/*******************************************************************************
* Copyright (c) 2006, 2008 Soyatec (http://www.soyatec.com) and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Soyatec - initial API and implementation
*******************************************************************************/
package org.eclipse.e4.xwt.databinding;
import org.eclipse.core.databinding.observable.IObservable;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.e4.xwt.IDataProvider;
import org.eclipse.e4.xwt.IValueConverter;
import org.eclipse.e4.xwt.XWTException;
import org.eclipse.e4.xwt.internal.core.Binding;
import org.eclipse.e4.xwt.internal.core.BindingGate;
import org.eclipse.e4.xwt.internal.core.BindingExpressionPath;
import org.eclipse.e4.xwt.internal.core.ScopeManager;
import org.eclipse.e4.xwt.metadata.ModelUtils;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.custom.CCombo;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Text;
/**
* The default implementation of the dataBinding object.
*
* @author jliu (jin.liu@soyatec.com)
*/
public class DataBinding extends AbstractDataBinding {
private IObservable observableWidget;
private BindingGate bindingGate;
/**
* Constructor for dataProvider.
*/
public DataBinding(Binding binding, IDataProvider dataProvider) {
super(binding, dataProvider);
assert dataProvider != null : "DataProvider is null";
}
/**
* Get bind value of two bindings.
*/
public Object getValue(Class<?> targetType) {
IObservable observableWidget = getObservableWidget();
IObservable observableSource = getObservableSource(ScopeManager.VALUE);
/*
* If observableWidget is null, we need only return the data from
* provider.
*/
if (observableWidget == null) {
if (observableSource == null) {
// TODO should raise an exception
return null;
}
if (targetType != null && !targetType.isInstance(observableSource)) {
return observableSource;
}
// convert to final value
Object value = observableSource;
if (observableSource instanceof IObservableValue) {
value = ((IObservableValue) observableSource).getValue();
}
return convertedValue(value);
}
BindingGate bindingContext = getBindingGate();
if (bindingContext != null && observableSource != null) {
Object target = getControl();
if (target instanceof Text
&& getTargetProperty().equalsIgnoreCase("text")) {
if (isSourcePropertyReadOnly()) {
Text text = (Text) target;
text.setEditable(false);
}
} else if (target instanceof Button
&& getTargetProperty().equalsIgnoreCase("selection")) {
if (isSourcePropertyReadOnly()) {
Button button = (Button) target;
button.setEnabled(false);
}
} else if ((target instanceof Combo || target instanceof CCombo)
&& getTargetProperty().equalsIgnoreCase("text")) {
if (isSourcePropertyReadOnly()) {
Control control = (Control) target;
control.setEnabled(false);
}
} else if (target instanceof MenuItem
&& getTargetProperty().equalsIgnoreCase("selection")) {
if (isSourcePropertyReadOnly()) {
MenuItem menuItem = (MenuItem) target;
menuItem.setEnabled(false);
}
}
bindingContext.bind(observableSource, observableWidget, this);
}
if (targetType != null && !targetType.isInstance(observableSource)) {
return observableSource;
}
// convert to final value
Object value = observableSource;
while (value instanceof IObservableValue) {
value = ((IObservableValue) value).getValue();
}
return convertedValue(value);
}
private BindingGate getBindingGate() {
if (this.bindingGate == null) {
IBindingContext dataBindingContext = getDataBindingContext();
this.bindingGate = new BindingGate(dataBindingContext);
}
return this.bindingGate;
}
private Object convertedValue(Object value) {
IValueConverter converter = getConverter();
if (converter != null) {
value = converter.convert(value);
}
return value;
}
public boolean isSourcePropertyReadOnly() {
IDataProvider dataProvider = getDataProvider();
try {
return ScopeManager.isPropertyReadOnly(dataProvider,
getSourcePropertyExpression());
} catch (XWTException e) {
}
return false;
}
public IObservable getObservableSource(int observeKind) {
IObservable observableSource = getObservableSource();
if (observableSource == null) {
IDataProvider dataProvider = getDataProvider();
observableSource = ScopeManager.observe(getControl(), dataProvider
.getData(null), getSourcePropertyExpression(),
getUpdateSourceTrigger(), observeKind);
if (observableSource != null) {
setObservableSource(observableSource);
}
}
return observableSource;
}
public IObservable getObservableWidget() {
if (observableWidget == null) {
Object target = getControl();
Object host = getHost();
String targetProperty = getTargetProperty();
targetProperty = ModelUtils.normalizePropertyName(targetProperty);
int observeKind = ScopeManager.AUTO;
if (host instanceof Viewer && "input".equals(targetProperty)) {
// It is possible to use List
getObservableSource(ScopeManager.COLLECTION);
IObservable observableSource = getObservableSource();
if (observableSource instanceof IObservableList) {
return null;
} else if (observableSource instanceof IObservableSet) {
return null;
}
}
try {
BindingExpressionPath path = getTargetPropertyExpression();
if (path.isEmptyPath()) {
return null;
}
observableWidget = ScopeManager.observe(target, host, path,
getUpdateSourceTrigger(), observeKind);
} catch (XWTException e) {
}
}
return observableWidget;
}
}