Java tutorial
/** * Copyright (c) 2013 Puppet Labs, Inc. and other contributors, as listed below. * 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: * Puppet Labs */ package com.puppetlabs.geppetto.pp.dsl.ui.editor.hover; import java.io.IOException; import java.net.URL; import java.util.Collections; import java.util.List; import com.puppetlabs.geppetto.pp.AssignmentExpression; import com.puppetlabs.geppetto.pp.AttributeOperation; import com.puppetlabs.geppetto.pp.Definition; import com.puppetlabs.geppetto.pp.ExpressionTE; import com.puppetlabs.geppetto.pp.LiteralNameOrReference; import com.puppetlabs.geppetto.pp.NodeDefinition; import com.puppetlabs.geppetto.pp.PPPackage; import com.puppetlabs.geppetto.pp.VariableExpression; import com.puppetlabs.geppetto.pp.VariableTE; import com.puppetlabs.geppetto.pp.VerbatimTE; import com.puppetlabs.geppetto.pp.dsl.adapters.CrossReferenceAdapter; import com.puppetlabs.geppetto.pp.dsl.ui.internal.PPDSLActivator; import org.eclipse.emf.common.util.URI; import org.eclipse.emf.ecore.EObject; import org.eclipse.emf.ecore.EStructuralFeature; import org.eclipse.emf.ecore.resource.URIConverter; import org.eclipse.jface.action.ToolBarManager; import org.eclipse.jface.internal.text.html.BrowserInformationControl; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.text.AbstractReusableInformationControlCreator; import org.eclipse.jface.text.DefaultInformationControl; import org.eclipse.jface.text.IInformationControl; import org.eclipse.jface.text.IInformationControlCreator; import org.eclipse.jface.text.IInputChangedListener; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Shell; import org.eclipse.xtext.resource.IEObjectDescription; import org.eclipse.xtext.ui.editor.hover.html.DefaultEObjectHoverProvider; import org.eclipse.xtext.ui.editor.hover.html.IXtextBrowserInformationControl; import org.eclipse.xtext.ui.editor.hover.html.XtextBrowserInformationControl; import org.eclipse.xtext.ui.editor.hover.html.XtextBrowserInformationControlInput; import org.eclipse.xtext.util.Files; import org.eclipse.xtext.util.PolymorphicDispatcher; import com.google.inject.Inject; /** * Provides Hover information - for what should there be a hover, and what (the actual content is * produce by {@link PPDocumentationProvider} (labels, documentation, and images). * */ public class PPHoverProvider extends DefaultEObjectHoverProvider { /** * Basically a copy of the class with the same name in DefaultEObjectHoverProvider. * A complete copy required since it is not possible to access the openDeclarationAction * instance and siable it from the outside. * */ public class PresenterControlCreator extends AbstractReusableInformationControlCreator { /** * @since 2.3 */ protected void configureControl(final IXtextBrowserInformationControl control, ToolBarManager tbm, String font) { final BackAction backAction = new BackAction(control); backAction.setEnabled(false); tbm.add(backAction); final ForwardAction forwardAction = new ForwardAction(control); tbm.add(forwardAction); forwardAction.setEnabled(false); final OpenDeclarationAction openDeclarationAction = new OpenDeclarationAction(control); tbm.add(openDeclarationAction); IInputChangedListener inputChangeListener = new IInputChangedListener() { public void inputChanged(Object newInput) { backAction.update(); forwardAction.update(); if (newInput == null) { } else if (newInput instanceof XtextBrowserInformationControlInput) { URI uri = createURI(((XtextBrowserInformationControlInput) newInput).getElement()); openDeclarationAction.setEnabled(uri != null); } } }; control.addInputChangeListener(inputChangeListener); tbm.update(true); addLinkListener(control); } @Override public IInformationControl doCreateInformationControl(Shell parent) { if (BrowserInformationControl.isAvailable(parent)) { ToolBarManager tbm = new ToolBarManager(SWT.FLAT); String font = "org.eclipse.jdt.ui.javadocfont"; // FIXME: mPreferenceConstants.APPEARANCE_JAVADOC_FONT; IXtextBrowserInformationControl control = new XtextBrowserInformationControl(parent, font, tbm); configureControl(control, tbm, font); return control; } // else { return new DefaultInformationControl(parent, true); // } } } private PolymorphicDispatcher<Boolean> hoverDispatcher = new PolymorphicDispatcher<Boolean>("_hover", 1, 1, Collections.singletonList(this), PolymorphicDispatcher.NullErrorHandler.