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XWT Documentation
What is XWT?
XWT stands for eclipse XML Window Toolkit. It is a powerful and lightweight declarative UI framework designed for Eclipse, based on XML as markup language.
XWT simplifies UI development by a physical separation of UI definition in XML from the run-time logic in programing language. It is very intuitive for creating interfaces directly or via tools such as Visual editor. especially for people with a background in web design and technologies.
Doc: Overview
Contents
Getting started
Hello, world!
Here is a simple example.
<Shell xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt"> <Shell.layout> <FillLayout/> </Shell.layout> <Button text="Hello, world!"> </Button> </Shell>
The same UI can be developed in Java corresponding:
Shell parent = new Shell(); parent.setLayout(new FillLayout()); Button button = new Button(parent, SWT.NONE); button.setText("Hello, world!");
To load and start a simple application, we use the class XWT:
Shell shell = (Shell)XWT.load(file); shell.pack(); shell.open(); while (!shell.isDisposed()) { if (!shell.getDisplay().readAndDispatch()) { shell.getDisplay().sleep(); } }
Or it's better to use the following API to handle event loop:
XWT.open(uri);
It is possible to load a UI resource under a Composite:
XWT.load(parent, uri);
To use XWT, your project must import at least the following plugins
org.eclipse.swt org.eclipse.jface org.eclipse.e4.xwt org.eclipse.jface.databinding org.eclipse.core.databinding com.ibm.icu
Event Handling
In the previous example, we just rewrite Java code in XML. This example illustrates the separation between UI and event handling.
The appearance is defined in XWT.
<Shell xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt" x:Class="ui.EventHandler"> <Shell.layout> <GridLayout/> </Shell.layout> <Button text="Click Me!" SelectionEvent="clickButton"> </Button> </Shell>
The extension attribute x:Class declares the Java class to handle all events. The Button event is handled by clickButton method in the class ui.EventHandler. The association is setup during the loading:
package ui; import org.eclipse.swt.Event; import org.eclipse.swt.Button; public class EventHandler { protected void clickButton(Event event) { Button button = (Button )event.widget; button.setText("Hello, world!"); } }
When the button gets selected, the method clickButton is invoked to change the Button text to "Hello, world!".
Layout
<Composite xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt"> <Composite.layout> <GridLayout numColumns="2"/> </Composite.layout> <Label text="Hello, world"/> <Text x:style="BORDER"> <Text.layoutData> <GridData horizontalAlignment="FILL" grabExcessHorizontalSpace="true"/> </Text.layoutData> </Text> </Composite>
- The simple element name (<Composite>) corresponds to a class name.
- The qualified element name (i.g. <Composite.layout>) corresponds to a property defined by an element.
- The default namespace corresponds to system packages.
- User defined package can be declared as a namespace in the format: ”clr-namespace:<package>=<jar>”
This is functionally equivalent to:
Composite parent = new Composite(shell, SWT.NONE); parent.setLayout(new GridLayout(2, false); Label label = new Label(parent, SWT.NULL); label.setText("Hello, world"); Text text = new Text(parent, SWT.BORDER); text.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.GRAB_HORIZONTAL));
Data Binding
The DataBinding engine relies on Eclipse DataBinding component. To enable this feature, your project must import at least the following plugins
org.eclipse.swt org.eclipse.jface org.eclipse.e4.xwt org.eclipse.jface.databinding org.eclipse.core.databinding org.eclipse.core.databinding.beans org.eclipse.core.databinding.property com.ibm.icu
If we bind the text attribute of Label to a property “Name” of a Person, here is the data binding expression:
<Label text="{binding path=Name}"/>
It has the same result as following, but the expression is in pure XML:
<Label> <Label.text> <Binding path=”Name”/> </Label.text> <Label>
The data context of Label should be a person.
JFace integration
The following example shows the JFace direct integration with ListViewer.
We have a Class Company that has a name and a collection of Employee. The company is bound to the root Composite object. The child Text is bound to Name of company and ListViewer to property employees of type Java Collection.
