jsf/plugins/org.eclipse.jst.jsf.core/src/org/eclipse/jst/jsf/designtime/internal/view/AbstractDTViewHandler.java - jsf/webtools.jsf - Git at Google

 /*******************************************************************************
  * Copyright (c) 2001, 2008 Oracle 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:
  *     Oracle Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jst.jsf.designtime.internal.view;

 import java.util.Collections;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.jst.jsf.common.internal.resource.ImmutableLifecycleListener;
 import org.eclipse.jst.jsf.common.runtime.internal.model.component.ComponentTypeInfo;
 import org.eclipse.jst.jsf.context.symbol.ISymbol;
 import org.eclipse.jst.jsf.designtime.context.DTFacesContext;
 import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.StalenessAdvisor;
 import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.StalenessListener;
 import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.VersionStamp;
 import org.eclipse.jst.jsf.designtime.internal.view.IDTViewHandler.ViewHandlerException.Cause;
 import org.eclipse.wst.common.componentcore.ComponentCore;

 /**
  * All IDTViewHandler's must sub-class this abstract class.
  *
  * @author cbateman
  *
  */
 public abstract class AbstractDTViewHandler implements IDTViewHandler
 {
     private final AtomicBoolean _isDisposed    = new AtomicBoolean(false);

     /**
      * the path separator
      */
     public static final String  PATH_SEPARATOR = "/"; //$NON-NLS-1$

     public abstract String calculateLocale(DTFacesContext context)
             throws ViewHandlerException;

     public final DTUIViewRoot createView(final DTFacesContext facesContext,
             final String viewId) throws ViewHandlerException
     {
         if (_isDisposed.get())
         {
             throw new IllegalStateException("View handler is disposed"); //$NON-NLS-1$
         }

         final DTUIViewRoot viewRoot = internalCreateView(facesContext, viewId);

         if (viewRoot == null)
         {
             throw new ViewHandlerException("Problem in createView", Cause.UNABLE_TO_CREATE_VIEW); //$NON-NLS-1$
         }
         viewRoot.setViewId(viewId);
         final VersionStamp versionStamp = createVersionStamp(facesContext,
                 viewId);
         if (versionStamp == null)
         {
             throw new ViewHandlerException(new Throwable(
                     "Bad version stamp detected"), Cause.BAD_VERSION_STAMP); //$NON-NLS-1$
         }
         viewRoot.setVersionStamp(versionStamp);

         final StalenessAdvisor advisor = createStalenessAdvisor(viewRoot,
                 facesContext, viewId);

         if (advisor == null)
         {
             throw new ViewHandlerException(new Throwable(
                     "Bad staleness advisor"), Cause.BAD_STALENESS_ADVISOR); //$NON-NLS-1$
         }
         viewRoot.setStalenessAdvisor(advisor);

         // lock down the tree
         viewRoot.setSubtreeProtected();

         registerView(viewRoot, facesContext, viewId);

         return viewRoot;
     }

     /**
      * @param facesContext
      * @param viewId
      * @return internal construction of the view root.
      */
     protected abstract DTUIViewRoot internalCreateView(
             final DTFacesContext facesContext, final String viewId);

     public abstract IResource getActionDefinition(DTFacesContext context,
             String viewId) throws ViewHandlerException;

     public abstract IPath getActionURL(DTFacesContext context,
             IResource resource, IPath requestPath) throws ViewHandlerException;

     public abstract IPath getRelativeActionPath(DTFacesContext context,
             String relativeToViewId, String uri) throws ViewHandlerException;

     public abstract IViewDefnAdapterFactory getViewMetadataAdapterFactory(
             DTFacesContext context) throws ViewHandlerException;

     public abstract boolean supportsViewDefinition(IFile file);


     public abstract void setLifecycleListener(ImmutableLifecycleListener listener);

     public final void dispose()
     {
         if (_isDisposed.compareAndSet(false, true))
         {
             doDispose();
         }
     }

     /**
      * Sub-classes should override to add disposal tasks
      */
     protected void doDispose()
     {
         // do nothing by default
     }

     /**
      * IMPORTANT: this method must not return null. All view creation will fail
      * for this handler when createVersionStamp() returns null. create() will
      * throw ViewHandlerException.
      *
      * @param facesContext
      * @param viewId
      * @return a new version stamp for the facesContext/viewId. The version
      *         stamp needs to be unique for all instances of viewId only, not
      *         all instances of component trees everywhere in the system.
      */
     protected abstract VersionStamp createVersionStamp(
             final DTFacesContext facesContext, final String viewId);

