river: add rules system

This is a breaking change and replaces the previous
csd-filter-add/remove and float-filter-add/remove commands.

See the riverctl(1) man page for documentation on the new system.

17 files changed, 662 insertions, 271 deletions

diff --git a/build.zig b/build.zig
index a3f1bde..1dd65eb 100644
--- a/build.zig
+++ b/build.zig
@@ -163,6 +163,7 @@ pub fn build(b: *zbs.Builder) !void {
         river.linkSystemLibrary("wlroots");
 
         river.addPackagePath("flags", "common/flags.zig");
+        river.addPackagePath("globber", "common/globber.zig");
         river.addCSourceFile("river/wlroots_log_wrapper.c", &[_][]const u8{ "-std=c99", "-O2" });
 
         // TODO: remove when zig issue #131 is implemented
@@ -254,6 +255,15 @@ pub fn build(b: *zbs.Builder) !void {
     if (fish_completion) {
         b.installFile("completions/fish/riverctl.fish", "share/fish/vendor_completions.d/riverctl.fish");
     }
+
+    {
+        const globber_test = b.addTest("common/globber.zig");
+        globber_test.setTarget(target);
+        globber_test.setBuildMode(mode);
+
+        const test_step = b.step("test", "Run the tests");
+        test_step.dependOn(&globber_test.step);
+    }
 }
 
 const ScdocStep = struct {
diff --git a/common/globber.zig b/common/globber.zig
new file mode 100644
index 0000000..ead0fe7
--- /dev/null
+++ b/common/globber.zig
@@ -0,0 +1,223 @@
+// Basic prefix, suffix, and substring glob matching.
+//
+// Released under the Zero Clause BSD (0BSD) license:
+//
+// Copyright 2023 Isaac Freund
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+const std = @import("std");
+const mem = std.mem;
+
+/// Validate a glob, returning error.InvalidGlob if it is empty, "**" or has a
+/// '*' at any position other than the first and/or last byte.
+pub fn validate(glob: []const u8) error{InvalidGlob}!void {
+    switch (glob.len) {
+        0 => return error.InvalidGlob,
+        1 => {},
+        2 => if (glob[0] == '*' and glob[1] == '*') return error.InvalidGlob,
+        else => if (mem.indexOfScalar(u8, glob[1 .. glob.len - 1], '*') != null) {
+            return error.InvalidGlob;
+        },
+    }
+}
+
+test validate {
+    const testing = std.testing;
+
+    _ = try validate("*");
+    _ = try validate("a");
+    _ = try validate("*a");
+    _ = try validate("a*");
+    _ = try validate("*a*");
+    _ = try validate("ab");
+    _ = try validate("*ab");
+    _ = try validate("ab*");
+    _ = try validate("*ab*");
+    _ = try validate("abc");
+    _ = try validate("*abc");
+    _ = try validate("abc*");
+    _ = try validate("*abc*");
+
+    try testing.expectError(error.InvalidGlob, validate(""));
+    try testing.expectError(error.InvalidGlob, validate("**"));
+    try testing.expectError(error.InvalidGlob, validate("***"));
+    try testing.expectError(error.InvalidGlob, validate("a*c"));
+    try testing.expectError(error.InvalidGlob, validate("ab*c*"));
+    try testing.expectError(error.InvalidGlob, validate("*ab*c"));
+    try testing.expectError(error.InvalidGlob, validate("ab*c"));
+    try testing.expectError(error.InvalidGlob, validate("a*bc*"));
+    try testing.expectError(error.InvalidGlob, validate("**a"));
+    try testing.expectError(error.InvalidGlob, validate("abc**"));
+}
+
+/// Return true if s is matched by glob.
+/// Asserts that the glob is valid, see `validate()`.
+pub fn match(s: []const u8, glob: []const u8) bool {
+    if (std.debug.runtime_safety) {
+        validate(glob) catch unreachable;
+    }
+
+    if (glob.len == 1) {
+        return glob[0] == '*' or mem.eql(u8, s, glob);
+    }
+
+    const suffix_match = glob[0] == '*';
+    const prefix_match = glob[glob.len - 1] == '*';
+
+    if (suffix_match and prefix_match) {
+        return mem.indexOf(u8, s, glob[1 .. glob.len - 1]) != null;
+    } else if (suffix_match) {
+        return mem.endsWith(u8, s, glob[1..]);
+    } else if (prefix_match) {
+        return mem.startsWith(u8, s, glob[0 .. glob.len - 1]);
+    } else {
+        return mem.eql(u8, s, glob);
+    }
+}
+
+test match {
+    const testing = std.testing;
+
+    try testing.expect(match("", "*"));
+
+    try testing.expect(match("a", "*"));
+    try testing.expect(match("a", "*a*"));
+    try testing.expect(match("a", "a*"));
+    try testing.expect(match("a", "*a"));
+    try testing.expect(match("a", "a"));
+
+    try testing.expect(!match("a", "b"));
+    try testing.expect(!match("a", "*b*"));
+    try testing.expect(!match("a", "b*"));
+    try testing.expect(!match("a", "*b"));
+
+    try testing.expect(match("ab", "*"));
+    try testing.expect(match("ab", "*a*"));
+    try testing.expect(match("ab", "*b*"));
+    try testing.expect(match("ab", "a*"));
+    try testing.expect(match("ab", "*b"));
+    try testing.expect(match("ab", "*ab*"));
+    try testing.expect(match("ab", "ab*"));
+    try testing.expect(match("ab", "*ab"));
+    try testing.expect(match("ab", "ab"));
+
+    try testing.expect(!match("ab", "b*"));
+    try testing.expect(!match("ab", "*a"));
+    try testing.expect(!match("ab", "*c*"));
+    try testing.expect(!match("ab", "c*"));
+    try testing.expect(!match("ab", "*c"));
+    try testing.expect(!match("ab", "ac"));
+    try testing.expect(!match("ab", "*ac*"));
+    try testing.expect(!match("ab", "ac*"));
+    try testing.expect(!match("ab", "*ac"));
+
+    try testing.expect(match("abc", "*"));
+    try testing.expect(match("abc", "*a*"));
+    try testing.expect(match("abc", "*b*"));
+    try testing.expect(match("abc", "*c*"));
+    try testing.expect(match("abc", "a*"));
+    try testing.expect(match("abc", "*c"));
+    try testing.expect(match("abc", "*ab*"));
+    try testing.expect(match("abc", "ab*"));
+    try testing.expect(match("abc", "*bc*"));
+    try testing.expect(match("abc", "*bc"));
+    try testing.expect(match("abc", "*abc*"));
+    try testing.expect(match("abc", "abc*"));
+    try testing.expect(match("abc", "*abc"));
+    try testing.expect(match("abc", "abc"));
+
+    try testing.expect(!match("abc", "*a"));
+    try testing.expect(!match("abc", "*b"));
+    try testing.expect(!match("abc", "b*"));
+    try testing.expect(!match("abc", "c*"));
+    try testing.expect(!match("abc", "*ab"));
+    try testing.expect(!match("abc", "bc*"));
+    try testing.expect(!match("abc", "*d*"));
+    try testing.expect(!match("abc", "d*"));
+    try testing.expect(!match("abc", "*d"));
+}
+
+/// Returns .lt if a is less general than b.
+/// Returns .gt if a is more general than b.
+/// Returns .eq if a and b are equally general.
+/// Both a and b must be valid globs, see `validate()`.
+pub fn order(a: []const u8, b: []const u8) std.math.Order {
+    if (std.debug.runtime_safety) {
+        validate(a) catch unreachable;
+        validate(b) catch unreachable;
+    }
+
+    if (mem.eql(u8, a, "*") and mem.eql(u8, b, "*")) {
+        return .eq;
+    } else if (mem.eql(u8, a, "*")) {
+        return .gt;
+    } else if (mem.eql(u8, b, "*")) {
+        return .lt;
+    }
+
+    const count_a = @as(u2, @boolToInt(a[0] == '*')) + @boolToInt(a[a.len - 1] == '*');
+    const count_b = @as(u2, @boolToInt(b[0] == '*')) + @boolToInt(b[b.len - 1] == '*');
+
+    if (count_a == 0 and count_b == 0) {
+        return .eq;
+    } else if (count_a == count_b) {
+        // This may look backwards since e.g. "c*" is more general than "cc*"
+        return std.math.order(b.len, a.len);
+    } else {
+        return std.math.order(count_a, count_b);
+    }
+}
+
+test order {
+    const testing = std.testing;
+    const Order = std.math.Order;
+
+    try testing.expectEqual(Order.eq, order("*", "*"));
+    try testing.expectEqual(Order.eq, order("*a*", "*b*"));
+    try testing.expectEqual(Order.eq, order("a*", "*b"));
+    try testing.expectEqual(Order.eq, order("*a", "*b"));
+    try testing.expectEqual(Order.eq, order("*a", "b*"));
+    try testing.expectEqual(Order.eq, order("a*", "b*"));
+
+    const descending = [_][]const u8{
+        "*",
+        "*a*",
+        "*b*",
+        "*a*",
+        "*ab*",
+        "*bab*",
+        "*a",
+        "b*",
+        "*b",
+        "*a",
+        "a",
+        "bababab",
+        "b",
+        "a",
+    };
+
+    for (descending) |a, i| {
+        for (descending[i..]) |b| {
+            try testing.expect(order(a, b) != .lt);
+        }
+    }
+
+    var ascending = descending;
+    mem.reverse([]const u8, &ascending);
+
+    for (ascending) |a, i| {
+        for (ascending[i..]) |b| {
+            try testing.expect(order(a, b) != .gt);
+        }
+    }
+}
diff --git a/completions/bash/riverctl b/completions/bash/riverctl
index f50ac3b..d1de796 100644
--- a/completions/bash/riverctl
+++ b/completions/bash/riverctl
@@ -8,9 +8,7 @@ function __riverctl_completion ()
 			keyboard-group-add \
 			keyboard-group-remove \
 			keyboard-layout \
-			csd-filter-add \
 			exit \
-			float-filter-add \
 			focus-output \
 			focus-view \
 			input \
@@ -18,6 +16,9 @@ function __riverctl_completion ()
 			list-input-configs \
 			move \
 			resize \
+			rule-add \
+			rule-del \
+			list-rules \
 			snap \
 			send-to-output \
 			spawn \
@@ -61,6 +62,8 @@ function __riverctl_completion ()
 			"focus-output"|"focus-view"|"send-to-output"|"swap") OPTS="next previous" ;;
 			"move"|"snap") OPTS="up down left right" ;;
 			"resize") OPTS="horizontal vertical" ;;
+			"rule-add"|"rule-del") OPTS="float no-float ssd csd" ;;
+			"list-rules") OPTS="float ssd" ;;
 			"map") OPTS="-release -repeat -layout" ;;
 			"unmap") OPTS="-release" ;;
 			"attach-mode") OPTS="top bottom" ;;
diff --git a/completions/fish/riverctl.fish b/completions/fish/riverctl.fish
index 35db6e8..a207156 100644
--- a/completions/fish/riverctl.fish
+++ b/completions/fish/riverctl.fish
@@ -12,9 +12,7 @@ end
 
