View state and application design - c++

Question

I have a toolbar controller which is capable of updating the toolbar state ( enabled/disabled, pressed/unpressed ) by querying document properties or the application framework. I have some buttons that represent the current state of a view.
From an application design standpoint I like having toolbar controller able to update the button state at any time given a document. I also prefer the toolbar controller & button handlers to have no internal state.
Options as I see it - looking for other suggestions:
Create a mechanism for visiting all views of a document with a visitor that can capture the state of the view which is then used to enable/disable/press/depress the button.
Create some connection between views and toolbar handlers that allows the toolbar buttons to directly ask the views.
Other??

Answer 1

you can try having an event loop for the view and update the state with a function call dispatch
Like this:
class ViewEventArgs{
public:
int eventNumber;
};
class ViewEvent{
public:
virtual void onViewChange(ViewEventChangeArgs args) = 0;
};
class ViewController{
public:
virtual void doPressed() = 0;
virtual void doChecked() = 0;
//other interface methods
};
class ToolbarView : public ViewEvent{
public:
//Your EVENT-LOOP kernel will fire these events depending upon the state change in the view
void onViewChange(ViewEventChangeArgs args)
{
switch(args.eventNumber){
case PRESSED:
getToolbarController()->doPressed();//the method dispatch
break;
case CHECKED:
getToolbarController()->doChecked();
}
}
//other parts of the view
};
class ToolbarController: public ViewController{
public:
void doPressed() { /*pressed*/ }
void doChecked() { /*checked*/ }
//implementations
};