Case Study: adding data and statistics

[ifi-stolz-refaktor.git] / case-study / jdt-after / ui / org / eclipse / jdt / internal / ui / navigator / NonEssentialElementsFilter.java

diff --git a/case-study/jdt-after/ui/org/eclipse/jdt/internal/ui/navigator/NonEssentialElementsFilter.java b/case-study/jdt-after/ui/org/eclipse/jdt/internal/ui/navigator/NonEssentialElementsFilter.java
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+/*******************************************************************************
+ * Copyright (c) 2000, 2011 IBM Corporation 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:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.internal.ui.navigator;
+
+
+import org.eclipse.jface.viewers.IStructuredContentProvider;
+import org.eclipse.jface.viewers.ITreeContentProvider;
+import org.eclipse.jface.viewers.StructuredViewer;
+import org.eclipse.jface.viewers.Viewer;
+import org.eclipse.jface.viewers.ViewerFilter;
+
+import org.eclipse.ui.navigator.CommonViewer;
+import org.eclipse.ui.navigator.IExtensionStateModel;
+import org.eclipse.ui.navigator.INavigatorContentService;
+
+import org.eclipse.jdt.core.IPackageFragment;
+import org.eclipse.jdt.core.JavaModelException;
+
+/**
+ *
+ * This filter is only applicable to instances of the Common Navigator.
+ *
+ * This filter will not allow essential elements to be blocked.
+ */
+public abstract class NonEssentialElementsFilter extends ViewerFilter {
+
+       private static final String JAVA_EXTENSION_ID = "org.eclipse.jdt.java.ui.javaContent"; //$NON-NLS-1$
+
+       private boolean isStateModelInitialized = false;
+       private IExtensionStateModel fStateModel = null;
+
+       private INavigatorContentService fContentService;
+
+       private ViewerFilter fDelegateFilter;
+
+       protected NonEssentialElementsFilter(ViewerFilter delegateFilter) {
+               fDelegateFilter = delegateFilter;
+       }
+
+       /* (non-Javadoc)
+        * @see org.eclipse.jface.viewers.ViewerFilter#select(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
+        */
+       @Override
+       public boolean select(Viewer viewer, Object parent, Object element) {
+               if (!isStateModelInitialized) {
+                       initStateModel(viewer);
+               }
+               if (fContentService == null || fStateModel == null) {
+                       return true;
+               } else if (element instanceof IPackageFragment) {
+                       if (isApplicable() && viewer instanceof StructuredViewer) {
+                               boolean isHierarchicalLayout= !fStateModel.getBooleanProperty(IExtensionStateConstants.Values.IS_LAYOUT_FLAT);
+                               try {
+                                       IPackageFragment fragment = (IPackageFragment) element;
+                                       if (isHierarchicalLayout && !fragment.isDefaultPackage() && fragment.hasSubpackages()) {
+                                               return hasFilteredChildren((StructuredViewer) viewer, fragment);
+                                       }
+                               } catch (JavaModelException e) {
+                                       return false;
+                               }
+                       }
+               }
+               return doSelect(viewer, parent, element);
+       }
+
+       private boolean hasFilteredChildren(StructuredViewer viewer, IPackageFragment fragment) {
+               Object[] children= getRawChildren(viewer, fragment);
+               ViewerFilter[] filters= viewer.getFilters();
+               for (int i= 0; i < filters.length; i++) {
+                       children= filters[i].filter(viewer, fragment, children);
+                       if (children.length == 0)
+                               return false;
+               }
+               return true;
+       }
+
+       private Object[] getRawChildren(StructuredViewer viewer, IPackageFragment fragment) {
+               IStructuredContentProvider provider = (IStructuredContentProvider) viewer.getContentProvider();
+               if (provider instanceof ITreeContentProvider) {
+                       return ((ITreeContentProvider)provider).getChildren(fragment);
+               }
+               return provider.getElements(fragment);
+       }
+
+       protected boolean doSelect(Viewer viewer, Object parent, Object element) {
+               return fDelegateFilter.select(viewer, parent, element);
+       }
+
+       private boolean isApplicable() {
+               return fContentService != null && fContentService.isVisible(JAVA_EXTENSION_ID) && fContentService.isActive(JAVA_EXTENSION_ID);
+       }
+
+       private synchronized void initStateModel(Viewer viewer) {
+               if (!isStateModelInitialized) {
+                       if (viewer instanceof CommonViewer) {
+
+                               CommonViewer commonViewer = (CommonViewer) viewer;
+                               fContentService = commonViewer.getNavigatorContentService();
+                               fStateModel = fContentService.findStateModel(JAVA_EXTENSION_ID);
+
+                               isStateModelInitialized = true;
+                       }
+               }
+       }
+}