Java tutorial
/******************************************************************************* * Copyright (c) 2009, 2015 Matthew Hall and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * Matthew Hall - initial API and implementation (bug 268472) * Matthew Hall - bug 300953 * Jeanderson Candido <http://jeandersonbc.github.io> - Bug 413611 * Simon Scholz <simon.scholz@vogella.com> - Bug 481620, 481358 ******************************************************************************/ package org.eclipse.jface.databinding.fieldassist; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.eclipse.core.databinding.ValidationStatusProvider; import org.eclipse.core.databinding.observable.DisposeEvent; import org.eclipse.core.databinding.observable.IDecoratingObservable; import org.eclipse.core.databinding.observable.IDisposeListener; import org.eclipse.core.databinding.observable.IObservable; import org.eclipse.core.databinding.observable.IObserving; import org.eclipse.core.databinding.observable.list.IListChangeListener; import org.eclipse.core.databinding.observable.list.IObservableList; import org.eclipse.core.databinding.observable.list.ListChangeEvent; import org.eclipse.core.databinding.observable.list.ListDiffVisitor; 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.swt.ISWTObservable; import org.eclipse.jface.databinding.viewers.IViewerObservable; import org.eclipse.jface.fieldassist.ControlDecoration; import org.eclipse.jface.viewers.Viewer; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Widget; /** * Decorates the underlying controls of the target observables of a * {@link ValidationStatusProvider} with {@link ControlDecoration}s mirroring * the current validation status. Only those target observables which implement * {@link ISWTObservable} or {@link IViewerObservable} are decorated. * * @since 1.4 */ public class ControlDecorationSupport { /** * Creates a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all target * observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatusProvider * the {@link ValidationStatusProvider} to monitor. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @return a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all * target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. */ public static ControlDecorationSupport create(ValidationStatusProvider validationStatusProvider, int position) { return create(validationStatusProvider, position, null, new ControlDecorationUpdater()); } /** * Creates a ControlDecorationSupport which observes the given validation * status and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement {@link ISWTObservable} * or {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, IObservable... targetsToBeDecorated) { return create(validationStatus, position, null, new ControlDecorationUpdater(), getObservableList(targetsToBeDecorated)); } /** * Creates a ControlDecorationSupport which observes the given validation * status and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement {@link ISWTObservable} * or {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, IObservableList<IObservable> targetsToBeDecorated) { return create(validationStatus, position, null, new ControlDecorationUpdater(), targetsToBeDecorated); } /** * Creates a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all target * observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatusProvider * the {@link ValidationStatusProvider} to monitor. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecoration} instances. * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @return a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all * target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. */ public static ControlDecorationSupport create(ValidationStatusProvider validationStatusProvider, int position, Composite composite) { return create(validationStatusProvider, position, composite, new ControlDecorationUpdater()); } /** * Creates a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT control * of all target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, Composite composite, IObservable... targetsToBeDecorated) { return create(validationStatus, position, composite, new ControlDecorationUpdater(), getObservableList(targetsToBeDecorated)); } /** * Creates a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT control * of all target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, Composite composite, IObservableList<IObservable> targetsToBeDecorated) { return create(validationStatus, position, composite, new ControlDecorationUpdater(), targetsToBeDecorated); } /** * Creates a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all target * observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatusProvider * the {@link ValidationStatusProvider} to monitor. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecoration} instances. * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @param updater * custom strategy for updating the {@link ControlDecoration}(s) * whenever the validation status changes. * @return a ControlDecorationSupport which observes the validation status * of the specified {@link ValidationStatusProvider}, and displays a * {@link ControlDecoration} over the underlying SWT control of all * target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. */ public static ControlDecorationSupport create(ValidationStatusProvider validationStatusProvider, int position, Composite composite, ControlDecorationUpdater updater) { return create(validationStatusProvider.getValidationStatus(), position, composite, updater, validationStatusProvider.getTargets()); } /** * Creates a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT control * of all target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @param updater * custom strategy for updating the {@link ControlDecoration}(s) * whenever the validation status changes. * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, Composite composite, ControlDecorationUpdater updater, IObservable... targetsToBeDecorated) { return create(validationStatus, position, composite, updater, getObservableList(targetsToBeDecorated)); } /** * Creates