Add abstraction for running a binding

Add run_binding function to bindings.h.

> Runs the given binding and handles parse errors. Returns a
> CommandResult for running the binding's command. Caller should render
> tree if needs_tree_render is true. Free with command_result_free().

include/bindings.h

@@ -9,6 +9,8 @@
  */
 #pragma once
 
+extern pid_t command_error_nagbar_pid;
+
 /**
  * The name of the default mode.
  *
@@ -57,3 +59,11 @@ void switch_mode(const char *new_mode);
  *
  */
 void check_for_duplicate_bindings(struct context *context);
+
+/**
+ * Runs the given binding and handles parse errors. Returns a CommandResult for
+ * running the binding's command. Caller should render tree if
+ * needs_tree_render is true. Free with command_result_free().
+ *
+ */
+CommandResult *run_binding(Binding *bind);

include/key_press.h

@@ -9,8 +9,6 @@
  */
 #pragma once
 
-extern pid_t command_error_nagbar_pid;
-
 /**
  * There was a key press. We compare this key code with our bindings table and pass
  * the bound action to parse_command().

src/bindings.c

@@ -8,6 +8,8 @@
  */
 #include "all.h"
 
+pid_t command_error_nagbar_pid = -1;
+
 /*
  * The name of the default mode.
  *
@@ -379,3 +381,45 @@ void check_for_duplicate_bindings(struct context *context) {
         }
     }
 }
+
+/*
+ * Runs the given binding and handles parse errors. Returns a CommandResult for
+ * running the binding's command. Caller should render tree if
+ * needs_tree_render is true. Free with command_result_free().
+ *
+ */
+CommandResult *run_binding(Binding *bind) {
+    /* We need to copy the command since “reload” may be part of the command,
+     * and then the memory that bind->command points to may not contain the
+     * same data anymore. */
+    char *command_copy = sstrdup(bind->command);
+    CommandResult *result = parse_command(command_copy, NULL);
+    free(command_copy);
+
+    if (result->needs_tree_render)
+        tree_render();
+
+    if (result->parse_error) {
+        char *pageraction;
+        sasprintf(&pageraction, "i3-sensible-pager \"%s\"\n", errorfilename);
+        char *argv[] = {
+            NULL, /* will be replaced by the executable path */
+            "-f",
+            config.font.pattern,
+            "-t",
+            "error",
+            "-m",
+            "The configured command for this shortcut could not be run successfully.",
+            "-b",
+            "show errors",
+            pageraction,
+            NULL
+        };
+        start_nagbar(&command_error_nagbar_pid, argv);
+        free(pageraction);
+    }
+
+    /* TODO: emit event for running a binding */
+
+    return result;
+}

src/key_press.c

@@ -9,50 +9,8 @@
  * key_press.c: key press handler
  *
  */
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/wait.h>
-#include <fcntl.h>
 #include "all.h"
 
-static int current_nesting_level;
-static bool parse_error_key;
-static bool command_failed;
-
-pid_t command_error_nagbar_pid = -1;
-
-static int json_boolean(void *ctx, int boolval) {
-    DLOG("Got bool: %d, parse_error_key %d, nesting_level %d\n", boolval, parse_error_key, current_nesting_level);
-
-    if (parse_error_key && current_nesting_level == 1 && boolval)
-        command_failed = true;
-
-    return 1;
-}
-
-static int json_map_key(void *ctx, const unsigned char *stringval, size_t stringlen) {
-    parse_error_key = (stringlen >= strlen("parse_error") &&
-                       strncmp((const char*)stringval, "parse_error", strlen("parse_error")) == 0);
-    return 1;
-}
-
-static int json_start_map(void *ctx) {
-    current_nesting_level++;
-    return 1;
-}
-
-static int json_end_map(void *ctx) {
-    current_nesting_level--;
-    return 1;
-}
-
-static yajl_callbacks command_error_callbacks = {
-    .yajl_boolean = json_boolean,
-    .yajl_start_map = json_start_map,
-    .yajl_map_key = json_map_key,
-    .yajl_end_map = json_end_map,
-};
-
 /*
  * There was a KeyPress or KeyRelease (both events have the same fields). We
  * compare this key code with our bindings table and pass the bound action to
@@ -72,53 +30,10 @@ void handle_key_press(xcb_key_press_event_t *event) {
     if (bind == NULL)
         return;
 
-    yajl_gen gen = yajl_gen_alloc(NULL);
+    CommandResult *result = run_binding(bind);
-
-    char *command_copy = sstrdup(bind->command);
-    CommandResult *result = parse_command(command_copy, gen);
-    free(command_copy);
 
     if (result->needs_tree_render)
         tree_render();
 
     command_result_free(result);
-
-    /* We parse the JSON reply to figure out whether there was an error
-     * ("success" being false in on of the returned dictionaries). */
-    const unsigned char *reply;
-    size_t length;
-    yajl_handle handle = yajl_alloc(&command_error_callbacks, NULL, NULL);
-    yajl_gen_get_buf(gen, &reply, &length);
-
-    current_nesting_level = 0;
-    parse_error_key = false;
-    command_failed = false;
-    yajl_status state = yajl_parse(handle, reply, length);
-    if (state != yajl_status_ok) {
-        ELOG("Could not parse my own reply. That's weird. reply is %.*s\n", (int)length, reply);
-    } else {
-        if (command_failed) {
-            char *pageraction;
-            sasprintf(&pageraction, "i3-sensible-pager \"%s\"\n", errorfilename);
-            char *argv[] = {
-                NULL, /* will be replaced by the executable path */
-                "-f",
-                config.font.pattern,
-                "-t",
-                "error",
-                "-m",
-                "The configured command for this shortcut could not be run successfully.",
-                "-b",
-                "show errors",
-                pageraction,
-                NULL
-            };
-            start_nagbar(&command_error_nagbar_pid, argv);
-            free(pageraction);
-        }
-    }
-
-    yajl_free(handle);
-
-    yajl_gen_free(gen);
 }