swaygrab: make focused output default

This makes swaygrab use the currently focused output as source if no
other output is defined with the `-o, --output <output>` option.

2 files changed, 47 insertions, 8 deletions

diff --git a/swaygrab/CMakeLists.txt b/swaygrab/CMakeLists.txt
index f664c01d..9035ac8b 100644
--- a/swaygrab/CMakeLists.txt
+++ b/swaygrab/CMakeLists.txt
@@ -1,9 +1,14 @@
+include_directories(
+        ${JSONC_INCLUDE_DIRS}
+)
+
 add_executable(swaygrab
         main.c
 )
 
 target_link_libraries(swaygrab
         sway-common
+        ${JSONC_LIBRARIES}
         rt
 )
 
diff --git a/swaygrab/main.c b/swaygrab/main.c
index 2c6cf2dd..671b8737 100644
--- a/swaygrab/main.c
+++ b/swaygrab/main.c
@@ -6,6 +6,7 @@
 #include <stdint.h>
 #include <math.h>
 #include <time.h>
+#include <json-c/json.h>
 #include "log.h"
 #include "ipc-client.h"
 #include "util.h"
@@ -110,9 +111,34 @@ 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;
+}
+
 int main(int argc, char **argv) {
         static int capture = 0, raw = 0;
         char *socket_path = NULL;
+        char *output = NULL;
         int framerate = 30;
 
         init_log(L_INFO);
@@ -120,6 +146,7 @@ int main(int argc, char **argv) {
         static struct option long_options[] = {
                 {"help", no_argument, NULL, 'h'},
                 {"capture", no_argument, NULL, 'c'},
+                {"output", required_argument, NULL, 'o'},
                 {"version", no_argument, NULL, 'v'},
                 {"socket", required_argument, NULL, 's'},
                 {"raw", no_argument, NULL, 'r'},
@@ -128,10 +155,11 @@ int main(int argc, char **argv) {
         };
 
         const char *usage =
-                "Usage: swaygrab [options] <output> [file]\n"
+                "Usage: swaygrab [options] [file]\n"
                 "\n"
                 "  -h, --help             Show help message and quit.\n"
                 "  -c, --capture          Capture video.\n"
+                "  -o, --output <output>  Output source.\n"
                 "  -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"
@@ -140,7 +168,7 @@ int main(int argc, char **argv) {
         int c;
         while (1) {
                 int option_index = 0;
-                c = getopt_long(argc, argv, "hcvs:r", long_options, &option_index);
+                c = getopt_long(argc, argv, "hco:vs:r", long_options, &option_index);
                 if (c == -1) {
                         break;
                 }
@@ -151,6 +179,9 @@ int main(int argc, char **argv) {
                 case 'r':
                         raw = 1;
                         break;
+                case 'o': // output
+                        output = strdup(optarg);
+                        break;
                 case 'c':
                         capture = 1;
                         break;
@@ -178,29 +209,32 @@ int main(int argc, char **argv) {
                 }
         }
 
-        char *file = NULL, *output = NULL;
+        char *file = NULL;
         if (raw) {
-                if (optind >= argc) {
+                if (optind >= argc + 1) {
                         sway_abort("Invalid usage. See `man swaygrab` %d %d", argc, optind);
                 }
-                output = argv[optind];
         } else {
-                if (optind >= argc - 1) {
+                if (optind >= argc) {
                         sway_abort("Invalid usage. See `man swaygrab`");
                 }
-                file = argv[optind + 1];
-                output = argv[optind];
+                file = argv[optind];
         }
 
         int socketfd = ipc_open_socket(socket_path);
         free(socket_path);
 
+        if (!output) {
+                output = get_focused_output(socketfd);
+        }
+
         if (!capture) {
                 grab_and_apply_magick(file, output, socketfd, raw);
         } else {
                 grab_and_apply_movie_magic(file, output, socketfd, raw, framerate);
         }
 
+        free(output);
         close(socketfd);
         return 0;
 }