Implement gaps (PR #2047)

include/sway/tree/arrange.h

@@ -3,6 +3,12 @@
 
 struct sway_container;
 
+// Remove gaps around container
+void remove_gaps(struct sway_container *c);
+
+// Add gaps around container
+void add_gaps(struct sway_container *c);
+
 // Determine the root container's geometry, then iterate to everything below
 void arrange_root(void);
 

include/sway/tree/container.h

@@ -86,6 +86,13 @@ struct sway_container {
 	double saved_x, saved_y;
 	double saved_width, saved_height;
 
+	// The gaps currently applied to the container.
+	double current_gaps;
+
+	bool has_gaps;
+	double gaps_inner;
+	double gaps_outer;
+
 	list_t *children;
 
 	struct sway_container *parent;

sway/commands.c

@@ -105,6 +105,8 @@ static struct cmd_handler handlers[] = {
 	{ "font", cmd_font },
 	{ "for_window", cmd_for_window },
 	{ "force_focus_wrapping", cmd_force_focus_wrapping },
+	{ "fullscreen", cmd_fullscreen },
+	{ "gaps", cmd_gaps },
 	{ "hide_edge_borders", cmd_hide_edge_borders },
 	{ "include", cmd_include },
 	{ "input", cmd_input },
@@ -114,6 +116,7 @@ static struct cmd_handler handlers[] = {
 	{ "seat", cmd_seat },
 	{ "set", cmd_set },
 	{ "show_marks", cmd_show_marks },
+	{ "smart_gaps", cmd_smart_gaps },
 	{ "workspace", cmd_workspace },
 	{ "workspace_auto_back_and_forth", cmd_ws_auto_back_and_forth },
 };

sway/commands/gaps.c

@@ -0,0 +1,183 @@
+#include <string.h>
+#include "sway/commands.h"
+#include "sway/config.h"
+#include "sway/tree/arrange.h"
+#include "log.h"
+#include "stringop.h"
+#include <math.h>
+
+enum gaps_op {
+	GAPS_OP_SET,
+	GAPS_OP_ADD,
+	GAPS_OP_SUBTRACT
+};
+
+enum gaps_scope {
+	GAPS_SCOPE_ALL,
+	GAPS_SCOPE_WORKSPACE,
+	GAPS_SCOPE_CURRENT
+};
+
+struct cmd_results *cmd_gaps(int argc, char **argv) {
+	struct cmd_results *error = checkarg(argc, "gaps", EXPECTED_AT_LEAST, 1);
+	if (error) {
+		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;
+			arrange_root();
+		} else if (strcmp(argv[1], "off") == 0) {
+			config->edge_gaps = false;
+			arrange_root();
+		} 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;
+			arrange_root();
+		} else {
+			return cmd_results_new(CMD_INVALID, "gaps",
+				"gaps edge_gaps on|off|toggle");
+		}
+	} 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;
+		}
+
+		// 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;
+			}
+		}
+
+		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;
+			}
+		}
+
+		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>"); 
+		}
+
+		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 (scope == GAPS_SCOPE_ALL) {
+			if (inner) {
+				config->gaps_inner = total;
+			} else {
+				config->gaps_outer = total;
+			}
+			arrange_root();
+		} else {
+			struct sway_container *c =
+				config->handler_context.current_container;
+			if (scope == GAPS_SCOPE_WORKSPACE && c->type != C_WORKSPACE) {
+				c = container_parent(c, C_WORKSPACE);
+			}
+			c->has_gaps = true;
+			if (inner) {
+				c->gaps_inner = total;
+			} else {
+				c->gaps_outer = total;
+			}
+
+			if (c->parent) {
+				arrange_children_of(c->parent);
+			} else {
+				arrange_root();
+			}
+		}
+	}
+
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}

sway/commands/smart_gaps.c

@@ -0,0 +1,28 @@
+#include <string.h>
+#include "sway/commands.h"
+#include "sway/config.h"
+#include "sway/tree/arrange.h"
+#include "sway/tree/view.h"
+#include "sway/tree/container.h"
+#include "log.h"
+#include "stringop.h"
+
+struct cmd_results *cmd_smart_gaps(int argc, char **argv) {
+	struct cmd_results *error = checkarg(argc, "smart_gaps", EXPECTED_AT_LEAST, 1);
+
+	if (error) {
+		return error;
+	}
+
+	if (strcmp(argv[0], "on") == 0) {
+		config->smart_gaps = true;
+		arrange_root();
+	} else if (strcmp(argv[0], "off") == 0) {
+		config->smart_gaps = false;
+		arrange_root();
+	} else {
+		return cmd_results_new(CMD_INVALID, "smart_gaps",
+			"Expected 'smart_gaps <on|off>' ");
+	}
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}