 # Actions
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'close'                  -d 'Close the focued view'
-complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'csd-filter-add'         -d 'Add app-id to the CSD filter list'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'exit'                   -d 'Exit the compositor, terminating the Wayland session'
-complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'float-filter-add'       -d 'Add app-id to the float filter list'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'focus-output'           -d 'Focus the next or previous output'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'focus-view'             -d 'Focus the next or previous view in the stack'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'input'                  -d 'Create a configuration rule for an input device'
@@ -49,6 +47,10 @@ complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'map-switch '
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'unmap'                  -d 'Remove the mapping defined by the arguments'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'unmap-pointer'          -d 'Remove the pointer mapping defined by the arguments'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'unmap-switch'           -d 'Remove the switch mapping defined by the arguments'
+# Rules
+complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'rule-add'               -d 'Apply an action to matching views'
+complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'rule-del'               -d 'Delete a rule added with rule-add'
+complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'list-rules'             -d 'Print rules in a given list'
 # Configuration
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'attach-mode'            -d 'Configure where new views should attach to the view stack'
 complete -c riverctl -x -n '__fish_riverctl_complete_arg 1' -a 'background-color'       -d 'Set the background color'
@@ -81,6 +83,9 @@ complete -c riverctl -x -n '__fish_seen_subcommand_from unmap'                -a
 complete -c riverctl -x -n '__fish_seen_subcommand_from attach-mode'          -a 'top bottom'
 complete -c riverctl -x -n '__fish_seen_subcommand_from focus-follows-cursor' -a 'disabled normal always'
 complete -c riverctl -x -n '__fish_seen_subcommand_from set-cursor-warp'      -a 'disabled on-output-change on-focus-change'
+complete -c riverctl -x -n '__fish_seen_subcommand_from rule-add'             -a 'float no-float ssd csd'
+complete -c riverctl -x -n '__fish_seen_subcommand_from rule-del'             -a 'float no-float ssd csd'
+complete -c riverctl -x -n '__fish_seen_subcommand_from list-rules'           -a 'float ssd'
 
