Adding new flags?

[Nikolay Sivov]

Igor Tarasov wrote:
> 2009/4/10 Nikolay Sivov <bunglehead at gmail.com>:
>   
>> Igor Tarasov wrote:
>>     
>>> Hi there!
>>>
>>> I try to implement as precise as possible one undocumented feature in
>>> comctl32, this all deals with one structure field. After lots of
>>> testing I know the following:
>>>
>>> 1. Default value for that field returned by getter is 0.
>>> 2. By default it is ignored in behavior.
>>> 3. If you change value by the setter, even to 0, behavior changes.
>>> 4. Negative values, such as (-1) also produce different behavior and
>>> cannot be used as "field not changed" flag.
>>>
>>> So, does that mean that I have to add new flag to the structure that
>>> would be set only if that field is changed, or there is another way to
>>> do that?
>>>
>>>
>>>       
>> What flag are you speaking about? Toolbar stuff?
>>
>>     
>
> Yep, it's about undocumented feature of iBitmap controlling buttons'
> size But it works only if cx is zero and iBitmap was not specifically
> set.
>
>   
So (-1) for iButton is reserved for not using imagelist bitmap at all 
and in some places this value checked for <0 instead of
== -1, right? Does it apply for separators only? If not maybe it's 
better to add something like BOOL IsiBitmapValid.
Let's get another opinions. (Hope you'll be ready with patch for today 
release)