Calculate config->font_height based on existing container titles

include/sway/config.h

@@ -304,7 +304,7 @@ struct sway_config {
 	enum sway_container_layout default_orientation;
 	enum sway_container_layout default_layout;
 	char *font;
-	int font_height;
+	size_t font_height;
 
 	// Flags
 	bool focus_follows_mouse;
@@ -461,7 +461,12 @@ struct bar_config *default_bar_config(void);
 
 void free_bar_config(struct bar_config *bar);
 
-int get_font_text_height(char *font);
+/**
+ * Updates the value of config->font_height based on the max title height
+ * reported by each container. If recalculate is true, the containers will
+ * recalculate their heights before reporting.
+ */
+void config_find_font_height(bool recalculate);
 
 /* Global config singleton. */
 extern struct sway_config *config;

include/sway/tree/container.h

@@ -89,6 +89,7 @@ struct sway_container {
 	struct wlr_texture *title_focused_inactive;
 	struct wlr_texture *title_unfocused;
 	struct wlr_texture *title_urgent;
+	size_t title_height;
 
 	struct {
 		struct wl_signal destroy;
@@ -198,4 +199,12 @@ struct sway_container *container_flatten(struct sway_container *container);
 
 void container_update_title_textures(struct sway_container *container);
 
+/**
+ * Calculate the container's title_height property.
+ */
+void container_calculate_title_height(struct sway_container *container);
+
+void container_update_title(struct sway_container *container,
+		const char *new_title);
+
 #endif

sway/commands/font.c

@@ -2,6 +2,7 @@
 #include <string.h>
 #include "sway/commands.h"
 #include "sway/config.h"
+#include "sway/tree/arrange.h"
 #include "log.h"
 #include "stringop.h"
 
@@ -13,6 +14,9 @@ struct cmd_results *cmd_font(int argc, char **argv) {
 	char *font = join_args(argv, argc);
 	free(config->font);
 	config->font = strdup(font);
-	config->font_height = get_font_text_height(font);
+	config_find_font_height(true);
+	if (!config->reading) {
+		arrange_root();
+	}
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
 }

sway/config.c

@@ -132,17 +132,6 @@ static void destroy_removed_seats(struct sway_config *old_config,
 	}
 }
 
-int get_font_text_height(char *font) {
-	cairo_t *cairo = cairo_create(NULL);
-	int text_height;
-	get_text_size(cairo, font, NULL, &text_height, 1, false,
-			"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-			"abcdefghijklmnopqrstuvwxyz"
-			"!@#$%^&*([{|");
-	cairo_destroy(cairo);
-	return text_height;
-}
-
 static void set_color(float dest[static 4], uint32_t color) {
 	dest[0] = ((color >> 16) & 0xff) / 255.0;
 	dest[1] = ((color >> 8) & 0xff) / 255.0;
@@ -182,7 +171,7 @@ static void config_defaults(struct sway_config *config) {
 	config->default_layout = L_NONE;
 	config->default_orientation = L_NONE;
 	if (!(config->font = strdup("monospace 10"))) goto cleanup;
-	config->font_height = get_font_text_height(config->font);
+	config->font_height = 0;
 
 	// floating view
 	config->floating_maximum_width = 0;
@@ -740,3 +729,20 @@ int workspace_output_cmp_workspace(const void *a, const void *b) {
 	const struct workspace_output *wsa = a, *wsb = b;
 	return lenient_strcmp(wsa->workspace, wsb->workspace);
 }
+
+static void find_font_height_iterator(struct sway_container *container,
+		void *data) {
+	bool *recalculate = data;
+	if (*recalculate) {
+		container_calculate_title_height(container);
+	}
+	if (container->title_height > config->font_height) {
+		config->font_height = container->title_height;
+	}
+}
+
+void config_find_font_height(bool recalculate) {
+	config->font_height = 0;
+	container_for_each_descendant_dfs(&root_container,
+			find_font_height_iterator, &recalculate);
+}

sway/tree/container.c

@@ -348,7 +348,7 @@ struct sway_container *container_view_create(struct sway_container *sibling,
 		swayc, title, sibling, sibling ? sibling->type : 0, sibling->name);
 	// Setup values
 	swayc->sway_view = sway_view;
-	swayc->name = title ? strdup(title) : NULL;
+	container_update_title(swayc, title);
 	swayc->width = 0;
 	swayc->height = 0;
 
@@ -611,3 +611,54 @@ void container_update_title_textures(struct sway_container *container) {
 	update_title_texture(container, &container->title_urgent,
 			&config->border_colors.urgent);
 }
+
+void container_calculate_title_height(struct sway_container *container) {
+	if (!container->name) {
+		container->title_height = 0;
+		return;
+	}
+	cairo_t *cairo = cairo_create(NULL);
+	int height;
+	get_text_size(cairo, config->font, NULL, &height, 1, false,
+			"%s", container->name);
+	cairo_destroy(cairo);
+	container->title_height = height;
+}
+
+static void container_notify_child_title_changed(
+		struct sway_container *container) {
+	if (!container || container->type != C_CONTAINER) {
+		return;
+	}
+	if (container->layout != L_TABBED && container->layout != L_STACKED) {
+		return;
+	}
+	if (container->name) {
+		free(container->name);
+	}
+	// TODO: iterate children and concatenate their titles
+	container->name = strdup("");
+	container_calculate_title_height(container);
+	container_update_title_textures(container);
+	container_notify_child_title_changed(container->parent);
+}
+
+void container_update_title(struct sway_container *container,
+		const char *new_title) {
+	if (container->name && strcmp(container->name, new_title) == 0) {
+		return;
+	}
+	if (container->name) {
+		free(container->name);
+	}
+	container->name = strdup(new_title);
+	container_calculate_title_height(container);
+	container_update_title_textures(container);
+	container_notify_child_title_changed(container->parent);
+
+	size_t prev_max_height = config->font_height;
+	config_find_font_height(false);
+	if (config->font_height != prev_max_height) {
+		arrange_root();
+	}
+}