[577425] SWTException: Invalid thread access in CDOCompareEditorUtil.createComparisonInput()

https://bugs.eclipse.org/bugs/show_bug.cgi?id=577425

16 files changed, 216 insertions, 114 deletions

diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutLabelProvider.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutLabelProvider.java
index f0dac3886b..b9b25353af 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutLabelProvider.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutLabelProvider.java
@@ -15,6 +15,7 @@ import org.eclipse.emf.cdo.internal.ui.ViewerUtil;
 import org.eclipse.emf.cdo.transfer.CDOTransferElement;
 
 import org.eclipse.net4j.util.StringUtil;
+import org.eclipse.net4j.util.ui.UIUtil;
 import org.eclipse.net4j.util.ui.views.ContainerItemProvider;
 
 import org.eclipse.emf.ecore.EClass;
@@ -226,12 +227,12 @@ public class CDOCheckoutLabelProvider extends LabelProvider implements ICommonLa
   {
     if (object instanceof ViewerUtil.Pending)
     {
-      return ContainerItemProvider.PENDING_IMAGE;
+      return ContainerItemProvider.pendingImage();
     }
 
     if (object instanceof ViewerUtil.Error)
     {
-      return ContainerItemProvider.ERROR_IMAGE;
+      return UIUtil.errorImage();
     }
 
     try
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
index 086541d048..96e7fb4759 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
@@ -361,7 +361,7 @@ public final class CDOCheckoutState
       {
         if (object instanceof ViewerUtil.Pending)
         {
-          return ContainerItemProvider.PENDING_COLOR;
+          return ContainerItemProvider.pendingColor();
         }
 
         if (object instanceof CDOObject)
@@ -508,7 +508,7 @@ public final class CDOCheckoutState
 
           if (element instanceof ViewerUtil.Pending)
           {
-            return ContainerItemProvider.PENDING_IMAGE;
+            return ContainerItemProvider.pendingImage();
           }
 
           if (element instanceof CDOElement)
diff --git a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/internal/ui/bundle/OM.java b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/internal/ui/bundle/OM.java
index c1f8ca4e05..265953e523 100644
--- a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/internal/ui/bundle/OM.java
+++ b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/internal/ui/bundle/OM.java
@@ -10,15 +10,11 @@
  */
 package org.eclipse.emf.cdo.transfer.internal.ui.bundle;
 
-import org.eclipse.emf.cdo.transfer.ui.TransferLabelProvider;
-import org.eclipse.emf.cdo.transfer.ui.swt.TransferDetailsComposite.UnmappedModelsLabelProvider;
-
 import org.eclipse.net4j.util.om.OMBundle;
 import org.eclipse.net4j.util.om.OMPlatform;
 import org.eclipse.net4j.util.om.log.OMLogger;
 import org.eclipse.net4j.util.om.trace.OMTracer;
 import org.eclipse.net4j.util.ui.UIActivator;
-import org.eclipse.net4j.util.ui.UIUtil;
 
 /**
  * The <em>Operations & Maintenance</em> class of this bundle.
@@ -51,12 +47,6 @@ public abstract class OM
     protected void doStart() throws Exception
     {
       INSTANCE = this;
-
-      UIUtil.syncExec(() -> {
-        // Bug 577425: If the classes below are first accessed from a non-UI thread SWT throws "Invalid thread access".
-        TransferLabelProvider.GRAY.isDisposed();
-        UnmappedModelsLabelProvider.GRAY.isDisposed();
-      });
     }
 
     @Override
diff --git a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/TransferLabelProvider.java b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/TransferLabelProvider.java
index ed983127f0..328669951a 100644
--- a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/TransferLabelProvider.java
+++ b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/TransferLabelProvider.java
@@ -37,9 +37,9 @@ import org.eclipse.swt.graphics.Image;
  */
 public class TransferLabelProvider extends LabelProvider implements ITableLabelProvider, ITableColorProvider
 {
-  public static final Color GRAY = UIUtil.getDisplay().getSystemColor(SWT.COLOR_GRAY);
+  public static final Color GRAY = UIUtil.initResource(display -> display.getSystemColor(SWT.COLOR_GRAY));
 
