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Re: treectrl with ctrl [message #23461 is a reply to message #23431]

Wed, 21 October 2009 08:45

mirek
Messages: 14265
Registered: November 2005

Ultimate Member

kohait00 wrote on Mon, 19 October 2009 03:07

the goal behind all this is to be able to put something down in the TreeCtrl (be it a key/value pair or a Ctrl content), tag with a kind of hash information and later be able to retrieve exactly this element again, using the key. well, as it seems it works quite well with the key/value approach, but using ctrl as content, there is no way to assign a hash, that is kept *inside* the tree ctrl and not propagated to the ctrl itself. Find'ing the key then results in a for loop, which again decides, where to take the value, from the internal key database or from the control.
but imagine controls that dont support GetData/SetData, like simple ParentCtrl containing others..this would not work.

thats somehow a drawback in double sense (we use the keys only for verification, not for hasching, --> performance)

maybe instead of setting up another SetData() in the Ctrl:: one could just think of an additional method in the TreeCtrl (and maybe the other controls with the same respective behaviour), something like a

void SetK(int id, Value key); which does *not* propagate it to a ctrl's SetData but still sets the internal keys, and a FindK(Value key) method which only searches the internal keys, no matter what content, control or key/value.

so one could still use the Find(Value key) methods, and use the others if one knows what to do.. changig the API is hard, when we have a lot of progs already used to this behaviour.

cheers

I guess things got a little bit confused. There are now 3 values associated with each node:

id
key
value

Embedded ctrls are using value. You can set key alone using

Set(id, key, GetValue(id))

the only a little bit tricky part is that if you set just single Value for node, it gets assigned to both key and value...

Now above is a little bit confused, but so am I reading your post Smile

Mirek

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