i3bar: Allow child to specify signals to use

We now wait for the child process to send the first line before stopping
it to use the signal which might be specified in the i3bar protocol
header
Since clients might use the same signal for both stop and cont, we also
save the stopped state of the child to avoid stopping it while hidden!

diff --git a/i3bar/include/child.h b/i3bar/include/child.h
index 38132e5d536f669581390cdedda727148864c146..d1c46890bc28e6534fdebf7987da54572c1e5bc0 100644 (file)
--- a/i3bar/include/child.h
+++ b/i3bar/include/child.h
@@ -10,6 +10,8 @@
 #ifndef CHILD_H_
 #define CHILD_H_
 
+#include <stdbool.h>
+
 #define STDIN_CHUNK_SIZE 1024
 
 typedef struct {
@@ -21,6 +23,16 @@ typedef struct {
      * even an int8_t, but still…
      */
     uint32_t version;
+
+    bool stopped;
+    /**
+     * The signal requested by the client to inform it of the hidden state of i3bar
+     */
+    int stop_signal;
+    /**
+     * The signal requested by the client to inform it of theun hidden state of i3bar
+     */
+    int cont_signal;
 } i3bar_child;
 
 /*

diff --git a/i3bar/include/parse_json_header.h b/i3bar/include/parse_json_header.h
index 6495eeb13a299ea23d5cd7e1972d1743d6afe483..79efddc6427acb9061ba39791b47bb5cb4ef2af7 100644 (file)
--- a/i3bar/include/parse_json_header.h
+++ b/i3bar/include/parse_json_header.h
@@ -13,15 +13,12 @@
 
 #include <stdint.h>
 
-/*
- * Determines the JSON i3bar protocol version from the given buffer. In case
- * the buffer does not contain valid JSON, or no version field is found, this
- * function returns -1. The amount of bytes consumed by parsing the header is
- * returned in *consumed (if non-NULL).
- *
- * The return type is an int32_t to avoid machines with different sizes of
- * 'int' to allow different values here. It’s highly unlikely we ever exceed
- * even an int8_t, but still…
+/**
+ * Parse the JSON protocol header to determine protocol version and features.
+ * In case the buffer does not contain a valid header (invalid JSON, or no
+ * version field found), the 'correct' field of the returned header is set to
+ * false. The amount of bytes consumed by parsing the header is returned in
+ * *consumed (if non-NULL).
  *
  */
 void parse_json_header(i3bar_child *child, const unsigned char *buffer, int length, unsigned int *consumed);

diff --git a/i3bar/src/child.c b/i3bar/src/child.c
index f3832d9c47a9ca8330f7e142d075e7ba8d91d60e..e4c0f35737a123de9d75f679e036eb6ab5137ed0 100644 (file)
--- a/i3bar/src/child.c
+++ b/i3bar/src/child.c
@@ -251,6 +251,11 @@ void stdin_io_first_line_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
      * in the future, but for now, we just discard it. */
     parse_json_header(&child, buffer, rec, &consumed);
     if (child.version > 0) {
+        /* If hide-on-modifier is set, we start of by sending the
+         * child a SIGSTOP, because the bars aren't mapped at start */
+        if (config.hide_on_modifier) {
+            stop_child();
+        }
         read_json_input(buffer + consumed, rec - consumed);
     } else {
         /* In case of plaintext, we just add a single block and change its
@@ -330,12 +335,6 @@ void start_child(char *command) {
 
                 dup2(fd[0], STDIN_FILENO);
 
-                /* If hide-on-modifier is set, we start of by sending the
-                 * child a SIGSTOP, because the bars aren't mapped at start */
-                if (config.hide_on_modifier) {
-                    stop_child();
-                }
-
                 break;
         }
     }
@@ -361,7 +360,8 @@ void start_child(char *command) {
  */
 void kill_child_at_exit(void) {
     if (child.pid > 0) {
-        kill(child.pid, SIGCONT);
+        if (child.cont_signal > 0 && child.stopped)
+            kill(child.pid, child.cont_signal);
         kill(child.pid, SIGTERM);
     }
 }
@@ -373,7 +373,8 @@ void kill_child_at_exit(void) {
  */
 void kill_child(void) {
     if (child.pid > 0) {
-        kill(child.pid, SIGCONT);
+        if (child.cont_signal > 0 && child.stopped)
+            kill(child.pid, child.cont_signal);
         kill(child.pid, SIGTERM);
         int status;
         waitpid(child.pid, &status, 0);
@@ -386,8 +387,9 @@ void kill_child(void) {
  *
  */
 void stop_child(void) {
-    if (child.pid > 0) {
-        kill(child.pid, SIGSTOP);
+    if (child.stop_signal > 0 && !child.stopped) {
+        child.stopped = true;
+        kill(child.pid, child.stop_signal);
     }
 }
 
@@ -396,7 +398,8 @@ void stop_child(void) {
  *
  */
 void cont_child(void) {
-    if (child.pid > 0) {
-        kill(child.pid, SIGCONT);
+    if (child.cont_signal > 0 && child.stopped) {
+        child.stopped = false;
+        kill(child.pid, child.cont_signal);
     }
 }

diff --git a/i3bar/src/parse_json_header.c b/i3bar/src/parse_json_header.c
index a3fefb8aee96e086e11e223b1fb63c307450b3be..80ec5af8f78d4de61bda169e442b5552ac57631e 100644 (file)
--- a/i3bar/src/parse_json_header.c
+++ b/i3bar/src/parse_json_header.c
@@ -29,6 +29,8 @@
 
 static enum {
     KEY_VERSION,
+    KEY_STOP_SIGNAL,
+    KEY_CONT_SIGNAL,
     NO_KEY
 } current_key;
 
@@ -43,6 +45,12 @@ static int header_integer(void *ctx, long val) {
         case KEY_VERSION:
             child->version = val;
             break;
+        case KEY_STOP_SIGNAL:
+            child->stop_signal = val;
+            break;
+        case KEY_CONT_SIGNAL:
+            child->cont_signal = val;
+            break;
         default:
             break;
     }
@@ -59,6 +67,10 @@ static int header_map_key(void *ctx, const unsigned char *stringval, unsigned in
 #endif
     if (CHECK_KEY("version")) {
         current_key = KEY_VERSION;
+    } else if (CHECK_KEY("stop_signal")) {
+        current_key = KEY_STOP_SIGNAL;
+    } else if (CHECK_KEY("cont_signal")) {
+        current_key = KEY_CONT_SIGNAL;
     }
     return 1;
 }
@@ -79,6 +91,8 @@ static yajl_callbacks version_callbacks = {
 
 static void child_init(i3bar_child *child) {
     child->version = 0;
+    child->stop_signal = SIGSTOP;
+    child->cont_signal = SIGCONT;
 }
 
 /*