implement "focused container" feature for swaygrab

include/swaygrab/json.h

@@ -0,0 +1,10 @@
+#include <json-c/json.h>
+#include "wlc/wlc.h"
+
+void init_json_tree(int socketfd);
+void free_json_tree();
+char *get_focused_output();
+char *create_payload(const char *output, struct wlc_geometry *g);
+struct wlc_geometry *get_container_geometry(json_object *container);
+json_object *get_focused_container();
+json_object *get_output_container(const char *output);

sway/ipc-json.c

@@ -169,7 +169,6 @@ static void ipc_json_describe_view(swayc_t *c, json_object *object) {
 	json_object_object_add(object, "percent", (percent > 0) ? json_object_new_double(percent) : NULL);
 	// TODO: make urgency actually work once Sway supports it
 	json_object_object_add(object, "urgent", json_object_new_boolean(false));
-
 	json_object_object_add(object, "layout",
 		(strcmp(layout, "null") == 0) ? NULL : json_object_new_string(layout));
 	json_object_object_add(object, "last_split_layout",

sway/ipc-server.c

@@ -43,6 +43,7 @@ static list_t *ipc_get_pixel_requests = NULL;
 struct get_pixels_request {
 	struct ipc_client *client;
 	wlc_handle output;
+	struct wlc_geometry geo;
 };
 
 struct sockaddr_un *ipc_user_sockaddr(void);
@@ -259,16 +260,12 @@ void ipc_get_pixels(wlc_handle output) {
 			continue;
 		}
 
-		const struct wlc_size *size = wlc_output_get_resolution(req->output);
-		struct wlc_geometry g = {
-			.size = *size,
-			.origin = { 0, 0 },
-		};
+		const struct wlc_size *size = &req->geo.size;
 		struct wlc_geometry g_out;
 		char response_header[9];
 		memset(response_header, 0, sizeof(response_header));
 		char *data = malloc(sizeof(response_header) + size->w * size->h * 4);
-		wlc_pixels_read(WLC_RGBA8888, &g, &g_out, data + sizeof(response_header));
+		wlc_pixels_read(WLC_RGBA8888, &req->geo, &g_out, data + sizeof(response_header));
 
 		response_header[0] = 1;
 		uint32_t *_size = (uint32_t *)(response_header + 1);
@@ -425,7 +422,30 @@ void ipc_client_handle_command(struct ipc_client *client) {
 	{
 		char response_header[9];
 		memset(response_header, 0, sizeof(response_header));
-		swayc_t *output = swayc_by_test(&root_container, output_by_name_test, buf);
+
+		json_object *obj = json_tokener_parse(buf);
+		json_object *o, *x, *y, *w, *h;
+
+		json_object_object_get_ex(obj, "output", &o);
+		json_object_object_get_ex(obj, "x", &x);
+		json_object_object_get_ex(obj, "y", &y);
+		json_object_object_get_ex(obj, "w", &w);
+		json_object_object_get_ex(obj, "h", &h);
+
+		struct wlc_geometry g = {
+			.origin = {
+				.x = json_object_get_int(x),
+				.y = json_object_get_int(y)
+			},
+			.size = {
+				.w = json_object_get_int(w),
+				.h = json_object_get_int(h)
+			}
+		};
+
+		swayc_t *output = swayc_by_test(&root_container, output_by_name_test, (void *)json_object_get_string(o));
+		json_object_put(obj);
+
 		if (!output) {
 			sway_log(L_ERROR, "IPC GET_PIXELS request with unknown output name");
 			ipc_send_reply(client, response_header, sizeof(response_header));
@@ -434,6 +454,7 @@ void ipc_client_handle_command(struct ipc_client *client) {
 		struct get_pixels_request *req = malloc(sizeof(struct get_pixels_request));
 		req->client = client;
 		req->output = output->handle;
+		req->geo = g;
 		list_add(ipc_get_pixel_requests, req);
 		wlc_output_schedule_render(output->handle);
 		goto exit_cleanup;

