Make gaps implementation consistent with i3-gaps

This changes our gaps implementation to behave like i3-gaps.

Our previous implementation allowed you to set gaps on a per container
basis. This isn't supported by i3-gaps and doesn't seem to have a
practical use case. The gaps_outer and gaps_inner properties on
containers are now removed as they just read the gaps_inner from the
workspace.

`gaps inner|outer <px>` no longer changes the gaps for all workspaces.
It only sets defaults for new workspaces.

`gaps inner|outer current|workspace|all set|plus|minus <px>` is now
runtime only, and the workspace option is now removed. `current` now
sets gaps for the current workspace as opposed to the current container.

`workspace <ws> gaps inner|outer <px>` is now implemented. This sets
defaults for a workspace.

This also fixes a bug where changing the layout of a split container
from linear to tabbed would cause gaps to not be applied to it until you
switch to another workspace and back.

5 files changed, 204 insertions, 157 deletions

diff --git a/sway/commands/gaps.c b/sway/commands/gaps.c
index d676e475..3791fcb4 100644
--- a/sway/commands/gaps.c
+++ b/sway/commands/gaps.c
@@ -1,4 +1,5 @@
 #include <string.h>
+#include <strings.h>
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/tree/arrange.h"
@@ -13,172 +14,167 @@ enum gaps_op {
 	GAPS_OP_SUBTRACT
 };
 
-enum gaps_scope {
-	GAPS_SCOPE_ALL,
-	GAPS_SCOPE_WORKSPACE,
-	GAPS_SCOPE_CURRENT
+struct gaps_data {
+	bool inner;
+	enum gaps_op operation;
+	int amount;
 };
 
-struct cmd_results *cmd_gaps(int argc, char **argv) {
-	struct cmd_results *error = checkarg(argc, "gaps", EXPECTED_AT_LEAST, 1);
-	if (error) {
+// gaps edge_gaps on|off|toggle
+static struct cmd_results *gaps_edge_gaps(int argc, char **argv) {
+	struct cmd_results *error;
+	if ((error = checkarg(argc, "gaps", EXPECTED_AT_LEAST, 2))) {
 		return error;
 	}
 
-	if (strcmp(argv[0], "edge_gaps") == 0) {
-		if ((error = checkarg(argc, "gaps", EXPECTED_AT_LEAST, 2))) {
-			return error;
-		}
-
-		if (strcmp(argv[1], "on") == 0) {
-			config->edge_gaps = true;
-		} else if (strcmp(argv[1], "off") == 0) {
-			config->edge_gaps = false;
-		} else if (strcmp(argv[1], "toggle") == 0) {
-			if (!config->active) {
-				return cmd_results_new(CMD_INVALID, "gaps",
-					"Cannot toggle gaps while not running.");
-			}
-			config->edge_gaps = !config->edge_gaps;
-		} else {
+	if (strcmp(argv[1], "on") == 0) {
+		config->edge_gaps = true;
+	} else if (strcmp(argv[1], "off") == 0) {
+		config->edge_gaps = false;
+	} else if (strcmp(argv[1], "toggle") == 0) {
+		if (!config->active) {
 			return cmd_results_new(CMD_INVALID, "gaps",
-				"gaps edge_gaps on|off|toggle");
+					"Cannot toggle gaps while not running.");
 		}
-		arrange_root();
+		config->edge_gaps = !config->edge_gaps;
 	} else {
-		int amount_idx = 0; // the current index in argv
-		enum gaps_op op = GAPS_OP_SET;
-		enum gaps_scope scope = GAPS_SCOPE_ALL;
-		bool inner = true;
-
-		if (strcmp(argv[0], "inner") == 0) {
-			amount_idx++;
-			inner = true;
-		} else if (strcmp(argv[0], "outer") == 0) {
-			amount_idx++;
-			inner = false;
-		}
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"gaps edge_gaps on|off|toggle");
+	}
+	arrange_root();
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}
 
-		// If one of the long variants of the gaps command is used
-		// (which starts with inner|outer) check the number of args
-		if (amount_idx > 0) { // if we've seen inner|outer
-			if (argc > 2) { // check the longest variant
-				error = checkarg(argc, "gaps", EXPECTED_EQUAL_TO, 4);
-				if (error) {
-					return error;
-				}
-			} else { // check the next longest format
-				error = checkarg(argc, "gaps", EXPECTED_EQUAL_TO, 2);
-				if (error) {
-					return error;
-				}
-			}
-		} else {
-			error = checkarg(argc, "gaps", EXPECTED_EQUAL_TO, 1);
-			if (error) {
-				return error;
-			}
-		}
+// gaps inner|outer <px>
+static struct cmd_results *gaps_set_defaults(int argc, char **argv) {
+	struct cmd_results *error = checkarg(argc, "gaps", EXPECTED_EQUAL_TO, 2);
+	if (error) {
+		return error;
+	}
 
