[569572] [UI] Allows to open a model editor on a CDOFileResource in a CDOCheckout

https://bugs.eclipse.org/bugs/show_bug.cgi?id=569572

10 files changed, 693 insertions, 139 deletions

diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/actions/OpenWithActionProvider.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/actions/OpenWithActionProvider.java
index e65fad2812..0b81a63a53 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/actions/OpenWithActionProvider.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/actions/OpenWithActionProvider.java
@@ -13,15 +13,17 @@ package org.eclipse.emf.cdo.explorer.ui.checkouts.actions;
 import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDUtil;
+import org.eclipse.emf.cdo.eresource.CDOFileResource;
 import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.eresource.CDOResourceFolder;
 import org.eclipse.emf.cdo.eresource.CDOResourceLeaf;
 import org.eclipse.emf.cdo.eresource.CDOResourceNode;
-import org.eclipse.emf.cdo.eresource.CDOTextResource;
 import org.eclipse.emf.cdo.explorer.CDOExplorerUtil;
 import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout;
 import org.eclipse.emf.cdo.explorer.ui.bundle.OM;
+import org.eclipse.emf.cdo.internal.explorer.CDOExplorerURIHandler;
 import org.eclipse.emf.cdo.internal.ui.dialogs.EditObjectDialog;
+import org.eclipse.emf.cdo.internal.ui.editor.CDOLobEditorInput;
 import org.eclipse.emf.cdo.transaction.CDOTransaction;
 import org.eclipse.emf.cdo.ui.CDOEditorOpener;
 import org.eclipse.emf.cdo.ui.CDOEditorUtil;
@@ -29,6 +31,7 @@ import org.eclipse.emf.cdo.util.CDOUtil;
 import org.eclipse.emf.cdo.view.CDOView;
 
 import org.eclipse.net4j.util.ObjectUtil;
+import org.eclipse.net4j.util.om.OMPlatform;
 import org.eclipse.net4j.util.ui.UIUtil;
 
 import org.eclipse.emf.common.command.BasicCommandStack;
@@ -46,7 +49,6 @@ import org.eclipse.jface.action.MenuManager;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IActionBars;
-import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IPartListener;
 import org.eclipse.ui.IWorkbenchPage;
@@ -63,37 +65,7 @@ import org.eclipse.ui.navigator.ICommonViewerWorkbenchSite;
  */
 public class OpenWithActionProvider extends CommonActionProvider
 {
-  // private static final String WORKBENCH_PART_KEY = IWorkbenchPart.class.getName();
-  //
-  // private static final Map<IEditorPart, Pair<CDOView, Pair<CDOResourceLeaf, String>>> VIEWS = new
-  // HashMap<IEditorPart, Pair<CDOView, Pair<CDOResourceLeaf, String>>>();
-  //
-  // private static final Map<Pair<CDOResourceLeaf, String>, Object> EDITORS = new HashMap<Pair<CDOResourceLeaf,
-  // String>, Object>();
-  //
-  // private static final Object EDITOR_OPENING = new Object();
-  //
-  // private static final IPartListener2 PART_LISTENER = new PartListener();
-  //
-  // private static final IPageListener PAGE_LISTENER = new PageListener();
-  //
-  // private static final IWindowListener WINDOW_LISTENER = new WindowListener();
-  //
-  // static
-  // {
-  // IWorkbench workbench = UIUtil.getWorkbench();
-  // for (IWorkbenchWindow window : workbench.getWorkbenchWindows())
-  // {
-  // window.addPageListener(PAGE_LISTENER);
-  //
-  // for (IWorkbenchPage page : window.getPages())
-  // {
-  // page.addPartListener(PART_LISTENER);
-  // }
-  // }
-  //
-  // workbench.addWindowListener(WINDOW_LISTENER);
-  // }
+  private static final boolean OMIT_LOB_HANDLER_URI = OMPlatform.INSTANCE.isProperty("org.eclipse.emf.cdo.explorer.ui.omitLobHandlerURI");
 
   private ICommonViewerWorkbenchSite viewSite;
 
@@ -224,61 +196,6 @@ public class OpenWithActionProvider extends CommonActionProvider
     return cdoObject.cdoResource();
   }
 