swaygrab/CMakeLists.txt

@@ -6,6 +6,7 @@ include_directories(
 
 add_executable(swaygrab
 	main.c
+	json.c
 )
 
 target_link_libraries(swaygrab

swaygrab/json.c

@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "ipc-client.h"
+#include "swaygrab/json.h"
+
+static json_object *tree;
+
+void init_json_tree(int socketfd) {
+	uint32_t len = 0;
+	char *res = ipc_single_command(socketfd, IPC_GET_TREE, NULL, &len);
+	tree = json_tokener_parse(res);
+}
+
+void free_json_tree() {
+	json_object_put(tree);
+}
+
+static bool is_focused(json_object *c) {
+	json_object *focused;
+	json_object_object_get_ex(c, "focused", &focused);
+	return json_object_get_boolean(focused);
+}
+
+static json_object *get_focused_container_r(json_object *c) {
+	json_object *name;
+	json_object_object_get_ex(c, "name", &name);
+	if (is_focused(c)) {
+		return c;
+	} else {
+		json_object *nodes, *node, *child;
+		json_object_object_get_ex(c, "nodes", &nodes);
+		int i;
+		for (i = 0; i < json_object_array_length(nodes); i++) {
+			node = json_object_array_get_idx(nodes, i);
+
+			if ((child = get_focused_container_r(node))) {
+				return child;
+			}
+		}
+
+		json_object_object_get_ex(c, "floating_nodes", &nodes);
+		for (i = 0; i < json_object_array_length(nodes); i++) {
+			node = json_object_array_get_idx(nodes, i);
+
+			if ((child = get_focused_container_r(node))) {
+				return child;
+			}
+		}
+
+	}
+
+	return NULL;
+}
+
+json_object *get_focused_container() {
+	return get_focused_container_r(tree);
+}
+
+char *get_focused_output() {
+	json_object *outputs, *output, *name;
+	json_object_object_get_ex(tree, "nodes", &outputs);
+
+	for (int i = 0; i < json_object_array_length(outputs); i++) {
+		output = json_object_array_get_idx(outputs, i);
+
+		if (get_focused_container_r(output)) {
+			json_object_object_get_ex(output, "name", &name);
+			return strdup(json_object_get_string(name));
+		}
+	}
+
+	return NULL;
+}
+
+char *create_payload(const char *output, struct wlc_geometry *g) {
+	char *payload_str = malloc(256);
+	json_object *payload = json_object_new_object();
+
+	json_object_object_add(payload, "output", json_object_new_string(output));
+	json_object_object_add(payload, "x", json_object_new_int(g->origin.x));
+	json_object_object_add(payload, "y", json_object_new_int(g->origin.y));
+	json_object_object_add(payload, "w", json_object_new_int(g->size.w));
+	json_object_object_add(payload, "h", json_object_new_int(g->size.h));
+
+	snprintf(payload_str, 256, "%s", json_object_to_json_string(payload));
+	return strdup(payload_str);
+}
+
+struct wlc_geometry *get_container_geometry(json_object *container) {
+	struct wlc_geometry *geo = malloc(sizeof(struct wlc_geometry));
+	json_object *rect, *x, *y, *w, *h;
+
+	json_object_object_get_ex(container, "rect", &rect);
+	json_object_object_get_ex(rect, "x", &x);
+	json_object_object_get_ex(rect, "y", &y);
+	json_object_object_get_ex(rect, "width", &w);
+	json_object_object_get_ex(rect, "height", &h);
+
+	geo->origin.x = json_object_get_int(x);
+	geo->origin.y = json_object_get_int(y);
+	geo->size.w = json_object_get_int(w);
+	geo->size.h = json_object_get_int(h);
+
+	return geo;
+}
+
+json_object *get_output_container(const char *output) {
+	json_object *outputs, *json_output, *name;
+	json_object_object_get_ex(tree, "nodes", &outputs);
+
+	for (int i = 0; i < json_object_array_length(outputs); i++) {
+		json_output = json_object_array_get_idx(outputs, i);
+		json_object_object_get_ex(json_output, "name", &name);
+
+		if (strcmp(json_object_get_string(name), output) == 0) {
+			return json_output;
+		}
+	}
+
+	return NULL;
+}

