diff options
Diffstat (limited to 'src/xml/node-observer.h')
| -rw-r--r-- | src/xml/node-observer.h | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/src/xml/node-observer.h b/src/xml/node-observer.h index 6052e48b6..8f317e2d0 100644 --- a/src/xml/node-observer.h +++ b/src/xml/node-observer.h @@ -29,7 +29,7 @@ namespace XML { /** * @brief Interface for XML node observers * - * This pure abstract class defines an interface for objects that can receive + * This class defines an interface for objects that can receive * XML node state change notifications. The observer has to be registered using * the Node::addObserver() method to be notified of changes of this node only, * or using Node::addSubtreeObserver() to also receive notifications about its @@ -40,6 +40,11 @@ namespace XML { * The method will be called again due to the XML modification performed in it. If you * don't take special precautions to ignore the second call, it will result in infinite * recursion. + * + * The virtual methods of this class do nothing by default, so you don't need to provide + * stubs for things you don't use. A good idea is to make the observer register itself + * on construction and unregister itself on destruction. This will ensure there are + * no dangling references. */ class NodeObserver { public: @@ -56,7 +61,7 @@ public: * @param child The newly added child node * @param prev The node after which the new child was inserted into the sibling order, or NULL */ - virtual void notifyChildAdded(Node &node, Node &child, Node *prev)=0; + virtual void notifyChildAdded(Node &node, Node &child, Node *prev) {} /** * @brief Child removal callback @@ -68,7 +73,7 @@ public: * @param child The removed child node * @param prev The node that was before the removed node in sibling order, or NULL */ - virtual void notifyChildRemoved(Node &node, Node &child, Node *prev)=0; + virtual void notifyChildRemoved(Node &node, Node &child, Node *prev) {} /** * @brief Child order change callback @@ -84,7 +89,7 @@ public: * @param new_prev The node that is before @c child after the order change */ virtual void notifyChildOrderChanged(Node &node, Node &child, - Node *old_prev, Node *new_prev)=0; + Node *old_prev, Node *new_prev) {} /** * @brief Content change callback @@ -98,7 +103,7 @@ public: */ virtual void notifyContentChanged(Node &node, Util::ptr_shared<char> old_content, - Util::ptr_shared<char> new_content)=0; + Util::ptr_shared<char> new_content) {} /** * @brief Attribute change callback @@ -112,7 +117,7 @@ public: */ virtual void notifyAttributeChanged(Node &node, GQuark name, Util::ptr_shared<char> old_value, - Util::ptr_shared<char> new_value)=0; + Util::ptr_shared<char> new_value) {} }; } // namespace XML |