-  // private static IEditorInput createEditorInput(String editorID, CDOCheckout checkout, CDOResourceLeaf resourceLeaf)
-  // {
-  // if (CDOEditorUtil.EDITOR_ID.equals(editorID))
-  // {
-  // return CDOEditorUtil.createEditorInput(editorID, resourceLeaf, false, true);
-  // }
-  //
-  // String path = resourceLeaf.getPath();
-  // URI uri = checkout.createResourceURI(path);
-  // return new URIEditorInput(uri);
-  // }
-  //
-  // private static void openEditor(final IWorkbenchPage page, final CDOObject object, final CDOResourceLeaf
-  // resourceLeaf,
-  // final String editorID, final Pair<CDOResourceLeaf, String> key)
-  // {
-  // new Job("Open")
-  // {
-  // @Override
-  // protected IStatus run(IProgressMonitor monitor)
-  // {
-  // final CDOCheckout checkout = CDOExplorerUtil.getCheckout(object);
-  // final CDOView view = checkout.openView();
-  //
-  // final CDOResourceLeaf contextualLeaf = view.getObject(resourceLeaf);
-  // final IEditorInput editorInput = createEditorInput(editorID, checkout, contextualLeaf);
-  //
-  // Shell shell = page.getWorkbenchWindow().getShell();
-  // if (!shell.isDisposed())
-  // {
-  // shell.getDisplay().asyncExec(new Runnable()
-  // {
-  // public void run()
-  // {
-  // try
-  // {
-  // IEditorPart editor = page.openEditor(editorInput, editorID);
-  // if (editor != null)
-  // {
-  // registerEditor(editor, view, key);
-  // }
-  // }
-  // catch (Exception ex)
-  // {
-  // OM.LOG.error(ex);
-  // }
-  // }
-  // });
-  // }
-  //
-  // return Status.OK_STATUS;
-  // }
-  // }.schedule();
-  // }
-
   public static void openEditor(IWorkbenchPage page, ComposedAdapterFactory adapterFactory, EObject object, String editorOpenerID)
   {
     if (page == null)
@@ -383,7 +300,7 @@ public class OpenWithActionProvider extends CommonActionProvider
         }
       }
     }
-    else if (resourceLeaf instanceof CDOTextResource)
+    else if (resourceLeaf instanceof CDOFileResource)
     {
       String editorID = CDOEditorUtil.getEffectiveEditorID(resourceLeaf);
       if (editorID != null)
@@ -395,7 +312,13 @@ public class OpenWithActionProvider extends CommonActionProvider
 
         try
         {
-          IEditorInput editorInput = CDOEditorUtil.createLobEditorInput(txLeaf, true);
+          CDOLobEditorInput editorInput = (CDOLobEditorInput)CDOEditorUtil.createLobEditorInput(txLeaf, true);
+
+          if (!OMIT_LOB_HANDLER_URI)
+          {
+            editorInput.setURI(CDOExplorerURIHandler.createURI(checkout, txLeaf));
+          }
+
           IEditorPart editor = page.openEditor(editorInput, editorID);
 