 # Subcommands for 'input'
 complete -c riverctl -x -n '__fish_seen_subcommand_from input; and __fish_riverctl_complete_arg 2' -a "(__riverctl_list_input_devices)"
diff --git a/completions/zsh/_riverctl b/completions/zsh/_riverctl
index 90e39d2..53b2194 100644
--- a/completions/zsh/_riverctl
+++ b/completions/zsh/_riverctl
@@ -9,9 +9,7 @@ _riverctl_subcommands()
     riverctl_subcommands=(
         # Actions
         'close:Close the focused view'
-        'csd-filter-add:Add app-id to the CSD filter list'
         'exit:Exit the compositor, terminating the Wayland session'
-        'float-filter-add:Add app-id to the float filter list'
         'focus-output:Focus the next or previous output'
         'focus-view:Focus the next or previous view in the stack'
         'move:Move the focused view in the specified direction'
@@ -43,6 +41,10 @@ _riverctl_subcommands()
         'unmap:Remove the mapping defined by the arguments'
         'unmap-pointer:Remove the pointer mapping defined by the arguments'
         'unmap-switch:Remove the switch mapping defined by the arguments'
+        # Rules
+        'rule-add:Apply an action to matching views'
+        'rule-del:Delete a rule added with rule-add'
+        'list-rules:Print rules in a given list'
         # Configuration
         'attach-mode:Configure where new views should attach to the view stack'
         'background-color:Set the background color'
@@ -181,6 +183,9 @@ _riverctl()
                 focus-follows-cursor) _alternative 'arguments:args:(disabled normal always)' ;;
                 set-cursor-warp) _alternative 'arguments:args:(disabled on-output-change on-focus-change)' ;;
                 hide-cursor) _riverctl_hide_cursor ;;
+                rule-add) _alternative 'arguments:args:(float no-float ssd csd)' ;;
+                rule-del) _alternative 'arguments:args:(float no-float ssd csd)' ;;
+                list-rules) _alternative 'arguments:args:(float ssd)' ;;
                 *) return 0 ;;
             esac
         ;;
diff --git a/doc/riverctl.1.scd b/doc/riverctl.1.scd
index 2b6bfd7..9809b4c 100644
--- a/doc/riverctl.1.scd
+++ b/doc/riverctl.1.scd
@@ -28,28 +28,9 @@ over the Wayland protocol.
 *close*
 	Close the focused view.
 
-*csd-filter-add* *app-id*|*title* _pattern_
-	Add _pattern_ to the CSD filter list. Views with this _pattern_ are told to
-	use client side decoration instead of the default server side decoration.
-	Note that this affects new views as well as already existing ones. Title
-	updates are not taken into account.
-
-*csd-filter-remove* *app-id*|*title* _pattern_
-	Remove _pattern_ from the CSD filter list. Note that this affects new views
-	as well as already existing ones.
-
 *exit*
 	Exit the compositor, terminating the Wayland session.
 
-*float-filter-add* *app-id*|*title* _pattern_
-	Add a pattern to the float filter list. Note that this affects only new
-	views, not already existing ones. Title updates are also not taken into
-	account.
-
-*float-filter-remove* *app-id*|*title* _pattern_
-	Remove an app-id or title from the float filter list. Note that this
-	affects only new views, not already existing ones.
-
 *focus-output* *next*|*previous*|*up*|*right*|*down*|*left*|_name_
 	Focus the next or previous output, the closest output in any direction
 	or an output by name.
@@ -192,18 +173,18 @@ A complete list may be found in _/usr/include/linux/input-event-codes.h_
 *enter-mode* _name_
 	Switch to given mode if it exists.
 
-*map* [_-release_|_-repeat_|_-layout_ _index_] _mode_ _modifiers_ _key_ _command_
+*map* [*-release*|*-repeat*|*-layout* _index_] _mode_ _modifiers_ _key_ _command_
 	Run _command_ when _key_ is pressed while _modifiers_ are held down
 	and in the specified _mode_.
 
-	- _-release_: if passed activate on key release instead of key press
-	- _-repeat_: if passed activate repeatedly until key release; may not
-	  be used with -release
-	- _-layout_: if passed, a specific layout is pinned to the mapping.
+	- *-release*: if passed activate on key release instead of key press
+	- *-repeat*: if passed activate repeatedly until key release; may not
+	  be used with *-release*
+	- *-layout*: if passed, a specific layout is pinned to the mapping.
 	  When the mapping is checked against a pressed key, this layout is
 	  used to translate the key independent of the active layout
 		- _index_: zero-based index of a layout set with the *keyboard-layout*
-		  command. If the index is out of range, the _-layout_ option will
+		  command. If the index is out of range, the *-layout* option will
 		  have no effect
 	- _mode_: name of the mode for which to create the mapping
 	- _modifiers_: one or more of the modifiers listed above, separated
@@ -239,10 +220,10 @@ A complete list may be found in _/usr/include/linux/input-event-codes.h_
 			- off
 	- _command_: any command that may be run with riverctl
 
-*unmap* [_-release_] _mode_ _modifiers_ _key_
+*unmap* [*-release*] _mode_ _modifiers_ _key_
 	Remove the mapping defined by the arguments:
 
-	- _-release_: if passed unmap the key release instead of the key press
+	- *-release*: if passed unmap the key release instead of the key press
 	- _mode_: name of the mode for which to remove the mapping
 	- _modifiers_: one or more of the modifiers listed above, separated
 	  by a plus sign (+).
@@ -263,6 +244,65 @@ A complete list may be found in _/usr/include/linux/input-event-codes.h_
 	- _lid_|_tablet_: the switch for which to remove the mapping
 	- _state_: a state as listed above
 
+## RULES
+
+Rules match either the app-id and title of views against a _glob_ pattern.
+A _glob_ is a string that may optionally have an _\*_ at the beginning and/or
+end. A _\*_ in a _glob_ matches zero or more arbitrary characters in the
+app-id or title.
+
+For example, _abc_ is matched by _a\*_, _\*a\*_, _\*b\*_, _\*c_, _abc_, and
+_\*_ but not matched by _\*a_, _b\*_, _\*b_, _\*c_, or _ab_. Note that _\*_
+matches everything while _\*\*_ and the empty string are invalid.
+
+*rule-add* _action_ [*-app-id* _glob_|*-title* _glob_]
+	Add a rule that applies an _action_ to views with *app-id* and *title*
+	matched by the respective _glob_. Omitting *-app-id* or *-title*
+	is equivalent to passing *-app-id* _\*_ or *-title* _\*_.
+
+	The supported _action_ types are:
+
+	- *float*: Make the view floating. Applies only to new views.
+	- *no-float*: Don't make the view floating. Applies only to
+	  new views.
+	- *ssd*: Use server-side decorations for the view. Applies to new
+	  and existing views.
+	- *csd*: Use client-side decorations for the view. Applies to new
+	  and existing views.
+
+	Both *float* and *no-float* rules are added to the same list,
+	which means that adding a *no-float* rule with the same arguments
+	as a *float* rule will overwrite it. The same holds for *ssd* and
+	*csd* rules.
+
+	If multiple rules in a list match a given view the most specific
+	rule will be applied. For example with the following rules
+	```
+	action  app-id  title
+	ssd     foo     bar
+	csd     foo     *
+	csd     *       bar
+	ssd     *       baz
+	```
+	a view with app-id 'foo' and title 'bar' would get ssd despite matching
+	two csd rules as the first rule is most specific. Furthermore a view
+	with app-id 'foo' and title 'baz' would get csd despite matching the
+	last rule in the list since app-id specificity takes priority over
+	title specificity.
+
+	If a view is not matched by any rule, river will respect the csd/ssd
+	wishes of the client and may start the view floating based on simple
+	heuristics intended to catch popup-like views.
+
+*rule-del* _action_ [*-app-id* _glob_|*-title* _glob_]
+	Delete a rule created using *rule-add* with the given arguments.
+
+*list-rules* *float*|*ssd*
+	Print the specified rule list. The output is ordered from most specific
+	to least specific, the same order in which views are checked against
+	when searching for a match. Only the first matching rule in the list
+	has an effect on a given view.
+
 ## CONFIGURATION
 