a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT control * of all target observables that implement {@link ISWTObservable} or * {@link IViewerObservable}. * * @param validationStatus * an {@link IObservable} containing an {@link IStatus}, which * will be tracked by the {@link ControlDecorationSupport}. * @param position * SWT alignment constant (e.g. SWT.LEFT | SWT.TOP) to use when * constructing {@link ControlDecorationSupport} * @param composite * the composite to use when constructing * {@link ControlDecoration} instances. * @param updater * custom strategy for updating the {@link ControlDecoration}(s) * whenever the validation status changes. * @param targetsToBeDecorated * the target observables, which contain widget to be decorated * according to the current validation status * @return a ControlDecorationSupport which observes the validation status * and displays a {@link ControlDecoration} over the underlying SWT * control of all target observables that implement * {@link ISWTObservable} or {@link IViewerObservable}. * @since 1.8 */ public static ControlDecorationSupport create(IObservableValue<IStatus> validationStatus, int position, Composite composite, ControlDecorationUpdater updater, IObservableList<IObservable> targetsToBeDecorated) { return new ControlDecorationSupport(validationStatus, targetsToBeDecorated, position, composite, updater); } private final int position; private final Composite composite; private final ControlDecorationUpdater updater; private IObservableValue<IStatus> validationStatus; private IObservableList<IObservable> targets; private IDisposeListener disposeListener = new IDisposeListener() { @Override public void handleDispose(DisposeEvent staleEvent) { dispose(); } }; private IValueChangeListener<IStatus> statusChangeListener = new IValueChangeListener<IStatus>() { @Override public void handleValueChange(ValueChangeEvent<? extends IStatus> event) { statusChanged(validationStatus.getValue()); } }; private IListChangeListener<IObservable> targetsChangeListener = new IListChangeListener<IObservable>() { @Override public void handleListChange(ListChangeEvent<? extends IObservable> event) { event.diff.accept(new TargetsListDiffAdvisor<>()); statusChanged(validationStatus.getValue()); } }; private static class TargetDecoration { public final IObservable target; public final ControlDecoration decoration; TargetDecoration(IObservable target, ControlDecoration decoration) { this.target = target; this.decoration = decoration; } } private class TargetsListDiffAdvisor<E extends IObservable> extends ListDiffVisitor<E> { @Override public void handleAdd(int index, E element) { targetAdded(element); } @Override public void handleRemove(int index, E element) { targetRemoved(element); } } private List<TargetDecoration> targetDecorations; private ControlDecorationSupport(IObservableValue<IStatus> validationStatus, IObservableList<IObservable> targetsToBeDecorated, int position, Composite composite, ControlDecorationUpdater updater) { this.position = position; this.composite = composite; this.updater = updater; this.validationStatus = validationStatus; Assert.isTrue(!this.validationStatus.isDisposed()); this.targets = targetsToBeDecorated; Assert.isTrue(!this.targets.isDisposed()); this.targetDecorations = new ArrayList<>(); validationStatus.addDisposeListener(disposeListener); validationStatus.addValueChangeListener(statusChangeListener); targets.addDisposeListener(disposeListener); targets.addListChangeListener(targetsChangeListener); for (Object name : targets) targetAdded((IObservable) name); statusChanged(validationStatus.getValue()); } private void targetAdded(IObservable target) { Control control = findControl(target); if (control != null) targetDecorations .add(new TargetDecoration(target, new ControlDecoration(control, position, composite))); } private void targetRemoved(IObservable target) { for (Iterator<TargetDecoration> it = targetDecorations.iterator(); it.hasNext();) { TargetDecoration targetDecoration = it.next(); if (targetDecoration.target == target) { targetDecoration.decoration.dispose(); it.remove(); } } } private Control findControl(IObservable target) { if (target instanceof ISWTObservable) { Widget widget = ((ISWTObservable) target).getWidget(); if (widget instanceof Control) return (Control) widget; } if (target instanceof IViewerObservable) { Viewer viewer = ((IViewerObservable) target).getViewer(); return viewer.getControl(); } if (target instanceof IDecoratingObservable) { IObservable decorated = ((IDecoratingObservable) target).getDecorated(); Control control = findControl(decorated); if (control != null) return control; } if (target instanceof IObserving) { Object observed = ((IObserving) target).getObserved(); if (observed instanceof IObservable) return findControl((IObservable) observed); } return null; } private void statusChanged(IStatus status) { for (TargetDecoration targetDecoration : targetDecorations) { ControlDecoration decoration = targetDecoration.decoration; updater.update(decoration, status); } } private static IObservableList<IObservable> getObservableList(IObservable[] observables) { IObservableList<IObservable> observableList = new WritableList<>(); java.util.Collections.addAll(observableList, observables); return observableList; } /** * Disposes this ControlDecorationSupport, including all control decorations * managed by it. A ControlDecorationSupport is automatically disposed when * its target ValidationStatusProvider is disposed. */ public void dispose() { if (validationStatus != null) { validationStatus.removeDisposeListener(disposeListener); validationStatus.removeValueChangeListener(statusChangeListener); validationStatus = null; } if (targets != null) { targets.removeDisposeListener(disposeListener); targets.removeListChangeListener(targetsChangeListener); targets = null; } disposeListener = null; statusChangeListener = null; targetsChangeListener = null; if (targetDecorations != null) { for (TargetDecoration targetDecoration : targetDecorations) { targetDecoration.decoration.dispose(); } targetDecorations.clear(); targetDecorations = null; } } }