4

I only want to execute a certain action with xdotool if the window is not visible to the user, this includes minimized windows, but also windows which are 100% covered by other windows (if no transparency is used at least). Ignoring the transparency issue is there a simple way to do this?

xdotool has a --onlyvisible option, but that only includes minimized windows, not covered windows. Of course there is the option of cycling through all visible windows, getting their window geometries and calculating how much of the window of interest they cover, but I do hope there is an easier and faster solution than doing this in bash.

Here is a nice illustration of the problem, but there it is only about listing windows, also it is for Max OS X. This question only has an answer which hints, but not shows how to do it by listing all visible windows with their respective z-order and calculating the visible area manually.

3

For completeness sake here is the naive / brute-force solution which I hoped is already implemented in some other utility. The fullyobscured notify-event in @Gilles link in the comment sounds very promising, but I wasn't sure how to get it to work, and this solution was also quite fun to implement.

The script simply calculates the coverage area of all overlapping window subtracting double counted areas and checks if it is as large as the window area. Because it correctly includes the frame borders the code looks a bit more complex than it could. It returns exit code 0 if fully covered and 1 if not. It takes a window ID as an argument. E.g. call it with if xcovered 0x1a00003; then echo 'covered!'; fi

Not counting the comments, debug comments and error-checking it could be only 40 lines long, surely even less. I actually wanted to use bc instead of python, but I couldn't find an easy way to transfer a bash array to a bc array.

#!/bin/bash
# Name: xcovered.sh
# Find out if C is completely or only partially covered by A or B
#  +-----------+
#  |   +===+   |
#  |   | +-------+
#  | C | |   B   |
#  |   | +-------+
#  +---| A |---+
#      +---+
# @return 0 if window ist not visible, 1 if visible
# Note: Only tested with three windows like in sketch above, but
#       it should also work for an arbitrary amount of overlapping windwows
wid=$1
if ! xwininfo -id $wid -stats | 'grep' -q 'IsViewable'; then return 0; fi

# get all stacked window ids after and including the given wid
wids=($(xprop -root | 'sed' -nE "/_NET_CLIENT_LIST_STACKING\(WINDOW\)/{ s|.*($wid)|\1|; s|,||g; p }"))
if [ ${#wids} -eq 0 ]; then
    echo -e "\e[31mCouldn't find specified window id $wid in _NET_CLIENT_LIST_STACKING(WINDOW)"'!'"\e[0m"
    return 2
fi
if [ ${#wids} -eq 1 ]; then return 0; fi

# Gather geometry of all windows in higher zorder / possibly lying on top
coords=(); frames=()
for owid in ${wids[@]}; do
    #xwininfo -id $owid | grep xwininfo
    if xwininfo -id $owid -stats | 'grep' -q 'IsViewable'; then
        # _NET_WM_ICON_GEOMETRY doesn't exist for xfce4-panel, thereby making this more difficult
        #coords=$(xprop -id $owid _NET_WM_ICON_GEOMETRY)
        #frames=$(xprop -id $owid _NET_FRAME_EXTENTS)
        x=($(xwininfo -id $owid -stats -wm | sed -nE '
            s|^[ \t]*Absolute upper-left X:[ \t]*([0-9]+).*|\1|Ip;
            s|^[ \t]*Absolute upper-left Y:[ \t]*([0-9]+).*|\1|Ip;
            s|^[ \t]*Width:[ \t]*([0-9]+).*|\1|Ip;
            s|^[ \t]*Height:[ \t]*([0-9]+).*|\1|Ip;
            /Frame extents:/I{ s|^[ \t}Frame Extents:[ \t]*||I; s|,||g; p; };
        ' | sed ':a; N; $!b a; s/\n/ /g '))
        if [ ! ${#x[@]} -eq 8 ]; then
            echo -e "\e[31mSomething went wrong when parsing the output of 'xwininfo -id $owid -stats -wm':\e[0m"
            xwininfo -id $owid -stats -wm
            exit 1
        fi
        # apply the frame width to the coordinates and window width
        # 0:x 1:y 2:w 3:h, border widths 4:left 5:right 6:top 7:bottom
        coords+=( "${x[0]}-${x[4]}, ${x[1]}-${x[6]}, ${x[2]}+${x[4]}+${x[5]}, ${x[3]}+${x[6]}+${x[7]}" )
    fi
done

IFS=','; python - <<EOF #| python
# Calculates the area of the union of all overlapping areas. If that area
# is equal to the window of interest area / size, then the window is covered.
# Note that the calcualted area can't be larger than that!
#   1
# D---C      => overlap given by H and B
# | H-|---G    x-overlap: max(0, xleft2-xright1)
# A---B   |         -> '1' and '2' is not known, that's why for left and right
#   |  2  |            use min, each
#   E-----F         -> max(0, min(xright1,xright2) - max(xleft1,xleft2) )
#                      Note that because of xleft<xright this can only
#                      result in xright1-xleft2 or xright2-xleft1
# All cases: 1 |     +--+ |   +--+ | +--+   | +--+      |
#            2 | +--+     | +--+   |   +--+ |      +--+ |
#      overlap |    0     |    2   |    2   |     0     |
def overlap( x1,y1,w1,h1, x2,y2,w2,h2, x3=0,y3=0,w3=65535,h3=65535 ):
    return max( 0, min(x1+w1,x2+w2,x3+w3) - max(x1,x2,x3) ) * \
           max( 0, min(y1+h1,y2+h2,y3+h3) - max(y1,y2,y3) )
x=[ ${coords[*]} ]
area=0
# Calculate overlap with window in question
# 0:x 1:y 2:w 3:h, border widths 0:left 1:right 2:top 3:bottom
for i in range( 4,len(x),4 ):
    area += overlap( *( x[0:4]+x[i:i+4] ) )

# subtract double counted areas i.e. areas overlapping to the window
# of interest and two other windows on top ... This is n**2
for i in range( 4,len(x),4 ):
    for j in range( i+4,len(x),4 ):
        area -= overlap( *( x[0:4]+x[i:i+4]+x[j:j+4] ) )

print "area =",area
print "woi  =",x[2]*x[3]
# exit code 0: if not fully covered, 1: if fully covered
exit( area < x[2]*x[3] )
EOF
exit $?
  • 1
    Beware that this doesn't take non-rectangular windows into account. Those are admittedly rare. Does this correctly report windows visible only on another desktop or entirely outside the screen area as invisible? – Gilles May 6 '16 at 0:50
  • I used your code to make it a Python module. Maybe you like to check it out: github.com/ikem-krueger/sleep-walker/blob/develop/src/usr/lib/… – Ikem Krueger Sep 15 '17 at 23:44
  • @user82110 Oh that's cool, thanks for the link! – mxmlnkn Sep 16 '17 at 22:18

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