61.Which GWT widget represents a panel that lays all of its widgets out in a single horizontal column?

HorizontalPanel widget represents a panel that lays all of its widgets out in a single horizontal column.

62.Which GWT widget represents a panel that lays all of its widgets out in a single vertical column?

VerticalPanel widget represents a panel that lays all of its widgets out in a single vertical column.

63.What is HorizontalSplitPanel in GWT?

HorizontalSplitPanel widget represents a panel that arranges two widgets in a single horizontal row and allows the user to interactively change the proportion of the width dedicated to each of the two widgets. Widgets contained within a HorizontalSplitPanel will be automatically decorated with scrollbars when necessary.

64.What is VerticalSplitPanel in GWT?

VerticalSplitPanel widget represents a A panel that arranges two widgets in a single vertical column and allows the user to interactively change the proportion of the height dedicated to each of the two widgets. Widgets contained within a VertialSplitPanel will be automatically decorated with scrollbars when necessary.

65.What is FlexTable in GWT?

FlexTable widget represents a flexible table that creates cells on demand. It can be jagged thatis, eachrowcancontainadifferentnumberofcells and individual cells can be set to span multiple rows or columns.

66.What is Grid in GWT?

Grid widget represents a rectangular grid that can contain text, html, or a child Widget within its cells. It must be resized explicitly to the desired number of rows and columns.

67.What is DeckPanel in GWT?

DeckPanel is a panel that displays all of its child widgets in a 'deck', where only one can be visible at a time. It is used by TabPanel.

68.What is DockPanel in GWT?

This widget represents a panel that lays its child widgets out "docked" at its outer edges, and allows its last widget to take up the remaining space in its center.

69.What is HTMLPanel in GWT?

This widget represents a panel that contains HTML, and which can attach child widgets to identified elements within that HTML.

70.What is TabPanel in GWT?

This widget represents a panel that represents a tabbed set of pages, each of which contains another widget. Its child widgets are shown as the user selects the various tabs associated with them. The tabs can contain arbitrary HTML.

71.What is Composite in GWT?

This widget represents a type of widget that can wrap another widget, hiding the wrapped widget's methods. When added to a panel, a composite behaves exactly as if the widget it wraps had been added.

72.Which GWT widget is the base class for panels that contain only one widget?

SimplePanel is the base class for panels that contain only one widget.

73.Which GWT widget represents a simple panel that wraps its contents in a scrollable area?

ScrollPanel widget represents a simple panel that wraps its contents in a scrollable area.

74.Which GWT widget represents a simple panel that makes its contents focusable?

FocusPanel widget represents a simple panel that makes its contents focusable, and adds the ability to catch mouse and keyboard events.

75.What is FormPanel in GWT?

This widget represents a panel that wraps its contents in an HTML <FORM> element.

76.What is PopupPanel in GWT?

This widget represents a panel that can pop up over other widgets. It overlays the browser's client area andanypreviously − createdpopups.

77.What is DialogBox in GWT?

This widget represents a form of popup that has a caption area at the top and can be dragged by the user. Unlike a PopupPanel, calls to PopupPanel.setWidthString and PopupPanel.setHeightString will set the width and height of the dialog box itself, even if a widget has not been added as yet.

78.Explain Event handling in GWT.?

GWT provides a event handler model similar to Java AWT or SWING User Interface frameworks.
A listener interface defines one or more methods that the widget calls to announce an event. GWT provides a list of interfaces corresponding to various possible events.
A class wishing to receive events of a particular type implements the associated handler interface and then passes a reference to itself to the widget to subscribe to a set of events.
For example, the Button class publishes click events so you will have to write a class to implement ClickHandler to handle click event.
All GWT event handlers have been extended from EventHandler interface and each handler has only a single method with a single argument. This argument is always an object of associated event type. Each event object have a number of methods to manipulate the passed event object.

79.How can you create a custom GWT Widget?

GWT provides three ways to create custom user interface elements. There are three general strategies to follow −

• Create a widget by extending Composite Class − This is the most common and easiest way to create custom widgets. Here you can use existing widgets to create composite view with custom properties.


• Create a widget using GWT DOM API in JAVA − GWT basic widgets are created in this way. Still its a very complicated way to create custom widget and should be used cautiously.


• Use JavaScript and wrap it in a widget using JSNI − This should generally only be done as a last resort. Considering the cross-browser implications of the native methods, it becomes very complicated and also becomes more difficult to debug.

80.What is GWT UiBinder?

• The UiBinder is a framework designed to separate Functionality and View of User Interface.
• The UiBinder framework allows developers to build gwt applications as HTML pages with GWT widgets configured throughout them.
• The UiBinder framework makes easier collaboration with UI designers who are more comfortable with XML, HTML and CSS than Java source code.
• The UIBinder provides a declarative way of defining User Interface.
• The UIBinder seperates the programmic logic from UI.
• The UIBinder is similar to what JSP is to Servlets.