Bug 205923 [Viewers] Javadoc for setAllChecked() does not mention that only visible items are checked
setAllChecked which was added (by me) in 3.2 does not mention that all chidren must be visible for it to be checked (see setSubtreeChecked). We will have to leave it as it is API and does not expand the tree but I think we should deprecate it as setSubtreeChecked is really the only useful one. Boris what is your opinion?
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CheckboxTreeViewer.java
public boolean getGrayed(Object element) {
        Widget widget = findItem(element);
        if (widget instanceof TreeItem) {
            return ((TreeItem) widget).getGrayed();
        }
        return false;
    }
    /**
     * Returns a list of grayed elements in this viewer's tree, 
     * including currently hidden ones that are marked as
     * grayed but are under a collapsed ancestor.
     * <p>
     * This method is typically used when preserving the interesting
     * state of a viewer; <code>setGrayedElements</code> is used during the restore.
     * </p>
     *
     * @return the array of grayed elements
     *
     * @see #setGrayedElements
     */
    public Object[] getGrayedElements() {
        List result = new ArrayList();
        internalCollectGrayed(result, getControl());
        return result.toArray();
    }
    /* (non-Javadoc)
     * Method declared on StructuredViewer.
     */
    protected void handleDoubleSelect(SelectionEvent event) {
        if (lastClickedItem != null) {