, and padding.

@param width the object's new width, in CSS units (e.g. "10px", "1em")

void setWidth(String width) {
 // This exists to deal with an inconsistency in IE's implementation where
 // it won't accept negative numbers in length measurements
 assert (extractLengthValue(width.trim().toLowerCase()) >= 0); // : "CSS widths should not be negative";
 Dom.setStyleAttribute(getElement(), "width", width);
}

void sinkBitlessEvent(String eventTypeName) #

inherited from UiObject

Sinks a named event. Note that only {@link Widget widgets} may actually receive events, but can receive events from all objects contained within them.

@param eventTypeName name of the event to sink on this element @see com.google.gwt.user.client.Event

void sinkBitlessEvent(String eventTypeName) {
 Dom.sinkBitlessEvent(getElement(), eventTypeName);
}

void sinkEvents(int eventBitsToAdd) #

inherited from Widget

Overridden to defer the call to super.sinkEvents until the first time this widget is attached to the dom, as a performance enhancement. Subclasses wishing to customize sinkEvents can preserve this deferred sink behavior by putting their implementation behind a check of <code>isOrWasAttached()</code>:

{@literal @}Override
public void sinkEvents(int eventBitsToAdd) {
  if (isOrWasAttached()) {
    /{@literal *} customized sink code goes here {@literal *}/
  } else {
    super.sinkEvents(eventBitsToAdd);
 }
} 
void sinkEvents(int eventBitsToAdd) {
 if (isOrWasAttached()) {
   super.sinkEvents(eventsToSink);
 } else {
   eventsToSink |= eventBitsToAdd;
 }
}

String toString() #

inherited from UiObject

This method is overridden so that any object can be viewed in the debugger as an HTML snippet.

@return a string representation of the object

String toString() {
 if (_element == null) {
   return "(null handle)";
 }
 return getElement().toString();
}

void unsinkEvents(int eventBitsToRemove) #

inherited from UiObject

Removes a set of events from this object's event list.

@param eventBitsToRemove a bitfield representing the set of events to be

     removed from this element's event set

@see #sinkEvents @see com.google.gwt.user.client.Event

void unsinkEvents(int eventBitsToRemove) {
 Dom.sinkEvents(getElement(), Dom.getEventsSunk(getElement()) & (~eventBitsToRemove));
}