swaygrab/main.c

@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <getopt.h>
@@ -10,16 +11,17 @@
 #include "log.h"
 #include "ipc-client.h"
 #include "util.h"
+#include "swaygrab/json.h"
 
 void sway_terminate(int exit_code) {
 	exit(exit_code);
 }
 
-void grab_and_apply_magick(const char *file, const char *output,
+void grab_and_apply_magick(const char *file, const char *payload,
 		int socketfd, int raw) {
-	uint32_t len = strlen(output);
+	uint32_t len = strlen(payload);
 	char *pixels = ipc_single_command(socketfd,
-			IPC_SWAY_GET_PIXELS, output, &len);
+			IPC_SWAY_GET_PIXELS, payload, &len);
 	uint32_t *u32pixels = (uint32_t *)(pixels + 1);
 	uint32_t width = u32pixels[0];
 	uint32_t height = u32pixels[1];
@@ -27,7 +29,13 @@ void grab_and_apply_magick(const char *file, const char *output,
 	pixels += 9;
 
 	if (width == 0 || height == 0) {
-		sway_abort("Unknown output %s.", output);
+		// indicates geometry was clamped by WLC because it was outside of the output's area
+		json_object *obj = json_tokener_parse(payload);
+		json_object *output;
+		json_object_object_get_ex(obj, "output", &output);
+		const char *name = json_object_get_string(output);
+		json_object_put(obj);
+		sway_abort("Unknown output %s.", name);
 	}
 
 	if (raw) {
@@ -50,22 +58,28 @@ void grab_and_apply_magick(const char *file, const char *output,
 	free(cmd);
 }
 
-void grab_and_apply_movie_magic(const char *file, const char *output,
+void grab_and_apply_movie_magic(const char *file, const char *payload,
 		int socketfd, int raw, int framerate) {
 	if (raw) {
 		sway_log(L_ERROR, "Raw capture data is not yet supported. Proceeding with ffmpeg normally.");
 	}
 
-	uint32_t len = strlen(output);
+	uint32_t len = strlen(payload);
 	char *pixels = ipc_single_command(socketfd,
-			IPC_SWAY_GET_PIXELS, output, &len);
+			IPC_SWAY_GET_PIXELS, payload, &len);
 	uint32_t *u32pixels = (uint32_t *)(pixels + 1);
 	uint32_t width = u32pixels[0];
 	uint32_t height = u32pixels[1];
 	pixels += 9;
 
 	if (width == 0 || height == 0) {
-		sway_abort("Unknown output %s.", output);
+		// indicates geometry was clamped by WLC because it was outside of the output's area
+		json_object *obj = json_tokener_parse(payload);
+		json_object *output;
+		json_object_object_get_ex(obj, "output", &output);
+		const char *name = json_object_get_string(output);
+		json_object_put(obj);
+		sway_abort("Unknown output %s.", name);
 	}
 
 	const char *fmt = "ffmpeg -f rawvideo -framerate %d "
@@ -86,9 +100,9 @@ void grab_and_apply_movie_magic(const char *file, const char *output,
 	int sleep = 0;
 	while (sleep != -1) {
 		clock_gettime(CLOCK_MONOTONIC, &start);
-		len = strlen(output);
+		len = strlen(payload);
 		pixels = ipc_single_command(socketfd,
-				IPC_SWAY_GET_PIXELS, output, &len);
+				IPC_SWAY_GET_PIXELS, payload, &len);
 		pixels += 9;
 		len -= 9;
 
@@ -112,30 +126,6 @@ void grab_and_apply_movie_magic(const char *file, const char *output,
 	free(cmd);
 }
 
