DefaultIDEEditorRendererExtension.java

/*******************************************************************************
 * Copyright (c) 2010, 2011 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.mylyn.docs.intent.bridge.ide.ui;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashSet;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Path;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EValidator;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
import org.eclipse.emf.edit.provider.IItemLabelProvider;
import org.eclipse.emf.edit.ui.provider.ExtendedImageRegistry;
import org.eclipse.emf.validation.marker.MarkerUtil;
import org.eclipse.jface.util.LocalSelectionTransfer;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension;
import org.eclipse.mylyn.docs.intent.client.ui.logger.IntentUiLogger;
import org.eclipse.mylyn.docs.intent.core.modelingunit.ExternalContentReference;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IEditorDescriptor;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.ide.IGotoMarker;
import org.eclipse.ui.part.FileEditorInput;
import org.eclipse.ui.part.ResourceTransfer;

/**
 * An default {@link IEditorRendererExtension} providing extension do drop {@link IFile}s in the IntentEditor,
 * open editors with FileEditorInputs...
 * 
 * @author <a href="mailto:alex.lagarde@obeo.fr">Alex Lagarde</a>
 */
public class DefaultIDEEditorRendererExtension implements IEditorRendererExtension {
	
	/**
	 * Constant used to determine the height of the image margin.
	 */
	private static final int IMAGE_HEIGHT_MARGIN = 5;

	/**
	 * Constant usde to determine the image width.
	 */
	private static final int IMAGE_WIDTH = 800;

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension#isRendererFor(org.eclipse.mylyn.docs.intent.core.modelingunit.ExternalContentReference)
	 */
	public boolean isRendererFor(ExternalContentReference externalContentReference) {
		// Can be applied on any external content reference (with low priority)
		return true;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension#openEditor(org.eclipse.mylyn.docs.intent.core.modelingunit.ExternalContentReference)
	 */
	public boolean openEditor(ExternalContentReference externalContentReference) {
		URI resourceToOpenURI = URI.createURI(externalContentReference.getUri().toString().trim());
		if ("intent".equals(resourceToOpenURI.scheme())
				&& externalContentReference.getExternalContent() != null) {
			resourceToOpenURI = EcoreUtil.getURI(externalContentReference.getExternalContent())
					.trimFragment();
		}
		if (resourceToOpenURI.isPlatformResource()) {
			String filePath = resourceToOpenURI.trimFragment().toPlatformString(true);

			// Step 1: Open editor with a file editor input
			IFile resourceFile = ResourcesPlugin.getWorkspace().getRoot().getFile(new Path(filePath));
			FileEditorInput editorInput = new FileEditorInput(resourceFile);
			if ("repomodel".equals(resourceToOpenURI.fileExtension())) {
				resourceToOpenURI = resourceToOpenURI.trimFileExtension();
			}
			IEditorDescriptor desc = PlatformUI.getWorkbench().getEditorRegistry()
					.getDefaultEditor(resourceToOpenURI.trimFragment().lastSegment());
			IEditorPart openedEditor = null;
			if (desc != null) {
				try {
					openedEditor = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage()
							.openEditor(editorInput, desc.getId());
				} catch (PartInitException e) {
					IntentUiLogger.logError(e);
				}
			}

			// Step 2: Update selection using a shadow marker
			if (openedEditor instanceof IGotoMarker && resourceToOpenURI.hasFragment()) {
				IMarker shadowMarker = null;
				try {
					// We create a shadow marker that will be deleted
					shadowMarker = resourceFile.createMarker(MarkerUtil.VALIDATION_MARKER_TYPE);
					shadowMarker.setAttribute(EValidator.URI_ATTRIBUTE, resourceToOpenURI.toString());

					// Update selection using the gotoMarker method
					((IGotoMarker)openedEditor).gotoMarker(shadowMarker);

