The Fl_Tile class lets you resize the children by dragging
the border between them:
Fl_Tile allows objects to be resized to zero dimensions.
To prevent this you can use the resizable() to limit where
corners can be dragged to.
Even though objects can be resized to zero sizes, they must
initially have non-zero sizes so the Fl_Tile can figure out
their layout. If desired, call position() after creating the
children but before displaying the window to set the borders where you
want.
The "borders" are part of the children -
Fl_Tile does not draw any graphics of its own. In the
example above, all of the children have FL_DOWN_BOX
types, and the "ridges" you see are actually two
adjacent FL_DOWN_BOX's drawn next to each other. All
neighboring widgets share the same edge - the widget's thick
borders make it appear as though the widgets aren't actually
touching, but they are. If the edges of adjacent widgets do not
touch, then it will be impossible to drag the corresponding
edges.
The destructor also deletes all the children. This allows a
whole tree to be deleted at once, without having to keep a pointer to
all the children in the user code. A kludge has been done so the
Fl_Tile and all of it's children can be automatic (local)
variables, but you must declare the Fl_Tilefirst, so
that it is destroyed last.