           page.addPartListener(new IPartListener()
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/CDOExplorerUtil.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/CDOExplorerUtil.java
index a0385b54d0..1255253850 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/CDOExplorerUtil.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/CDOExplorerUtil.java
@@ -39,6 +39,11 @@ import java.util.LinkedList;
  */
 public final class CDOExplorerUtil
 {
+  /**
+   * @since 4.8
+   */
+  public static final String URI_SCHEME = "cdo.checkout";
+
   public static CDORepositoryManager getRepositoryManager()
   {
     return OM.getRepositoryManager();
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/CDOExplorerURIHandler.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/CDOExplorerURIHandler.java
new file mode 100644
index 0000000000..21da85f350
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/CDOExplorerURIHandler.java
@@ -0,0 +1,325 @@
+/*
+ * Copyright (c) 2020 Eike Stepper (Loehne, Germany) 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:
+ *    Eike Stepper - initial API and implementation
+ */
+package org.eclipse.emf.cdo.internal.explorer;
+
+import org.eclipse.emf.cdo.common.commit.CDOCommitInfo;
+import org.eclipse.emf.cdo.common.lob.CDOBlob;
+import org.eclipse.emf.cdo.common.lob.CDOClob;
+import org.eclipse.emf.cdo.common.lob.CDOLobStore;
+import org.eclipse.emf.cdo.common.util.CDOException;
+import org.eclipse.emf.cdo.common.util.CDOResourceNodeNotFoundException;
+import org.eclipse.emf.cdo.eresource.CDOBinaryResource;
+import org.eclipse.emf.cdo.eresource.CDOResourceNode;
+import org.eclipse.emf.cdo.eresource.CDOTextResource;
+import org.eclipse.emf.cdo.explorer.CDOExplorerUtil;
+import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout;
+import org.eclipse.emf.cdo.transaction.CDOTransaction;
+import org.eclipse.emf.cdo.view.CDOView;
+
+import org.eclipse.emf.internal.cdo.view.CDOURIHandler;
+
+import org.eclipse.net4j.util.io.IOUtil;
+import org.eclipse.net4j.util.io.ReaderInputStream;
+
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.resource.URIConverter;
+import org.eclipse.emf.ecore.resource.impl.URIHandlerImpl;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+
+/**
+ * @author Eike Stepper
+ */
+public abstract class CDOExplorerURIHandler<NODE extends CDOResourceNode> extends URIHandlerImpl
+{
+  public static final CDOExplorerURIHandler<CDOTextResource> TEXT = new TextURIHandler();
+
+  public static final CDOExplorerURIHandler<CDOBinaryResource> BINARY = new BinaryURIRHandler();
+
+  private final String scheme;
+
+  protected CDOExplorerURIHandler(String schemeType)
+  {
+    this.scheme = CDOExplorerUtil.URI_SCHEME + "." + schemeType;
+  }
+
+  public final String getScheme()
+  {
+    return scheme;
+  }
+
+  @Override
+  public boolean canHandle(URI uri)
+  {
+    return scheme.equals(uri.scheme());
+  }
+
+  @Override
+  public boolean exists(URI uri, Map<?, ?> options)
+  {
+    CDOView view = getView(uri);
+    NODE node = null;
+
+    try
+    {
+      node = getNode(view, uri.path());
+    }
+    catch (CDOResourceNodeNotFoundException ex)
+    {
+      //$FALL-THROUGH$
+    }
+
+    return node != null;
+  }
+
+  @Override
+  public Map<String, ?> getAttributes(URI uri, Map<?, ?> options)
+  {
+    CDOView view = getView(uri);
+    Map<String, ?> attributes = CDOURIHandler.getAttributes(view, uri.path(), options);
+
+    // The view of a checkout is always read-only, so remove this attribute.
+    attributes.remove(URIConverter.ATTRIBUTE_READ_ONLY);
+
+    return attributes;
+  }
+
+  @Override
+  public InputStream createInputStream(URI uri, Map<?, ?> options) throws IOException
+  {
+    CDOView view = getView(uri);
+    NODE node = getNode(view, uri.path());
+    return createInputStream(node);
+  }
+
+  @Override
+  public OutputStream createOutputStream(URI uri, Map<?, ?> options) throws IOException
+  {
+    return new ByteArrayOutputStream()
+    {
+      @Override
+      public void close() throws IOException
+      {
+        super.close();
+        byte[] bytes = toByteArray();
+
+        CDOCheckout checkout = getCheckout(uri);
+        CDOLobStore lobStore = checkout.getView().getSession().options().getLobCache();
+
+        modify(checkout, uri.path(), true, node -> setContents(node, bytes, lobStore));
+      }
+    };
+  }
+
+  @Override
+  public void delete(URI uri, Map<?, ?> options) throws IOException
+  {
+    CDOCheckout checkout = getCheckout(uri);
+    modify(checkout, uri.path(), false, node -> node.delete(options));
+  }
+
+  protected abstract NODE getNode(CDOView view, String path) throws CDOResourceNodeNotFoundException;
+
+  protected abstract NODE getOrCreateNode(CDOTransaction transaction, String path);
+
+  protected abstract InputStream createInputStream(NODE node) throws IOException;
+
+  protected abstract void setContents(NODE node, byte[] bytes, CDOLobStore lobStore) throws IOException;
+