				} catch (CoreException e) {
					// Silent catch
					e.printStackTrace();
				} finally {
					if (shadowMarker != null) {
						try {
							shadowMarker.delete();
						} catch (CoreException e) {
							// Silent catch
						}
					}
				}
			}
			return true;
		}
		return false;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension#getAdditionalTransfers()
	 */
	public Collection<Transfer> getAdditionalTransfers() {
		// Adding the Resource transfer to be able to directly drop IFiles inside the Intent editor
		Collection<Transfer> transfers = new ArrayList<Transfer>();
		transfers.add(ResourceTransfer.getInstance());
		transfers.add(LocalSelectionTransfer.getTransfer());
		return transfers;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension#getEObjectsFromDropTargetEvent(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public Collection<? extends EObject> getEObjectsFromDropTargetEvent(DropTargetEvent event) {
		Collection<EObject> eObjects = new LinkedHashSet<EObject>();
		try {
			Collection<Resource> emfResources = new LinkedHashSet<Resource>();
			// If directly dropping an IFile
			if (event.data instanceof IResource[]) {
				IResource[] droppedResources = (IResource[])event.data;
				for (int i = 0; i < droppedResources.length; i++) {
					emfResources.add(getEMFResourceFromIResource(droppedResources[i]));
				}
			} else if (event.data instanceof IStructuredSelection) {
				// If dropping a selection of IFiles
				Iterator iterator = ((IStructuredSelection)event.data).iterator();
				while (iterator.hasNext()) {
					Object element = iterator.next();
					if (element instanceof IResource) {
						emfResources.add(getEMFResourceFromIResource((IResource)element));
					}
				}
			}
			for (Resource emfResource : emfResources) {
				if (emfResource != null && emfResource.getContents().iterator().hasNext()) {
					eObjects.add(emfResource.getContents().iterator().next());
				}
			}
		} catch (IllegalArgumentException e) {
			// Nothing to do, the drop event was not valid for this extension
		}
		return eObjects;
	}

	/**
	 * Returns an emfResource corresponding to the given {@link IResource} (if any).
	 * 
	 * @param iResource
	 *            the {@link IResource} to analyse
	 * @return an emfResource corresponding to the given {@link IResource}, or null if none find
	 */
	private Resource getEMFResourceFromIResource(IResource iResource) {
		// Try to get the EMF ressource corresponding to this file
		URI resourceURI = URI.createPlatformResourceURI(iResource.getFullPath().toString(), true);
		try {
			return new ResourceSetImpl().getResource(resourceURI, true);
			// CHECKSTYLE:OFF
		} catch (Exception e) {
			// CHECKSTYLE:ON
			IntentUiLogger.logError("Could not perform drop of the resource at URI " + resourceURI
					+ " because a bridge to represent such files as models is missing", e);
		}
		return null;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.mylyn.docs.intent.client.ui.editor.renderers.IEditorRendererExtension#getImage(org.eclipse.mylyn.docs.intent.core.modelingunit.ExternalContentReference)
	 */
	public Image getImage(ExternalContentReference externalContentReference) {
		Image image = null;
		if (externalContentReference.getExternalContent() != null) {

			// Determine string to render
			IItemLabelProvider labeProvider = (IItemLabelProvider)new ComposedAdapterFactory(
					ComposedAdapterFactory.Descriptor.Registry.INSTANCE).adapt(
					externalContentReference.getExternalContent(), IItemLabelProvider.class);
			if (labeProvider != null) {
				String label = labeProvider.getText(externalContentReference.getExternalContent());

				Display display = Display.getDefault();
				int fontHeight = new GC(new Image(display, 1, 1)).getFontMetrics().getHeight();
				int imageHeight = fontHeight + IMAGE_HEIGHT_MARGIN;
				image = new Image(display, IMAGE_WIDTH, imageHeight);
				GC gc = new GC(image);

				// Render icon
				int iconWidth = 5;
				gc.setForeground(display.getSystemColor(SWT.COLOR_DARK_GRAY));

				Object iconURL = labeProvider.getImage(externalContentReference.getExternalContent());
				Image icon = ExtendedImageRegistry.getInstance().getImage(iconURL);

				if (icon != null) {
					gc.drawImage(icon, 0, 5);
					iconWidth += icon.getImageData().width + 2;
				}
				// Render text
				gc.drawText(label, iconWidth, 5);
				gc.dispose();
			}

		}

		return image;
	}

}