Window is a widget that owns an event queue and that can have a canvas through which an application can render to the window. Window also acts as a parent for sub windows and gadgets. A window may also have a geometry manager, for managing the layout of its sub windows and gadgets.

The class is defined in inc/oops/r3window.h header file.

Every GUI application must have a main window. To create a main window:

    #include <oops/r3window.h>

    R3OBJ *mainwin;
    mainwin = R3New(R3CLID_WINDOW,
                    R3WA_SubClass, R3SUBCL_MAINWINDOW,
                    R3WA_Title, "my application",
                    R3WA_CloseGadget, TRUE,
                    R3WA_Zoom, TRUE,
                    R3WA_SizeGadget, TRUE,
                    R3WA_DragBar, TRUE,
                    ...,
                    R3TAG_END);

To create a child window for the main window:

    subwin = R3New(R3CLID_WINDOW,
                   R3WGA_Parent, mainwindow,
                   R3WA_SubClass, R3SUBCL_SUBWINDOW,
                   ....
                   R3TAG_END);

The parent-child relation ship is defined by using the R3WGA_Parent attribute. The main window is the top level window in application and the only window who doesn't have parent.

There are three kind of sub windows:

The window class defines large number of options and methods which allow you to create and manage all possible type of windows one might need. The 'samples/kernel/' folder contains numerous examples demonstrating window class..