[SOLVED] Creating IGUIEnvironment object, what abut id ??

[WhyMe]

Hello.
I have not idea how and where to find explaint abut "id" number in function, like addbutton(...).
The default number of id is -1. Why ??
What is happen, when I set id = -1,0, > 1 or < -1 ??

I have hope, I wrote it clearly.
Regards.

[chronologicaldot]

An ID is what you can use to find your GUI elements without having a direct pointer to them. For example, in general, programs add their GUI elements to the GUI environment's root GUI element, which you can get via the following:

Code: Select all

 
IrrlichtDevice* device = createDevice();
device->getGUIEnvironment()->getRootGUIElement();
 

Once you have a pointer to a GUI element (such as the root GUI element), you can find it based on it's given ID via the function virtual IGUIElement * getElementFromId (s32 id, bool searchchildren=false) const.
The function returns a pointer to the first GUI element found with that ID.
NOTE: The only GUI elements that are searched are the GUI element itself (on which you called the function) and its children. In order to search the children (child GUI elements) of the children (child GUI elements), you must pass a "true" as the second parameter to this function.

The fact that the ID is set to -1 by default means nothing. It's convenient as a programmer to say -1 means "no ID". You could use it as an ID if you wanted.
DO NOT use 0 as an ID (if you want to use getElementFromId() that is) because it is reserved for the root GUI element.

Hope that helps.

[WhyMe]

Well, ok I understand how it was made.
So, the ID can be all digits in integer range (except 0).

Thank you for respond.