bin: add a random wallpaper script

2 files changed, 151 insertions, 0 deletions

diff --git a/bin/random_wallpaper b/bin/random_wallpaper
new file mode 100755
index 0000000..15d2da9
--- /dev/null
+++ b/bin/random_wallpaper
@@ -0,0 +1,149 @@
+#!/usr/bin/python3
+# Reads a given directory and set a random
+# wallpaper using the images on that dir.
+
+import subprocess
+import os
+import os.path
+import re
+import random
+import sys
+import tempfile
+
+class Display:
+    index           = None
+    name            = None
+    offset          = None
+    size            = None
+
+    wall_filename   = None
+
+    def __lt__(self, other):
+        if self.offset[1] != other.offset[1]:
+            return self.offset[1] < other.offset[1]
+        return self.offset[0] < other.offset[0]
+
+def detect_screen_geometry():
+    screen      = None
+    displays    = []
+
+    p = subprocess.Popen('xrandr', stdout = subprocess.PIPE, text = True)
+    for line in p.stdout:
+        if line.startswith('Screen'):
+            if screen:
+                sys.stderr.write('Multiple X screens, not supported by this script\n')
+                raise NotImplementedError
+
+            m = re.search(r'current (\d*) x (\d*),', line)
+            try:
+                screen = [int(m.group(1)), int(m.group(2))]
+            except:
+                sys.stderr.write('Unsupported screen specification line: %s' % line)
+                raise
+        elif ' connected ' in line:
+            m = re.match(r'(\S*) connected (\S+ )*(\d*)x(\d*)([+-]\d*)([+-]\d*)', line)
+            if m:
+                d = Display()
+
+                d.name = m.group(1)
+                d.offset = (int(m.group(5)), int(m.group(6)))
+                d.size   = (int(m.group(3)), int(m.group(4)))
+
+                if d.size[0] <= 0 or d.size[1] <= 0:
+                    sys.stderr.write('Invalid non-positive display dimensions\n')
+                    raise ValueError
+                if d.offset[0] < 0 or d.offset[1] < 0:
+                    sys.stderr.write('Negative display geometry offset, this is not supported\n')
+                    raise NotImplementedError
+
+                displays.append(d)
+
+    if screen is None:
+        sys.stderr.write('Missing screen specification in xrandr output\n')
+        raise ValueError
+
+    # sort the displays in the render scan order
+    displays = sorted(displays)
+    for i, d in enumerate(displays):
+        d.index = i
+
+    return screen, displays
+
+
+if len(sys.argv) < 3:
+    sys.stderr.write('Usage: %s <wallpaper_dir> <state dir> <display number 0> [<display number 1> ... ]\n'%(sys.argv[0]))
+    sys.exit(-1)
+
+# parse the commandline
+wall_dir    = os.path.expandvars(sys.argv[1])
+state_dir   = os.path.expandvars(sys.argv[2])
+
+sys.stderr.write('Trying directory %s.\n'%wall_dir)
+if not os.path.isdir(wall_dir):
+    sys.stderr.write('Path %s is not a directory, aborting.\n'%wall_dir)
+    sys.exit(-1)
+if not os.path.isdir(state_dir):
+    sys.stderr.write('Invalid state dir supplied, won\'t store/use any state\n')
+    state_dir = None
+
+screen, displays = detect_screen_geometry()
+
+sys.stderr.write('The X screen resolution is %dx%d.\n' % (screen[0], screen[1]))
+sys.stderr.write('The connected displays are:\n')
+for i, d in enumerate(displays):
+    sys.stderr.write('    %d: %s - %d x %d at (%d, %d)\n' % (d.index, d.name, d.size[0], d.size[1], d.offset[0], d.offset[1]))
+
+# pick a new wallpaper for each specified display
+files = os.listdir(wall_dir)
+random.seed()
+
+if len(sys.argv) >= 4 and sys.argv[3] == 'all':
+    disp_indices = range(len(displays))
+else:
+    disp_indices = map(int, sys.argv[3:])
+
+for d_idx in disp_indices:
+    if d_idx >= len(displays):
+        sys.stderr.write('Display index %d is too large, there are only %d connected displays\n'
+                         % (d_idx, len(displays)))
+        raise ValueError
+    d = displays[d_idx]
+
+    wallfile = random.choice(files)
+    sys.stderr.write('Picking wall %s for display %d (%s)\n' % (wallfile, d.index, d.name))
+
+    if state_dir:
+        fname = os.path.join(state_dir, '%d.png' % d.index)
+    else:
+        d.tfile = tempfile.NamedTemporaryFile()
+        fname   = d.tfile.name
+
+    subprocess.check_call(['convert', '-size', '%dx%d' %(d.size[0], d.size[1]), 'canvas:black',
+                           os.path.join(wall_dir, wallfile), '-resize', '%dx%d' % (d.size[0], d.size[1]),
+                           '-gravity', 'center', '-composite', fname])
+    d.wall_filename = fname
+
+# compose the wallpaper file
+tf = tempfile.NamedTemporaryFile()
+cmdline = ['convert', '-size', '%dx%d' % (screen[0], screen[1]), 'canvas:black']
+for d in displays:
+    fname = d.wall_filename
+
+    if fname is None and state_dir:
+        tmpname = os.path.join(state_dir, '%d.png' % d.index)
+        if os.path.isfile(tmpname):
+            fname = tmpname
+
+    if fname is not None:
+        cmdline.extend([fname, '-geometry', '+%d+%d' %(d.offset[0], d.offset[1]), '-composite'])
+cmdline.append('png:' + tf.name)
+subprocess.check_call(cmdline)
+
+# set the background
+try:
+    subprocess.check_call(['feh', '--bg-center', '--no-xinerama', tf.name])
+except (subprocess.CalledProcessError, OSError):
+    sys.stderr.write('Error setting the wallpaper. Is feh installed?\n')
+    sys.exit(-1)
+
+sys.exit(0)
diff --git a/desktop.conf.yaml b/desktop.conf.yaml
index 3176647..717384a 100644
--- a/desktop.conf.yaml
+++ b/desktop.conf.yaml
@@ -1,4 +1,5 @@
 - create:
+    - ~/.cache/wallpaper
     - ~/.config/mpv
     - ~/.config/mpv/scripts
     - ~/.urxvt/ext
@@ -7,6 +8,7 @@
     ~/.config/mpv/config: dotfiles/mpv
     ~/.config/mpv/scripts/xscreensaver.lua: mpv/xscreensaver.lua
     ~/.local/bin/brightness_monitor:  bin/brightness_monitor
+    ~/.local/bin/random_wallpaper:    bin/random_wallpaper
     ~/.local/bin/randr_output_toggle: bin/randr_output_toggle
     ~/.local/bin/ssh_sk_clean:  bin/ssh_sk_clean
     ~/.local/bin/udev_match:    bin/udev_match