The first thing that comes to mind when reading "data that is associated with the component" is data binding. I think it is a mistake to build
What do you mean by this? Could you give an example?
The majority of the current proposals (mine included) have taken the approach of providing native interoperability with the OS-specific data structures. This is very difficult to maintain properly and support generic code because of the different names of the data elements, types used (long or float) and whether an area is (position + size) or (top-left + bottom-right). Also, most OSs have (0,0) being the top-left corner, but MacOS has (0,0) being bottom-left.
With this in mind, I have taken a drastic approach: do not provide native interoperability for size, position and area. I have designed them as:
struct position{ float x; float y; }; struct size{ float dx; float dy; }; struct area { float top; float left; float width; float height; };
This means that the interface must convert these to the native representations and vise versa.
I would say that this is the correct approach. As a side-node, I'm moderately against having float coordinates. Why would you think int is not enough? Best, John -- John Torjo, Contributing editor, C/C++ Users Journal -- "Win32 GUI Generics" -- generics & GUI do mix, after all -- http://www.torjo.com/win32gui/ -- http://www.torjo.com/cb/ - Click, Build, Run!