     /**
      * IMPORTANT: this method must not return null. All view creation will fail
      * for this handler when createStalenessAdvisor returns null.
      *
      * @param viewRoot
      * @param facesContext
      * @param viewId
      * @return a new staleness advisor.
      */
     protected abstract StalenessAdvisor createStalenessAdvisor(
             final DTUIViewRoot viewRoot, DTFacesContext facesContext,
             String viewId);

     /**
      * Called by createView immediately before returning.  Provides sub-class
      * a chance to register a fully initialized view root with any stateful
      * activities such as automatic change tracking and caching.
      *
      * @param viewRoot
      * @param context
      * @param viewId
      */
     protected void registerView(DTUIViewRoot viewRoot, final DTFacesContext context, final String viewId)
     {
         // do nothing by default
     }

     public String getViewId(final DTFacesContext context, final IResource res)
     {
         // TODO: sync with WebrootUtil?
         String strWebrootPath = ""; //$NON-NLS-1$
         final IProject project = res.getProject();
         final IPath path = res.getFullPath();
         final IPath webContentPath = getWebContentPath(project);
         if (webContentPath != null && webContentPath.isPrefixOf(path))
         {
             final int start = path.matchingFirstSegments(webContentPath);
             final String[] segments = path.segments();
             for (int i = start, n = path.segmentCount(); i < n; i++)
             {
                 strWebrootPath = strWebrootPath + PATH_SEPARATOR + segments[i];
             }
         }
         return strWebrootPath;
     }

     private IPath getWebContentPath(final IProject project)
     {
         if (project != null)
         {
             return ComponentCore.createComponent(project).getRootFolder()
                     .getUnderlyingFolder().getFullPath();
         }
         return null;
     }

     /**
      * A default DTUIViewRoot that represents an uncreatable or uninitializable
      * view root.
      *
      */
     protected static final class NullViewRoot extends DTUIViewRoot
     {
         /**
          *
          */
         private static final long serialVersionUID = 1187035338610719171L;

         /**
          */
         protected NullViewRoot()
         {
             super(null, null, new ComponentTypeInfo("", "", "","")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
         }

         @Override
         public IAdaptable getServices()
         {
             return new IAdaptable()
             {
                 public Object getAdapter(Class adapter)
                 {
                     // no services
                     return null;
                 }
             };
         }

 		@Override
 		protected Map<String, ISymbol> doGetMapForScope(int scopeMask) {
 			return Collections.emptyMap();
 		}

     }

     /**
      * Provides a simple time-based stamp that makes almost impossible to create
      * the same timestamp twice. To do so, two threads would need to get the
      * same system simulataneously and get same number back from the same
      * gaussian distribution.
      *
      * @author cbateman
      *
      */
     protected static class TimeBasedVersionStamp extends VersionStamp
     {
         /**
          *
          */
         private static final long serialVersionUID = 5557828245936568977L;
         private final long        timestamp;
         private final long        randomStamp;

         /**
          *
          */
         public TimeBasedVersionStamp()
         {
             super();
             // use the millisecond time, since it is offset from a known
             // point on all platform, whereas no guarantee is made about
             // the nano time value.
             this.timestamp = System.currentTimeMillis();
             // this protects against two threads constructing two time
             // stamp objects "simulataneously" and having the same time based
             // stamp. Math.random is thread-safe.
             this.randomStamp = (long) (Long.MAX_VALUE * Math.random());
         }

         @Override
         public int hashCode()
         {
             return (int) (timestamp ^ randomStamp);
         }

         @Override
         protected boolean isEqual(final VersionStamp other)
         {
             return other instanceof TimeBasedVersionStamp
                     && (timestamp == ((TimeBasedVersionStamp) other).timestamp)
                     && (randomStamp == ((TimeBasedVersionStamp) other).randomStamp);
         }
     }

     /**
      * Returns a default staleness advisor that always returns false.
      *
      * @author cbateman
      *
      */
     protected static final class NullStalenessAdvisor extends StalenessAdvisor
     {
         /**
          *
          */
         private static final long serialVersionUID = 5946420948320047613L;

         @Override
         public boolean isStale()
         {
             return false;
         }

         @Override
         public void addListener(final StalenessListener listener)
         {
             // do nothing
         }