 *attach-mode* *top*|*bottom*
diff --git a/river/Config.zig b/river/Config.zig
index 08bca49..5a14529 100644
--- a/river/Config.zig
+++ b/river/Config.zig
@@ -18,13 +18,14 @@ const Self = @This();
 
 const std = @import("std");
 const mem = std.mem;
+const globber = @import("globber");
 const xkb = @import("xkbcommon");
 
 const util = @import("util.zig");
 
 const Server = @import("Server.zig");
 const Mode = @import("Mode.zig");
-const View = @import("View.zig");
+const RuleList = @import("RuleList.zig");
 
 pub const AttachMode = enum {
     top,
@@ -72,13 +73,8 @@ mode_to_id: std.StringHashMap(u32),
 /// All user-defined keymap modes, indexed by mode id
 modes: std.ArrayListUnmanaged(Mode),
 
-/// Sets of app_ids and titles which will be started floating
-float_filter_app_ids: std.StringHashMapUnmanaged(void) = .{},
-float_filter_titles: std.StringHashMapUnmanaged(void) = .{},
-
-/// Sets of app_ids and titles which are allowed to use client side decorations
-csd_filter_app_ids: std.StringHashMapUnmanaged(void) = .{},
-csd_filter_titles: std.StringHashMapUnmanaged(void) = .{},
+float_rules: RuleList = .{},
+ssd_rules: RuleList = .{},
 
 /// The selected focus_follows_cursor mode
 focus_follows_cursor: FocusFollowsCursorMode = .disabled,
@@ -152,64 +148,11 @@ pub fn deinit(self: *Self) void {
     for (self.modes.items) |*mode| mode.deinit();
     self.modes.deinit(util.gpa);
 
-    {
-        var it = self.float_filter_app_ids.keyIterator();
-        while (it.next()) |key| util.gpa.free(key.*);
-        self.float_filter_app_ids.deinit(util.gpa);
-    }
-
-    {
-        var it = self.float_filter_titles.keyIterator();
-        while (it.next()) |key| util.gpa.free(key.*);
-        self.float_filter_titles.deinit(util.gpa);
-    }
-
-    {
-        var it = self.csd_filter_app_ids.keyIterator();
-        while (it.next()) |key| util.gpa.free(key.*);
-        self.csd_filter_app_ids.deinit(util.gpa);
-    }
-
-    {
-        var it = self.csd_filter_titles.keyIterator();
-        while (it.next()) |key| util.gpa.free(key.*);
-        self.csd_filter_titles.deinit(util.gpa);
-    }
+    self.float_rules.deinit();
+    self.ssd_rules.deinit();
 
     util.gpa.free(self.default_layout_namespace);
 
     self.keymap.unref();
     self.xkb_context.unref();
 }
-
-pub fn shouldFloat(self: Self, view: *View) bool {
-    if (view.getAppId()) |app_id| {
-        if (self.float_filter_app_ids.contains(std.mem.span(app_id))) {
-            return true;
-        }
-    }
-
-    if (view.getTitle()) |title| {
-        if (self.float_filter_titles.contains(std.mem.span(title))) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
-pub fn csdAllowed(self: Self, view: *View) bool {
-    if (view.getAppId()) |app_id| {
-        if (self.csd_filter_app_ids.contains(std.mem.span(app_id))) {
-            return true;
-        }
-    }
-
-    if (view.getTitle()) |title| {
-        if (self.csd_filter_titles.contains(std.mem.span(title))) {
-            return true;
-        }
-    }
-
-    return false;
-}
diff --git a/river/Cursor.zig b/river/Cursor.zig
index e0949c5..d7497f9 100644
--- a/river/Cursor.zig
+++ b/river/Cursor.zig
@@ -877,7 +877,7 @@ fn processMotion(self: *Self, device: *wlr.InputDevice, time: u32, delta_x: f64,
 
             {
                 // Modify the pending box, taking constraints into account
-                const border_width = if (data.view.pending.borders) server.config.border_width else 0;
+                const border_width = if (data.view.pending.ssd) server.config.border_width else 0;
 
                 var output_width: i32 = undefined;
                 var output_height: i32 = undefined;
diff --git a/river/LayoutDemand.zig b/river/LayoutDemand.zig
index a6f8ffa..a127938 100644
--- a/river/LayoutDemand.zig
+++ b/river/LayoutDemand.zig
@@ -132,7 +132,7 @@ pub fn apply(self: *Self, layout: *Layout) void {
 
