1.0M2

XWT

The ComboViewer of JFace can be defined in the same way as ListViewer and TableViewer using the standard JFace class.

This milestone has simplified the declaration of JFace viewer. The ILabelProvider and IContentProvider are not needed any more.

Here is the code for TableViewer,

  <TableViewer input="{Binding Path=employees}">
	<TableViewer.columns>
		<TableViewerColumn width="150" text="Name" displayMemberPath="name"/>
		<TableViewerColumn width="150" text="Age" displayMemberPath="age"/>
	</TableViewer.columns>
	<TableViewer.control.layoutData>
		<GridData horizontalAlignment="FILL"
        		grabExcessHorizontalSpace="true"/>
	</TableViewer.control.layoutData> 
  </TableViewer>

Her is the code for ComboViewer,

  <ComboViewer input="{Binding Path=employees}" displayMemberPath="name">
	<ComboViewer.control.layoutData>
		<GridData horizontalAlignment="FILL"
        		grabExcessHorizontalSpace="true"/>
	</ComboViewer.control.layoutData>
  </ComboViewer>

And the code of ListViewer

  <ListViewer input="{Binding Path=employees}" displayMemberPath="name">
	<ListViewer.control.layoutData>
		<GridData horizontalAlignment="FILL"
        		grabExcessHorizontalSpace="true"/>
	</ListViewer.control.layoutData>
  </ListViewer>

 

A new class ViewerFilter is provided to define a filter in a JFace viewer. This class contains a collection of Condition which is used as predicate to select the elements to display.

  <TableViewer Name="TableViewer" input="{Binding Path=employees}" >
	<TableViewer.filters>
		<ViewerFilter>
			<ViewerFilter.conditions>
				<Condition property="age" value="30" operator="GT"/>
				<Condition property="name" value="Th*" operator="LIKE"/>
			</ViewerFilter.conditions>
		</ViewerFilter>
	</TableViewer.filters>
	
	<TableViewer.columns>
		<TableViewerColumn width="150" text="Name" displayMemberPath="name"/>
		<TableViewerColumn width="150" text="Age" displayMemberPath="age"/>
	</TableViewer.columns>
  </TableViewer>

This TableViewer displays all Employee whose name is started with "Th" and ago is great than 30.

A new IObservable management is implemented in XWT for each UI resource unit. XWT keeps now all instances of IObservable. It allows developers to get the IObservableValue and then modify observed values with automatically notifications in UI and in behind data. The service is provided in the main class XWT:

IObservableValue XWT.getObservableValue(Object control, Object data, String path);

XWT starts to provide a transparent "Declarative Data Binding" solution to hide all complexity of JFace data binding. The master/detail presentation is supported straightforward in the path expression of Data Binding. The expression language is extended to complete the missing type in programming language.

For example, the element type of a collection is always missing in binary class in Java. This information is necessary to build the Data binding chain in Mater/Detail pattern. In the following example, we have a class Company with a property "employees" in a collection or an array. The employees are displayed in a ListViewer, when user select an element, its name will be displayed in the Label below..

  <ListViewer name="master" input="{Binding Path=employees}" displayMemberPath="name">
	<ListViewer.control.layoutData>
		<GridData horizontalAlignment="FILL"
        		grabExcessHorizontalSpace="true"/>
	</ListViewer.control.layoutData>
  </ListViewer>
  <Label text="{Binding elementName=master,path=singleSelection.(j:Employee.name)}"/>

The property "name" in the binding expression is prefixed by its type Employee and enclosed by a parenthese.

Here is the example Snippet017 of Jface Data binding ported in XWT:

This Milestone integrates a new type UpdateSourceTrigger. And a new property "updateSourceTrigger" is added in the class Binding and therefore in Data Binding expression. This class indicates when the modification to Data Binding source model will occur. Most of UI Element has only one possibility like check Button. But Text has two possibilities: when the content gets changed, or when the focus gets loosed.

  <Text text="{Binding path=name,updateSourceTrigger=FocusOut}">

The following operators are added in Condition and all classes of Trigger to extend the expression capability: