#!/bin/sh
# 
# Date: Sat, 23 Jul 88 22:15:33 EDT
# To: NeWS-makers@brillig.umd.edu
# Subject: Can't Keep a Good Clock Down.
# From: frame!gergle!greg@Sun.COM
# 
# I always litter my screen with windows, and have to uncover my
# clock to read it. I decided I was going to write a clock which would
# be smart enough to keep itself visible. I thought it was going to be easy,
# but I found no good way to find a free spot on the root canvas. I stooped
# to traversing the canvas list, and doing rectangle list calculations
# in PostScript. If anyone has a better way please let me know. I cringe
# every time I see the clock change knowing what its doing. If there isn't
# a better way, others may find the "findplace" routine below usefull.
# 
# 	-greg.
# 
# 
# Bugs: This is not an accurate clock, because it relies on a sleep in the
# shell script to feed the correct time to NeWS.
# 
# 
# ------------------------------------------------------------------------

DATECOMMAND="date +%H:%M"
trap "echo systemdict /DigitalTime null put | psh;exit" 15 2

# Need to put a non null value in DigitalTime
echo "systemdict /DigitalTime (`$DATECOMMAND`) put" | psh

psh  <<GIVETONEWS
{
/Height 64 def
/Width 0 def
/Xpos 10 def
/Ypos 10 def
/CX 100 def
/CY 100 def
/myfont /Times-Roman findfont Height scalefont def
/erase { Xpos Ypos Width Height rectpath
        clipcanvas PaintRoot newpath clipcanvas
        } def
myfont setfont
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% The Following code up the next line of % finds the free spot on the
% root canvas

%
% Leave the rectangle of a Canvas on the stack.
%
/getcanvasrect { % canvas ==> array canvas
    dup /Mapped get
        { dup getcanvaslocation [ 3 1 roll
        gsave
        3 index setcanvas
        clippath pathbbox 4 -2 roll pop pop
        grestore
        ] exch
        } if
    } def

%
% Get the Rectangles of all the Mapped&Opaque Canvases on the Display.
% Each is left in an array [x y w h] on the stack
%
/getcanvasrects { framebuffer /TopCanvas get getcanvasrect nextcanvas } def

/nextcanvas {
    /CanvasBelow get dup null ne { getcanvasrect nextcanvas} { pop } ifelse
    } def


%
% Find the largest rectangle unoccupied in the root canvas which will fit
% the given width & heigth. Return false if it does not exist.
%
/findplace { % w h ==> x y w h bool
    /outrects [ getcanvasrects ] def
    /inrects [[ clippath pathbbox ]] def

    outrects { subtractfromall pause } forall
    /maxarea -1 def
    /keeper null def
    inrects { /r exch def r 2 get 2 index gt
                { r 3 get 1 index gt
                    { r 2 get r 3 get mul dup maxarea gt
                        { /maxarea exch store /keeper r store }
                        { pop }
                        ifelse
                    } if
                } if
            } forall
    pause pop pop
    keeper null eq
        { false }
        { keeper aload pop true}
        ifelse
    } def

%
% Subtract this rect from all the inrects.
%
/subtractfromall { % [x y w h] ==> -
    /r exch def
    /inrects [ inrects { subtractrect } forall ] def
    } def

%
% Subtract rectangle r from the rectangle on the stack if it intersects
%
/subtractrect { % [x y w h] ==> 1-4 of [x y w h]
    dup r hitrect
        { r mungerect } if
    } def

%
% check if 2 rects intersect
%
/hitrect { % [x y w h] [x y w h] ==> bool
    /r2 exch def /r1 exch def
    r1 0 get r1 2 get add r2 0 get ge dup
        { pop r2 0 get r2 2 get add r1 0 get ge dup
            { pop r1 1 get r1 3 get add r2 1 get ge dup
                { pop r2 1 get r2 3 get add r1 1 get ge
                } if
            } if
        } if
    } def
%
% Subtract the top rectangle from the rectangle underneath
% Rectangles have already been tested, they must intersect.
%
/mungerect { % [x y w h] [x y w h ] ==> 1-4 of [x y w h]
    /r2 exch def /r1 exch def
        % left piece
    r2 0 get r1 0 get sub dup 0 gt              % w bool
        { r1 4 array copy dup 2 4 -1 roll put } % [x y w h]
        { pop }
    ifelse
        % right piece
    r1 0 get r1 2 get add r2 0 get r2 2 get add sub dup 0 gt  % w bool
        { [ r2 0 get r2 2 get add r1 1 get 4 -1 roll r1 3 get ] } % [x y w h]
        { pop }
    ifelse
        % bottom piece
    r2 1 get r1 1 get sub dup 0 gt              % h bool
        { r1 4 array copy dup 3 4 -1 roll put } % [x y w h]
        { pop }
    ifelse
        % top piece
    r1 1 get r1 3 get add r2 1 get r2 3 get add sub dup 0 gt  % h bool
        { [ r1 0 get r2 1 get r2 3 get add r1 2 get 5 -1 roll ] } % [x y w h]
        { pop }
    ifelse
    } def
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    {
    DigitalTime null ne
        {
        /NewWidth DigitalTime stringwidth pop 10 add def
        NewWidth Height findplace
            {  2 div 3 -1 roll add 3 1 roll 2 div add   % cy cx
              dup CX ne 2 index CY ne or       % cy cy bool  have we moved
                    { erase } if
            /CX exch store /CY exch store
            } if

        /Width NewWidth store
        /Xpos CX Width 2 div sub def
        /Ypos CY Height 2 div sub def
        Xpos Ypos Width Height dup 4 div
        5 1 roll rrectpath
        0 setgray fill 1 setgray
        Xpos 5 add Ypos 10 add moveto
        DigitalTime show
        }
        { erase quit } ifelse
        .5 sleep
    } loop
} fork
GIVETONEWS

while true
do
echo "systemdict /DigitalTime (`$DATECOMMAND`) put" | psh
sleep 55
done