-  public static final Color RED = UIUtil.getDisplay().getSystemColor(SWT.COLOR_RED);
+  public static final Color RED = UIUtil.initResource(display -> display.getSystemColor(SWT.COLOR_RED));
 
   private CDOTransfer transfer;
 
diff --git a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/swt/TransferDetailsComposite.java b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/swt/TransferDetailsComposite.java
index c93216a2f1..37927d327f 100644
--- a/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/swt/TransferDetailsComposite.java
+++ b/plugins/org.eclipse.emf.cdo.transfer.ui/src/org/eclipse/emf/cdo/transfer/ui/swt/TransferDetailsComposite.java
@@ -587,9 +587,11 @@ public class TransferDetailsComposite extends Composite implements IListener
    */
   public static class UnmappedModelsLabelProvider extends LabelProvider implements IColorProvider
   {
-    public static final Color GRAY = UIUtil.getDisplay().getSystemColor(SWT.COLOR_GRAY);
+    @Deprecated
+    public static final Color GRAY = null;
 
-    public static final Color RED = UIUtil.getDisplay().getSystemColor(SWT.COLOR_RED);
+    @Deprecated
+    public static final Color RED = null;
 
     private CDOTransfer transfer;
 
@@ -627,11 +629,11 @@ public class TransferDetailsComposite extends Composite implements IListener
         ModelTransferResolution resolution = context.getResolution(uri);
         if (resolution != null) // TODO Test type of resolution
         {
-          return GRAY;
+          return UIUtil.grayColor();
         }
       }
 
-      return RED;
+      return UIUtil.redColor();
     }
 
     @Override
diff --git a/plugins/org.eclipse.emf.cdo.ui.compare/META-INF/MANIFEST.MF b/plugins/org.eclipse.emf.cdo.ui.compare/META-INF/MANIFEST.MF
index 8b9a7cdd62..dfabc23b77 100644
--- a/plugins/org.eclipse.emf.cdo.ui.compare/META-INF/MANIFEST.MF
+++ b/plugins/org.eclipse.emf.cdo.ui.compare/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.emf.cdo.ui.compare;singleton:=true
-Bundle-Version: 4.6.3.qualifier
+Bundle-Version: 4.7.0.qualifier
 Bundle-Activator: org.eclipse.emf.cdo.ui.internal.compare.bundle.OM$Activator
 Bundle-Vendor: %providerName
 Bundle-ClassPath: .
@@ -21,7 +21,7 @@ Import-Package: com.google.common.base;version="[27.0.0,30.2.0)",
  com.google.common.collect;version="[27.0.0,30.2.0)",
  com.google.common.cache;version="[27.0.0,30.2.0)",
  com.google.common.util.concurrent;version="[27.0.0,30.2.0)"
-Export-Package: org.eclipse.emf.cdo.ui.compare;version="4.6.3",
- org.eclipse.emf.cdo.ui.internal.compare;version="4.6.3";x-friends:="org.eclipse.emf.cdo.explorer.ui",
- org.eclipse.emf.cdo.ui.internal.compare.bundle;version="4.6.3";x-internal:=true
+Export-Package: org.eclipse.emf.cdo.ui.compare;version="4.7.0",
+ org.eclipse.emf.cdo.ui.internal.compare;version="4.7.0";x-friends:="org.eclipse.emf.cdo.explorer.ui",
+ org.eclipse.emf.cdo.ui.internal.compare.bundle;version="4.7.0";x-internal:=true
 Automatic-Module-Name: org.eclipse.emf.cdo.ui.compare
diff --git a/plugins/org.eclipse.emf.cdo.ui.compare/pom.xml b/plugins/org.eclipse.emf.cdo.ui.compare/pom.xml
index 5512332f7c..4e24f1b829 100644
--- a/plugins/org.eclipse.emf.cdo.ui.compare/pom.xml
+++ b/plugins/org.eclipse.emf.cdo.ui.compare/pom.xml
@@ -25,7 +25,7 @@
 
   <groupId>org.eclipse.emf.cdo</groupId>
   <artifactId>org.eclipse.emf.cdo.ui.compare</artifactId>
-  <version>4.6.3-SNAPSHOT</version>
+  <version>4.7.0-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
 
