Java tutorial
/******************************************************************************* * Copyright (c) 2011 Red Hat, Inc. * Distributed under license by Red Hat, Inc. All rights reserved. * This program is 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: * Red Hat, Inc. - initial API and implementation ******************************************************************************/ package org.jboss.tools.common.ui.databinding; import org.eclipse.core.databinding.AggregateValidationStatus; import org.eclipse.core.databinding.Binding; import org.eclipse.core.databinding.DataBindingContext; import org.eclipse.core.databinding.UpdateValueStrategy; import org.eclipse.core.databinding.ValidationStatusProvider; import org.eclipse.core.databinding.beans.BeanProperties; import org.eclipse.core.databinding.observable.IObservableCollection; import org.eclipse.core.databinding.observable.list.WritableList; import org.eclipse.core.databinding.observable.value.IObservableValue; import org.eclipse.core.databinding.observable.value.IValueChangeListener; import org.eclipse.core.databinding.observable.value.ValueChangeEvent; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.IStatus; import org.eclipse.jface.databinding.fieldassist.ControlDecorationSupport; import org.eclipse.jface.databinding.swt.WidgetProperties; import org.eclipse.jface.wizard.IWizardPage; import org.eclipse.osgi.util.NLS; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Text; import org.jboss.tools.common.ui.CommonUIMessages; /** * @author Andr Dietisheim */ public class DataBindingUtils { /** * Binds the enabled status of the given button to the validity status of * the given providers. If those are not provided the validation status of * the whole context is used. * * @param button * the button whose enablement is bound * @param validationStatusProviders * the providers that shall toggle the button enablement * @param dbc * the data binding context to use when binding */ public static void bindEnablementToValidationStatus(final Control control, DataBindingContext dbc, Binding... bindings) { bindEnablementToValidationStatus(control, IStatus.OK, dbc, bindings); } public static void bindEnablementToValidationStatus(final Control control, int enabledSeverityMask, DataBindingContext dbc, Binding... bindings) { dbc.bindValue(WidgetProperties.enabled().observe(control), createAggregateValidationStatus(dbc, bindings), new UpdateValueStrategy(UpdateValueStrategy.POLICY_NEVER), new UpdateValueStrategy().setConverter(new StatusSeverity2BooleanConverter(enabledSeverityMask))); } /** * Creates an aggregated validation status for the given providers and * databinding context. If no providers are given the whole context is used * a provider. * * @param validationStatusProviders * to use * @param dbc * the data binding context to use * @return */ protected static AggregateValidationStatus createAggregateValidationStatus(DataBindingContext dbc, Binding... bindings) { AggregateValidationStatus aggregatedValidationStatus; if (bindings.length == 0) { aggregatedValidationStatus = new AggregateValidationStatus(dbc, AggregateValidationStatus.MAX_SEVERITY); } else { aggregatedValidationStatus = new AggregateValidationStatus(toObservableCollection(bindings), AggregateValidationStatus.MAX_SEVERITY); } return aggregatedValidationStatus; } /** * Returns an observable collection for a given array of validation status * providers. * * @param observableValue * the array of observable values * @return an observable collection */ private static IObservableCollection toObservableCollection( ValidationStatusProvider... validationStatusProviders) { WritableList observableCollection = new WritableList(); for (ValidationStatusProvider validationStatusProvider : validationStatusProviders) { observableCollection.add(validationStatusProvider); } return observableCollection; } /** * Binds the given text field with the given name to the given model * property. A validator, that wont validate if there's no content in the * text field is attached. * * @param text * the text field to bind * @param fieldName * the name of the text field * @param modelProperty * the property of the model to bind to * @param model * the model to bind to * @param dbc * the data binding context to use * @return */ public static Binding bindMandatoryTextField(Text text, String fieldName, String modelProperty, Object model, DataBindingContext dbc) { Binding binding = dbc .bindValue(WidgetProperties.text(SWT.Modify).observe(text), BeanProperties.value(modelProperty).observe(model), new UpdateValueStrategy().setAfterGetValidator(new MandatoryStringValidator(NLS .bind(CommonUIMessages.MANDATORYSTRING_VALIDATOR_MUST_PROVIDE_VALUE, fieldName))), null); ControlDecorationSupport.create(binding, SWT.LEFT | SWT.TOP); return binding; } /** * Observe and print validation state changes. Utility method to ease bug * tracking. * * @param label the label to use when printing validation state changes * @param dbc the databinding context to observe for validation changes */ public static void observeAndPrintValidationState(final String label, DataBindingContext dbc) { AggregateValidationStatus status = new AggregateValidationStatus(dbc, AggregateValidationStatus.MAX_SEVERITY); status.addValueChangeListener(new IValueChangeListener() { @Override public void handleValueChange(ValueChangeEvent event) { System.err.println("========================"); System.err.println(label); System.err.println("------------------------"); System.err.println(event.diff.getNewValue()); System.err.println("========================"); } }); } /** * Observe and print validation state changes. Utility method to ease bug * tracking in wizards. * * @param label the label to use when printing validation state changes * @param dbc the databinding context to observe for validation changes * @param wizardPage the wizard page whose databinding context shall get observed */ public static void observeAndPrintValidationState(IWizardPage wizardPage, DataBindingContext dbc) { observeAndPrintValidationState(wizardPage.getName(), dbc); } /** * Adds the given value change listener to the given observable and removes * it once the given control is disposed. * * @param listener * the listener that shall be added * @param observable * the observable that the listener shall be attached to * @param control * the control that triggers removal once it's disposed */ public static void addDisposableValueChangeListener(final IValueChangeListener listener, final IObservableValue observable, Control control) { Assert.isLegal(listener != null); Assert.isLegal(observable != null); Assert.isLegal(control != null); if (control.isDisposed()) { return; } observable.addValueChangeListener(listener); control.addDisposeListener(new DisposeListener() { @Override public void widgetDisposed(DisposeEvent e) { observable.removeValueChangeListener(listener); } }); } }