structuredviewer.java

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				if (filter.isFilterProperty(element, property)) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Returns a new hashtable using the given capacity and this viewer's element comparer.
	 * 
	 * @param capacity the initial capacity of the hashtable
	 * @return a new hashtable
	 * 
	 * @since 3.0
	 */
	CustomHashtable newHashtable(int capacity) {
		return new CustomHashtable(capacity, getComparer());
	}

	/**
	 * Attempts to preserves the current selection across a run of the given
	 * code.
	 * <p>
	 * The default implementation of this method:
	 * <ul>
	 * <li>discovers the old selection (via <code>getSelection</code>)</li>
	 * <li>runs the given runnable</li>
	 * <li>attempts to restore the old selection (using
	 * <code>setSelectionToWidget</code></li>
	 * <li>rediscovers the resulting selection (via <code>getSelection</code>)
	 * </li>
	 * <li>calls <code>handleInvalidSelection</code> if the selection did not
	 * take</li>
	 * <li>calls <code>postUpdateHook</code></li>
	 * </ul>
	 * </p>
	 * 
	 * @param updateCode
	 *            the code to run
	 */
	protected void preservingSelection(Runnable updateCode) {

		ISelection oldSelection = null;
		try {
			// preserve selection
			oldSelection = getSelection();
			inChange = restoreSelection = true;

			// perform the update
			updateCode.run();

		} finally {
			inChange = false;

			// restore selection
			if (restoreSelection) {
				setSelectionToWidget(oldSelection, false);
			}

			// send out notification if old and new differ
			ISelection newSelection = getSelection();
			if (!newSelection.equals(oldSelection)) {
				handleInvalidSelection(oldSelection, newSelection);
			}
		}
	}

	/*
	 * Non-Javadoc. Method declared on Viewer.
	 */
	public void refresh() {
		refresh(getRoot());
	}

	/**
	 * Refreshes this viewer with information freshly obtained from this
	 * viewer's model. If <code>updateLabels</code> is <code>true</code>
	 * then labels for otherwise unaffected elements are updated as well.
	 * Otherwise, it assumes labels for existing elements are unchanged, and
	 * labels are only obtained as needed (for example, for new elements).
	 * <p>
	 * Calling <code>refresh(true)</code> has the same effect as
	 * <code>refresh()</code>.
	 * <p>
	 * Note that the implementation may still obtain labels for existing
	 * elements even if <code>updateLabels</code> is false. The intent is
	 * simply to allow optimization where possible.
	 * 
	 * @param updateLabels
	 *            <code>true</code> to update labels for existing elements,
	 *            <code>false</code> to only update labels as needed, assuming
	 *            that labels for existing elements are unchanged.
	 * 
	 * @since 2.0
	 */
	public void refresh(boolean updateLabels) {
		refresh(getRoot(), updateLabels);
	}

	/**
	 * Refreshes this viewer starting with the given element.
	 * <p>
	 * Unlike the <code>update</code> methods, this handles structural changes
	 * to the given element (e.g. addition or removal of children). If only the
	 * given element needs updating, it is more efficient to use the
	 * <code>update</code> methods.
	 * </p>
	 * 
	 * @param element
	 *            the element
	 */
	public void refresh(final Object element) {
		preservingSelection(new Runnable() {
			public void run() {
				internalRefresh(element);
			}
		});
	}

	/**
	 * Refreshes this viewer starting with the given element. Labels are updated
	 * as described in <code>refresh(boolean updateLabels)</code>.
	 * <p>
	 * Unlike the <code>update</code> methods, this handles structural changes
	 * to the given element (e.g. addition or removal of children). If only the
	 * given element needs updating, it is more efficient to use the
	 * <code>update</code> methods.
	 * </p>
	 * 
	 * @param element
	 *            the element
	 * @param updateLabels
	 *            <code>true</code> to update labels for existing elements,
	 *            <code>false</code> to only update labels as needed, assuming
	 *            that labels for existing elements are unchanged.
	 * 
	 * @since 2.0
	 */
	public void refresh(final Object element, final boolean updateLabels) {
		preservingSelection(new Runnable() {
			public void run() {
				internalRefresh(element, updateLabels);
			}
		});
	}