sway/meson.build

@@ -44,6 +44,7 @@ sway_sources = files(
 	'commands/for_window.c',
 	'commands/force_focus_wrapping.c',
 	'commands/fullscreen.c',
+	'commands/gaps.c',
 	'commands/hide_edge_borders.c',
 	'commands/kill.c',
 	'commands/mark.c',
@@ -64,6 +65,7 @@ sway_sources = files(
 	'commands/seat/fallback.c',
 	'commands/set.c',
 	'commands/show_marks.c',
+	'commands/smart_gaps.c',
 	'commands/split.c',
 	'commands/sticky.c',
 	'commands/swaybg_command.c',

sway/tree/arrange.c

@@ -43,6 +43,7 @@ void arrange_output(struct sway_container *output) {
 			"called arrange_output() on non-output container")) {
 		return;
 	}
+
 	const struct wlr_box *output_box = wlr_output_layout_get_box(
 			root_container.sway_root->output_layout,
 			output->sway_output->wlr_output);
@@ -52,6 +53,7 @@ void arrange_output(struct sway_container *output) {
 	output->height = output_box->height;
 	wlr_log(L_DEBUG, "Arranging output '%s' at %f,%f",
 			output->name, output->x, output->y);
+	
 	for (int i = 0; i < output->children->length; ++i) {
 		struct sway_container *workspace = output->children->items[i];
 		arrange_workspace(workspace);
@@ -67,18 +69,62 @@ void arrange_workspace(struct sway_container *workspace) {
 			"called arrange_workspace() on non-workspace container")) {
 		return;
 	}
+
 	struct sway_container *output = workspace->parent;
 	struct wlr_box *area = &output->sway_output->usable_area;
 	wlr_log(L_DEBUG, "Usable area for ws: %dx%d@%d,%d",
 			area->width, area->height, area->x, area->y);
+
+	remove_gaps(workspace);
+
 	workspace->width = area->width;
 	workspace->height = area->height;
 	workspace->x = output->x + area->x;
 	workspace->y = output->y + area->y;
+
+	add_gaps(workspace);
+
 	wlr_log(L_DEBUG, "Arranging workspace '%s' at %f, %f",
 			workspace->name, workspace->x, workspace->y);
 	arrange_children_of(workspace);
-	container_damage_whole(workspace);
+}
+
+void remove_gaps(struct sway_container *c) {
+	if (c->current_gaps == 0) {
+		wlr_log(L_DEBUG, "Removing gaps: not gapped: %p", c);
+		return;
+	}
+
+	c->width += c->current_gaps * 2;
+	c->height += c->current_gaps * 2;
+	c->x -= c->current_gaps;
+	c->y -= c->current_gaps;
+
+	c->current_gaps = 0;
+
+	wlr_log(L_DEBUG, "Removing gaps %p", c);
+}
+
+void add_gaps(struct sway_container *c) {
+	if (c->current_gaps > 0 || c->type == C_CONTAINER) {
+		wlr_log(L_DEBUG, "Not adding gaps: %p", c);
+		return;
+	}
+
+	if (c->type == C_WORKSPACE &&
+		!(config->edge_gaps || (config->smart_gaps && c->children->length > 1))) {
+		return;
+	}
+
+	double gaps = c->has_gaps ? c->gaps_inner : config->gaps_inner;
+
+	c->x += gaps;
+	c->y += gaps;
+	c->width -= 2 * gaps;
+	c->height -= 2 * gaps;
+	c->current_gaps = gaps;
+
+	wlr_log(L_DEBUG, "Adding gaps: %p", c);
 }
 
 static void apply_horiz_layout(struct sway_container *parent) {
@@ -99,6 +145,7 @@ static void apply_horiz_layout(struct sway_container *parent) {
 	double total_width = 0;
 	for (size_t i = 0; i < num_children; ++i) {
 		struct sway_container *child = parent->children->items[i];
+
 		if (child->width <= 0) {
 			if (num_children > 1) {
 				child->width = parent->width / (num_children - 1);
@@ -106,6 +153,7 @@ static void apply_horiz_layout(struct sway_container *parent) {
 				child->width = parent->width;
 			}
 		}
+		remove_gaps(child);
 		total_width += child->width;
 	}
 	double scale = parent->width / total_width;
@@ -121,12 +169,19 @@ static void apply_horiz_layout(struct sway_container *parent) {
 				child, child->type, child->width, scale);
 		child->x = child_x;
 		child->y = parent->y + parent_offset;
-		child->width = floor(child->width * scale);
 		child->height = parent_height;
+
+		if (i == num_children - 1) {
+			// Make last child use remaining width of parent
+			child->width = parent->x + parent->width - child->x;
+		} else {
+			child->width = floor(child->width * scale);
+		}
+
 		child_x += child->width;
+
+		add_gaps(child);
 	}
-	// Make last child use remaining width of parent
-	child->width = parent->x + parent->width - child->x;
 }
 
 static void apply_vert_layout(struct sway_container *parent) {
@@ -141,12 +196,13 @@ static void apply_vert_layout(struct sway_container *parent) {
 		parent_offset =
 			container_titlebar_height() * parent->parent->children->length;
 	}
-	size_t parent_height = parent->height - parent_offset;
+	size_t parent_height = parent->height + parent_offset;
 