         @Override
         public void removeListener(final StalenessListener listener)
         {
             // do nothing
         }

         public boolean isAccessible()
         {
             return true;
         }
     }
 }
	/*******************************************************************************
	* Copyright (c) 2001, 2008 Oracle 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:
	* Oracle Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jst.jsf.designtime.internal.view;

	import java.util.Collections;
	import java.util.Map;
	import java.util.concurrent.atomic.AtomicBoolean;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.jst.jsf.common.internal.resource.ImmutableLifecycleListener;
	import org.eclipse.jst.jsf.common.runtime.internal.model.component.ComponentTypeInfo;
	import org.eclipse.jst.jsf.context.symbol.ISymbol;
	import org.eclipse.jst.jsf.designtime.context.DTFacesContext;
	import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.StalenessAdvisor;
	import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.StalenessListener;
	import org.eclipse.jst.jsf.designtime.internal.view.DTUIViewRoot.VersionStamp;
	import org.eclipse.jst.jsf.designtime.internal.view.IDTViewHandler.ViewHandlerException.Cause;
	import org.eclipse.wst.common.componentcore.ComponentCore;

	/**
	* All IDTViewHandler's must sub-class this abstract class.
	*
	* @author cbateman
	*
	*/
	public abstract class AbstractDTViewHandler implements IDTViewHandler
	{
	private final AtomicBoolean _isDisposed = new AtomicBoolean(false);

	/**
	* the path separator
	*/
	public static final String PATH_SEPARATOR = "/"; //$NON-NLS-1$

	public abstract String calculateLocale(DTFacesContext context)
	throws ViewHandlerException;

	public final DTUIViewRoot createView(final DTFacesContext facesContext,
	final String viewId) throws ViewHandlerException
	{
	if (_isDisposed.get())
	{
	throw new IllegalStateException("View handler is disposed"); //$NON-NLS-1$
	}

	final DTUIViewRoot viewRoot = internalCreateView(facesContext, viewId);

	if (viewRoot == null)
	{
	throw new ViewHandlerException("Problem in createView", Cause.UNABLE_TO_CREATE_VIEW); //$NON-NLS-1$
	}
	viewRoot.setViewId(viewId);
	final VersionStamp versionStamp = createVersionStamp(facesContext,
	viewId);
	if (versionStamp == null)
	{
	throw new ViewHandlerException(new Throwable(
	"Bad version stamp detected"), Cause.BAD_VERSION_STAMP); //$NON-NLS-1$
	}
	viewRoot.setVersionStamp(versionStamp);

	final StalenessAdvisor advisor = createStalenessAdvisor(viewRoot,
	facesContext, viewId);

	if (advisor == null)
	{
	throw new ViewHandlerException(new Throwable(
	"Bad staleness advisor"), Cause.BAD_STALENESS_ADVISOR); //$NON-NLS-1$
	}
	viewRoot.setStalenessAdvisor(advisor);

	// lock down the tree
	viewRoot.setSubtreeProtected();

	registerView(viewRoot, facesContext, viewId);

	return viewRoot;
	}

	/**
	* @param facesContext
	* @param viewId
	* @return internal construction of the view root.
	*/
	protected abstract DTUIViewRoot internalCreateView(
	final DTFacesContext facesContext, final String viewId);

	public abstract IResource getActionDefinition(DTFacesContext context,
	String viewId) throws ViewHandlerException;

	public abstract IPath getActionURL(DTFacesContext context,
	IResource resource, IPath requestPath) throws ViewHandlerException;

	public abstract IPath getRelativeActionPath(DTFacesContext context,
	String relativeToViewId, String uri) throws ViewHandlerException;

	public abstract IViewDefnAdapterFactory getViewMetadataAdapterFactory(
	DTFacesContext context) throws ViewHandlerException;

	public abstract boolean supportsViewDefinition(IFile file);


	public abstract void setLifecycleListener(ImmutableLifecycleListener listener);

	public final void dispose()
	{
	if (_isDisposed.compareAndSet(false, true))
	{
	doDispose();
	}
	}

	/**
	* Sub-classes should override to add disposal tasks
	*/
	protected void doDispose()
	{
	// do nothing by default
	}

	/**
	* IMPORTANT: this method must not return null. All view creation will fail
	* for this handler when createVersionStamp() returns null. create() will
	* throw ViewHandlerException.
	*
	* @param facesContext
	* @param viewId
	* @return a new version stamp for the facesContext/viewId. The version
	* stamp needs to be unique for all instances of viewId only, not
	* all instances of component trees everywhere in the system.
	*/
	protected abstract VersionStamp createVersionStamp(
	final DTFacesContext facesContext, final String viewId);

