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JFace Data Binding/Tutorial
Data Binding Tutorial
Terms
- Model: a Model represents the Domain Model of your Application.
- Target: a Target represents the GUI side.
A first simple binding
Looking at the example snippets, you'll see a few SWT examples. This time, we'll create a very simple RCP view. Our createPartControl method has just one Text Element:
public void createPartControl(Composite parent){ name = new Text(testGroup, SWT.BORDER); final GridData gd_name = new GridData(SWT.FILL, SWT.CENTER, true, false); name.setLayoutData(gd_name); }
That Text name represents the Target of our binding. Let's add a simple Model:
static class Person { // A property... String name = "HelloWorld"; public String getName() { return name; } public void setName(String name) { this.name = name; } }
To create your first binding, you need to instantiate a DataBindingContext. Create a method like this:
private DataBindingContext initDataBindings() { DataBindingContext bindingContext = new DataBindingContext(); return bindingContext; }
Next, we add a IObservableValue Object for the Target:
private DataBindingContext initDataBindings() { DataBindingContext bindingContext = new DataBindingContext(); IObservableValue nameTextObserveWidget = SWTObservables.observeText(name, SWT.FocusOut); return bindingContext; }
The observeText method takes two params
- name: the observed Control
- event: when the model will be updated. Choices are SWT.FocusOut, SWT.Modify or SWT.NONE
Second, we add a IObservableValue Object for the Model:
private DataBindingContext initDataBindings() { DataBindingContext bindingContext = new DataBindingContext(); IObservableValue nameTextObserveWidget = SWTObservables.observeText(name, SWT.FocusOut); IObservableValue personNameObserveValue = BeansObservables.observeValue(person, "name"); return bindingContext; }
The observeValue method takes two params
- bean: the observed bean
- propertyName: the name of the observed property, in our case the persons name.
Last, we need to bind Target and Model. This is done through the DataBindingContext#bindValue method:
private DataBindingContext initDataBindings() { DataBindingContext bindingContext = new DataBindingContext(); IObservableValue nameTextObserveWidget = SWTObservables.observeText(name, SWT.FocusOut); IObservableValue personNameObserveValue = BeansObservables.observeValue(person, "name"); bindingContext.bindValue(nameTextObserveWidget, personNameObserveValue, null, null); return bindingContext; }
The bindValue method takes four params
- targetObservableValue: our first created IObservableValue
- modelObservableValue: our second created IObservableValue
- UpdateValueStrategy targetToModel: will be dicusssed later
- UpdateValueStrategy modelToTarget: will be dicusssed later
That's it. You successfully created your first JFace Data Binding !