+  private CDOCheckout getCheckout(URI uri)
+  {
+    String id = uri.authority();
+
+    CDOCheckout checkout = CDOExplorerUtil.getCheckout(id);
+    if (checkout == null)
+    {
+      throw new CDOException("No checkout exists for " + uri);
+    }
+
+    if (!checkout.isOpen())
+    {
+      throw new CDOException("Checkout '" + checkout.getLabel() + "' is not open");
+    }
+
+    return checkout;
+  }
+
+  private CDOView getView(URI uri)
+  {
+    CDOCheckout checkout = getCheckout(uri);
+    return checkout.getView();
+  }
+
+  private void modify(CDOCheckout checkout, String path, boolean createOnDemand, ResourceNodeModifier<NODE> modifier) throws IOException
+  {
+    CDOTransaction transaction = null;
+
+    try
+    {
+      transaction = checkout.openTransaction();
+
+      NODE node = createOnDemand ? getOrCreateNode(transaction, path) : getNode(transaction, path);
+      modifier.modify(node);
+
+      CDOCommitInfo commitInfo = transaction.commit();
+      if (commitInfo != null)
+      {
+        CDOView view = checkout.getView();
+        view.waitForUpdate(commitInfo.getTimeStamp());
+      }
+    }
+    catch (Exception ex)
+    {
+      throw IOUtil.ioException(ex);
+    }
+    finally
+    {
+      IOUtil.closeSilent(transaction);
+    }
+  }
+
+  private static CDOExplorerURIHandler<?> getURIHandler(CDOResourceNode node)
+  {
+    if (node instanceof CDOTextResource)
+    {
+      return TEXT;
+    }
+
+    if (node instanceof CDOBinaryResource)
+    {
+      return TEXT;
+    }
+
+    return null;
+  }
+
+  public static URI createURI(CDOCheckout checkout, CDOResourceNode node)
+  {
+    CDOExplorerURIHandler<?> uriHandler = getURIHandler(node);
+    if (uriHandler == null)
+    {
+      return null;
+    }
+
+    String scheme = uriHandler.getScheme();
+    String authority = checkout.getID();
+    String[] segments = node.getURI().segments();
+
+    return URI.createHierarchicalURI(scheme, authority, null, segments, null, null);
+  }
+
+  /**
+   * @author Eike Stepper
+   */
+  @FunctionalInterface
+  private interface ResourceNodeModifier<NODE extends CDOResourceNode>
+  {
+    public void modify(NODE node) throws IOException;
+  }
+
+  /**
+   * @author Eike Stepper
+   */
+  private static final class TextURIHandler extends CDOExplorerURIHandler<CDOTextResource>
+  {
+    public TextURIHandler()
+    {
+      super("text");
+    }
+
+    @Override
+    protected CDOTextResource getNode(CDOView view, String path) throws CDOResourceNodeNotFoundException
+    {
+      return view.getTextResource(path);
+    }
+
+    @Override
+    protected CDOTextResource getOrCreateNode(CDOTransaction transaction, String path)
+    {
+      return transaction.getOrCreateTextResource(path);
+    }
+
+    @Override
+    protected InputStream createInputStream(CDOTextResource node) throws IOException
+    {
+      CDOClob clob = node.getContents();
+      if (clob == null)
+      {
+        return new InputStream()
+        {
+          @Override
+          public int read() throws IOException
+          {
+            return IOUtil.EOF;
+          }
+        };
+      }
+
+      return new ReaderInputStream(clob.getContents(), node.getEncoding());
+    }
+
+    @Override
+    protected void setContents(CDOTextResource node, byte[] bytes, CDOLobStore lobStore) throws IOException
+    {
+      String encoding = node.getEncoding();
+      if (encoding == null)
+      {
+        encoding = StandardCharsets.UTF_8.toString();
+      }
+
+      CDOClob clob = new CDOClob(new StringReader(new String(bytes, encoding)), lobStore);
+      node.setContents(clob);
+    }
+  }
+
+  /**
+   * @author Eike Stepper
+   */
+  private static final class BinaryURIRHandler extends CDOExplorerURIHandler<CDOBinaryResource>
+  {
+    public BinaryURIRHandler()
+    {
+      super("binary");
+    }
+
+    @Override
+    protected CDOBinaryResource getNode(CDOView view, String path) throws CDOResourceNodeNotFoundException
+    {
+      return view.getBinaryResource(path);
+    }
+
+    @Override
+    protected CDOBinaryResource getOrCreateNode(CDOTransaction transaction, String path)
+    {
+      return transaction.getOrCreateBinaryResource(path);
+    }
+
+    @Override
+    protected InputStream createInputStream(CDOBinaryResource node) throws IOException
+    {
+      return node.getContents().getContents();
+    }
+
+    @Override
+    protected void setContents(CDOBinaryResource node, byte[] bytes, CDOLobStore lobStore) throws IOException
+    {
+      CDOBlob blob = new CDOBlob(new ByteArrayInputStream(bytes), lobStore);
+      node.setContents(blob);
+    }
+  }
+}
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/bundle/OM.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/bundle/OM.java
index 1d803b960d..f6470f5b55 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/bundle/OM.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/bundle/OM.java
@@ -11,6 +11,7 @@
  */
 package org.eclipse.emf.cdo.internal.explorer.bundle;
 
