add xdotool type --aftermodifiers option

This waits for the user to release any modifier keys that are currently held before starting to type. This allows avoiding race conditions when xdotool is called from a keyboard shortcut, and starts to type characters with the modifier still held. Currently the usual way to do so is with --clearmodifiers, but this introduces its own race conditions (see e.g. issue #43) if the physical key is released while the typing is in progress.

Author: scgtrp

cmd_type.c

@@ -26,15 +26,17 @@ int cmd_type(context_t *context) {
 
   /* Options */
   int clear_modifiers = 0;
+  int after_modifiers = 0;
   useconds_t delay = 12000; /* 12ms between keystrokes default */
 
   enum {
-    opt_unused, opt_clearmodifiers, opt_delay, opt_help, opt_window, opt_args,
-    opt_terminator, opt_file
+    opt_unused, opt_clearmodifiers, opt_aftermodifiers, opt_delay, opt_help,
+    opt_window, opt_args, opt_terminator, opt_file
   };
 
   struct option longopts[] = {
     { "clearmodifiers", no_argument, NULL, opt_clearmodifiers },
+    { "aftermodifiers", no_argument, NULL, opt_aftermodifiers },
     { "delay", required_argument, NULL, opt_delay },
     { "help", no_argument, NULL, opt_help },
     { "window", required_argument, NULL, opt_window },
@@ -50,6 +52,7 @@ int cmd_type(context_t *context) {
     "--window <windowid>    - specify a window to send keys to\n"
     "--delay <milliseconds> - delay between keystrokes\n"
     "--clearmodifiers       - reset active modifiers (alt, etc) while typing\n"
+    "--aftermodifiers       - wait for modifiers to be released before typing\n"
     "--args N  - how many arguments to expect in the exec command. This is\n"
     "            useful for ending an exec and continuing with more xdotool\n"
     "            commands\n"
@@ -76,6 +79,9 @@ int cmd_type(context_t *context) {
       case opt_clearmodifiers:
         clear_modifiers = 1;
         break;
+      case opt_aftermodifiers:
+        after_modifiers = 1;
+        break;
       case opt_help:
         printf(usage, cmd);
         consume_args(context, context->argc);
@@ -180,6 +186,15 @@ int cmd_type(context_t *context) {
   }
 
   window_each(context, window_arg, {
+    if (after_modifiers) {
+      for (;;) {
+	xdo_get_active_modifiers(context->xdo, NULL, &active_mods_n);
+	if (active_mods_n == 0) {
+	  break;
+	}
+	usleep(30000);
+      }
+    }
     if (clear_modifiers) {
       xdo_get_active_modifiers(context->xdo, &active_mods, &active_mods_n);
       xdo_clear_active_modifiers(context->xdo, window, active_mods, active_mods_n);

xdo.c

@@ -1631,15 +1631,20 @@ void _xdo_send_modifier(const xdo_t *xdo, int modmask, int is_press) {
 int xdo_get_active_modifiers(const xdo_t *xdo, charcodemap_t **keys,
                                     int *nkeys) {
   /* For each keyboard device, if an active key is a modifier,
-   * then add the keycode to the keycode list */
+   * then add the keycode to the keycode list.
+   * 
+   * If keys is null, only count the number of modifiers pressed,
+   * without recording them. */
 
   char keymap[32]; /* keycode map: 256 bits */
   int keys_size = 10;
   int keycode = 0;
   int mod_index, mod_key;
   XModifierKeymap *modifiers = XGetModifierMapping(xdo->xdpy);
   *nkeys = 0;
-  *keys = malloc(keys_size * sizeof(charcodemap_t));
+  if (keys) {
+    *keys = malloc(keys_size * sizeof(charcodemap_t));
+  }
 
   XQueryKeymap(xdo->xdpy, keymap);
 
@@ -1654,15 +1659,20 @@ int xdo_get_active_modifiers(const xdo_t *xdo, charcodemap_t **keys,
          * 'xdotool key --clearmodifiers ...' sometimes failed trying
          * to clear modifiers that didn't exist since charcodemap_t's modmask was
          * uninitialized */
-        memset(*keys + *nkeys, 0, sizeof(charcodemap_t));
-
-        (*keys)[*nkeys].code = keycode;
-        (*nkeys)++;
-
-        if (*nkeys == keys_size) {
-          keys_size *= 2;
-          *keys = realloc(keys, keys_size * sizeof(charcodemap_t));
-        }
+	if (keys) {
+	  memset(*keys + *nkeys, 0, sizeof(charcodemap_t));
+
+	  (*keys)[*nkeys].code = keycode;
+	  (*nkeys)++;
+
+	  if (*nkeys == keys_size) {
+	    keys_size *= 2;
+	    *keys = realloc(keys, keys_size * sizeof(charcodemap_t));
+	  }
+	}
+	else {
+	  (*nkeys)++;
+	}
       }
     }
   }