<Boolean>get()) { @Override protected Boolean handleNoSuchMethod(Object... params) { return false; } }; private static final String styleSheetFileName = "/css/PPHoverStyleSheet.css"; @Inject private PPDocumentationProvider documentationProvider; private PresenterControlCreator presenterControlCreator; protected Boolean _hover(AttributeOperation o) { return true; } protected Boolean _hover(Definition o) { return true; } protected Boolean _hover(EObject o) { List<IEObjectDescription> xrefs = CrossReferenceAdapter.get(o); if (xrefs != null && xrefs.size() > 0) return true; return false; } protected Boolean _hover(LiteralNameOrReference o) { EStructuralFeature feature = o.eContainingFeature(); if (feature == PPPackage.Literals.RESOURCE_EXPRESSION__RESOURCE_EXPR) return true; if (feature == PPPackage.Literals.PARENTHESISED_EXPRESSION__EXPR) { if (o.eContainer().eContainer() instanceof ExpressionTE) return true; } List<IEObjectDescription> xrefs = CrossReferenceAdapter.get(o); if (xrefs != null && xrefs.size() > 0) return true; return false; } protected Boolean _hover(NodeDefinition o) { return true; } protected Boolean _hover(VariableExpression o) { if (o.eContainer() instanceof AssignmentExpression && o.eContainingFeature() == PPPackage.Literals.BINARY_EXPRESSION__LEFT_EXPR) return false; return true; } protected Boolean _hover(VariableTE o) { return true; } protected Boolean _hover(VerbatimTE o) { return hasHover(o.eContainer()); } /** * Overrides the default implementation which does not seem to link to something somewhere else than in * the same file. Also, does not handle hovers without a target very well. * * @see org.eclipse.xtext.ui.editor.hover.html.DefaultEObjectHoverProvider#createURI(org.eclipse.emf.ecore.EObject) */ @Override protected org.eclipse.emf.common.util.URI createURI(EObject o) { IEObjectDescription target = documentationProvider.xref(o); if (target == null) return null; // should disable the link as well final URIConverter uriConverter = o.eResource().getResourceSet().getURIConverter(); final URI uri = target.getEObjectURI(); final URI normalized = uriConverter.normalize(uri); return normalized; } @Override protected String getFirstLine(EObject o) { StringBuilder builder = new StringBuilder(); Image image = documentationProvider.getImage(o); if (image != null) { URL imageURL = PPDSLActivator.getDefault().getImagesOnFSRegistry() .getImageURL(ImageDescriptor.createFromImage(image)); builder.append("<IMG src=\"").append(imageURL.toExternalForm()).append("\"/>"); } builder.append("<b>").append(getLabel(o)).append("</b>"); String label = documentationProvider.getText(o); if (label != null) builder.append(" <span class='target'>- ").append(documentationProvider.getText(o)).append("</span>"); return builder.toString(); } /** * Overrides the default implementation simply because the PPPresenterControlCreator always enables * the OpenDeclaration link. * * @see org.eclipse.xtext.ui.editor.hover.html.DefaultEObjectHoverProvider#getInformationPresenterControlCreator() */ @Override public IInformationControlCreator getInformationPresenterControlCreator() { if (presenterControlCreator == null) presenterControlCreator = new PresenterControlCreator(); // specialisation return presenterControlCreator; } @Override protected boolean hasHover(EObject o) { Boolean result = hoverDispatcher.invoke(o); // TODO: make this a trace setting instead... // System.out.println("Hover query (" + result + ") for: " + o.getClass()); // For debugging, finding what to react to return result; } @Override protected String loadStyleSheet() { URL styleSheetURL = PPDSLActivator.getInstance().getBundle().getEntry(styleSheetFileName); if (styleSheetURL != null) try { return Files.readStreamIntoString(styleSheetURL.openStream()); } catch (IOException e) { // ignore } return super.loadStyleSheet(); } }