	/**
	 * 
	 * Refreshes the given TableItem with the given element. Calls
	 * <code>doUpdateItem(..., false)</code>.
	 * <p>
	 * This method is internal to the framework; subclassers should not call
	 * this method.
	 * </p>
	 * @param widget
     *            the widget
	 * @param element
     *            the element
	 */
	protected final void refreshItem(Widget widget, Object element) {
		SafeRunnable.run(new UpdateItemSafeRunnable(widget, element, true));
	}

	/**
	 * Removes the given open listener from this viewer. Has no affect if an
	 * identical listener is not registered.
	 * 
	 * @param listener
	 *            a double-click listener
	 */
	public void removeOpenListener(IOpenListener listener) {
		openListeners.remove(listener);
	}

	/*
	 * (non-Javadoc) Method declared on IPostSelectionProvider.
	 */
	public void removePostSelectionChangedListener(ISelectionChangedListener listener) {
		postSelectionChangedListeners.remove(listener);
	}

	/**
	 * Removes the given double-click listener from this viewer. Has no affect
	 * if an identical listener is not registered.
	 * 
	 * @param listener
	 *            a double-click listener
	 */
	public void removeDoubleClickListener(IDoubleClickListener listener) {
		doubleClickListeners.remove(listener);
	}

	/**
	 * Removes the given filter from this viewer, and triggers refiltering and
	 * resorting of the elements if required. Has no effect if the identical
	 * filter is not registered.
	 * 
	 * @param filter
	 *            a viewer filter
	 */
	public void removeFilter(ViewerFilter filter) {
		Assert.isNotNull(filter);
		if (filters != null) {
			// Note: can't use List.remove(Object). Use identity comparison
			// instead.
			for (Iterator i = filters.iterator(); i.hasNext();) {
				Object o = i.next();
				if (o == filter) {
					i.remove();
					refresh();
					if (filters.size() == 0) {
						filters = null;
					}
					return;
				}
			}
		}
	}

	/**
	 * Discards this viewer's filters and triggers refiltering and resorting of
	 * the elements.
	 */
	public void resetFilters() {
		if (filters != null) {
			filters = null;
			refresh();
		}
	}

	/**
	 * Ensures that the given element is visible, scrolling the viewer if
	 * necessary. The selection is unchanged.
	 * 
	 * @param element
	 *            the element to reveal
	 */
	public abstract void reveal(Object element);

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.ContentViewer#setContentProvider(org.eclipse.jface.viewers.IContentProvider)
	 */
	public void setContentProvider(IContentProvider provider) {
		assertContentProviderType(provider);
		super.setContentProvider(provider);
	}

	/**
	 * Assert that the content provider is of one of the
	 * supported types.
	 * @param provider
	 */
	protected void assertContentProviderType(IContentProvider provider) {
		Assert.isTrue(provider instanceof IStructuredContentProvider);
	}

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.Viewer#setInput(java.lang.Object)
	 */
	public final void setInput(Object input) {

		try {
			//		fInChange= true;

			unmapAllElements();

			super.setInput(input);

		} finally {
			//		fInChange= false;
		}
	}

	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.Viewer#setSelection(org.eclipse.jface.viewers.ISelection, boolean)
	 */
	public void setSelection(ISelection selection, boolean reveal) {
		/**
		 * <p>
		 * If the new selection differs from the current selection the hook
		 * <code>updateSelection</code> is called.
		 * </p>
		 * <p>
		 * If <code>setSelection</code> is called from within
		 * <code>preserveSelection</code>, the call to
		 * <code>updateSelection</code> is delayed until the end of
		 * <code>preserveSelection</code>.
		 * </p>
		 * <p>
		 * Subclasses do not typically override this method, but implement
		 * <code>setSelectionToWidget</code> instead.
		 * </p>
		 */
		Control control = getControl();
		if (control == null || control.isDisposed()) {
			return;
		}
		if (!inChange) {
			setSelectionToWidget(selection, reveal);
			ISelection sel = getSelection();
			updateSelection(sel);
			firePostSelectionChanged(new SelectionChangedEvent(this, sel));
		} else {
			restoreSelection = false;
			setSelectionToWidget(selection, reveal);
		}
	}

