start work on PaperWM-inspired extensions to Sway setup

2 files changed, 276 insertions, 43 deletions

diff --git a/scripts/desktop/i3status-wrapper b/scripts/desktop/i3status-wrapper
index 665630b3..3c5502cd 100755
--- a/scripts/desktop/i3status-wrapper
+++ b/scripts/desktop/i3status-wrapper
@@ -2,7 +2,7 @@
 
 # i3status-wrapper -- wrapper for i3status(1), plus other monitoring
 #
-# Copyright (C) 2019, 2021-2023 Sean Whitton
+# Copyright (C) 2019, 2021-2024 Sean Whitton
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -27,6 +27,10 @@ use Local::Desktop;
 use IO::Pipe;
 use IPC::Shareable;
 use Sys::Hostname;
+use POSIX "floor", "mkfifo";
+use File::Basename "basename", "dirname";
+use File::Spec::Functions "catfile";
+use List::Util "first", "max";
 
 $| = 1;
 
@@ -42,72 +46,238 @@ unless ($i3status) {
 
 tie my %info, "IPC::Shareable", undef, { destroy => 1 };
 
-unless (fork // warn "couldn't fork monitoring loop") {
-    my $caffeinated_id;
+sub with_ignored_events (&) {
+    system $wmipc, "-q", "-t", "send_tick", "i3status-wrapper-ign";
+    $_[0]->();
+    system $wmipc, "-q", "-t", "send_tick", "i3status-wrapper-unign";
+}
 
+unless (fork // warn "couldn't fork monitoring loop") {
     open my $events, "-|",
-      $wmipc, "-t", "subscribe", "-m", '[ "window", "workspace" ]';
+      $wmipc, "-t", "subscribe", "-m", '[ "tick", "window", "workspace" ]';
 
-    sub register_caffeinated {
-	$caffeinated_id = $_[0]->{id};
-	$info{caffeinated_name} = $_[0]->{name};
-	kill USR1 => $i3status;
+    # Determine the initial state -- the WM might just have been reloaded.
+    # Move any previously-hidden containers to a fresh workspace for perusal.
+
+    my @old_ids;
+    for (@{decode_json `$wmipc -t get_workspaces`}) {
+	$info{focused_ws} = $_->{name} if $_->{focused};
+	push @old_ids, $1 if $_->{name} =~ /\A\*(\d+)\*\z/;
+    }
+    if (@old_ids) {
+	fresh_workspace(go => 1);
+	wmipc map("[con_id=$_] move container workspace current", @old_ids),
+	  "focus child";
     }
+    update_paper_ws_cols();
+
+    # Now loop forever reading events, assuming no exceptions.
 
-    sub clear_caffeinated {
-	undef $caffeinated_id;
-	undef $info{caffeinated_name};
-	kill USR1 => $i3status;
+    sub new_container {
+	# New window on one of our monitored workspaces.
+	# Push a window off the workspace to accommodate new one.
+	# Leave it to a later loop iteration to update the focus.
+	my $ws = $info{paper_ws}{$info{focused_ws}};
+	my $cols = $ws->{cols};
+	my $i = first { $cols->[$_] == $ws->{focused_col} } 0..$#$cols;
+	splice $cols->@*, $i+1, 0, shift->{container}{id};
+	if ($ws->{monocle} || $cols->@* > $ws->{ncols}) {
+	    with_ignored_events {
+		my $pushed = shift $cols->@*;
+		wmipc hide_con($pushed);
+		push $ws->{off_left}->@*, $pushed;
+	    };
+	}
     }
+    eval {
+	while (my $e = decode_json <$events>) {
+	    state $last_e;
 
-    # Determine the initial state -- the WM might just have been reloaded.
+	    # New containers
+	    if ($last_e && $last_e->{change} && $last_e->{change} eq "new") {
+		new_container($last_e)
+		  unless $e->{change} && $e->{change} eq "floating";
+		undef $last_e;
+	    } elsif ($e->{change} && $e->{change} eq "new"
+		     && exists $info{paper_ws}{$info{focused_ws}}) {
+		# We have to go round the loop once more to find out if it's
+		# just a floating dialog that we'll ignore.
+		$last_e = $e;
+	    } elsif ($e->{change} && $e->{change} eq "floating"
+		     && $e->{container}{type} ne "floating_con") {
+		# A container stopped floating -- it's as though it's new.
+		new_container($e);
+		$info{paper_ws}{$info{focused_ws}}{focused_col}
+		  = $e->{container}{id};
+	    }
 