-		if (argc == 4) {
-			// Long format: all|workspace|current.
-			if (strcmp(argv[amount_idx], "all") == 0) {
-				amount_idx++;
-				scope = GAPS_SCOPE_ALL;
-			} else if (strcmp(argv[amount_idx], "workspace") == 0) {
-				amount_idx++;
-				scope = GAPS_SCOPE_WORKSPACE;
-			} else if (strcmp(argv[amount_idx], "current") == 0) {
-				amount_idx++;
-				scope = GAPS_SCOPE_CURRENT;
-			}
-
-			// Long format: set|plus|minus
-			if (strcmp(argv[amount_idx], "set") == 0) {
-				amount_idx++;
-				op = GAPS_OP_SET;
-			} else if (strcmp(argv[amount_idx], "plus") == 0) {
-				amount_idx++;
-				op = GAPS_OP_ADD;
-			} else if (strcmp(argv[amount_idx], "minus") == 0) {
-				amount_idx++;
-				op = GAPS_OP_SUBTRACT;
-			}
-		}
+	bool inner;
+	if (strcasecmp(argv[0], "inner") == 0) {
+		inner = true;
+	} else if (strcasecmp(argv[0], "outer") == 0) {
+		inner = false;
+	} else {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer <px>'");
+	}
 
-		char *end;
-		double val = strtod(argv[amount_idx], &end);
-
-		if (strlen(end) && val == 0.0) { // invalid <amount>
-			// guess which variant of the command was attempted
-			if (argc == 1) {
-				return cmd_results_new(CMD_INVALID, "gaps", "gaps <amount>");
-			}
-			if (argc == 2) {
-				return cmd_results_new(CMD_INVALID, "gaps",
-					"gaps inner|outer <amount>");
-			}
-			return cmd_results_new(CMD_INVALID, "gaps",
-				"gaps inner|outer all|workspace|current set|plus|minus <amount>");
-		}
+	char *end;
+	int amount = strtol(argv[1], &end, 10);
+	if (strlen(end) && strcasecmp(end, "px") != 0) {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer <px>'");
+	}
 
-		if (amount_idx == 0) { // gaps <amount>
-			config->gaps_inner = val;
-			config->gaps_outer = val;
-			arrange_root();
-			return cmd_results_new(CMD_SUCCESS, NULL, NULL);
-		}
-		// Other variants. The middle-length variant (gaps inner|outer <amount>)
-		// just defaults the scope to "all" and defaults the op to "set".
-
-		double total;
-		switch (op) {
-			case GAPS_OP_SUBTRACT: {
-				total = (inner ? config->gaps_inner : config->gaps_outer) - val;
-				if (total < 0) {
-					total = 0;
-				}
-				break;
-			}
-			case GAPS_OP_ADD: {
-				total = (inner ? config->gaps_inner : config->gaps_outer) + val;
-				break;
-			}
-			case GAPS_OP_SET: {
-				total = val;
-				break;
-			}
-		}
+	if (inner) {
+		config->gaps_inner = amount;
+	} else {
+		config->gaps_outer = amount;
+	}
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}
 
