source: java/Framclipse/com.framsticks.framclipse.ui/src/com/framsticks/framclipse/ui/FramScriptSourceViewerConfiguration.java @ 438

package com.framsticks.framclipse.ui;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.jface.internal.text.html.HTMLTextPresenter;
import org.eclipse.jface.text.DefaultInformationControl;
import org.eclipse.jface.text.IInformationControl;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextHover;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.xtext.nodemodel.ICompositeNode;
import org.eclipse.xtext.nodemodel.ILeafNode;
import org.eclipse.xtext.nodemodel.util.NodeModelUtils;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.ui.editor.XtextSourceViewerConfiguration;
import org.eclipse.xtext.ui.editor.model.IXtextDocument;
import org.eclipse.xtext.util.concurrent.IUnitOfWork;

import com.framsticks.framclipse.framScript.Function;
import com.framsticks.framclipse.framScript.Invocation;
import com.framsticks.framclipse.framScript.Proposable;
import com.framsticks.framclipse.framScript.QualifiedExpression;
import com.framsticks.framclipse.framScript.VariableDeclaration;
import com.framsticks.framclipse.framScript.VariableRef;
import com.framsticks.framclipse.ui.contentassist.DescriptorProvider;
import com.google.inject.Inject;

@SuppressWarnings("restriction")
public class FramScriptSourceViewerConfiguration extends XtextSourceViewerConfiguration {

        @Inject
        private DescriptorProvider descripter;

        @Override
        public IInformationControlCreator getInformationControlCreator(ISourceViewer sourceViewer) {
                return new IInformationControlCreator() {
                        public IInformationControl createInformationControl(Shell parent) {
                                return new DefaultInformationControl(parent, new HTMLTextPresenter(true));
                        }
                };
        }

        @Override
        public ITextHover getTextHover(final ISourceViewer sourceViewer, String contentType) {
                return new ITextHover() {

                        @Override
                        public IRegion getHoverRegion(ITextViewer textViewer, int offset) {
                                return new Region(offset, 0);
                        }

                        @Override
                        public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
                                final int offset = hoverRegion.getOffset();
                                final IXtextDocument model = (IXtextDocument) sourceViewer.getDocument();
                                return model.readOnly(new IUnitOfWork<String, XtextResource>() {

                                        @Override
                                        public String exec(XtextResource state) throws Exception {
                                                ICompositeNode root = state.getParseResult().getRootNode();
//                                              AbstractNode current = ParseTreeUtil.getCurrentOrFollowingNodeByOffset(root, offset);
                                                ILeafNode current = NodeModelUtils.findLeafNodeAtOffset(root, offset);
//                                              EObject semantic = NodeUtil.getNearestSemanticObject(current);
                                                EObject semantic = current.getSemanticElement();

                                                if (semantic instanceof QualifiedExpression) {
                                                        return getMessage((QualifiedExpression) semantic);
                                                }
                                                return null;
                                        }
                                });
                        }
                };
        }

        private String getMessage(QualifiedExpression expression) {
                if (expression instanceof Invocation) {
                        Function function = ((Invocation) expression).getFunction();
                        if (function instanceof Proposable) {
                                return descripter.description(((Proposable) function).description());
                        }
                } else if (expression instanceof VariableRef) {
                        VariableDeclaration var = ((VariableRef) expression).getVar();
                        if (var instanceof Proposable) {
                                return descripter.description(((Proposable) var).description());
                        }
                }
                return null;
        }

}