<Composite xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt" xmlns:j="clr-namespace:jface.listviewer" x:DataContext="{StaticResource myCompany}"> <Composite.layout> <GridLayout numColumns="2"/> </Composite.layout> <x:Composite.Resources> <j:Company x:Key="myCompany" Name="Soyatec"> <j:Company.employees> <j:Employee Name="Thomas"/> <j:Employee Name="Jin"/> </j:Company.employees> </j:Company> </x:Composite.Resources> <Label text="Name"/> <Text text="{Binding Path=Name}"/> <ListViewer input="{Binding Path=employees}"> <ListViewer.contentProvider> <j:ContentProvider/> </ListViewer.contentProvider> <ListViewer.labelProvider> <j:LabelProvider/> </ListViewer.labelProvider> <ListViewer.control.layoutData> <GridData horizontalAlignment="FILL" grabExcessHorizontalSpace="true" horizontalSpan="2"/> </ListViewer.control.layoutData> </ListViewer> </Composite>
Features
Extensibility and Re-usability
In case, if you have your own layout named as ui.MyGridLayout, it can be used directly. The code will be:
<Composite xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt" xmlns:y="cls-namespace:ui"> <Composite.layout> <y:MyGridLayout numColumns="2"/> </Composite.layout> <Label text="Hello, world"/> <Text x:style="BORDER"> <Text.layoutData> <GridData horizontalAlignment="FILL" grabExcessHorizontalSpace="true"/> </Text.layoutData> </Text> </Composite>
In the same way, a customized UI component can be used directly:
<Composite xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt" xmlns:y="cls-namespace:ui"> <Composite.layout> <GridLayout numColumns="2"/> </Composite.layout> <y:PersonView /> <y:PersonView.layoutData> <GridData horizontalAlignment="FILL" grabExcessHorizontalSpace="true"/> </y:PersonView.layoutData> </y:PersonView> </Composite>
Where the ui.PersonView is a UI component developed by two files:
XWT file PersonView.xwt
<Composite xmlns="http://www.eclipse.org/xwt/presentation" xmlns:x="http://www.eclipse.org/xwt" x:Class="ui.PersonView" xmlns:y="cls-namespace:ui"> <Composite.layout> <GridLayout numColumns="2"/> </Composite.layout> <Label text="Name"/> <Text x:style="BORDER"> <Text.layoutData> <GridData horizontalAlignment="FILL" grabExcessHorizontalSpace="true"/> </Text.layoutData> </Text> </Composite>
Java class PersonView.java
package ui; import org.eclipse.swt.widgets.Composite; public class PersonView extends Composite { ... }
Style
XWT is a high extensible framework. It can be extended easily in almost all aspects, including Style. When we talk about the Style, we talk about CSS in general. Indeed, CSS is one of more used declarative style solution in Web. But it is not the only one.
From the point of view of its definition, there are two kinds of style: inline style and external style. Inline style is defined in UI resource file. External style is specified in a separated file.
XWT provides a general style concept.
Inline style
External style
Basic concept
CSS
Dynamic UI
Control binding
Control binding is a kind of data binding, but UI control is used as data binding source.
Trigger
Property Trigger
See this post: Property Trigger
Data Trigger
See this post: Data Trigger
Event Trigger
Data Binding
Java Bean Binding and Pojo Binding
EMF Binding
XML Binding
User-defined Binding
Animation
Property Animation
Class | Properties | Widget |
ColorAnimation | background, foreground | Control |
IntAnimation | alpha | Shell |
PointAnimation | location | Control |
SizeAnimation | size | Control |
RectangleAnimation | bounds | Control |
Using Key Frames
Plugins
XWT framework consists of several plugins. Each plugin has a specifc role.
Plugins | Description |
org.eclipse.e4.xwt | Main plugin of XWT. It contains XWT engine, and it is independent of eclipse. It can be bundled directly in a standalone Java application. |
org.eclipse.e4.xwt.emf | It is an integration plugin, which provides some default configuration to work with EMF dynamic object such as data converter, data provider. |
org.eclipse.e4.xwt.pde | This plugin connects XWT in eclipse environment by providing:some extension points for the Metaclass, Style, etc. It defines the default implementation of IViewPart and IEditorPart. |
org.eclipse.e4.xwt.css | It is an integration with CSS style.. |
org.eclipse.e4.xwt.forms | This plugin makes eclipse forms be marked up natively. |
org.eclipse.e4.xwt.xml | This plugin enables XWT UI form to connect the same data binding expression with XML file. |
org.eclipse.e4.xwt.workbench | It is an integration plugin of XWT in e4 workbench. It defines the default view part and editor. |
Environment and integration
e4 Workbench integration
EMF integration
The plugin org.eclipse.e4.xwt.emf handles the connection of XWT with EMF. Particuliarily, il provides the data binding with EMF dynamic object, known as EObject.
Eclipse RCP integration
WYSIWYG Designer
In e4 build, there are two Visual tools:
- XML based editor with instant preview is provided.
- WYSIWYG Designer
Some screen shots can be found in this blog: XWT Visual Designer
References
SWT Developer Guide
FAQ
Web Demos
e4 Demo with e4 Workbench Designer
Articles and Tutorials
- Eclipse e4 highlights - Yi Ming Huang, Software Engineer, IBM
- Hello, world! - Yves YANG
- Lars Vogel's Tutorial
Work Areas
- PMF (on going)
- e4 Designer Bug: 297241 (on going)
- Aminmation Bug: 298224 (on going)
- DnD Bug: 267191 (in preparation)
- JavaScript support Bug: 266772 (in preparation)
- UI Template
Interested Parties
- Thales (Defense)
- Saab (Defense)
- CCR (Reinsurance)
Contributors
Soyatec | Initial and main contributor |
Hasan Ceylan |
|
Erdal Karaca |
|