             // Here we apply the offset to align the coords with the origin of the
             // usable area and shrink the dimensions to accommodate the border size.
-            const border_width = if (view.inflight.borders) server.config.border_width else 0;
+            const border_width = if (view.inflight.ssd) server.config.border_width else 0;
             view.inflight.box = .{
                 .x = proposed.x + output.usable_box.x + border_width,
                 .y = proposed.y + output.usable_box.y + border_width,
diff --git a/river/RuleList.zig b/river/RuleList.zig
new file mode 100644
index 0000000..db765e7
--- /dev/null
+++ b/river/RuleList.zig
@@ -0,0 +1,106 @@
+// This file is part of river, a dynamic tiling wayland compositor.
+//
+// Copyright 2023 The River Developers
+//
+// 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
+// the Free Software Foundation, version 3.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+const RuleList = @This();
+
+const std = @import("std");
+const mem = std.mem;
+
+const globber = @import("globber");
+const util = @import("util.zig");
+
+const View = @import("View.zig");
+
+const Rule = struct {
+    app_id_glob: []const u8,
+    title_glob: []const u8,
+    value: bool,
+};
+
+/// Ordered from most specific to most general.
+/// Ordered first by app-id generality then by title generality.
+rules: std.ArrayListUnmanaged(Rule) = .{},
+
+pub fn deinit(list: *RuleList) void {
+    for (list.rules.items) |rule| {
+        util.gpa.free(rule.app_id_glob);
+        util.gpa.free(rule.title_glob);
+    }
+    list.rules.deinit(util.gpa);
+}
+
+pub fn add(list: *RuleList, rule: Rule) error{OutOfMemory}!void {
+    const index = for (list.rules.items) |*existing, i| {
+        if (mem.eql(u8, rule.app_id_glob, existing.app_id_glob) and
+            mem.eql(u8, rule.title_glob, existing.title_glob))
+        {
+            existing.value = rule.value;
+            return;
+        }
+
+        switch (globber.order(rule.app_id_glob, existing.app_id_glob)) {
+            .lt => break i,
+            .eq => {
+                if (globber.order(rule.title_glob, existing.title_glob) == .lt) {
+                    break i;
+                }
+            },
+            .gt => {},
+        }
+    } else list.rules.items.len;
+
+    const owned_app_id_glob = try util.gpa.dupe(u8, rule.app_id_glob);
+    errdefer util.gpa.free(owned_app_id_glob);
+
+    const owned_title_glob = try util.gpa.dupe(u8, rule.title_glob);
+    errdefer util.gpa.free(owned_title_glob);
+
+    try list.rules.insert(util.gpa, index, .{
+        .app_id_glob = owned_app_id_glob,
+        .title_glob = owned_title_glob,
+        .value = rule.value,
+    });
+}
+
+pub fn del(list: *RuleList, rule: Rule) void {
+    for (list.rules.items) |existing, i| {
+        if (mem.eql(u8, rule.app_id_glob, existing.app_id_glob) and
+            mem.eql(u8, rule.title_glob, existing.title_glob))
+        {
+            util.gpa.free(existing.app_id_glob);
+            util.gpa.free(existing.title_glob);
+            _ = list.rules.orderedRemove(i);
+            return;
+        }
+    }
+}
+
+/// Returns the value of the most specific rule matching the view.
+/// Returns null if no rule matches.
+pub fn match(list: *RuleList, view: *View) ?bool {
+    const app_id = mem.sliceTo(view.getAppId(), 0) orelse "";
+    const title = mem.sliceTo(view.getTitle(), 0) orelse "";
+
+    for (list.rules.items) |rule| {
+        if (globber.match(app_id, rule.app_id_glob) and
+            globber.match(title, rule.title_glob))
+        {
+            return rule.value;
+        }
+    }
+
+    return null;
+}
diff --git a/river/View.zig b/river/View.zig
index a436903..24934dd 100644
--- a/river/View.zig
+++ b/river/View.zig
@@ -72,13 +72,13 @@ pub const State = struct {
     float: bool = false,
     fullscreen: bool = false,
     urgent: bool = false,
-    borders: bool = true,
+    ssd: bool = false,
     resizing: bool = false,
 
     /// Modify the x/y of the given state by delta_x/delta_y, clamping to the
     /// bounds of the output.
     pub fn move(state: *State, delta_x: i32, delta_y: i32) void {
-        const border_width = if (state.borders) server.config.border_width else 0;
+        const border_width = if (state.ssd) server.config.border_width else 0;
 
         var output_width: i32 = math.maxInt(i32);
         var output_height: i32 = math.maxInt(i32);
@@ -106,7 +106,7 @@ pub const State = struct {
         var output_height: i32 = undefined;
         output.wlr_output.effectiveResolution(&output_width, &output_height);
 
-        const border_width = if (state.borders) server.config.border_width else 0;
+        const border_width = if (state.ssd) server.config.border_width else 0;
         state.box.width = math.min(state.box.width, output_width - (2 * border_width));
         state.box.height = math.min(state.box.height, output_height - (2 * border_width));
 
@@ -265,7 +265,7 @@ pub fn updateCurrent(view: *Self) void {
     view.tree.node.setPosition(box.x, box.y);
     view.popup_tree.node.setPosition(box.x, box.y);
 
-    const enable_borders = view.current.borders and !view.current.fullscreen;
+    const enable_borders = view.current.ssd and !view.current.fullscreen;
 
     const border_width: c_int = config.border_width;
     view.borders.left.node.setEnabled(enable_borders);
@@ -428,7 +428,12 @@ pub fn map(view: *Self) !void {
 
     view.foreign_toplevel_handle.map();
 
-    view.pending.borders = !server.config.csdAllowed(view);
+    if (server.config.float_rules.match(view)) |float| {
+        view.pending.float = float;
+    }
+    if (server.config.ssd_rules.match(view)) |ssd| {
+        view.pending.ssd = ssd;
+    }
 
     if (server.input_manager.defaultSeat().focused_output) |output| {
         // Center the initial pending box on the output
diff --git a/river/XdgDecoration.zig b/river/XdgDecoration.zig
index 8eb44b8..39c28c7 100644
--- a/river/XdgDecoration.zig
+++ b/river/XdgDecoration.zig
@@ -42,7 +42,14 @@ pub fn init(wlr_decoration: *wlr.XdgToplevelDecorationV1) void {
     wlr_decoration.events.destroy.add(&decoration.destroy);
     wlr_decoration.events.request_mode.add(&decoration.request_mode);
 
-    handleRequestMode(&decoration.request_mode, decoration.wlr_decoration);
+    const ssd = server.config.ssd_rules.match(xdg_toplevel.view) orelse
+        (decoration.wlr_decoration.requested_mode != .client_side);
+
+    // TODO(wlroots): make sure this is properly batched in a single configure
+    // with all other initial state when wlroots makes this possible.
+    _ = wlr_decoration.setMode(if (ssd) .server_side else .client_side);
+
+    xdg_toplevel.view.pending.ssd = ssd;
 }
 
 // TODO(wlroots): remove this function when updating to 0.17.0
@@ -72,9 +79,13 @@ fn handleRequestMode(
     const decoration = @fieldParentPtr(XdgDecoration, "request_mode", listener);
 
     const xdg_toplevel = @intToPtr(*XdgToplevel, decoration.wlr_decoration.surface.data);
-    if (server.config.csdAllowed(xdg_toplevel.view)) {
-        _ = decoration.wlr_decoration.setMode(.client_side);
-    } else {
-        _ = decoration.wlr_decoration.setMode(.server_side);
+    const view = xdg_toplevel.view;
+
+    const ssd = server.config.ssd_rules.match(xdg_toplevel.view) orelse
+        (decoration.wlr_decoration.requested_mode != .client_side);
+
+    if (view.pending.ssd != ssd) {
+        view.pending.ssd = ssd;
+        server.root.applyPending();
     }
 }
diff --git a/river/XdgToplevel.zig b/river/XdgToplevel.zig
index 64c3f99..188be4b 100644
--- a/river/XdgToplevel.zig
+++ b/river/XdgToplevel.zig
@@ -115,6 +115,7 @@ pub fn configure(self: *Self) bool {
         (inflight.focus != 0) == (current.focus != 0) and
         inflight_fullscreen == current_fullscreen and
         inflight_float == current_float and
+        inflight.ssd == current.ssd and
         inflight.resizing == current.resizing)
     {
         return false;
@@ -130,6 +131,10 @@ pub fn configure(self: *Self) bool {
         _ = self.xdg_toplevel.setTiled(.{ .top = true, .bottom = true, .left = true, .right = true });
     }
 
