wm¶

window-manager core: windows, z-order, focus, menu (//#use wm)
NAME
    wm - window-manager core: windows, z-order, focus, menu (//#use wm)

SYNOPSIS
    //#use abi
    //#use ptr
    //#use wm           cc splices /lib/lib_wm.c
    //#define GLDATA .. //#define GLSTAT ..   (the library pokes them raw)

DESCRIPTION
    Up to four windows with visibility, z-order, focus, title-bar drag,
    close boxes, and a Mac-style press-drag-release MENU along the top of
    the screen. The library owns the CHROME (frames, title bars, close
    boxes, the drag outline, the menu, the painter's repaint, hit
    testing); the client owns CONTENT and the event pump.

    Each window's content draws under its own WINDOW/VWPORT pair, so the
    app paints in LOCAL coordinates with hardware clipping and
    paint-order occlusion. The client must provide two callbacks:

        int   wm_content(int i);   draw window i's content (local coords;
                                   the library has set the mapping)
        char *wm_title(int i);     window i's title string

THE EVENT PUMP
    Drive it from ptr_ev() (man ptr):

        t = ptr_ev();
        if      (t == 1) { r = wm_press(ptr_x, ptr_y); ... }
        else if (t == 2) { wm_dragm(ptr_x, ptr_y); }
        else if (t == 3) { wm_drop(ptr_x, ptr_y); }

    wm_press returns: 0 miss, 1 handled (raise / drag-arm), 2 a menu item
    was chosen (index in wm_msel), 3 a window was closed (index in
    wm_closed). The menu tracks its own press-drag-release inside
    wm_press.

KEY GLOBALS
    wm_n                number of windows (<= 4)
    wmx/wmy wmw/wmh     each window's bottom-left + outer size (window coords)
    wmvis[i]            1 = shown
    wmz[i]              stacking order, bottom first
    wm_mtitle wm_mitems wm_mcount   the menu (up to 6 x 16-char rows)
    wm_msel             wm_press result 2: the chosen item
    wm_closed           wm_press result 3: the closed window

NOTES
    This is the client-side window kernel used by the full-screen desk /
    finder programs; the resident WM kernel folded into the OS is a
    separate path (see docs/p8x-wm-design.md). Content lives in the app.

SEE ALSO
    ptr, gfx, finder, desk, wdesk