-    my $workspaces = @{ decode_json `$wmipc -t get_workspaces` };
-    wsbuttons($workspaces > 1 ? "yes" : "no");
+	    # Closing containers
+	    elsif (($e->{change} && $e->{change} eq "close"
+		    || $e->{change} && $e->{change} eq "floating"
+		    && $e->{container}{type} eq "floating_con")
+		   && exists $info{paper_ws}{$info{focused_ws}}) {
+		# We just drop the column here.  When the focus change event
+		# comes in, that part of the loop is responsible for pulling
+		# in another container as a replacement, if necessary.
+		my $cols = $info{paper_ws}{$info{focused_ws}}{cols};
+		my $i = first { $cols->[$_] == $e->{container}{id} }
+		  0..$#$cols;
+		splice $cols->@*, $i, 1;
+	    }
 
-    my @trees = decode_json `$wmipc -t get_tree`;
-    while (@trees) {
-	for ((shift @trees)->{nodes}->@*) {
-	    if (grep $_ eq "caffeinated", $_->{marks}->@*) {
-		register_caffeinated($_);
-		last;
-	    } else {
-		unshift @trees, $_;
+	    # Other container changes
+	    elsif ($e->{change} && $e->{change} eq "focus"
+		   && $e->{container} && $e->{container}{type} eq "con"
+		   && exists $info{paper_ws}{$info{focused_ws}}
+		   && !$info{paper_ws}{$info{focused_ws}}{monocle}) {
+		# Change of window focus on one of our monitored workspaces.
+		# Update which column we think is focused.
+		my $ws = $info{paper_ws}{$info{focused_ws}};
+		$ws->{focused_col} = $e->{container}{id};
+
+		# If the change of focus was triggered by a container closing,
+		# we might need to pull in a container.
+		if ($ws->{ncols} > $ws->{cols}->@*
+		    && ($ws->{off_left}->@* || $ws->{off_right}->@*)) {
+		    my $cols = $ws->{cols};
+		    my $i = first { $cols->[$_] eq $e->{container}{id} }
+		      0..$#$cols;
+		    my $mid_i = floor @$cols/2;
+		    if ($ws->{off_left}->@*
+			&& ($i < $mid_i || !$ws->{off_right}->@*)) {
+			with_ignored_events {
+			    my $pulled = pop $ws->{off_left}->@*;
+			    wmipc +("focus left")x$i,
+			      show_con($pulled), "move left",
+			      ("focus right")x$i;
+			    unshift @$cols, $pulled;
+			    $ws->{focused_col} = $cols->[$i];
+			};
+		    } elsif ($ws->{off_right}->@*
+			     && ($i >= $mid_i || !$ws->{off_left}->@*)) {
+			with_ignored_events {
+			    my $j = $#$cols - $i;
+			    my $pulled = pop $ws->{off_right}->@*;
+			    wmipc +("focus right")x$j,
+			      show_con($pulled), ("focus left")x$j;
+			    push @$cols, $pulled;
+			    $ws->{focused_col} = $cols->[$i+1];
+			};
+		    }
+		}
+	    } elsif ($e->{change} && $e->{change} eq "move") {
+		update_paper_ws_cols();
 	    }
-	}
-    }
 
-    # Now loop forever reading events, assuming no exceptions.
+	    # Ticks
+	    elsif ($e->{payload} && $e->{payload} eq "i3status-wrapper-ign") {
+		# Ignore everything until tick telling us to unignore.
+		# Thread that sent the ignore is responsible for updating data
+		# structures in the meantime.
+		while (my $next = decode_json <$events>) {
+		    last if $next->{payload}
+		      && $next->{payload} eq "i3status-wrapper-unign";
+		}
+	    }
 
