Java tutorial
/******************************************************************************* * Copyright (c) 2007 IBM Corporation 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: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.ui.tests.manual; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import org.eclipse.core.databinding.observable.Diffs; import org.eclipse.core.databinding.observable.list.WritableList; import org.eclipse.core.databinding.observable.map.ComputedObservableMap; import org.eclipse.core.databinding.observable.set.IObservableSet; import org.eclipse.core.databinding.observable.value.ComputedValue; 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.databinding.observable.value.WritableValue; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.jface.databinding.viewers.ObservableListContentProvider; import org.eclipse.jface.databinding.viewers.ObservableMapLabelProvider; import org.eclipse.jface.databinding.viewers.ViewersObservables; import org.eclipse.jface.internal.databinding.provisional.swt.ControlUpdater; import org.eclipse.jface.layout.GridDataFactory; import org.eclipse.jface.layout.GridLayoutFactory; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.viewers.TableViewer; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.ui.ISaveablePart; import org.eclipse.ui.ISaveablesLifecycleListener; import org.eclipse.ui.ISaveablesSource; import org.eclipse.ui.Saveable; import org.eclipse.ui.SaveablesLifecycleEvent; import org.eclipse.ui.part.ViewPart; public class ViewWithSaveables extends ViewPart implements ISaveablesSource, ISaveablePart { WritableList saveables = new WritableList(); IObservableValue dirty = new ComputedValue() { protected Object calculate() { for (Iterator it = saveables.iterator(); it.hasNext();) { MySaveable saveable = (MySaveable) it.next(); if (saveable.isDirty()) { return Boolean.TRUE; } } return Boolean.FALSE; } }; private TableViewer viewer; private IObservableValue selection; public ViewWithSaveables() { } public void createPartControl(Composite parent) { viewer = new TableViewer(parent, SWT.BORDER); GridDataFactory.fillDefaults().grab(true, true).span(4, 1).applyTo(viewer.getControl()); ObservableListContentProvider observableListContentProvider = new ObservableListContentProvider(); viewer.setContentProvider(observableListContentProvider); viewer.setLabelProvider(new ObservableMapLabelProvider( new DirtyObservableMap(observableListContentProvider.getKnownElements())) { public String getColumnText(Object element, int columnIndex) { return getText(element); } public String getText(Object element) { MySaveable saveable = (MySaveable) element; return (saveable.isDirty() ? "*" : "") + saveable.toString(); } }); viewer.setInput(saveables); { Button button = new Button(parent, SWT.PUSH); button.setText("Add"); button.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { addSaveable(); } }); } selection = ViewersObservables.observeSingleSelection(viewer); { final Button button = new Button(parent, SWT.PUSH); button.setText("Remove"); button.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { removeSaveable(); } }); new ControlUpdater(button) { protected void updateControl() { button.setEnabled(selection.getValue() != null); } }; } { final Button button = new Button(parent, SWT.CHECK); button.setText("dirty"); button.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { MySaveable saveable = (MySaveable) selection.getValue(); saveable.setDirty(button.getSelection()); } }); new ControlUpdater(button) { protected void updateControl() { MySaveable saveable = (MySaveable) selection.getValue(); if (saveable == null) { button.setEnabled(false); button.setSelection(false); } else { button.setEnabled(true); // we know that isDirty is implemented using a // WritableValue, // and thus a dependency on that writable value will // result from // calling isDirty(). button.setSelection(saveable.isDirty()); } } }; } getSite().setSelectionProvider(viewer); dirty.addValueChangeListener(new IValueChangeListener() { public void handleValueChange(ValueChangeEvent event) { firePropertyChange(ISaveablePart.PROP_DIRTY); } }); GridLayoutFactory.fillDefaults().numColumns(4).equalWidth(false).generateLayout(parent); } void removeSaveable() { Saveable[] toRemove = getActiveSaveables(); ISaveablesLifecycleListener lifecycleListener = (ISaveablesLifecycleListener) getSite() .getService(ISaveablesLifecycleListener.class); SaveablesLifecycleEvent event = new SaveablesLifecycleEvent(this, SaveablesLifecycleEvent.PRE_CLOSE, toRemove, false); lifecycleListener.handleLifecycleEvent(event); if (!event.isVeto()) { saveables.removeAll(Arrays.asList(toRemove)); lifecycleListener.handleLifecycleEvent( new SaveablesLifecycleEvent(this, SaveablesLifecycleEvent.POST_CLOSE, toRemove, false)); } } void addSaveable() { MySaveable saveable = new MySaveable(); saveables.add(saveable); ISaveablesLifecycleListener lifecycleListener = (ISaveablesLifecycleListener) getSite() .getService(ISaveablesLifecycleListener.class); lifecycleListener.handleLifecycleEvent(new SaveablesLifecycleEvent(this, SaveablesLifecycleEvent.POST_OPEN, new Saveable[] { saveable }, false)); } public void setFocus() { } public Saveable[] getActiveSaveables() { Saveable selectedSaveable = (Saveable) selection.getValue(); return selectedSaveable == null ? new Saveable[0] : new Saveable[] { selectedSaveable }; } public Saveable[] getSaveables() { return (Saveable[]) saveables.toArray(new Saveable[saveables.size()]); } public void doSave(IProgressMonitor monitor) { Assert.isTrue(false, "Save operations should happen through the saveables."); } public void doSaveAs() { } public boolean isDirty() { return ((Boolean) dirty.getValue()).booleanValue(); } public boolean isSaveAsAllowed() { return false; } public boolean isSaveOnCloseNeeded() { return true; } class MySaveable extends Saveable { private IObservableValue myDirty = new WritableValue(Boolean.FALSE, Boolean.TYPE); public void doSave(IProgressMonitor monitor) throws CoreException { setDirty(false); } public boolean equals(Object object) { return this == object; } public ImageDescriptor getImageDescriptor() { return null; } public String getName() { return toString(); } public String getToolTipText() { return toString(); } public int hashCode() { return System.identityHashCode(this); } public boolean isDirty() { return ((Boolean) myDirty.getValue()).booleanValue(); } IObservableValue getDirty() { return myDirty; } void setDirty(boolean dirty) { myDirty.setValue(Boolean.valueOf(dirty)); } } class DirtyObservableMap extends ComputedObservableMap { Map writableValueToElement = new HashMap(); private IValueChangeListener valueChangeListener = new IValueChangeListener() { public void handleValueChange(ValueChangeEvent event) { fireMapChange(Diffs.createMapDiffSingleChange(writableValueToElement.get(event.getSource()), event.diff.getOldValue(), event.diff.getNewValue())); } }; public DirtyObservableMap(IObservableSet knownElements) { super(knownElements); init(); } protected Object doGet(Object key) { MySaveable saveable = (MySaveable) key; return Boolean.valueOf(saveable.isDirty()); } protected Object doPut(Object key, Object value) { MySaveable saveable = (MySaveable) key; Boolean oldValue = Boolean.valueOf(saveable.isDirty()); saveable.setDirty(((Boolean) value).booleanValue()); keySet().add(key); return oldValue; } protected void hookListener(Object key) { MySaveable saveable = (MySaveable) key; IObservableValue oValue = saveable.getDirty(); writableValueToElement.put(oValue, saveable); oValue.addValueChangeListener(valueChangeListener); } protected void unhookListener(Object key) { MySaveable saveable = (MySaveable) key; saveable.getDirty().removeValueChangeListener(valueChangeListener); writableValueToElement.remove(saveable.getDirty()); } } }