+import org.eclipse.emf.cdo.internal.explorer.CDOExplorerURIHandler;
 import org.eclipse.emf.cdo.internal.explorer.checkouts.CDOCheckoutManagerImpl;
 import org.eclipse.emf.cdo.internal.explorer.repositories.CDORepositoryManagerImpl;
 
@@ -21,7 +22,16 @@ import org.eclipse.net4j.util.om.OSGiActivator;
 import org.eclipse.net4j.util.om.log.OMLogger;
 import org.eclipse.net4j.util.om.trace.OMTracer;
 
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.emf.ecore.resource.URIConverter;
+import org.eclipse.emf.ecore.resource.impl.BinaryResourceImpl;
+import org.eclipse.emf.ecore.resource.impl.ResourceFactoryImpl;
+import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
+import org.eclipse.emf.ecore.xmi.impl.XMIResourceImpl;
+
 import java.io.File;
+import java.util.Map;
 
 /**
  * The <em>Operations & Maintenance</em> class of this bundle.
@@ -40,6 +50,8 @@ public abstract class OM
 
   private static final String STATE_LOCATION = OMPlatform.INSTANCE.getProperty("org.eclipse.emf.cdo.explorer.stateLocation");
 
+  private static final boolean OMIT_CHECKOUT_FILE_URI_HANDLERS = OMPlatform.INSTANCE.isProperty("org.eclipse.emf.cdo.explorer.omitCheckoutFileURIHandlers");
+
   private static String stateLocation;
 
   private static CDORepositoryManagerImpl repositoryManager;
@@ -116,6 +128,54 @@ public abstract class OM
    */
   public static final class Activator extends OSGiActivator
   {
+    private static final Resource.Factory TEXT_RESOURCE_FACTORY = new XMIResourceFactoryImpl()
+    {
+      @Override
+      public Resource createResource(URI uri)
+      {
+        return new XMIResourceImpl(uri)
+        {
+          private URIConverter uriConverter;
+
+          @Override
+          protected URIConverter getURIConverter()
+          {
+            if (uriConverter == null)
+            {
+              uriConverter = super.getURIConverter();
+              uriConverter.getURIHandlers().add(0, CDOExplorerURIHandler.TEXT);
+            }
+
+            return uriConverter;
+          }
+        };
+      }
+    };
+
+    private static final Resource.Factory BINARY_RESOURCE_FACTORY = new ResourceFactoryImpl()
+    {
+      @Override
+      public Resource createResource(URI uri)
+      {
+        return new BinaryResourceImpl(uri)
+        {
+          private URIConverter uriConverter;
+
+          @Override
+          protected URIConverter getURIConverter()
+          {
+            if (uriConverter == null)
+            {
+              uriConverter = super.getURIConverter();
+              uriConverter.getURIHandlers().add(0, CDOExplorerURIHandler.TEXT);
+            }
+
+            return uriConverter;
+          }
+        };
+      }
+    };
+
     public Activator()
     {
       super(BUNDLE);
@@ -126,6 +186,13 @@ public abstract class OM
     {
       super.doStart();
 