-char *get_focused_output(int socketfd) {
-	uint32_t len = 0;
-	char *res = ipc_single_command(socketfd, IPC_GET_WORKSPACES, NULL, &len);
-	json_object *workspaces = json_tokener_parse(res);
-
-	int length = json_object_array_length(workspaces);
-	json_object *workspace, *focused, *json_output;
-	char *output = NULL;
-	int i;
-	for (i = 0; i < length; ++i) {
-		workspace = json_object_array_get_idx(workspaces, i);
-		json_object_object_get_ex(workspace, "focused", &focused);
-		if (json_object_get_boolean(focused) == TRUE) {
-			json_object_object_get_ex(workspace, "output", &json_output);
-			output = strdup(json_object_get_string(json_output));
-			break;
-		}
-	}
-
-	json_object_put(workspaces);
-	free(res);
-	return output;
-}
-
 char *default_filename(const char *extension) {
 	int ext_len = strlen(extension);
 	int len = 28 + ext_len; // format: "2015-12-17-180040_swaygrab.ext"
@@ -154,6 +144,7 @@ int main(int argc, char **argv) {
 	char *socket_path = NULL;
 	char *output = NULL;
 	int framerate = 30;
+	bool grab_focused = false;
 
 	init_log(L_INFO);
 
@@ -165,6 +156,7 @@ int main(int argc, char **argv) {
 		{"socket", required_argument, NULL, 's'},
 		{"raw", no_argument, NULL, 'r'},
 		{"rate", required_argument, NULL, 'R'},
+		{"focused", no_argument, NULL, 'f'},
 		{0, 0, 0, 0}
 	};
 
@@ -177,16 +169,20 @@ int main(int argc, char **argv) {
 		"  -v, --version          Show the version number and quit.\n"
 		"  -s, --socket <socket>  Use the specified socket.\n"
 		"  -R, --rate <rate>      Specify framerate (default: 30)\n"
-		"  -r, --raw              Write raw rgba data to stdout.\n";
+		"  -r, --raw              Write raw rgba data to stdout.\n"
+		"  -f, --focused          Grab the focused container.\n";
 
 	int c;
 	while (1) {
 		int option_index = 0;
-		c = getopt_long(argc, argv, "hco:vs:R:r", long_options, &option_index);
+		c = getopt_long(argc, argv, "hco:vs:R:rf", long_options, &option_index);
 		if (c == -1) {
 			break;
 		}
 		switch (c) {
+		case 'f':
+			grab_focused = true;
+			break;
 		case 's': // Socket
 			socket_path = strdup(optarg);
 			break;
@@ -235,10 +231,32 @@ int main(int argc, char **argv) {
 	int socketfd = ipc_open_socket(socket_path);
 	free(socket_path);
 
-	if (!output) {
-		output = get_focused_output(socketfd);
+	init_json_tree(socketfd);
+
+	struct wlc_geometry *geo;
+
+	if (grab_focused) {
+		output = get_focused_output();
+		json_object *con = get_focused_container();
+		json_object *name;
+		json_object_object_get_ex(con, "name", &name);
+		geo = get_container_geometry(con);
+		free(con);
+	} else {
+		if (!output) {
+			output = get_focused_output();
+		}
+		geo = get_container_geometry(get_output_container(output));
+		// the geometry of the output in the get_tree response is relative to a global (0, 0).
+		// we need it to be relative to itself, so set origin to (0, 0) always.
+		geo->origin.x = 0;
+		geo->origin.y = 0;
 	}
 
+	const char *payload = create_payload(output, geo);
+
+	free(geo);
+
 	if (!file) {
 		if (!capture) {
 			file = default_filename("png");
@@ -248,11 +266,12 @@ int main(int argc, char **argv) {
 	}
 
 	if (!capture) {
-		grab_and_apply_magick(file, output, socketfd, raw);
+		grab_and_apply_magick(file, payload, socketfd, raw);
 	} else {
-		grab_and_apply_movie_magic(file, output, socketfd, raw, framerate);
+		grab_and_apply_movie_magic(file, payload, socketfd, raw, framerate);
 	}
 
+	free_json_tree();
 	free(output);
 	free(file);
 	close(socketfd);