Content deleted Content added
|
|
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return topic != NO_HELP_TOPIC;
}
virtual void setHandler(HelpHandler*, Topic) {}
virtual void handleHelp() {
std::cout << "HelpHandler::handleHelp\n";
// (optional) implements the successor link.
if (successor != nullptr) {
successor->handleHelp();
}
}
virtual ~HelpHandler() = default;
HelpHandler(const HelpHandler&) = delete; // rule of three
HelpHandler& operator=(const HelpHandler&) = delete;
private:
HelpHandler* successor;
Topic topic;
};
class Widget : public HelpHandler {
button->handleHelp();
}
</syntaxhighlight>
The program output is:
<syntaxhighlight lang="c++">
Button::handleHelp
</syntaxhighlight>
{{wikibooks|Computer Science Design Patterns|Chain of responsibility|Chain-of-responsibility implementations in various languages}}
== Implementations ==
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