-    eval {
-	while (my $event = decode_json <$events>) {
-	    if ($event->{change} eq "mark") {
-		if (grep $_ eq "caffeinated", $event->{container}{marks}->@*)
-		{
-		    register_caffeinated($event->{container});
-		} elsif ($caffeinated_id
-		    and $caffeinated_id == $event->{container}{id}) {
+	    # Workspace changes
+	    elsif ($e->{change} && $e->{change} eq "focus" && $e->{current}) {
+		$info{focused_ws} = $e->{current}{name};
+	    } elsif ($e->{change} && $e->{change} eq "init"
+		     && $e->{current}) {
+		$info{paper_ws}{$e->{current}{name}}
+		  = { off_left => [], off_right => [],
+		      ncols => 2, cols => [] };
+	    } elsif ($e->{change} && $e->{change} eq "empty"
+		     && $e->{current}) {
+		delete $info{paper_ws}{$e->{current}{name}};
+	    }
+
+	    # Mark changes
+	    elsif ($e->{change} && $e->{change} eq "mark") {
+		if (grep $_ eq "caffeinated", $e->{container}{marks}->@*) {
+		    register_caffeinated($e->{container});
+		} elsif ($info{caffeinated_id}
+			 and $info{caffeinated_id} == $e->{container}{id}) {
 		    clear_caffeinated();
 		}
-	    } elsif ($event->{change} eq "init") {
-		++$workspaces == 2 and wsbuttons("yes");
-	    } elsif ($event->{change} eq "empty") {
-		--$workspaces == 1 and wsbuttons("no");
-		# For simplicity, only fresh-workspace script calls
-		# compact_workspaces atm.  For greater consistency we could
-		# call it here, too, without supplying a leave_gap argument.
 	    }
 	}
     };
 
     # Give up if there's a decoding error.  We can't ignore the problem
-    # because we don't want our ideas regarding how many workspaces there are,
-    # and whether anything is caffeinated, to get out of sync.
+    # because we don't want our ideas regarding what workspaces there are, and
+    # whether anything is caffeinated, to get out of sync.
     #
     # The user can use the WM's "reload" command to restart this loop.
     $@ and wsbuttons("yes"), clear_caffeinated();
 }
 
+my $wm_ipc_socket = $ENV{SWAYSOCK} || $ENV{I3SOCK};
+(basename $wm_ipc_socket) =~ /\d[\d.]*\d/;
+my $cmdpipe = catfile dirname($wm_ipc_socket), "i3status-wrapper.$&.pipe";
+-e and unlink for $cmdpipe;
+
+unless (fork // warn "couldn't fork command pipe reader") {
+    mkfifo $cmdpipe, 0700 or die "mkfifo $cmdpipe failed: $!";
+    open my $cmdpipe_r, "<", $cmdpipe;
+
+    # Hold the pipe open with a writer that won't write anything.
+    open my $cmdpipe_w, ">", $cmdpipe;
+
+    while (my $cmd = <$cmdpipe_r>) {
+	my $ws = $info{paper_ws}{$info{focused_ws}};
+
+	if ($cmd =~ /^(focus|move) (left|right)$/) {
+	    my @cols = $ws->{cols}->@*;
+	    my ($i) = grep $cols[$_] == $ws->{focused_col}, 0..$#cols;
+	    my $move = $1 eq "move";
+	    $2 eq "right" ? $i++ : $i--;
+	    if ($ws->{cols}->@* > $i >= 0) {
+		wmipc $cmd;
+	    } elsif ($i == @cols && $ws->{off_right}->@*) {
+		with_ignored_events {
+		    my $pushed = shift $ws->{cols}->@*;
+		    my $pulled = pop $ws->{off_right}->@*;
+		    my @cmds = show_con($pulled);
+		    push $ws->{off_left}->@*, $pushed;
+		    if ($move) {
+			push @cmds, "focus left", "move right";
+			my $tem = pop $ws->{cols}->@*;
+			push $ws->{cols}->@*, $pulled, $tem;
+		    } else {
+			$ws->{focused_col} = $pulled;
+			push $ws->{cols}->@*, $pulled;
+		    }
+
+		    wmipc @cmds, hide_con($pushed);
+		};
+		kill USR1 => $i3status;
+	    } elsif ($i == -1 && $ws->{off_left}->@*) {
+		with_ignored_events {
+		    my $pushed = pop $ws->{cols}->@*;
+		    my $pulled = pop $ws->{off_left}->@*;
+		    my @cmds = show_con($pulled);
+		    push $ws->{off_right}->@*, $pushed;
+
+		    if ($move) {
+			push @cmds, "focus left";
+			my $tem = shift $ws->{cols}->@*;
+			unshift $ws->{cols}->@*, $tem, $pulled;
+		    } else {
+			push @cmds, "move left";
+			$ws->{focused_col} = $pulled;
+			unshift $ws->{cols}->@*, $pulled;
+		    }
+
+		    wmipc @cmds, hide_con($pushed);
+		};
+		kill USR1 => $i3status;
+	    }
+	}
+    }
+}
+
 $pipe->reader;
 open STDIN, "<&=", $pipe->fileno or die "couldn't reopen STDIN!";
 
