Create MDI frame - %fr
%fr is used in a parent window to define a frame into which child windows are
placed. These windows can be moved and re-sized within this MDI (multi-document
interface) frame. The format takes two integer arguments that define the width
and height of the frame in pixels. A MDI frame can be preceded by the pivot
(%pv), in which case it will expand as the window expands. An example using %fr
appears with %aw below.
A grave accent (`) can be added to %fr to cause it to maintain a handle
identifying the currently selected child window. An extra integer argument is
supplied to hold the returned handle. The integer will be zero if there is no
child window. When a child window is created, the handle is obtained by using
%hw (see Window handle - %hw). A comparison
may then be made between the handle updated by %fr and those previously
returned by %hw.