 </project>
diff --git a/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/compare/CDOCompareEditorUtil.java b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/compare/CDOCompareEditorUtil.java
index ae46604f22..d7dee71ad9 100644
--- a/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/compare/CDOCompareEditorUtil.java
+++ b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/compare/CDOCompareEditorUtil.java
@@ -96,8 +96,10 @@ public final class CDOCompareEditorUtil
 {
   /**
    * @since 4.6
+   * @deprecated As of 4.7 use {@link #compareImage()}.
    */
-  public static final Image COMPARE_IMAGE = OM.getImage("icons/compare.gif");
+  @Deprecated
+  public static final Image COMPARE_IMAGE = null;
 
   /**
    * @since 4.4
@@ -119,11 +121,26 @@ public final class CDOCompareEditorUtil
 
   private static final ThreadLocal<List<Runnable>> DISPOSE_RUNNABLES = new ThreadLocal<>();
 
+  private static Image compareImage;
+
   private CDOCompareEditorUtil()
   {
   }
 
   /**
+   * @since 4.7
+   */
+  public static Image compareImage()
+  {
+    if (compareImage == null)
+    {
+      compareImage = OM.getImage("icons/compare.gif");
+    }
+
+    return compareImage;
+  }
+
+  /**
    * @since 4.4
    */
   public static void closeTransactionAfterCommit(CDOTransaction transaction)
@@ -849,7 +866,7 @@ public final class CDOCompareEditorUtil
     @Override
     public Image getTitleImage()
     {
-      return COMPARE_IMAGE;
+      return compareImage();
     }
 
     public void setDisposeRunnables(List<Runnable> disposeRunnables)
diff --git a/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/bundle/OM.java b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/bundle/OM.java
index 15086e27b5..a6be4c1f42 100644
--- a/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/bundle/OM.java
+++ b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/bundle/OM.java
@@ -11,14 +11,11 @@
  */
 package org.eclipse.emf.cdo.ui.internal.compare.bundle;
 
-import org.eclipse.emf.cdo.ui.compare.CDOCompareEditorUtil;
-
 import org.eclipse.net4j.util.om.OMBundle;
 import org.eclipse.net4j.util.om.OMPlatform;
 import org.eclipse.net4j.util.om.log.OMLogger;
 import org.eclipse.net4j.util.om.trace.OMTracer;
 import org.eclipse.net4j.util.ui.UIActivator;
-import org.eclipse.net4j.util.ui.UIUtil;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.edit.ui.provider.ExtendedImageRegistry;
@@ -68,14 +65,5 @@ public abstract class OM
       super(BUNDLE);
       INSTANCE = this;
     }
-
-    @Override
-    protected void doStart() throws Exception
-    {
-      UIUtil.syncExec(() -> {
-        // Bug 577425: If the classes below are first accessed from a non-UI thread SWT throws "Invalid thread access".
-        CDOCompareEditorUtil.COMPARE_IMAGE.isDisposed();
-      });
-    }
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/bundle/OM.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/bundle/OM.java
index 1d686e8488..57256e95e3 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/bundle/OM.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/bundle/OM.java
@@ -11,10 +11,8 @@
  */
 package org.eclipse.emf.cdo.internal.ui.bundle;
 
-import org.eclipse.emf.cdo.internal.ui.dialogs.PackageRegistryDialog;
 import org.eclipse.emf.cdo.ui.CDOEditorOpener;
 import org.eclipse.emf.cdo.ui.CDOLabelDecorator;
-import org.eclipse.emf.cdo.ui.CDOLabelProvider;
 import org.eclipse.emf.cdo.ui.OverlayImage;
 
 import org.eclipse.net4j.util.om.OMBundle;
@@ -24,7 +22,6 @@ import org.eclipse.net4j.util.om.pref.OMPreference;
 import org.eclipse.net4j.util.om.pref.OMPreferences;
 import org.eclipse.net4j.util.om.trace.OMTracer;
 import org.eclipse.net4j.util.ui.UIActivator;
-import org.eclipse.net4j.util.ui.UIUtil;
 
 import org.eclipse.emf.common.CommonPlugin;
 import org.eclipse.emf.common.util.URI;
@@ -151,12 +148,6 @@ public abstract class OM
     protected void doStart() throws Exception
     {
       CDOEditorOpener.Registry.INSTANCE.activate();
-
-      UIUtil.syncExec(() -> {
-        // Bug 577425: If the classes below are first accessed from a non-UI thread SWT throws "Invalid thread access".
-        PackageRegistryDialog.PRODUCT_GROUP.toString();
-        CDOLabelProvider.getColor(null);
-      });
     }
 
