bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/PagePartSelectionTracker.java

package org.eclipse.ui.internal;

/*
 * (c) Copyright IBM Corp. 2000, 2001, 2002.
 * All Rights Reserved.
 */

import org.eclipse.jface.viewers.*;
import org.eclipse.ui.*;

/**
 * Provides debug view selection management/notification for
 * a debug view in a specific workbench page. This selection
 * provider sheilds clients from a debug view openning and closing,
 * and still provides selection notification/information even
 * when the debug view is not the active part.
 */
public class PagePartSelectionTracker extends AbstractPartSelectionTracker implements IPartListener, ISelectionChangedListener {
	
	/**
	 * The workbench page for which this is tracking selection.
	 */
	private IWorkbenchPage fPage;
	
	/**
	 * The part in this tracker's page, or <code>null</code> if one is not open.
	 */
	private IWorkbenchPart fPart;
	
	private ISelectionChangedListener selectionListener = new ISelectionChangedListener() {
		public void selectionChanged(SelectionChangedEvent event) {
			fireSelection(getPart(), event.getSelection());
		}
	};
	private ISelectionChangedListener postSelectionListener = new ISelectionChangedListener() {
		public void selectionChanged(SelectionChangedEvent event) {
			firePostSelection(getPart(), event.getSelection());
		}
	};
	public PagePartSelectionTracker(IWorkbenchPage page, String partId) {
		super(partId);
		setPage(page);
		page.addPartListener(this);
		IViewPart part = page.findView(partId);
		if (part != null) {
			setPart(part, false);
		}
	}
	
	/**
	 * Disposes this selection provider - removes all listeners
	 * currently registered.
	 */
	public void dispose() {
		setPart(null, false);
		setPage(null);
		super.dispose();
	}

	/*
	 * @see IPartListener#partActivated(IWorkbenchPart)
	 */
	public void partActivated(IWorkbenchPart part) {
	}

	/*
	 * @see IPartListener#partBroughtToTop(IWorkbenchPart)
	 */
	public void partBroughtToTop(IWorkbenchPart part) {
	}

	/**
	 * @see IPartListener#partClosed(IWorkbenchPart)
	 */
	public void partClosed(IWorkbenchPart part) {
		if (part.getSite().getId().equals(getPartId())) {
			setPart(null, true);
		}	
	}

	/*
	 * @see IPartListener#partDeactivated(IWorkbenchPart)
	 */
	public void partDeactivated(IWorkbenchPart part) {
	}

	/**
	 * @see IPartListener#partOpened(IWorkbenchPart)
	 */
	public void partOpened(IWorkbenchPart part) {
		if (part.getSite().getId().equals(getPartId())) {
			setPart(part, true);
		}
	}
	/**
	 * The selection has changed in the part being tracked.
	 * Forward it to the listeners.
	 * 
	 * @see ISelectionChangedListener#selectionChanged
	 */
	public void selectionChanged(SelectionChangedEvent event) {
		fireSelection(getPart(), event.getSelection());
	}


	/**
	 * Sets the page this selection provider works for
	 * 
	 * @param page workbench page
	 */
	private void setPage(IWorkbenchPage page) {
		fPage = page;
	}
	
	/**
	 * Returns the page this selection provider works for
	 * 
	 * @return workbench page
	 */
	protected IWorkbenchPage getPage() {
		return fPage;
	}	
	
	/**
	 * Returns the part this is tracking, 
	 * or <code>null</code> if it is not open
	 * 
	 * @return part., or <code>null</code>
	 */
	protected IWorkbenchPart getPart() {
		return fPart;
	}	
	
	/*
	 * @see AbstractPartSelectionTracker#getSelection()
	 */
	public ISelection getSelection() {
		IWorkbenchPart part = getPart();
		if (part != null) {
			ISelectionProvider sp = part.getSite().getSelectionProvider();
			if (sp !=  null) {
				return sp.getSelection();
			}
		}
		return null;
	}


	/**
	 * @see AbstractDebugSelectionProvider#getSelectionProvider()
	 */
	protected ISelectionProvider getSelectionProvider() {
		IWorkbenchPart part = getPart();
		if (part != null) {
			return part.getSite().getSelectionProvider();
		} 
		return null;
	}	

	/**
	 * Sets the part for this selection tracker.
	 * 
	 * @param part the part
	 * @param notify whether to send notification that the selection has changed.
	 */
	private void setPart(IWorkbenchPart part, boolean notify) {
		if (fPart != null) {
			// remove myself as a listener from the existing part
			ISelectionProvider sp = fPart.getSite().getSelectionProvider();
			if (sp != null) {
				sp.removeSelectionChangedListener(selectionListener);
				if(sp instanceof StructuredViewer)
					((StructuredViewer)sp).removePostSelectionChangedListener(postSelectionListener);	
				else
					sp.removeSelectionChangedListener(postSelectionListener);
			}			
		}
		fPart = part;
		ISelection sel =  null; 
		if (part != null) {
			ISelectionProvider sp = part.getSite().getSelectionProvider();
			if (sp != null) {
				sp.addSelectionChangedListener(selectionListener);
				if(sp instanceof StructuredViewer)
					((StructuredViewer)sp).addPostSelectionChangedListener(postSelectionListener);	
				else
					sp.addSelectionChangedListener(postSelectionListener);
				if (notify) {
					// get the selection to send below
					sel = sp.getSelection();
				}
			}
		}
		if (notify) {
			fireSelection(part, sel);
			firePostSelection(part, sel);
		}
	}
}