 	// Calculate total height of children
 	double total_height = 0;
 	for (size_t i = 0; i < num_children; ++i) {
 		struct sway_container *child = parent->children->items[i];
+
 		if (child->height <= 0) {
 			if (num_children > 1) {
 				child->height = parent_height / (num_children - 1);
@@ -154,6 +210,7 @@ static void apply_vert_layout(struct sway_container *parent) {
 				child->height = parent_height;
 			}
 		}
+		remove_gaps(child);
 		total_height += child->height;
 	}
 	double scale = parent_height / total_height;
@@ -170,11 +227,18 @@ static void apply_vert_layout(struct sway_container *parent) {
 		child->x = parent->x;
 		child->y = child_y;
 		child->width = parent->width;
-		child->height = floor(child->height * scale);
+
+		if (i == num_children - 1) {
+			// Make last child use remaining height of parent
+			child->height = parent->y + parent_offset + parent_height - child->y;
+		} else {
+			child->height = floor(child->height * scale);
+		}
+
 		child_y += child->height;
+
+		add_gaps(child);
 	}
-	// Make last child use remaining height of parent
-	child->height = parent->y + parent_offset + parent_height - child->y;
 }
 
 static void apply_tabbed_or_stacked_layout(struct sway_container *parent) {
@@ -191,10 +255,12 @@ static void apply_tabbed_or_stacked_layout(struct sway_container *parent) {
 	size_t parent_height = parent->height - parent_offset;
 	for (int i = 0; i < parent->children->length; ++i) {
 		struct sway_container *child = parent->children->items[i];
+		remove_gaps(child);
 		child->x = parent->x;
 		child->y = parent->y + parent_offset;
 		child->width = parent->width;
 		child->height = parent_height;
+		add_gaps(child);
 	}
 }
 
@@ -211,6 +277,7 @@ void arrange_children_of(struct sway_container *parent) {
 	if (workspace->type != C_WORKSPACE) {
 		workspace = container_parent(workspace, C_WORKSPACE);
 	}
+
 	if (workspace->sway_workspace->fullscreen) {
 		// Just arrange the fullscreen view and jump out
 		view_autoconfigure(workspace->sway_workspace->fullscreen);
@@ -241,6 +308,11 @@ void arrange_children_of(struct sway_container *parent) {
 	// Apply x, y, width and height to children and recurse if needed
 	for (int i = 0; i < parent->children->length; ++i) {
 		struct sway_container *child = parent->children->items[i];
+		if (parent->has_gaps && !child->has_gaps) {
+			child->has_gaps = true;
+			child->gaps_inner = parent->gaps_inner;
+			child->gaps_outer = parent->gaps_outer;
+		}
 		if (child->type == C_VIEW) {
 			view_autoconfigure(child->sway_view);
 		} else {

sway/tree/container.c

@@ -124,6 +124,11 @@ struct sway_container *container_create(enum sway_container_type type) {
 	wl_signal_add(&c->events.reparent, &c->reparent);
 	c->reparent.notify = handle_reparent;
 
+	c->has_gaps = false;
+	c->gaps_inner = 0;
+	c->gaps_outer = 0;
+	c->current_gaps = 0;
+
 	return c;
 }
 

sway/tree/layout.c

@@ -871,6 +871,8 @@ struct sway_container *container_split(struct sway_container *child,
 
 	wlr_log(L_DEBUG, "creating container %p around %p", cont, child);
 
+	remove_gaps(child);
+
 	cont->prev_layout = L_NONE;
 	cont->width = child->width;
 	cont->height = child->height;
@@ -879,6 +881,9 @@ struct sway_container *container_split(struct sway_container *child,
 
 	struct sway_seat *seat = input_manager_get_default_seat(input_manager);
 	bool set_focus = (seat_get_focus(seat) == child);
+	
+	add_gaps(cont);
+
 	if (child->type == C_WORKSPACE) {
 		struct sway_container *workspace = child;
 		while (workspace->children->length) {
@@ -906,7 +911,7 @@ struct sway_container *container_split(struct sway_container *child,
 	}
 
 	container_notify_subtree_changed(cont);
-
+	arrange_children_of(cont);
 	return cont;
 }