     @Override
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/dialogs/PackageRegistryDialog.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/dialogs/PackageRegistryDialog.java
index d7953cf21f..a3ac33b886 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/dialogs/PackageRegistryDialog.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/dialogs/PackageRegistryDialog.java
@@ -65,8 +65,6 @@ public class PackageRegistryDialog extends TitleAreaDialog
 
   private static final String TITLE = Messages.getString("PackageRegistryDialog.0"); //$NON-NLS-1$
 
-  private static final Color GRAY = UIUtil.getDisplay().getSystemColor(SWT.COLOR_GRAY);
-
   private IWorkbenchPage page;
 
   private CDOSession session;
@@ -306,7 +304,7 @@ public class PackageRegistryDialog extends TitleAreaDialog
         return null;
       }
 
-      return GRAY;
+      return UIUtil.grayColor();
     }
   }
 
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOEditor.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOEditor.java
index b27c725e34..2519dd2a29 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOEditor.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/editor/CDOEditor.java
@@ -1653,7 +1653,7 @@ public class CDOEditor extends MultiPageEditorPart implements IEditingDomainProv
         {
           if (element instanceof ViewerUtil.Pending)
           {
-            return ContainerItemProvider.PENDING_IMAGE;
+            return ContainerItemProvider.pendingImage();
           }
 
           Image image = super.getImage(element);
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOLabelProvider.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOLabelProvider.java
index 873f142ad1..776adaf975 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOLabelProvider.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOLabelProvider.java
@@ -33,8 +33,6 @@ import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.widgets.Control;
-import org.eclipse.ui.ISharedImages;
-import org.eclipse.ui.PlatformUI;
 
 /**
  * A {@link org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider AdapterFactoryLabelProvider} specialization
@@ -49,13 +47,7 @@ import org.eclipse.ui.PlatformUI;
  */
 public class CDOLabelProvider extends AdapterFactoryLabelProvider implements IColorProvider, IFontProvider
 {
-  private static final Color COLOR_PERMISSION_NONE = UIUtil.getDisplay().getSystemColor(SWT.COLOR_GRAY);
-
-  private static final Color COLOR_PERMISSION_READ = UIUtil.getDisplay().getSystemColor(SWT.COLOR_DARK_CYAN);
-
-  private static final Color COLOR_CONFLICT = UIUtil.getDisplay().getSystemColor(SWT.COLOR_RED);
-
-  private static final Image ERROR_IMAGE = PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJS_ERROR_TSK);
+  private static Color readPermissionColor;
 
   private Font bold;
 
@@ -132,7 +124,7 @@ public class CDOLabelProvider extends AdapterFactoryLabelProvider implements ICo
     }
     catch (Exception ex)
     {
-      return ERROR_IMAGE;
+      return getErrorImage();
     }
   }
 
@@ -222,17 +214,17 @@ public class CDOLabelProvider extends AdapterFactoryLabelProvider implements ICo
       {
         if (object.cdoConflict())
         {
-          return COLOR_CONFLICT;
+          return getConflictColor();
         }
 
         CDOPermission permission = object.cdoPermission();
         switch (permission)
         {
         case NONE:
-          return COLOR_PERMISSION_NONE;
+          return getNoPermissionColor();
 
         case READ:
-          return COLOR_PERMISSION_READ;
+          return getReadPermissionColor();
 
         default:
           //$FALL-THROUGH$
@@ -246,4 +238,29 @@ public class CDOLabelProvider extends AdapterFactoryLabelProvider implements ICo
     // Use default
     return null;
   }
+
+  private static Color getNoPermissionColor()
+  {
+    return UIUtil.grayColor();
+  }
+
+  private static Color getReadPermissionColor()
+  {
+    if (readPermissionColor == null)
+    {
+      readPermissionColor = UIUtil.getDisplay().getSystemColor(SWT.COLOR_DARK_CYAN);
+    }
+
+    return readPermissionColor;
+  }
+
+  private static Color getConflictColor()
+  {
+    return UIUtil.redColor();
+  }
+
+  private static Image getErrorImage()
+  {
+    return UIUtil.errorImage();
+  }
 }
diff --git a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/internal/ui/bundle/OM.java b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/internal/ui/bundle/OM.java
index 699d60476c..2b0f279f4d 100644
--- a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/internal/ui/bundle/OM.java
+++ b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/internal/ui/bundle/OM.java
@@ -15,8 +15,6 @@ import org.eclipse.net4j.util.om.OMPlatform;
 import org.eclipse.net4j.util.om.log.OMLogger;
 import org.eclipse.net4j.util.om.trace.OMTracer;
 import org.eclipse.net4j.util.ui.UIActivator;
-import org.eclipse.net4j.util.ui.UIUtil;
-import org.eclipse.net4j.util.ui.views.ContainerItemProvider;
 