+      if (!OMIT_CHECKOUT_FILE_URI_HANDLERS)
+      {
+        Map<String, Object> factoryMap = Resource.Factory.Registry.INSTANCE.getProtocolToFactoryMap();
+        factoryMap.put(CDOExplorerURIHandler.TEXT.getScheme(), TEXT_RESOURCE_FACTORY);
+        factoryMap.put(CDOExplorerURIHandler.BINARY.getScheme(), BINARY_RESOURCE_FACTORY);
+      }
+
       stateLocation = STATE_LOCATION != null ? STATE_LOCATION : BUNDLE.getStateLocation();
       initializeManagers(new File(stateLocation));
     }
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutViewProvider.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutViewProvider.java
index 1e0a054cea..caae1dc27c 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutViewProvider.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutViewProvider.java
@@ -39,7 +39,7 @@ import java.util.Map;
  */
 public class CDOCheckoutViewProvider extends AbstractCDOViewProvider
 {
-  public static final String SCHEME = "cdo.checkout";
+  public static final String SCHEME = CDOExplorerUtil.URI_SCHEME;
 
   // TODO Move to activator and deactivate via stop().
   private static final ReferenceMonitor<ResourceSet> MONITOR = new ReferenceMonitor<ResourceSet>()
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOLobEditorInput.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOLobEditorInput.java
index 2bf858fff1..922fe5f0e3 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOLobEditorInput.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOLobEditorInput.java
@@ -12,6 +12,8 @@ package org.eclipse.emf.cdo.internal.ui.editor;
 
 import org.eclipse.emf.cdo.eresource.CDOResourceLeaf;
 
+import org.eclipse.emf.common.util.URI;
+
 import org.eclipse.core.runtime.PlatformObject;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.ui.IEditorInput;
@@ -28,6 +30,8 @@ public class CDOLobEditorInput extends PlatformObject implements IEditorInput
 
   private final boolean commitOnSave;
 
+  private URI uri;
+
   public CDOLobEditorInput(CDOResourceLeaf resource)
   {
     this(resource, false);
@@ -49,6 +53,16 @@ public class CDOLobEditorInput extends PlatformObject implements IEditorInput
     return commitOnSave;
   }
 
+  public final URI getURI()
+  {
+    return uri == null ? resource.getURI() : uri;
+  }
+
+  public final void setURI(URI uri)
+  {
+    this.uri = uri;
+  }
+
   @Override
   public boolean exists()
   {
@@ -78,4 +92,18 @@ public class CDOLobEditorInput extends PlatformObject implements IEditorInput
   {
     return resource.getURI().toString();
   }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public <T> T getAdapter(Class<T> type)
+  {
+    T adapter = super.getAdapter(type);
+
+    if (adapter == null && type == URI.class)
+    {
+      adapter = (T)getURI();
+    }
+
+    return adapter;
+  }
 }
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOURIHandler.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOURIHandler.java
index d749af89f4..5be36fc821 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOURIHandler.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/view/CDOURIHandler.java
@@ -11,11 +11,15 @@
  */
 package org.eclipse.emf.internal.cdo.view;
 
+import org.eclipse.emf.cdo.common.branch.CDOBranch;
+import org.eclipse.emf.cdo.common.commit.CDOCommitInfo;
 import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.eresource.CDOResourceFolder;
 import org.eclipse.emf.cdo.eresource.CDOResourceNode;
+import org.eclipse.emf.cdo.session.CDOSession;
 import org.eclipse.emf.cdo.transaction.CDOTransaction;
 import org.eclipse.emf.cdo.util.CDOURIUtil;
+import org.eclipse.emf.cdo.view.CDOView;
 import org.eclipse.emf.cdo.view.CDOViewProvider;
 import org.eclipse.emf.cdo.view.CDOViewProvider.CDOViewProvider2;
 import org.eclipse.emf.cdo.view.CDOViewProviderRegistry;
@@ -101,26 +105,7 @@ public class CDOURIHandler implements URIHandler
   @Override
   public void delete(URI uri, Map<?, ?> options) throws IOException
   {
-    String path = CDOURIUtil.extractResourcePath(uri);
-    CDOTransaction transaction = null;
-
-    try
-    {
-      transaction = view.getSession().openTransaction();
-      CDOResourceNode node = transaction.getResourceNode(path);
-      node.delete(options);
-      transaction.commit();
-    }
-    catch (Exception ex)
-    {
-      IOException ioException = new IOException(ex.getMessage());
-      ioException.initCause(ex);
-      throw ioException;
-    }
-    finally
-    {
-      IOUtil.closeSilent(transaction);
-    }
+    modify(uri, node -> node.delete(options));
   }
 
