[RP] a proper frame tree?

[twb]

I've been thinking about the best  / simplest way to specify the frame
tree.

typedef struct {
    int x,y,width,height;
    rp_frame_or_window *child; //Child is either a split or a window.
    Bool child_is_window;      
} rp_top_level_frame; //Special because has a GEOM.


typedef struct {
    Bool isVert; //Made by a split or vsplit?
    rp_frame_or_window *child0[2]; //Has two children
    Bool child_is_window[2];
    float ratio; //How much of the split is used by the first child (0-1).
} rp_split_frame; 


typedef union {
    XWindow w; 
    rp_split_frame f;
} rp_frame_or_window;


On a vanilla display, there's only one TL frame.  On multi-screen, one
for each screen.   On xinerama, either one for each  monitor, or a big
one which might not all be visible.


This makes destruction/creation of  frames *very* simple.  Um, not too
sure about how resizing would work.

Also, you  never have more than  two kids, which means  the parent can
remember the kids, which is simpler than X11's kid-remembers-parent.

O'course, changing the frame  paradigm will need pretty hefty rewrite,
so I'm  not issuing  any ultimatums or  anything, just  formalising my
ideas so far.

-trent