/*******************************************************************************
 * Copyright (c) 2000, 2006 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.ui.internal.ide.model;

import org.eclipse.core.commands.operations.IUndoContext;
import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.runtime.IAdapterFactory;
import org.eclipse.ui.IActionFilter;
import org.eclipse.ui.IElementFactory;
import org.eclipse.ui.IPersistableElement;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.model.IWorkbenchAdapter;

/**
 * Dispenses adapters for various core objects.
 * Returns IWorkbenchAdapter adapters, used for displaying,
 * navigating, and populating menus for core objects.
 */
public class WorkbenchAdapterFactory implements IAdapterFactory {
    private Object workspaceAdapter = new WorkbenchWorkspace();

    private Object rootAdapter = new WorkbenchRootResource();

    private Object projectAdapter = new WorkbenchProject();

    private Object folderAdapter = new WorkbenchFolder();

    private Object fileAdapter = new WorkbenchFile();

    private Object markerAdapter = new WorkbenchMarker();

    private Object resourceFactory = new ResourceFactory();

    private Object workspaceFactory = new WorkspaceFactory();

    /**
     * Returns the IActionFilter for an object.
     */
    protected Object getActionFilter(Object o) {
        if (o instanceof IResource) {
            switch (((IResource) o).getType()) {
            case IResource.FILE:
                return fileAdapter;
            case IResource.FOLDER:
                return folderAdapter;
            case IResource.PROJECT:
                return projectAdapter;
            }
        }
        if (o instanceof IMarker) {
            return markerAdapter;
        }
        return null;
    }

    /**
     * Returns an object which is an instance of the given class
     * associated with the given object. Returns <code>null</code> if
     * no such object can be found.
     *
     * @param o the adaptable object being queried
     *   (usually an instance of <code>IAdaptable</code>)
     * @param adapterType the type of adapter to look up
     * @return a object castable to the given adapter type, 
     *    or <code>null</code> if this adapter provider 
     *    does not have an adapter of the given type for the
     *    given object
     */
    public Object getAdapter(Object o, Class adapterType) {
        if (adapterType.isInstance(o)) {
            return o;
        }
        if (adapterType == IWorkbenchAdapter.class) {
            return getWorkbenchElement(o);
        }
        if (adapterType == IPersistableElement.class) {
            return getPersistableElement(o);
        }
        if (adapterType == IElementFactory.class) {
            return getElementFactory(o);
        }
        if (adapterType == IActionFilter.class) {
            return getActionFilter(o);
        }
        if (adapterType == IUndoContext.class) {
        	return getUndoContext(o);
        }
        return null;
    }

    /**
     * Returns the collection of adapter types handled by this
     * provider.
     * <p>
     * This method is generally used by an adapter manager
     * to discover which adapter types are supported, in advance
     * of dispatching any actual <code>getAdapter</code> requests.
     * </p>
     *
     * @return the collection of adapter types
     */
    public Class[] getAdapterList() {
        return new Class[] { IWorkbenchAdapter.class, IElementFactory.class,
                IPersistableElement.class, IActionFilter.class, IUndoContext.class };
    }

    /**
     * Returns an object which is an instance of IElementFactory
     * associated with the given object. Returns <code>null</code> if
     * no such object can be found.
     */
    protected Object getElementFactory(Object o) {
        if (o instanceof IResource) {
            return resourceFactory;
        }
        if (o instanceof IWorkspace) {
            return workspaceFactory;
        }
        return null;
    }

    /**
     * Returns an object which is an instance of IPersistableElement
     * associated with the given object. Returns <code>null</code> if
     * no such object can be found.
     */
    protected Object getPersistableElement(Object o) {
        if (o instanceof IResource) {
            return new ResourceFactory((IResource) o);
        }
        if (o instanceof IWorkspace) {
            return workspaceFactory;
        }
        return null;
    }

    /**
     * Returns an object which is an instance of IWorkbenchAdapter
     * associated with the given object. Returns <code>null</code> if
     * no such object can be found.
     */
    protected Object getWorkbenchElement(Object o) {
        if (o instanceof IResource) {
            switch (((IResource) o).getType()) {
            case IResource.FILE:
                return fileAdapter;
            case IResource.FOLDER:
                return folderAdapter;
            case IResource.PROJECT:
                return projectAdapter;
            }
        }
        if (o instanceof IWorkspaceRoot) {
            return rootAdapter;
        }
        if (o instanceof IWorkspace) {
            return workspaceAdapter;
        }
        if (o instanceof IMarker) {
            return markerAdapter;
        }
        return null;
    }
    
    /**
     * Returns the IUndoContext for an object.
     */
    protected Object getUndoContext(Object o) {
        if (o instanceof IWorkspace) {
            return PlatformUI.getWorkbench().getOperationSupport().getUndoContext();
        }
        return null;
    }
}