Add i3 auto layout

bin/i3autolayout

@@ -0,0 +1,106 @@
+#!/usr/bin/env python
+
+import i3
+import re
+import subprocess
+import getopt
+import sys
+import os
+
+
+def find_parent(window_id):
+    """
+        Find the parent of a given window id
+    """
+    root_window = i3.get_tree()
+    result = [None]
+
+    def finder(n, p=None):
+        if result[0] is not None:
+            return
+        for node in n:
+            if node['id'] == window_id:
+                result[0] = p
+                return
+            if len(node['nodes']):
+                finder(node['nodes'], node)
+
+    finder(root_window['nodes'])
+    return result[0]
+
+
+def set_layout():
+    """
+        Set the layout/split for the currently
+        focused window to either vertical or
+        horizontal, depending on its width/height
+    """
+    current_win = i3.filter(nodes=[], focused=True)
+    for win in current_win:
+        parent = find_parent(win['id'])
+
+        if (parent and "rect" in parent
+                   and parent['layout'] != 'tabbed'
+                   and parent['layout'] != 'stacked'):
+            height = parent['rect']['height']
+            width = parent['rect']['width']
+
+            if height > width:
+                new_layout = 'vertical'
+            else:
+                new_layout = 'horizontal'
+
+            i3.split(new_layout)
+
+
+def print_help():
+    print("Usage: " + sys.argv[0] + " [-p path/to/pid.file]")
+    print("")
+    print("Options:")
+    print("    -p path/to/pid.file   Saves the PID for this program in the filename specified")
+    print("")
+
+
+def main():
+    """
+        Main function - listen for window focus
+        changes and call set_layout when focus
+        changes
+    """
+    opt_list, args = getopt.getopt(sys.argv[1:], 'hp:')
+    pid_file = None
+    for opt in opt_list:
+        if opt[0] == "-h":
+            print_help()
+            sys.exit()
+        if opt[0] == "-p":
+            pid_file = opt[1]
+
+    if pid_file:
+        with open(pid_file, 'w') as f:
+            f.write(str(os.getpid()))
+
+
+    process = subprocess.Popen(
+        ['xprop', '-root', '-spy'],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE
+    )
+    regex = re.compile(b'^_NET_CLIENT_LIST_STACKING|^_NET_ACTIVE_WINDOW')
+
+    last_line = ""
+    while True:
+        line = process.stdout.readline()
+        if line == b'': #X is dead
+            break
+        if line == last_line:
+            continue
+        if regex.match(line):
+            set_layout()
+        last_line = line
+
+    process.kill()
+    sys.exit()
+
+if __name__ == "__main__":
+    main()