1 files changed, 167 insertions, 0 deletions
diff --git a/bundles/org.eclipse.wst.jsdt.ui/src/org/eclipse/wst/jsdt/internal/ui/navigator/deferred/LoadingModelNode.java b/bundles/org.eclipse.wst.jsdt.ui/src/org/eclipse/wst/jsdt/internal/ui/navigator/deferred/LoadingModelNode.java
new file mode 100644
index 00000000..5f16a002
--- /dev/null
+++ b/bundles/org.eclipse.wst.jsdt.ui/src/org/eclipse/wst/jsdt/internal/ui/navigator/deferred/LoadingModelNode.java
@@ -0,0 +1,167 @@
+/*******************************************************************************
+ * Copyright (c) 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.wst.jsdt.internal.ui.navigator.deferred;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.eclipse.jface.resource.ImageDescriptor;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.wst.jsdt.internal.ui.JavaPluginImages;
+import org.eclipse.wst.jsdt.internal.ui.packageview.PackageFragmentRootContainer;
+import org.eclipse.wst.jsdt.internal.ui.packageview.PackagesMessages;
+
+public class LoadingModelNode {
+	
+	private static ImageDescriptor loadingOne;
+	private static ImageDescriptor loadingTwo;
+	private static ImageDescriptor loadingThree;
+	private static ImageDescriptor loadingFour;
+	
+	private static final Set loadingFiles = new HashSet();
+	private static final Map placeHolders = new HashMap();
+
+	static {
+		try {
+			loadingOne = JavaPluginImages.DESC_TOOL_LOADING_1;
+			loadingTwo = JavaPluginImages.DESC_TOOL_LOADING_2;
+			loadingThree = JavaPluginImages.DESC_TOOL_LOADING_3;
+			loadingFour = JavaPluginImages.DESC_TOOL_LOADING_4;
+		} catch (RuntimeException e) {
+			loadingOne = ImageDescriptor.getMissingImageDescriptor();
+			loadingTwo = ImageDescriptor.getMissingImageDescriptor();
+			loadingThree = ImageDescriptor.getMissingImageDescriptor();
+			loadingFour = ImageDescriptor.getMissingImageDescriptor();
+		}
+	}
+ 
+	private String text; 
+	private String text1;
+	private String text2;
+	private String text3;
+	private int count = 0; 
+	private boolean disposed = false;
+	private PackageFragmentRootContainer packageFragmentRootContainer;
+	
+	/**
+	 * Return a place holder node to sit in the tree until data is available.
+	 * This place holder node will be animated for the user's enjoyment. 
+	 *  
+	 * @param modelFile The modelFile to be loaded
+	 * @return A new unique place holder for this file for a given load cycle
+	 */
+	public static LoadingModelNode createPlaceHolder(PackageFragmentRootContainer packageFragmentRootContainer) {
+		LoadingModelNode node = null;
+		synchronized (LoadingModelNode.class) {
+			if(placeHolders.containsKey(packageFragmentRootContainer))
+				node = (LoadingModelNode) placeHolders.get(packageFragmentRootContainer);
+			else 			
+				placeHolders.put(packageFragmentRootContainer, node = new LoadingModelNode(packageFragmentRootContainer));
+		}
+		return node;
+	}
+	
+	public LoadingModelNode(PackageFragmentRootContainer packageFragmentRootContainer) {
+		text = PackagesMessages.LoadingJavaScriptNode;
+		text1 = text  + "."; //$NON-NLS-1$
+		text2 = text  + ".."; //$NON-NLS-1$
+		text3 = text  + "..."; //$NON-NLS-1$
+		this.packageFragmentRootContainer = packageFragmentRootContainer;
+	}
+
+	public String getText() {
+
+		switch ( count % 4) {
+			case 0 :
+				return text;
+			case 1 :
+				return text1;
+			case 2 :
+				return text2;
+			case 3 :
+			default :
+				return text3;
+		} 
+	}
+
+	public Image getImage() {
+		switch ( count = (++count % 4)) {
+			case 0 :
+				return loadingOne.createImage();
+			case 1 :
+				return loadingTwo.createImage();
+			case 2 :
+				return loadingThree.createImage();
+			case 3 :
+			default :
+				return loadingFour.createImage();
+		}
+	}  
+	
+	public boolean isDisposed() {
+		return disposed;
+	}
+	
+	public void dispose() {
+		synchronized (LoadingModelNode.class) {
+			disposed = true;
+			placeHolders.remove(packageFragmentRootContainer);	
+			loadingFiles.remove(packageFragmentRootContainer);
+		}
+	}
+
+	/**
+	 * Employ a Test and Set (TST) primitive to ensure 
+	 * that only job is spawned to load the model file
+	 *   
+	 * 
+	 * @return True only if no other jobs are trying to load this model.
+	 */
+	public static boolean canBeginLoading(PackageFragmentRootContainer packageFragmentRootContainer) {
+		synchronized (LoadingModelNode.class) {  
+			if(loadingFiles.contains(packageFragmentRootContainer))
+				return false;
+			loadingFiles.add(packageFragmentRootContainer);
+			return true;
+		}
+
+	}
+
+	/**
+	 * Return true if a job has requested permission to load the model file   
+	 * @param modelFile The model file that should be loaded
+	 * @return True only if a job is trying to load the model.
+	 */
+	public static boolean isBeingLoaded(PackageFragmentRootContainer packageFragmentRootContainer) {
+		synchronized (LoadingModelNode.class) {  
+			return loadingFiles.contains(packageFragmentRootContainer);
+		}
+	}
+	
+	
+	public int hashCode() {	
+		return packageFragmentRootContainer.hashCode();
+	}
+	  
+	public boolean equals(Object o) {
+		if(o instanceof LoadingModelNode) {
+			return packageFragmentRootContainer.equals( ((LoadingModelNode)o).packageFragmentRootContainer );
+		}
+		return false; 
+	}
+
+	public String toString() {
+		return "LoadingModelNode for " + packageFragmentRootContainer.getLabel(); //$NON-NLS-1$
+	}
+
+}