Re: SetMode(Enum) vs. SetModeA(), SetModeB()...
{ Parts that are not necessary to establish context, including the banner,
should be removed from your quoting. -mod }
On May 4, 1:21 am, "chase.bradf...@saic.com"
<chase.bradf...@gmail.com> wrote:
When writing a class that can be in exactly one of many modes, what
interface should I provide for changing the mode?
Two techniques come to mind for this.
1) Define a Mode enumerated type, with a method SetMode that takes a
Mode argument and switches across them.
2) For each mode, have a no argument method to change into that mode.
I can think of some cases where technique 1 is preferred, for
instance, when the mode needs to be stored as a variable and restored
later. This could occur in the case of a stack, where changing modes
pushes current modes onto a stack, then unwinding could be performed
with SetMode( stack.top() ).
On the other hand, technique 2 has it's benefits, such as performance
and no need for parameter checking in the event that the client
performs a bad cast from an int.
Adaptors could easily be written to go from one interface to the
other, which makes me favor the second approach, but I'd like to know
some other takes on this before I put my thoughts to actual code.
{ banner removed -mod }
Also consider using pattern "state". Something like this:
struct Mode
{
virtual void foo() = 0;
virtual void bar(int, int) = 0;
};
struct YourClassWithModes
{
void SetMode(Mode * mode);
};
P.S.
SetMode(Enum) is superior to SetModeA()/SetModeB() in one more case:
You easily can query current mode.
HTH,
Roman Perepelitsa.
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