Implement "attach-mode"

river/command/attach_mode.zig

@@ -0,0 +1,41 @@
+// This file is part of river, a dynamic tiling wayland compositor.
+//
+// Copyright 2020 Leon Henrik Plickat
+//
+// 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, either version 3 of the License, or
+// (at your option) any later version.
+//
+// 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 util = @import("../util.zig");
+
+const Error = @import("../command.zig").Error;
+const Seat = @import("../Seat.zig");
+
+pub fn attach_mode(
+    allocator: *std.mem.Allocator,
+    seat: *Seat,
+    args: []const []const u8,
+    out: *?[]const u8,
+) Error!void {
+    if (args.len < 2) return Error.NotEnoughArguments;
+    if (args.len > 2) return Error.TooManyArguments;
+
+    if (std.mem.eql(u8, "top", args[1])) {
+        seat.focused_output.attach_mode = .top;
+    } else if (std.mem.eql(u8, "bottom", args[1])) {
+        seat.focused_output.attach_mode = .bottom;
+    } else {
+        return Error.UnknownOption;
+    }
+}