+    if (self.decoration) |decoration| {
+        _ = decoration.wlr_decoration.setMode(if (inflight.ssd) .server_side else .client_side);
+    }
+
     _ = self.xdg_toplevel.setResizing(inflight.resizing);
 
     // Only track configures with the transaction system if they affect the dimensions of the view.
@@ -226,9 +231,8 @@ fn handleMap(listener: *wl.Listener(void)) void {
         (state.min_width == state.max_width or state.min_height == state.max_height);
 
     if (self.xdg_toplevel.parent != null or has_fixed_size) {
-        // If the self.xdg_toplevel has a parent or has a fixed size make it float
-        view.pending.float = true;
-    } else if (server.config.shouldFloat(view)) {
+        // If the self.xdg_toplevel has a parent or has a fixed size make it float.
+        // This will be overwritten in View.map() if the view is matched by a rule.
         view.pending.float = true;
     }
 
diff --git a/river/XwaylandView.zig b/river/XwaylandView.zig
index 274e8ed..fe90a10 100644
--- a/river/XwaylandView.zig
+++ b/river/XwaylandView.zig
@@ -51,6 +51,8 @@ set_override_redirect: wl.Listener(*wlr.XwaylandSurface) =
 // Listeners that are only active while the view is mapped
 set_title: wl.Listener(*wlr.XwaylandSurface) = wl.Listener(*wlr.XwaylandSurface).init(handleSetTitle),
 set_class: wl.Listener(*wlr.XwaylandSurface) = wl.Listener(*wlr.XwaylandSurface).init(handleSetClass),
+set_decorations: wl.Listener(*wlr.XwaylandSurface) =
+    wl.Listener(*wlr.XwaylandSurface).init(handleSetDecorations),
 request_fullscreen: wl.Listener(*wlr.XwaylandSurface) =
     wl.Listener(*wlr.XwaylandSurface).init(handleRequestFullscreen),
 request_minimize: wl.Listener(*wlr.XwaylandSurface.event.Minimize) =
@@ -168,6 +170,7 @@ pub fn handleMap(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface:
     // Add listeners that are only active while mapped
     xwayland_surface.events.set_title.add(&self.set_title);
     xwayland_surface.events.set_class.add(&self.set_class);
+    xwayland_surface.events.set_decorations.add(&self.set_decorations);
     xwayland_surface.events.request_fullscreen.add(&self.request_fullscreen);
     xwayland_surface.events.request_minimize.add(&self.request_minimize);
 
@@ -194,12 +197,14 @@ pub fn handleMap(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface:
         false;
 
     if (self.xwayland_surface.parent != null or has_fixed_size) {
-        // If the toplevel has a parent or has a fixed size make it float
-        view.pending.float = true;
-    } else if (server.config.shouldFloat(view)) {
+        // If the toplevel has a parent or has a fixed size make it float by default.
+        // This will be overwritten in View.map() if the view is matched by a rule.
         view.pending.float = true;
     }
 
+    // This will be overwritten in View.map() if the view is matched by a rule.
+    view.pending.ssd = !xwayland_surface.decorations.no_border;
+
     view.pending.fullscreen = xwayland_surface.fullscreen;
 
     view.map() catch {
@@ -276,6 +281,19 @@ fn handleSetClass(listener: *wl.Listener(*wlr.XwaylandSurface), _: *wlr.Xwayland
     self.view.notifyAppId();
 }
 
+fn handleSetDecorations(listener: *wl.Listener(*wlr.XwaylandSurface), _: *wlr.XwaylandSurface) void {
+    const self = @fieldParentPtr(Self, "set_decorations", listener);
+    const view = self.view;
+
+    const ssd = server.config.ssd_rules.match(view) orelse
+        !self.xwayland_surface.decorations.no_border;
+
+    if (view.pending.ssd != ssd) {
+        view.pending.ssd = ssd;
+        server.root.applyPending();
+    }
+}
+
 fn handleRequestFullscreen(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface: *wlr.XwaylandSurface) void {
     const self = @fieldParentPtr(Self, "request_fullscreen", listener);
     if (self.view.pending.fullscreen != xwayland_surface.fullscreen) {
diff --git a/river/command.zig b/river/command.zig
index 8e541d7..ede1704 100644
--- a/river/command.zig
+++ b/river/command.zig
@@ -47,28 +47,32 @@ const command_impls = std.ComptimeStringMap(
         .{ "border-color-urgent",       @import("command/config.zig").borderColorUrgent },
         .{ "border-width",              @import("command/config.zig").borderWidth },
         .{ "close",                     @import("command/close.zig").close },
-        .{ "csd-filter-add",            @import("command/filter.zig").csdFilterAdd },
-        .{ "csd-filter-remove",         @import("command/filter.zig").csdFilterRemove },
         .{ "declare-mode",              @import("command/declare_mode.zig").declareMode },
         .{ "default-layout",            @import("command/layout.zig").defaultLayout },
         .{ "enter-mode",                @import("command/enter_mode.zig").enterMode },
         .{ "exit",                      @import("command/exit.zig").exit },
-        .{ "float-filter-add",          @import("command/filter.zig").floatFilterAdd },
-        .{ "float-filter-remove",       @import("command/filter.zig").floatFilterRemove },
         .{ "focus-follows-cursor",      @import("command/focus_follows_cursor.zig").focusFollowsCursor },
         .{ "focus-output",              @import("command/output.zig").focusOutput },
         .{ "focus-previous-tags",       @import("command/tags.zig").focusPreviousTags },
         .{ "focus-view",                @import("command/focus_view.zig").focusView },
         .{ "hide-cursor",               @import("command/cursor.zig").cursor },
         .{ "input",                     @import("command/input.zig").input },
+        .{ "keyboard-group-add",        @import("command/keyboard_group.zig").keyboardGroupAdd },
+        .{ "keyboard-group-create",     @import("command/keyboard_group.zig").keyboardGroupCreate },
+        .{ "keyboard-group-destroy",    @import("command/keyboard_group.zig").keyboardGroupDestroy },
+        .{ "keyboard-group-remove",     @import("command/keyboard_group.zig").keyboardGroupRemove },
+        .{ "keyboard-layout",           @import("command/keyboard.zig").keyboardLayout },
         .{ "list-input-configs",        @import("command/input.zig").listInputConfigs},
         .{ "list-inputs",               @import("command/input.zig").listInputs },
+        .{ "list-rules",                @import("command/rule.zig").listRules},
         .{ "map",                       @import("command/map.zig").map },
         .{ "map-pointer",               @import("command/map.zig").mapPointer },
         .{ "map-switch",                @import("command/map.zig").mapSwitch },
         .{ "move",                      @import("command/move.zig").move },
         .{ "output-layout",             @import("command/layout.zig").outputLayout },
         .{ "resize",                    @import("command/move.zig").resize },
+        .{ "rule-add",                  @import("command/rule.zig").ruleAdd },
+        .{ "rule-del",                  @import("command/rule.zig").ruleDel },
         .{ "send-layout-cmd",           @import("command/layout.zig").sendLayoutCmd },
         .{ "send-to-output",            @import("command/output.zig").sendToOutput },
         .{ "send-to-previous-tags",     @import("command/tags.zig").sendToPreviousTags },
@@ -89,11 +93,6 @@ const command_impls = std.ComptimeStringMap(
         .{ "unmap-switch",              @import("command/map.zig").unmapSwitch },
         .{ "xcursor-theme",             @import("command/xcursor_theme.zig").xcursorTheme },
         .{ "zoom",                      @import("command/zoom.zig").zoom },
-        .{ "keyboard-layout",           @import("command/keyboard.zig").keyboardLayout },
-        .{ "keyboard-group-create",     @import("command/keyboard_group.zig").keyboardGroupCreate },
-        .{ "keyboard-group-destroy",    @import("command/keyboard_group.zig").keyboardGroupDestroy },
-        .{ "keyboard-group-add",        @import("command/keyboard_group.zig").keyboardGroupAdd },
-        .{ "keyboard-group-remove",     @import("command/keyboard_group.zig").keyboardGroupRemove },
     },
 );
 // zig fmt: on
@@ -107,6 +106,7 @@ pub const Error = error{
     InvalidButton,
     InvalidCharacter,
     InvalidDirection,
+    InvalidGlob,
     InvalidPhysicalDirection,
     InvalidOutputIndicator,
     InvalidOrientation,
@@ -136,7 +136,7 @@ pub fn run(
     try impl_fn(seat, args, out);
 }
 