@@ -148,3 +318,56 @@ sub wsbuttons {
     return unless $ENV{XDG_CURRENT_DESKTOP} eq "sway";
     wmipc "bar bar-0 workspace_buttons $_[0]";
 }
+
+sub register_caffeinated {
+    $info{caffeinated_id} = $_[0]->{id};
+    $info{caffeinated_name} = $_[0]->{name};
+    kill USR1 => $i3status;
+}
+
+sub clear_caffeinated {
+    undef $info{caffeinated_id};
+    undef $info{caffeinated_name};
+    kill USR1 => $i3status;
+}
+
+sub update_paper_ws_cols {
+    my @trees = decode_json `$wmipc -t get_tree`;
+    while (@trees) {
+	foreach my $node ((shift @trees)->{nodes}->@*) {
+	    if ($node->{type} eq "workspace"
+		&& grep $_ eq $node->{name}, @all_workspaces) {
+		my $entry = $info{paper_ws}{$node->{name}}
+		  //= { off_left => [], off_right => [] };
+
+		# Here we assume that the containers for the columns are
+		# directly below the type=workspace node.  That won't be true
+		# if workspace_layout is not configured to 'default'.
+		foreach my $child_id ($node->{focus}->@*) {
+		    my $child_node
+		      = first { $_->{id} == $child_id } $node->{nodes}->@*;
+		    $entry->{focused_col} = $child_id, last
+		      if $child_node->{type} eq "con";
+		}
+
+		$entry->{cols} = [];
+		foreach my $child_node ($node->{nodes}->@*) {
+		    push $entry->{cols}->@*, $child_node->{id}
+		      if $child_node->{type} eq "con";
+		}
+		$entry->{ncols} = max 2, scalar $entry->{cols}->@*;
+	    } elsif (grep $_ eq "caffeinated", $node->{marks}->@*) {
+		register_caffeinated($node);
+	    }
+	    unshift @trees, $node;
+	}
+    }
+}
+
+sub hide_con {
+    sprintf "[con_id=%s] move container to workspace %s", $_[0], "*$_[0]*"
+}
+
+sub show_con{
+    sprintf "[con_id=%s] move container to workspace current, focus", $_[0]
+}
diff --git a/scripts/desktop/i3status-wrapper-msg b/scripts/desktop/i3status-wrapper-msg
new file mode 100755
index 00000000..602014e3
--- /dev/null
+++ b/scripts/desktop/i3status-wrapper-msg
@@ -0,0 +1,10 @@
+#!/bin/sh
+
+[ -n "$1" ] || exit 127
+socket=${SWAYSOCK:-$I3SOCK}
+pipe="$(printf "%s/i3status-wrapper.%s.pipe" \
+	       "$(dirname "$socket")" \
+	       "$(basename "$socket" \
+		      | sed -n 's/^[^0-9]*\([0-9][0-9.]*[0-9]\).*/\1/p')")"
+[ -w "$pipe" ] || exit 127
+echo "$@" >"$pipe"