 import org.eclipse.jface.resource.ImageDescriptor;
 
@@ -52,16 +50,5 @@ public abstract class OM
       super(BUNDLE);
       INSTANCE = this;
     }
-
-    @Override
-    protected void doStart() throws Exception
-    {
-      UIUtil.syncExec(() -> {
-        // Bug 577425: If the classes below are first accessed from a non-UI thread SWT throws "Invalid thread access".
-        ContainerItemProvider.PENDING_COLOR.isDisposed();
-        ContainerItemProvider.PENDING_IMAGE.isDisposed();
-        ContainerItemProvider.ERROR_IMAGE.isDisposed();
-      });
-    }
   }
 }
diff --git a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/UIUtil.java b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/UIUtil.java
index 71121d8974..166060bde1 100644
--- a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/UIUtil.java
+++ b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/UIUtil.java
@@ -50,6 +50,7 @@ import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Widget;
+import org.eclipse.ui.ISharedImages;
 import org.eclipse.ui.IViewSite;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.IWorkbenchPage;
@@ -63,6 +64,7 @@ import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
+import java.util.function.Function;
 
 /**
  * @author Eike Stepper
@@ -74,11 +76,56 @@ public final class UIUtil
    */
   public static final String ERROR_LOG_ID = "org.eclipse.pde.runtime.LogView"; //$NON-NLS-1$
 
+  private static Color redColor;
+
+  private static Color grayColor;
+
+  private static Image errorImage;
+
   private UIUtil()
   {
   }
 
   /**
+   * @since 3.12
+   */
+  public static Color redColor()
+  {
+    if (redColor == null)
+    {
+      redColor = UIUtil.getDisplay().getSystemColor(SWT.COLOR_RED);
+    }
+
+    return redColor;
+  }
+
+  /**
+   * @since 3.12
+   */
+  public static Color grayColor()
+  {
+    if (grayColor == null)
+    {
+      grayColor = UIUtil.getDisplay().getSystemColor(SWT.COLOR_GRAY);
+    }
+
+    return grayColor;
+  }
+
+  /**
+   * @since 3.12
+   */
+  public static Image errorImage()
+  {
+    if (errorImage == null)
+    {
+      errorImage = PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJS_ERROR_TSK);
+    }
+
+    return errorImage;
+  }
+
+  /**
    * @since 3.1
    */
   public static void copyToClipboard(Display display, String text)
@@ -563,6 +610,34 @@ public final class UIUtil
   }
 
   /**
+   * @since 3.12
+   */
+  public static <T> T initResource(Function<Display, T> initializer)
+  {
+    Display display = getDisplay();
+    if (display == null)
+    {
+      OM.LOG.warn("Display is not available");
+      return null;
+    }
+
+    Object[] result = { null };
+
+    try
+    {
+      syncExec(() -> result[0] = initializer.apply(display));
+    }
+    catch (Throwable ex)
+    {
+      OM.LOG.warn(ex);
+    }
+
+    @SuppressWarnings("unchecked")
+    T value = (T)result[0];
+    return value;
+  }
+
+  /**
    * @since 3.5
    */
   public static void syncExec(Runnable runnable)
diff --git a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/views/ContainerItemProvider.java b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/views/ContainerItemProvider.java
index 815e4dfe4a..6752da382d 100644
--- a/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/views/ContainerItemProvider.java
+++ b/plugins/org.eclipse.net4j.util.ui/src/org/eclipse/net4j/util/ui/views/ContainerItemProvider.java
@@ -52,20 +52,9 @@ import java.util.Objects;
  */
 public class ContainerItemProvider<CONTAINER extends IContainer<Object>> extends ItemProvider<CONTAINER>
 {
-  /**
-   * @since 3.5
-   */
-  public static final Color PENDING_COLOR = UIUtil.getDisplay().getSystemColor(SWT.COLOR_DARK_GRAY);
+  private static Color pendingColor;
 
