Child windows – PB Docs 2017

Child windows are always opened from within a main or pop-up
window, which becomes the child window’s parent.

A child window exists only within its parent. You can move the
child window within the parent window, but not outside the parent.
When you move a portion of a child window beyond the parent,
PowerBuilder clips the child so that only the portion within the
parent window is visible. When you move the parent window, the child
window moves with the parent and maintains the same position relative
to the parent.

Child windows cannot have menus and are never considered the
active window. They can have title bars and can be minimizable,
maximizable, and resizable. When they are maximized, they fill the
space of their parent; when they are minimized, their icon displays at
the bottom of their parent.

The initial position of the child is relative to the parent and
not to the entire screen. A child window closes when you close its
parent.

You will probably not use child windows very often. Typically,
if you want to display windows inside other windows, you will write
MDI applications, where much of the window management happens
automatically.

For more on building MDI applications, see Building
an MDI Application in Application Techniques.