   @Override
@@ -144,33 +129,10 @@ public class CDOURIHandler implements URIHandler
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public Map<String, ?> getAttributes(URI uri, Map<?, ?> options)
   {
-    Map<String, Object> result = new HashMap<>();
-    String path = CDOURIUtil.extractResourcePath(uri);
-    CDOResourceNode node = view.getResourceNode(path);
-    if (node != null)
-    {
-      Set<String> requestedAttributes = (Set<String>)options.get(URIConverter.OPTION_REQUESTED_ATTRIBUTES);
-      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_TIME_STAMP))
-      {
-        long stamp = node instanceof CDOResource ? ((CDOResource)node).getTimeStamp() : URIConverter.NULL_TIME_STAMP;
-        result.put(URIConverter.ATTRIBUTE_TIME_STAMP, stamp);
-      }
-
-      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_DIRECTORY))
-      {
-        result.put(URIConverter.ATTRIBUTE_DIRECTORY, node instanceof CDOResourceFolder);
-      }
-
-      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_READ_ONLY))
-      {
-        result.put(URIConverter.ATTRIBUTE_READ_ONLY, view.isReadOnly());
-      }
-    }
-
-    return result;
+    String path = getPath(uri);
+    return getAttributes(view, path, options);
   }
 
   @Override
@@ -180,6 +142,12 @@ public class CDOURIHandler implements URIHandler
     // storing that attribute in the server. Due to CDOResouce distributed nature, changing it wouldn't make much sense.
   }
 
+  void setViewProvider2(CDOViewProvider2 viewProvider2)
+  {
+    this.viewProvider2 = viewProvider2;
+    viewURI = viewProvider2.getViewURI(view);
+  }
+
   private String getPath(URI uri)
   {
     if (CDO_URI_SCHEME.equals(uri.scheme()))
@@ -198,9 +166,76 @@ public class CDOURIHandler implements URIHandler
     return null;
   }
 
-  void setViewProvider2(CDOViewProvider2 viewProvider2)
+  private void modify(URI uri, ResourceNodeModifier modifier) throws IOException
   {
-    this.viewProvider2 = viewProvider2;
-    viewURI = viewProvider2.getViewURI(view);
+    if (view.isHistorical())
+    {
+      throw new IOException("View is historical: " + view);
+    }
+
+    String path = getPath(uri);
+    CDOTransaction transaction = null;
+
+    try
+    {
+      CDOSession session = view.getSession();
+      CDOBranch branch = view.getBranch();
+      transaction = session.openTransaction(branch);
+
+      CDOResourceNode node = transaction.getResourceNode(path);
+      modifier.modify(node);
+
+      CDOCommitInfo commitInfo = transaction.commit();
+      if (commitInfo != null)
+      {
+        view.waitForUpdate(commitInfo.getTimeStamp());
+      }
+    }
+    catch (Exception ex)
+    {
+      throw IOUtil.ioException(ex);
+    }
+    finally
+    {
+      IOUtil.closeSilent(transaction);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  public static Map<String, ?> getAttributes(CDOView view, String path, Map<?, ?> options)
+  {
+    Map<String, Object> result = new HashMap<>();
+
+    CDOResourceNode node = view.getResourceNode(path);
+    if (node != null)
+    {
+      Set<String> requestedAttributes = (Set<String>)options.get(URIConverter.OPTION_REQUESTED_ATTRIBUTES);
+      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_TIME_STAMP))
+      {
+        long stamp = node instanceof CDOResource ? ((CDOResource)node).getTimeStamp() : URIConverter.NULL_TIME_STAMP;
+        result.put(URIConverter.ATTRIBUTE_TIME_STAMP, stamp);
+      }
+
+      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_DIRECTORY))
+      {
+        result.put(URIConverter.ATTRIBUTE_DIRECTORY, node instanceof CDOResourceFolder);
+      }
+
+      if (requestedAttributes == null || requestedAttributes.contains(URIConverter.ATTRIBUTE_READ_ONLY))
+      {
+        result.put(URIConverter.ATTRIBUTE_READ_ONLY, view.isReadOnly());
+      }
+    }
+
+    return result;
+  }
+
+  /**
+   * @author Eike Stepper
+   */
+  @FunctionalInterface
+  private interface ResourceNodeModifier
+  {
+    public void modify(CDOResourceNode node) throws IOException;
   }
 }
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IORunnable.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IORunnable.java
index 7c40dabea0..8876a0bb30 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IORunnable.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IORunnable.java
@@ -16,6 +16,7 @@ import java.io.IOException;
 /**
  * @author Eike Stepper
  */
+@FunctionalInterface
 public interface IORunnable<IO extends Closeable>
 {
   public void run(IO io) throws IOException;
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IOUtil.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IOUtil.java
index 9bb821777f..a55380e4d9 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IOUtil.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/IOUtil.java
@@ -108,6 +108,21 @@ public final class IOUtil
   }
 
