Support WLR_INPUT_DEVICE_SWITCH in sway

This commit adds support for laptop lid and tablet
mode switches as provided by evdev/libinput and
handled by wlroots.

Adds a new bindswitch command with syntax:
bindswitch <switch>:<state> <command>

Where <switch> is one of:
tablet for WLR_SWITCH_TYPE_TABLET_MODE
lid for WLR_SWITCH_TYPE_LID

<state> is one of:
on for WLR_SWITCH_STATE_ON
off for WLR_SWITCH_STATE_OFF
toggle for WLR_SWITCH_STATE_TOGGLE

(Note that WLR_SWITCH_STATE_TOGGLE doesn't map to
libinput and will trigger at both on and off events)

1 files changed, 118 insertions, 0 deletions

diff --git a/sway/commands/bind.c b/sway/commands/bind.c
index 172e6b8a..b3d391da 100644
--- a/sway/commands/bind.c
+++ b/sway/commands/bind.c
@@ -29,6 +29,28 @@ void free_sway_binding(struct sway_binding *binding) {
         free(binding);
 }
 
+void free_switch_binding(struct sway_switch_binding *binding) {
+        if (!binding) {
+                return;
+        }
+        free(binding->command);
+        free(binding);
+}
+
+/**
+ * Returns true if the bindings have the same switch type and state combinations.
+ */
+static bool binding_switch_compare(struct sway_switch_binding *binding_a,
+                struct sway_switch_binding *binding_b) {
+        if (binding_a->type != binding_b->type) {
+                return false;
+        }
+        if (binding_a->state != binding_b->state) {
+                return false;
+        }
+        return true;
+}
+
 /**
  * Returns true if the bindings have the same key and modifier combinations.
  * Note that keyboard layout is not considered, so the bindings might actually
@@ -325,6 +347,102 @@ struct cmd_results *cmd_bindcode(int argc, char **argv) {
         return cmd_bindsym_or_bindcode(argc, argv, true);
 }
 
+struct cmd_results *cmd_bindswitch(int argc, char **argv) {
+
+        struct cmd_results *error = NULL;
+        if ((error = checkarg(argc, "bindswitch", EXPECTED_AT_LEAST, 2))) {
+                return error;
+        }
+        struct sway_switch_binding *binding = calloc(1, sizeof(struct sway_switch_binding));
+        if (!binding) {
+                return cmd_results_new(CMD_FAILURE, "Unable to allocate binding");
+        }
+
+        bool warn = true;
+
+        // Handle flags
+        while (argc > 0) {
+                if (strcmp("--locked", argv[0]) == 0) {
+                        binding->flags |= BINDING_LOCKED;
+                } else if (strcmp("--no-warn", argv[0]) == 0) {
+                        warn = false;
+                } else {
+                        break;
+                }
+                argv++;
+                argc--;
+        }
+
+        if (argc < 2) {
+                free(binding);
+                return cmd_results_new(CMD_FAILURE,
+                        "Invalid bindswitch command (expected at least 2 "
+                        "non-option arguments, got %d)", argc);
+        }
+        binding->command = join_args(argv + 1, argc - 1);
+
+        list_t *split = split_string(argv[0], ":");
+        if (split->length != 2) {
+                free_switch_binding(binding);
+                return cmd_results_new(CMD_FAILURE,
+                        "Invalid bindswitch command (expected two arguments with "
+                        "format <switch>:<state> <action>, got %d)", argc);
+        }
+        if (strcmp(split->items[0], "tablet") == 0) {
+                binding->type = WLR_SWITCH_TYPE_TABLET_MODE;
+        } else if (strcmp(split->items[0], "lid") == 0) {
+                binding->type = WLR_SWITCH_TYPE_LID;
+        } else {
+                free_switch_binding(binding);
+                return cmd_results_new(CMD_FAILURE,
+                        "Invalid bindswitch command (expected switch binding: "
+                        "unknown switch %s)", split->items[0]);
+        }
+        if (strcmp(split->items[1], "on") == 0) {
+                binding->state = WLR_SWITCH_STATE_ON;
+        } else if (strcmp(split->items[1], "off") == 0) {
+                binding->state = WLR_SWITCH_STATE_OFF;
+        } else if (strcmp(split->items[1], "toggle") == 0) {
+                binding->state = WLR_SWITCH_STATE_TOGGLE;
+        } else {
+                free_switch_binding(binding);
+                return cmd_results_new(CMD_FAILURE,
+                        "Invalid bindswitch command "
+                        "(expected switch state: unknown state %d)",
+                                        split->items[0]);
+        }
+        list_free_items_and_destroy(split);
+
+        list_t *mode_bindings = config->current_mode->switch_bindings;
+
+        // overwrite the binding if it already exists
+        bool overwritten = false;
+        for (int i = 0; i < mode_bindings->length; ++i) {
+                struct sway_switch_binding *config_binding = mode_bindings->items[i];
+                if (binding_switch_compare(binding, config_binding)) {
+                        sway_log(SWAY_INFO, "Overwriting binding '%s' from `%s` to `%s`",
+                                 argv[0], binding->command, config_binding->command);
+                        if (warn) {
+                                config_add_swaynag_warning("Overwriting binding"
+                                        "'%s' to `%s` from `%s`",
+                                        argv[0], binding->command,
+                                        config_binding->command);
+                        }
+                        free_switch_binding(config_binding);
+                        mode_bindings->items[i] = binding;
+                        overwritten = true;
+                }
+        }
+
+        if (!overwritten) {
+                list_add(mode_bindings, binding);
+        }
+
+        sway_log(SWAY_DEBUG, "bindswitch - Bound %s to command `%s`",
+                        argv[0], binding->command);
+        return cmd_results_new(CMD_SUCCESS, NULL);
+}
+
 /**
  * Execute the command associated to a binding
  */