-/// Return a short error message for the given error. Passing Error.Other is UB
+/// Return a short error message for the given error. Passing Error.Other is invalid.
 pub fn errToMsg(err: Error) [:0]const u8 {
     return switch (err) {
         Error.NoCommand => "no command given",
@@ -149,6 +149,7 @@ pub fn errToMsg(err: Error) [:0]const u8 {
         Error.InvalidButton => "invalid button",
         Error.InvalidCharacter => "invalid character in argument",
         Error.InvalidDirection => "invalid direction. Must be 'next' or 'previous'",
+        Error.InvalidGlob => "invalid glob. '*' is only allowed as the first and/or last character",
         Error.InvalidPhysicalDirection => "invalid direction. Must be 'up', 'down', 'left' or 'right'",
         Error.InvalidOutputIndicator => "invalid indicator for an output. Must be 'next', 'previous', 'up', 'down', 'left', 'right' or a valid output name",
         Error.InvalidOrientation => "invalid orientation. Must be 'horizontal', or 'vertical'",
diff --git a/river/command/filter.zig b/river/command/filter.zig
deleted file mode 100644
index cb07c7d..0000000
--- a/river/command/filter.zig
+++ /dev/null
@@ -1,147 +0,0 @@
-// This file is part of river, a dynamic tiling wayland compositor.
-//
-// Copyright 2020 The River Developers
-//
-// 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
-// the Free Software Foundation, version 3.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program. If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-const assert = std.debug.assert;
-const mem = std.mem;
-
-const server = &@import("../main.zig").server;
-const util = @import("../util.zig");
-
-const View = @import("../View.zig");
-const Error = @import("../command.zig").Error;
-const Seat = @import("../Seat.zig");
-
-const FilterKind = enum {
-    @"app-id",
-    title,
-};
-
-pub fn floatFilterAdd(
-    _: *Seat,
-    args: []const [:0]const u8,
-    _: *?[]const u8,
-) Error!void {
-    if (args.len < 3) return Error.NotEnoughArguments;
-    if (args.len > 3) return Error.TooManyArguments;
-
-    const kind = std.meta.stringToEnum(FilterKind, args[1]) orelse return Error.UnknownOption;
-    const map = switch (kind) {
-        .@"app-id" => &server.config.float_filter_app_ids,
-        .title => &server.config.float_filter_titles,
-    };
-
-    const key = args[2];
-    const gop = try map.getOrPut(util.gpa, key);
-    if (gop.found_existing) return;
-    errdefer assert(map.remove(key));
-    gop.key_ptr.* = try util.gpa.dupe(u8, key);
-}
-
-pub fn floatFilterRemove(
-    _: *Seat,
-    args: []const [:0]const u8,
-    _: *?[]const u8,
-) Error!void {
-    if (args.len < 3) return Error.NotEnoughArguments;
-    if (args.len > 3) return Error.TooManyArguments;
-
-    const kind = std.meta.stringToEnum(FilterKind, args[1]) orelse return Error.UnknownOption;
-    const map = switch (kind) {
-        .@"app-id" => &server.config.float_filter_app_ids,
-        .title => &server.config.float_filter_titles,
-    };
-
-    const key = args[2];
-    if (map.fetchRemove(key)) |kv| util.gpa.free(kv.key);
-}
-
-pub fn csdFilterAdd(
-    _: *Seat,
-    args: []const [:0]const u8,
-    _: *?[]const u8,
-) Error!void {
-    if (args.len < 3) return Error.NotEnoughArguments;
-    if (args.len > 3) return Error.TooManyArguments;
-
-    const kind = std.meta.stringToEnum(FilterKind, args[1]) orelse return Error.UnknownOption;
-    const map = switch (kind) {
-        .@"app-id" => &server.config.csd_filter_app_ids,
-        .title => &server.config.csd_filter_titles,
-    };
-
-    const key = args[2];
-    const gop = try map.getOrPut(util.gpa, key);
-    if (gop.found_existing) return;
-    errdefer assert(map.remove(key));
-    gop.key_ptr.* = try util.gpa.dupe(u8, key);
-
-    csdFilterUpdateViews(kind, key, .add);
-    server.root.applyPending();
-}
-
-pub fn csdFilterRemove(
-    _: *Seat,
-    args: []const [:0]const u8,
-    _: *?[]const u8,
-) Error!void {
-    if (args.len < 3) return Error.NotEnoughArguments;
-    if (args.len > 3) return Error.TooManyArguments;
-
-    const kind = std.meta.stringToEnum(FilterKind, args[1]) orelse return Error.UnknownOption;
-    const map = switch (kind) {
-        .@"app-id" => &server.config.csd_filter_app_ids,
-        .title => &server.config.csd_filter_titles,
-    };
-
-    const key = args[2];
-    if (map.fetchRemove(key)) |kv| {
-        util.gpa.free(kv.key);
-        csdFilterUpdateViews(kind, key, .remove);
-        server.root.applyPending();
-    }
-}
-
-fn csdFilterUpdateViews(kind: FilterKind, pattern: []const u8, operation: enum { add, remove }) void {
-    var it = server.root.views.iterator(.forward);
-    while (it.next()) |view| {
-        if (view.impl == .xdg_toplevel) {
-            if (view.impl.xdg_toplevel.decoration) |decoration| {
-                if (viewMatchesPattern(kind, pattern, view)) {
-                    switch (operation) {
-                        .add => {
-                            _ = decoration.wlr_decoration.setMode(.client_side);
-                            view.pending.borders = false;
-                        },
-                        .remove => {
-                            _ = decoration.wlr_decoration.setMode(.server_side);
-                            view.pending.borders = true;
-                        },
-                    }
-                }
-            }
-        }
-    }
-}
-
-fn viewMatchesPattern(kind: FilterKind, pattern: []const u8, view: *View) bool {
-    const p = switch (kind) {