	/**
	 * Parlays the given list of selected elements into selections on this
	 * viewer's control.
	 * <p>
	 * Subclasses should override to set their selection based on the given list
	 * of elements.
	 * </p>
	 * 
	 * @param l
	 *            list of selected elements (element type: <code>Object</code>)
	 *            or <code>null</code> if the selection is to be cleared
	 * @param reveal
	 *            <code>true</code> if the selection is to be made visible,
	 *            and <code>false</code> otherwise
	 */
	protected abstract void setSelectionToWidget(List l, boolean reveal);

	/**
	 * Converts the selection to a <code>List</code> and calls
	 * <code>setSelectionToWidget(List, boolean)</code>. The selection is
	 * expected to be an <code>IStructuredSelection</code> of elements. If
	 * not, the selection is cleared.
	 * <p>
	 * Subclasses do not typically override this method, but implement
	 * <code>setSelectionToWidget(List, boolean)</code> instead.
	 * 
	 * @param selection
	 *            an IStructuredSelection of elements
	 * @param reveal
	 *            <code>true</code> to reveal the first element in the
	 *            selection, or <code>false</code> otherwise
	 */
	protected void setSelectionToWidget(ISelection selection, boolean reveal) {
		if (selection instanceof IStructuredSelection) {
			setSelectionToWidget(((IStructuredSelection) selection).toList(), reveal);
		} else {
			setSelectionToWidget((List) null, reveal);
		}
	}

	/**
	 * Sets this viewer's sorter and triggers refiltering and resorting of this
	 * viewer's element. Passing <code>null</code> turns sorting off.  
     * <p>
     * It is recommended to use <code>setComparator()</code> instead.
     * </p>
	 * 
	 * @param sorter
	 *            a viewer sorter, or <code>null</code> if none
	 */
	public void setSorter(ViewerSorter sorter) {
		if (this.sorter != sorter) {
			this.sorter = sorter;
			refresh();
		}
	}

	/**
	 * Sets this viewer's comparator to be used for sorting elements, and triggers refiltering and 
	 * resorting of this viewer's element.  <code>null</code> turns sorting off.
	 * To get the viewer's comparator, call <code>getComparator()</code>.
     * <p>
     * IMPORTANT: This method was introduced in 3.2. If a reference to this viewer object 
     * is passed to clients who call <code>getSorter()<code>, null may be returned from
     * from that method even though the viewer is sorting its elements using the
     * viewer's comparator.
     * </p>
	 * 
	 * @param comparator a viewer comparator, or <code>null</code> if none
     *
     * @since 3.2
	 */
	public void setComparator(ViewerComparator comparator){
		if (this.sorter != comparator){
			this.sorter = comparator;
			refresh();
		}
	}
	
	/**
	 * Configures whether this structured viewer uses an internal hash table to
	 * speeds up the mapping between elements and SWT items. This must be called
	 * before the viewer is given an input (via <code>setInput</code>).
	 * 
	 * @param enable
	 *            <code>true</code> to enable hash lookup, and
	 *            <code>false</code> to disable it
	 */
	public void setUseHashlookup(boolean enable) {
		Assert.isTrue(getInput() == null,
				"Can only enable the hash look up before input has been set");//$NON-NLS-1$
		if (enable) {
			elementMap = newHashtable(CustomHashtable.DEFAULT_CAPACITY);
		} else {
			elementMap = null;
		}
	}

	/**
	 * Sets the comparer to use for comparing elements, or <code>null</code>
	 * to use the default <code>equals</code> and <code>hashCode</code>
	 * methods on the elements themselves.
	 * 
	 * @param comparer
	 *            the comparer to use for comparing elements or
	 *            <code>null</code>
	 */
	public void setComparer(IElementComparer comparer) {
		this.comparer = comparer;
		if (elementMap != null) {
			elementMap = new CustomHashtable(elementMap, comparer);
		}