org.eclipse.osbp.xtext.oxtype.ui/src/org/eclipse/osbp/xtext/oxtype/ui/imports/EObjectChooser.java

/*******************************************************************************
 * Copyright (c) 2011 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.osbp.xtext.oxtype.ui.imports;

import static com.google.common.collect.Iterables.toArray;

import java.util.List;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.jface.window.Window;
import org.eclipse.osbp.xtext.oxtype.imports.EObjectUsage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.dialogs.ListDialog;
import org.eclipse.ui.dialogs.SearchPattern;
import org.eclipse.xtext.naming.IQualifiedNameProvider;
import org.eclipse.xtext.naming.QualifiedName;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.ui.editor.XtextEditor;
import org.eclipse.xtext.ui.editor.utils.EditorUtils;
import org.eclipse.xtext.ui.label.AbstractLabelProvider;
import org.eclipse.xtext.util.ITextRegion;
import org.eclipse.xtext.util.concurrent.IUnitOfWork;
import org.eclipse.xtext.xbase.ui.imports.Messages;

import com.google.inject.Inject;

/**
 * Copy of xtexts {@link org.eclipse.xtext.xbase.ui.imports.TypeChooser}
 */
@SuppressWarnings("restriction")
public class EObjectChooser {

	@Inject
	private ILabelProvider labelProvider;

	@Inject
	private IQualifiedNameProvider nameProvider;

	private ISelection originalSelection;

	public EObject choose(final List<EObject> candidateTypes, Iterable<EObjectUsage> usages,
			final XtextResource resource) {
		XtextEditor activeXtextEditor = EditorUtils.getActiveXtextEditor();
		revealInEditor(activeXtextEditor, usages, resource);
		Shell shell = Display.getDefault().getActiveShell();
		IStructuredContentProvider contentProvider = new ContentProvider();
		Dialog dialog = new Dialog(shell, new LabelProvider(labelProvider), contentProvider);
		dialog.setInput(candidateTypes);
		dialog.setInitialSelections(new EObject[] { candidateTypes.get(0) });
		int result = dialog.open();
		if (originalSelection != null)
			activeXtextEditor.getSelectionProvider().setSelection(originalSelection);
		if (result == Window.OK)
			return (EObject) dialog.getResult()[0];
		else
			return null;
	}

	protected void revealInEditor(XtextEditor activeXtextEditor, Iterable<EObjectUsage> usages,
			final XtextResource resource) {
		boolean isRevealUsages = activeXtextEditor.getDocument()
				.priorityReadOnly(new IUnitOfWork<Boolean, XtextResource>() {
					public Boolean exec(XtextResource state) throws Exception {
						return state.getURI().equals(resource.getURI());
					}
				});
		if (isRevealUsages) {
			originalSelection = activeXtextEditor.getSelectionProvider().getSelection();
			ITextRegion firstOccurrence = usages.iterator().next().getTextRegion();
			activeXtextEditor.selectAndReveal(firstOccurrence.getOffset(), firstOccurrence.getLength());
		}
	}

	protected static class ContentProvider implements IStructuredContentProvider {
		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		}

		public void dispose() {
		}

		@SuppressWarnings("unchecked")
		public Object[] getElements(Object inputElement) {
			return toArray((List<EObject>) inputElement, EObject.class);
		}
	}

	protected class LabelProvider extends AbstractLabelProvider {

		public LabelProvider(ILabelProvider delegate) {
			super(delegate);
		}

		@Override
		protected String doGetText(Object element) {
			QualifiedName fqn = nameProvider.getFullyQualifiedName((EObject) element);
			return fqn != null ? fqn.toString() : "no label found";
		}
	}

	protected class Filter extends ViewerFilter {

		private SearchPattern searchPattern;

		public Filter(String pattern) {
			searchPattern = new SearchPattern();
			searchPattern.setPattern(pattern);
		}

		@Override
		public boolean select(Viewer viewer, Object parentElement, Object element) {
			return searchPattern.matches(nameProvider.getFullyQualifiedName((EObject) element).toString());
		}
	}

	protected class Dialog extends ListDialog {

		protected Text searchControl;

		public Dialog(Shell parent, ILabelProvider labelProvider, IStructuredContentProvider contentProvider) {
			super(parent);
			setTitle(Messages.OrganizeImports); // $NON-NLS-1$
			setMessage(Messages.TypeChooser_dialogTitle);
			setAddCancelButton(true);
			setContentProvider(contentProvider);
			setLabelProvider(labelProvider);
		}

		@Override
		protected Label createMessageArea(Composite composite) {
			Label label = super.createMessageArea(composite);
			searchControl = new Text(composite, SWT.BORDER | SWT.SEARCH | SWT.ICON_CANCEL);
			setDefaultGridData(searchControl);
			ModifyListener textModifyListener = new ModifyListener() {
				public void modifyText(ModifyEvent e) {
					applyFilter();
				}
			};
			searchControl.addModifyListener(textModifyListener);
			searchControl.addKeyListener(new KeyAdapter() {
				@Override
				public void keyPressed(KeyEvent e) {
					if (e.keyCode == SWT.ARROW_DOWN) {
						TableViewer tableViewer = getTableViewer();
						tableViewer.getTable().setFocus();
						if (tableViewer.getSelection().isEmpty()) {
							Object firstElement = tableViewer.getElementAt(0);
							if (firstElement != null) {
								tableViewer.setSelection(new StructuredSelection(firstElement));
							}
						}
					}
				}
			});
			return label;
		}

		private void setDefaultGridData(Control control) {
			control.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.GRAB_HORIZONTAL));
		}

		protected void applyFilter() {
			String searchPattern = searchControl.getText();
			if (searchPattern != null) {
				getTableViewer().resetFilters();
				getTableViewer().addFilter(new Filter(searchPattern));
			}
		}
	}

}