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
item = item.getParentItem();
            while (item != null) {
                item.setGrayed(state);
                item = item.getParentItem();
            }
            return true;
        }
        return false;
    }
    /**
     * Sets the checked state for the given element and its visible
     * children in this viewer.
     * Assumes that the element has been expanded before. To enforce
     * that the item is expanded, call <code>expandToLevel</code>
     * for the element.
     * Does not fire events to check state listeners.
     *
     * @param element the element
     * @param state <code>true</code> if the item should be checked,
     *  and <code>false</code> if it should be unchecked
     * @return <code>true</code> if the checked state could be set, 
     *  and <code>false</code> otherwise
     */
    public boolean setSubtreeChecked(Object element, boolean state) {
        Widget widget = internalExpand(element, false);
        if (widget instanceof TreeItem) {
            TreeItem item = (TreeItem) widget;
            item.setChecked(state);
            setCheckedChildren(item, state);
            return true;