	/**
	* IMPORTANT: this method must not return null. All view creation will fail
	* for this handler when createStalenessAdvisor returns null.
	*
	* @param viewRoot
	* @param facesContext
	* @param viewId
	* @return a new staleness advisor.
	*/
	protected abstract StalenessAdvisor createStalenessAdvisor(
	final DTUIViewRoot viewRoot, DTFacesContext facesContext,
	String viewId);

	/**
	* Called by createView immediately before returning. Provides sub-class
	* a chance to register a fully initialized view root with any stateful
	* activities such as automatic change tracking and caching.
	*
	* @param viewRoot
	* @param context
	* @param viewId
	*/
	protected void registerView(DTUIViewRoot viewRoot, final DTFacesContext context, final String viewId)
	{
	// do nothing by default
	}

	public String getViewId(final DTFacesContext context, final IResource res)
	{
	// TODO: sync with WebrootUtil?
	String strWebrootPath = ""; //$NON-NLS-1$
	final IProject project = res.getProject();
	final IPath path = res.getFullPath();
	final IPath webContentPath = getWebContentPath(project);
	if (webContentPath != null && webContentPath.isPrefixOf(path))
	{
	final int start = path.matchingFirstSegments(webContentPath);
	final String[] segments = path.segments();
	for (int i = start, n = path.segmentCount(); i < n; i++)
	{
	strWebrootPath = strWebrootPath + PATH_SEPARATOR + segments[i];
	}
	}
	return strWebrootPath;
	}

	private IPath getWebContentPath(final IProject project)
	{
	if (project != null)
	{
	return ComponentCore.createComponent(project).getRootFolder()
	.getUnderlyingFolder().getFullPath();
	}
	return null;
	}

	/**
	* A default DTUIViewRoot that represents an uncreatable or uninitializable
	* view root.
	*
	*/
	protected static final class NullViewRoot extends DTUIViewRoot
	{
	/**
	*
	*/
	private static final long serialVersionUID = 1187035338610719171L;

	/**
	*/
	protected NullViewRoot()
	{
	super(null, null, new ComponentTypeInfo("", "", "","")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
	}

	@Override
	public IAdaptable getServices()
	{
	return new IAdaptable()
	{
	public Object getAdapter(Class adapter)
	{
	// no services
	return null;
	}
	};
	}

	@Override
	protected Map<String, ISymbol> doGetMapForScope(int scopeMask) {
	return Collections.emptyMap();
	}

	}

	/**
	* Provides a simple time-based stamp that makes almost impossible to create
	* the same timestamp twice. To do so, two threads would need to get the
	* same system simulataneously and get same number back from the same
	* gaussian distribution.
	*
	* @author cbateman
	*
	*/
	protected static class TimeBasedVersionStamp extends VersionStamp
	{
	/**
	*
	*/
	private static final long serialVersionUID = 5557828245936568977L;
	private final long timestamp;
	private final long randomStamp;

	/**
	*
	*/
	public TimeBasedVersionStamp()
	{
	super();
	// use the millisecond time, since it is offset from a known
	// point on all platform, whereas no guarantee is made about
	// the nano time value.
	this.timestamp = System.currentTimeMillis();
	// this protects against two threads constructing two time
	// stamp objects "simulataneously" and having the same time based
	// stamp. Math.random is thread-safe.
	this.randomStamp = (long) (Long.MAX_VALUE * Math.random());
	}

	@Override
	public int hashCode()
	{
	return (int) (timestamp ^ randomStamp);
	}

	@Override
	protected boolean isEqual(final VersionStamp other)
	{
	return other instanceof TimeBasedVersionStamp
	&& (timestamp == ((TimeBasedVersionStamp) other).timestamp)
	&& (randomStamp == ((TimeBasedVersionStamp) other).randomStamp);
	}
	}

	/**
	* Returns a default staleness advisor that always returns false.
	*
	* @author cbateman
	*
	*/
	protected static final class NullStalenessAdvisor extends StalenessAdvisor
	{
	/**
	*
	*/
	private static final long serialVersionUID = 5946420948320047613L;

	@Override
	public boolean isStale()
	{
	return false;
	}

	@Override
	public void addListener(final StalenessListener listener)
	{
	// do nothing
	}

	@Override
	public void removeListener(final StalenessListener listener)
	{
	// do nothing
	}

	public boolean isAccessible()
	{
	return true;
	}
	}
	}