-        .@"app-id" => mem.span(view.getAppId()),
-        .title => mem.span(view.getTitle()),
-    } orelse return false;
-
-    return mem.eql(u8, pattern, p);
-}
diff --git a/river/command/rule.zig b/river/command/rule.zig
new file mode 100644
index 0000000..c9665af
--- /dev/null
+++ b/river/command/rule.zig
@@ -0,0 +1,164 @@
+// This file is part of river, a dynamic tiling wayland compositor.
+//
+// Copyright 2023 The River Developers
+//
+// 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
+// the Free Software Foundation, version 3.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const fmt = std.fmt;
+
+const globber = @import("globber");
+const flags = @import("flags");
+
+const server = &@import("../main.zig").server;
+const util = @import("../util.zig");
+
+const Error = @import("../command.zig").Error;
+const RuleList = @import("../RuleList.zig");
+const Seat = @import("../Seat.zig");
+const View = @import("../View.zig");
+
+const Action = enum {
+    float,
+    @"no-float",
+    ssd,
+    csd,
+};
+
+pub fn ruleAdd(_: *Seat, args: []const [:0]const u8, _: *?[]const u8) Error!void {
+    if (args.len < 2) return Error.NotEnoughArguments;
+
+    const result = flags.parser([:0]const u8, &.{
+        .{ .name = "app-id", .kind = .arg },
+        .{ .name = "title", .kind = .arg },
+    }).parse(args[2..]) catch {
+        return error.InvalidValue;
+    };
+
+    if (result.args.len > 0) return Error.TooManyArguments;
+
+    const action = std.meta.stringToEnum(Action, args[1]) orelse return Error.UnknownOption;
+    const app_id_glob = result.flags.@"app-id" orelse "*";
+    const title_glob = result.flags.title orelse "*";
+
+    try globber.validate(app_id_glob);
+    try globber.validate(title_glob);
+
+    switch (action) {
+        .float, .@"no-float" => {
+            try server.config.float_rules.add(.{
+                .app_id_glob = app_id_glob,
+                .title_glob = title_glob,
+                .value = (action == .float),
+            });
+        },
+        .ssd, .csd => {
+            try server.config.ssd_rules.add(.{
+                .app_id_glob = app_id_glob,
+                .title_glob = title_glob,
+                .value = (action == .ssd),
+            });
+            apply_ssd_rules();
+            server.root.applyPending();
+        },
+    }
+}
+
+pub fn ruleDel(_: *Seat, args: []const [:0]const u8, _: *?[]const u8) Error!void {
+    if (args.len < 2) return Error.NotEnoughArguments;
+
+    const result = flags.parser([:0]const u8, &.{
+        .{ .name = "app-id", .kind = .arg },
+        .{ .name = "title", .kind = .arg },
+    }).parse(args[2..]) catch {
+        return error.InvalidValue;
+    };
+
+    if (result.args.len > 0) return Error.TooManyArguments;
+
+    const action = std.meta.stringToEnum(Action, args[1]) orelse return Error.UnknownOption;
+    const app_id_glob = result.flags.@"app-id" orelse "*";
+    const title_glob = result.flags.title orelse "*";
+
+    switch (action) {
+        .float, .@"no-float" => {
+            server.config.float_rules.del(.{
+                .app_id_glob = app_id_glob,
+                .title_glob = title_glob,
+                .value = (action == .float),
+            });
+        },
+        .ssd, .csd => {
+            server.config.ssd_rules.del(.{
+                .app_id_glob = app_id_glob,
+                .title_glob = title_glob,
+                .value = (action == .ssd),
+            });
+            apply_ssd_rules();
+            server.root.applyPending();
+        },
+    }
+}
+
+fn apply_ssd_rules() void {
+    var it = server.root.views.iterator(.forward);
+    while (it.next()) |view| {
+        if (server.config.ssd_rules.match(view)) |ssd| {
+            view.pending.ssd = ssd;
+        }
+    }
+}
+
+pub fn listRules(_: *Seat, args: []const [:0]const u8, out: *?[]const u8) Error!void {
+    if (args.len < 2) return error.NotEnoughArguments;
+    if (args.len > 2) return error.TooManyArguments;
+
+    const list = std.meta.stringToEnum(enum { float, ssd }, args[1]) orelse return Error.UnknownOption;
+
+    const rules = switch (list) {
+        .float => server.config.float_rules.rules.items,
+        .ssd => server.config.ssd_rules.rules.items,
+    };
+
+    var action_column_max = "action".len;
+    var app_id_column_max = "app-id".len;
+    for (rules) |rule| {
+        const action = switch (list) {
+            .float => if (rule.value) "float" else "no-float",
+            .ssd => if (rule.value) "ssd" else "csd",
+        };
+        action_column_max = @max(action_column_max, action.len);
+        app_id_column_max = @max(app_id_column_max, rule.app_id_glob.len);
+    }
+    action_column_max += 2;
+    app_id_column_max += 2;
+
+    var buffer = std.ArrayList(u8).init(util.gpa);
+    const writer = buffer.writer();
+
+    try fmt.formatBuf("action", .{ .width = action_column_max, .alignment = .Left }, writer);
+    try fmt.formatBuf("app-id", .{ .width = app_id_column_max, .alignment = .Left }, writer);
+    try writer.writeAll("title\n");
+
+    for (rules) |rule| {
+        const action = switch (list) {
+            .float => if (rule.value) "float" else "no-float",
+            .ssd => if (rule.value) "ssd" else "csd",
+        };
+        try fmt.formatBuf(action, .{ .width = action_column_max, .alignment = .Left }, writer);
+        try fmt.formatBuf(rule.app_id_glob, .{ .width = app_id_column_max, .alignment = .Left }, writer);
+        try writer.print("{s}\n", .{rule.title_glob});
+    }
+
+    out.* = buffer.toOwnedSlice();
+}