Thread: Getting interior window size

With a function like "CreateWindow", the size you specify is for the whole window as opposed to the interior space. For example, BitBlt a 1024x768 image into the window of this same size and you'll see a little bit chopped off on the right and quite a bit chopped off on the bottom. This is because the window itself is 1024x768 rather than the interior space and elements like the title bar, menu, and even borders take away some of this. If it was the interior space, the whole image will fill the whole interior without any waste or chopping. How do I determine this interior space? Is there a function I can use, or, as I currently do, I have to repeatedly use "GetSystemMetrics" to find the sizes of these things then add them onto the window's size to get the actual result? If there's a predefined Windows function, I would like to know what this function is so I can get a window, with greater ease, of the intended interior size. Thanks.

You can use GetClientRect to get the 'interior' area, but you have to calc manually the other elements areas (usually the toolbar and status areas) from the wm_size msg, and rest it to the window's interior area; first set the position for all the static elements, then get their external window area (GetWindowRect), get the parent window client rect (interior area), and then rest the header and footer element's area (and lateral elements if that's the case).

I.e. if you have a toolbar and a status, you will set their position, and then rest its external area from the parent area:

Code:

//hwnd means the parent window handle
case WM_SIZE:
    {
    RECT area,r_toolbar,r_status;

    SendMessage(toolbar,TB_AUTOSIZE,0,0);//posite the static elements
    SendMessage(status,WM_SIZE,0,0);
    
    GetWindowRect(toolbar,&r_toolbar);//get the areas
    GetWindowRect(status,&r_status);
    GetClientRect(hwnd,&area);
    
    area.top=r_toolbar.bottom-r_toolbar.top;//calc the 'free' space
    area.bottom-=(r_status.bottom-r_status.top);
    area.bottom-=area.top;
    
    //you got it :)
    }
break;

Hope that helps
Niara

GetClientRect - I saw that function before I asked here, but couldn't tell if that was what I needed. It's probably the word "client" that made it questioned. Thanks though for the help. I can clean out more variables now.