-  /**
-   * @since 3.5
-   */
-  public static final Image PENDING_IMAGE = SharedIcons.getImage(SharedIcons.OBJ_PENDING);
-
-  /**
-   * @since 3.5
-   */
-  public static final Image ERROR_IMAGE = SharedIcons.getImage(SharedIcons.OBJ_ERROR);
+  private static Image pendingImage;
 
   private Map<Object, Node> nodes = new HashMap<>();
 
@@ -410,7 +399,7 @@ public class ContainerItemProvider<CONTAINER extends IContainer<Object>> extends
   {
     if (obj instanceof ContainerItemProvider.SlowElement)
     {
-      return PENDING_COLOR;
+      return pendingColor();
     }
 
     return super.getForeground(obj);
@@ -421,18 +410,44 @@ public class ContainerItemProvider<CONTAINER extends IContainer<Object>> extends
   {
     if (obj instanceof ContainerItemProvider.SlowElement)
     {
-      return PENDING_IMAGE;
+      return pendingImage();
     }
 
     if (obj instanceof ContainerItemProvider.ErrorElement)
     {
-      return ERROR_IMAGE;
+      return UIUtil.errorImage();
     }
 
     return super.getImage(obj);
   }
 
   /**
+   * @since 3.12
+   */
+  public static Color pendingColor()
+  {
+    if (pendingColor == null)
+    {
+      pendingColor = UIUtil.getDisplay().getSystemColor(SWT.COLOR_DARK_GRAY);
+    }
+
+    return pendingColor;
+  }
+
+  /**
+   * @since 3.12
+   */
+  public static Image pendingImage()
+  {
+    if (pendingImage == null)
+    {
+      pendingImage = SharedIcons.getImage(SharedIcons.OBJ_PENDING);
+    }
+
+    return pendingImage;
+  }
+
+  /**
    * @since 3.5
    */
   public static IContainer<Object> createSlowInput(final String text)
@@ -970,6 +985,31 @@ public class ContainerItemProvider<CONTAINER extends IContainer<Object>> extends
   /**
    * @author Eike Stepper
    * @since 3.1
+   */
+  public class ErrorElement
+  {
+    private IContainer<Object> container;
+
+    public ErrorElement(IContainer<Object> container)
+    {
+      this.container = container;
+    }
+
+    public IContainer<Object> getContainer()
+    {
+      return container;
+    }
+
+    @Override
+    public String toString()
+    {
+      return getErrorText(container);
+    }
+  }
+
+  /**
+   * @author Eike Stepper
+   * @since 3.1
    * @deprecated As of 3.5 use {@link SlowElement}.
    */
   @Deprecated
@@ -990,27 +1030,23 @@ public class ContainerItemProvider<CONTAINER extends IContainer<Object>> extends
   }
 
   /**
-   * @author Eike Stepper
-   * @since 3.1
+   * @since 3.5
+   * @deprecated As of 3.12 use {@link #pendingColor()}.
    */
-  public class ErrorElement
-  {
-    private IContainer<Object> container;
-
-    public ErrorElement(IContainer<Object> container)
-    {
-      this.container = container;
-    }
+  @Deprecated
+  public static final Color PENDING_COLOR = UIUtil.getDisplay().getSystemColor(SWT.COLOR_DARK_GRAY);
 
-    public IContainer<Object> getContainer()
-    {
-      return container;
-    }
+  /**
+   * @since 3.5
+   * @deprecated As of 3.12 use {@link #pendingImage()}.
+   */
+  @Deprecated
+  public static final Image PENDING_IMAGE = SharedIcons.getImage(SharedIcons.OBJ_PENDING);
 
-    @Override
-    public String toString()
-    {
-      return getErrorText(container);
-    }
-  }
+  /**
+   * @since 3.5
+   * @deprecated As of 3.12 use {@link UIUtil#errorImage()}.
+   */
+  @Deprecated
+  public static final Image ERROR_IMAGE = SharedIcons.getImage(SharedIcons.OBJ_ERROR);
 }