Merge pull request #78 from okraits/master

i3-cycle-focus.py: cycle through all previously focused windows

Author: Tony Crisci

examples/i3-cycle-focus.py

@@ -0,0 +1,166 @@
+#!/usr/bin/env python3
+
+import os
+import socket
+import selectors
+import threading
+from argparse import ArgumentParser
+import i3ipc
+
+SOCKET_FILE = '/tmp/i3-cycle-focus'
+MAX_WIN_HISTORY = 16
+UPDATE_DELAY = 2.0
+
+
+class FocusWatcher:
+
+    def __init__(self):
+        self.i3 = i3ipc.Connection()
+        self.i3.on('window::focus', self.on_window_focus)
+        self.listening_socket = socket.socket(socket.AF_UNIX,
+                                              socket.SOCK_STREAM)
+        if os.path.exists(SOCKET_FILE):
+            os.remove(SOCKET_FILE)
+        self.listening_socket.bind(SOCKET_FILE)
+        self.listening_socket.listen(1)
+        self.window_list = []
+        self.window_list_lock = threading.RLock()
+        self.focus_timer = None
+        self.window_index = 1
+
+    def update_windowlist(self, window_id):
+        with self.window_list_lock:
+            if window_id in self.window_list:
+                self.window_list.remove(window_id)
+            self.window_list.insert(0, window_id)
+            if len(self.window_list) > MAX_WIN_HISTORY:
+                del self.window_list[MAX_WIN_HISTORY:]
+            self.window_index = 1
+
+    def get_valid_windows(self):
+        tree = self.i3.get_tree()
+        if args.active_workspace:
+            return set(w.id for w in tree.find_focused().workspace().leaves())
+        elif args.visible_workspaces:
+            ws_list = []
+            w_set = set()
+            for item in self.i3.get_outputs():
+                ws_list.append(item["current_workspace"])
+            for ws in tree.workspaces():
+                if str(ws.num) in ws_list:
+                    for w in ws.leaves():
+                        w_set.add(w.id)
+            return w_set
+        else:
+            return set(w.id for w in tree.leaves())
+
+    def on_window_focus(self, i3conn, event):
+        if args.ignore_float and (event.container.props.floating == "user_on" or
+                                  event.container.props.floating == "auto_on"):
+            return
+        if UPDATE_DELAY != 0.0:
+            if self.focus_timer is not None:
+                self.focus_timer.cancel()
+            self.focus_timer = threading.Timer(UPDATE_DELAY,
+                                               self.update_windowlist,
+                                               [event.container.props.id])
+            self.focus_timer.start()
+        else:
+            self.update_windowlist(event.container.props.id)
+
+    def launch_i3(self):
+        self.i3.main()
+
+    def launch_server(self):
+        selector = selectors.DefaultSelector()
+
+        def accept(sock):
+            conn, addr = sock.accept()
+            selector.register(conn, selectors.EVENT_READ, read)
+
+        def read(conn):
+            data = conn.recv(1024)
+            if data == b'switch':
+                with self.window_list_lock:
+                    windows = self.get_valid_windows()
+                    for window_id in self.window_list[self.window_index:]:
+                        if window_id not in windows:
+                            self.window_list.remove(window_id)
+                        else:
+                            if self.window_index < (len(self.window_list) - 1):
+                                self.window_index += 1
+                            else:
+                                self.window_index = 0
+                            self.i3.command('[con_id=%s] focus' % window_id)
+                            break
+            elif not data:
+                selector.unregister(conn)
+                conn.close()
+
+        selector.register(self.listening_socket, selectors.EVENT_READ, accept)
+
+        while True:
+            for key, event in selector.select():
+                callback = key.data
+                callback(key.fileobj)
+
+    def run(self):
+        t_i3 = threading.Thread(target=self.launch_i3)
+        t_server = threading.Thread(target=self.launch_server)
+        for t in (t_i3, t_server):
+            t.start()
+
+
+if __name__ == '__main__':
+    parser = ArgumentParser(prog='i3-cycle-focus.py',
+        description="""
+        Cycle backwards through the history of focused windows (aka Alt-Tab).
+        This script should be launched from ~/.xsession or ~/.xinitrc.
+        Use the `--history` option to set the maximum number of windows to be
+        stored in the focus history (Default 16 windows).
+        Use the `--delay` option to set the delay between focusing the
+        selected window and updating the focus history (Default 2.0 seconds).
+        Use a value of 0.0 seconds to toggle focus only between the current
+        and the previously focused window. Use the `--ignore-floating` option
+        to exclude all floating windows when cycling and updating the focus
+        history. Use the `--visible-workspaces` option to include windows on
+        visible workspaces only when cycling the focus history. Use the
+        `--active-workspace` option to include windows on the active workspace
+        only when cycling the focus history.
+
+        To trigger focus switching, execute the script from a keybinding with
+        the `--switch` option.""")
+    parser.add_argument('--history', dest='history',
+                        help='Maximum number of windows in the focus history',
+                        type=int)
+    parser.add_argument('--delay', dest='delay',
+                        help='Delay before updating focus history',
+                        type=float)
+    parser.add_argument('--ignore-floating', dest='ignore_float',
+                        action='store_true', help='Ignore floating windows '
+                        'when cycling and updating the focus history')
+    parser.add_argument('--visible-workspaces', dest='visible_workspaces',
+                        action='store_true', help='Include windows on visible '
+                        'workspaces only when cycling the focus history')
+    parser.add_argument('--active-workspace', dest='active_workspace',
+                        action='store_true', help='Include windows on the '
+                        'active workspace only when cycling the focus history')
+    parser.add_argument('--switch', dest='switch', action='store_true',
+                        help='Switch to the previous window', default=False)
+    args = parser.parse_args()
+
+    if args.history:
+        MAX_WIN_HISTORY = args.history
+    if args.delay:
+        UPDATE_DELAY = args.delay
+    else:
+        if args.delay == 0.0:
+            UPDATE_DELAY = args.delay
+    if not args.switch:
+        focus_watcher = FocusWatcher()
+        focus_watcher.run()
+    else:
+        client_socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        client_socket.connect(SOCKET_FILE)
+        client_socket.send(b'switch')
+        client_socket.close()