-		if (scope == GAPS_SCOPE_ALL) {
-			if (inner) {
-				config->gaps_inner = total;
-			} else {
-				config->gaps_outer = total;
-			}
-			arrange_root();
-		} else {
-			if (scope == GAPS_SCOPE_WORKSPACE) {
-				struct sway_workspace *ws = config->handler_context.workspace;
-				ws->has_gaps = true;
-				if (inner) {
-					ws->gaps_inner = total;
-				} else {
-					ws->gaps_outer = total;
-				}
-				arrange_workspace(ws);
-			} else {
-				struct sway_container *c = config->handler_context.container;
-				c->has_gaps = true;
-				if (inner) {
-					c->gaps_inner = total;
-				} else {
-					c->gaps_outer = total;
-				}
-				arrange_workspace(c->workspace);
-			}
-		}
+static void configure_gaps(struct sway_workspace *ws, void *_data) {
+	struct gaps_data *data = _data;
+	int *prop = data->inner ? &ws->gaps_inner : &ws->gaps_outer;
+
+	switch (data->operation) {
+	case GAPS_OP_SET:
+		*prop = data->amount;
+		break;
+	case GAPS_OP_ADD:
+		*prop += data->amount;
+		break;
+	case GAPS_OP_SUBTRACT:
+		*prop -= data->amount;
+		break;
+	}
+	arrange_workspace(ws);
+}
+
+// gaps inner|outer current|all set|plus|minus <px>
+static struct cmd_results *gaps_set_runtime(int argc, char **argv) {
+	struct cmd_results *error = checkarg(argc, "gaps", EXPECTED_EQUAL_TO, 4);
+	if (error) {
+		return error;
+	}
+
+	struct gaps_data data;
+
+	if (strcasecmp(argv[0], "inner") == 0) {
+		data.inner = true;
+	} else if (strcasecmp(argv[0], "outer") == 0) {
+		data.inner = false;
+	} else {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer current|all set|plus|minus <px>'");
+	}
+
+	bool all;
+	if (strcasecmp(argv[1], "current") == 0) {
+		all = false;
+	} else if (strcasecmp(argv[1], "all") == 0) {
+		all = true;
+	} else {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer current|all set|plus|minus <px>'");
+	}
+
+	if (strcasecmp(argv[2], "set") == 0) {
+		data.operation = GAPS_OP_SET;
+	} else if (strcasecmp(argv[2], "plus") == 0) {
+		data.operation = GAPS_OP_ADD;
+	} else if (strcasecmp(argv[2], "minus") == 0) {
+		data.operation = GAPS_OP_SUBTRACT;
+	} else {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer current|all set|plus|minus <px>'");
+	}
+
+	char *end;
+	data.amount = strtol(argv[3], &end, 10);
+	if (strlen(end) && strcasecmp(end, "px") != 0) {
+		return cmd_results_new(CMD_INVALID, "gaps",
+				"Expected 'gaps inner|outer current|all set|plus|minus <px>'");
+	}
+
+	if (all) {
+		root_for_each_workspace(configure_gaps, &data);
+	} else {
+		configure_gaps(config->handler_context.workspace, &data);
 	}
 
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
 }
+
+// gaps edge_gaps on|off|toggle
+// gaps inner|outer <px> - sets defaults for workspaces
+// gaps inner|outer current|all set|plus|minus <px> - runtime only
+struct cmd_results *cmd_gaps(int argc, char **argv) {
+	struct cmd_results *error = checkarg(argc, "gaps", EXPECTED_AT_LEAST, 2);
+	if (error) {
+		return error;
+	}
+
+	if (strcmp(argv[0], "edge_gaps") == 0) {
+		return gaps_edge_gaps(argc, argv);
+	}
+
+	if (argc == 2) {
+		return gaps_set_defaults(argc, argv);
+	}
+	if (argc == 4) {
+		if (config->active) {
+			return gaps_set_runtime(argc, argv);
+		} else {
+			return cmd_results_new(CMD_INVALID, "gaps",
+					"This syntax can only be used when sway is running");
+		}
+	}
+	return cmd_results_new(CMD_INVALID, "gaps",
+			"Expected 'gaps inner|outer <px>' or "
+			"'gaps inner|outer current|all set|plus|minus <px>'");
+}
diff --git a/sway/commands/layout.c b/sway/commands/layout.c
index ef3ec1cb..c2ce2e78 100644
--- a/sway/commands/layout.c
+++ b/sway/commands/layout.c
@@ -138,15 +138,14 @@ struct cmd_results *cmd_layout(int argc, char **argv) {
 			}
 			container->layout = new_layout;
 			container_update_representation(container);
-			arrange_container(container);
 		} else {
 			if (old_layout != L_TABBED && old_layout != L_STACKED) {
 				workspace->prev_split_layout = old_layout;
 			}
 			workspace->layout = new_layout;
 			workspace_update_representation(workspace);
-			arrange_workspace(workspace);
 		}
+		arrange_workspace(workspace);
 	}
 