   /**
+   * @since 3.13
+   */
+  public static IOException ioException(Exception ex)
+  {
+    if (ex instanceof IOException)
+    {
+      return (IOException)ex;
+    }
+  
+    IOException ioException = new IOException(ex.getMessage());
+    ioException.initCause(ex);
+    return ioException;
+  }
+
+  /**
    * @since 3.1
    */
   public static void print(StackTraceElement[] elements)
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/ReaderInputStream.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/ReaderInputStream.java
new file mode 100644
index 0000000000..b9291ef374
--- /dev/null
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/io/ReaderInputStream.java
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2020 Eike Stepper (Loehne, Germany) 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:
+ *    Eike Stepper - initial API and implementation
+ */
+package org.eclipse.net4j.util.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import java.nio.Buffer;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * An input stream for reading a {@link Reader}.
+ *
+ * @author Eike Stepper
+ * @since 3.13
+ */
+public class ReaderInputStream extends InputStream
+{
+  private static final int MASK = 0xFF;
+
+  private final Charset charset;
+
+  private Reader reader;
+
+  private CharBuffer chars = CharBuffer.allocate(IOUtil.DEFAULT_BUFFER_SIZE);
+
+  private ByteBuffer bytes;
+
+  public ReaderInputStream(Reader reader, String encoding) throws IOException
+  {
+    this.reader = reader;
+    charset = encoding == null ? StandardCharsets.UTF_8 : Charset.forName(encoding);
+  }
+
+  public ReaderInputStream(Reader reader) throws IOException
+  {
+    this(reader, null);
+  }
+
+  @Override
+  public int available() throws IOException
+  {
+    checkClosed();
+    ensureBytes();
+
+    if (bytes == null)
+    {
+      return 0;
+    }
+
+    return bytes.remaining();
+  }
+
+  @Override
+  public int read(byte[] b, int off, int len) throws IOException
+  {
+    checkClosed();
+
+    if (len == 0)
+    {
+      return 0;
+    }
+
+    ensureBytes();
+    if (bytes == null)
+    {
+      return IOUtil.EOF;
+    }
+
+    int count = 0;
+    do
+    {
+      ensureBytes();
+
+      if (bytes == null)
+      {
+        // No more to read.
+        break;
+      }
+
+      int toRead = Math.min(bytes.remaining(), len - count);
+      bytes.get(b, off + count, toRead);
+      count = count + toRead;
+    } while (count < len);
+
+    return count;
+  }
+
+  @Override
+  public int read() throws IOException
+  {
+    checkClosed();
+
+    ensureBytes();
+    if (bytes == null)
+    {
+      return IOUtil.EOF;
+    }
+
+    return bytes.get() & MASK;
+  }
+
+  @Override
+  public void close() throws IOException
+  {
+    if (reader != null)
+    {
+      reader.close();
+      reader = null;
+      bytes = null;
+      chars = null;
+    }
+  }
+
+  private void ensureBytes() throws IOException
+  {
+    if (bytes == null || !bytes.hasRemaining())
+    {
+      checkClosed();
+
+      Buffer buffer = chars;
+      buffer.rewind();
+
+      int count = reader.read(chars);
+      if (count > 0)
+      {
+        buffer.flip();
+        bytes = charset.encode(chars);
+      }
+      else
+      {
+        bytes = null;
+      }
+    }
+  }
+
+  private void checkClosed() throws IOException
+  {
+    if (reader == null)
+    {
+      throw new IOException("Reader is closed"); //$NON-NLS-1$
+    }
+  }
+}