DocumentObserverDynamic Class Reference
Declared in |
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template <class T> class DocumentObserverDynamic; |
flip::DocumentObserverDynamic allows to attach an observer to the document after the document was created.
flip::DocumentObserver has a lifetime longer than the document : it needs to be constructed before the document is constructed, and needs to be destroyed after the document is destroyed.
flip::DocumentObserverDynamic is exactly the inverse : it is constructed anytime after a document is constructed, and is destroyed anytime before the document is destroyed.
A flip::DocumentObserverDynamic takes a document as a parameter, and a document can have any number of dynamic observers at the same time.
Important: flip::DocumentObserverDynamics can and will be called in any order. If you need to order observers, then use composition.
Template Parameters
| The root class to observer. |
Member Functions Synopsys
Constructs the |
Member Functions
Constructor
template <class F> DocumentObserverDynamic (Document & document, F f); |
Constructs the dynamic document observer, passing the document to observe as well as a callable matching the signature void (T &), typically a lambda function.
Example:
using Observer = flip::DocumentObserverDynamic <MyRootClass>; |
Observer observer {document, [](MyRootClass & root){ |
if (root.changed ()) |
{ |
// ... |
} |
}}; |