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
diff --git a/sway/commands/workspace.c b/sway/commands/workspace.c
index 2ce7872d..63f29641 100644
--- a/sway/commands/workspace.c
+++ b/sway/commands/workspace.c
@@ -20,6 +20,8 @@ static struct workspace_config *workspace_config_find_or_create(char *ws_name) {
 		return NULL;
 	}
 	wsc->workspace = strdup(ws_name);
+	wsc->gaps_inner = -1;
+	wsc->gaps_outer = -1;
 	list_add(config->workspace_configs, wsc);
 	return wsc;
 }
@@ -37,6 +39,7 @@ struct cmd_results *cmd_workspace(int argc, char **argv) {
 	}
 
 	int output_location = -1;
+	int gaps_location = -1;
 
 	for (int i = 0; i < argc; ++i) {
 		if (strcasecmp(argv[i], "output") == 0) {
@@ -44,6 +47,12 @@ struct cmd_results *cmd_workspace(int argc, char **argv) {
 			break;
 		}
 	}
+	for (int i = 0; i < argc; ++i) {
+		if (strcasecmp(argv[i], "gaps") == 0) {
+			gaps_location = i;
+			break;
+		}
+	}
 	if (output_location >= 0) {
 		if ((error = checkarg(argc, "workspace", EXPECTED_EQUAL_TO, output_location + 2))) {
 			return error;
@@ -57,6 +66,35 @@ struct cmd_results *cmd_workspace(int argc, char **argv) {
 		}
 		free(wsc->output);
 		wsc->output = strdup(argv[output_location + 1]);
+	} else if (gaps_location >= 0) {
+		if ((error = checkarg(argc, "workspace", EXPECTED_EQUAL_TO, gaps_location + 3))) {
+			return error;
+		}
+		char *ws_name = join_args(argv, argc - 3);
+		struct workspace_config *wsc = workspace_config_find_or_create(ws_name);
+		free(ws_name);
+		if (!wsc) {
+			return cmd_results_new(CMD_FAILURE, "workspace gaps",
+					"Unable to allocate workspace output");
+		}
+		int *prop = NULL;
+		if (strcasecmp(argv[gaps_location + 1], "inner") == 0) {
+			prop = &wsc->gaps_inner;
+		} else if (strcasecmp(argv[gaps_location + 1], "outer") == 0) {
+			prop = &wsc->gaps_outer;
+		} else {
+			return cmd_results_new(CMD_FAILURE, "workspace gaps",
+					"Expected 'workspace <ws> gaps inner|outer <px>'");
+		}
+		char *end;
+		int val = strtol(argv[gaps_location + 2], &end, 10);
+
+		if (strlen(end)) {
+			free(end);
+			return cmd_results_new(CMD_FAILURE, "workspace gaps",
+					"Expected 'workspace <ws> gaps inner|outer <px>'");
+		}
+		*prop = val >= 0 ? val : 0;
 	} else {
 		if (config->reading || !config->active) {
 			return cmd_results_new(CMD_DEFER, "workspace", NULL);
diff --git a/sway/tree/container.c b/sway/tree/container.c
index baaa82fd..e329f835 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -1022,7 +1022,7 @@ void container_add_gaps(struct sway_container *c) {
 
 	struct sway_workspace *ws = c->workspace;
 
-	c->current_gaps = ws->has_gaps ? ws->gaps_inner : config->gaps_inner;
+	c->current_gaps = ws->gaps_inner;
 	c->x += c->current_gaps;
 	c->y += c->current_gaps;
 	c->width -= 2 * c->current_gaps;
diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index d65a3e4c..9dd5c815 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -68,6 +68,20 @@ struct sway_workspace *workspace_create(struct sway_output *output,
 	ws->output_priority = create_list();
 	workspace_output_add_priority(ws, output);
 
+	ws->gaps_outer = config->gaps_outer;
+	ws->gaps_inner = config->gaps_inner;
+	if (name) {
+		struct workspace_config *wsc = workspace_find_config(name);
+		if (wsc) {
+			if (wsc->gaps_outer != -1) {
+				ws->gaps_outer = wsc->gaps_outer;
+			}
+			if (wsc->gaps_inner != -1) {
+				ws->gaps_inner = wsc->gaps_inner;
+			}
+		}
+	}
+
 	output_add_workspace(output, ws);
 	output_sort_workspaces(output);
 
@@ -632,13 +646,13 @@ void workspace_add_gaps(struct sway_workspace *ws) {
 		return;
 	}
 
-	ws->current_gaps = ws->has_gaps ? ws->gaps_outer : config->gaps_outer;
+	ws->current_gaps = ws->gaps_outer;
 
 	if (ws->layout == L_TABBED || ws->layout == L_STACKED) {
 		// We have to add inner gaps for this, because children of tabbed and
 		// stacked containers don't apply their own gaps - they assume the
 		// tabbed/stacked container is using gaps.
-		ws->current_gaps += ws->has_gaps ? ws->gaps_inner : config->gaps_inner;
+		ws->current_gaps += ws->gaps_inner;
 	}
 
 	ws->x += ws->current_gaps;