Be more lenient with compose+shift

Makefile

@@ -1,6 +1,5 @@
 INSTALL=install
 PREFIX=/usr
-MANDIR?=/local/man/man1
 
 TARGET := xcape
 
@@ -9,18 +8,13 @@ CFLAGS += `pkg-config --cflags xtst x11`
 LDFLAGS += `pkg-config --libs xtst x11`
 LDFLAGS += -pthread
 
-all: $(TARGET)
-
 $(TARGET): xcape.c
 	$(CC) $(CFLAGS) -o $@ $< $(LDFLAGS)
 
 install:
-	$(INSTALL) -d -m 0755 $(DESTDIR)$(PREFIX)/bin
+	$(INSTALL) -Dm 755 $(TARGET) $(DESTDIR)$(PREFIX)/bin/$(TARGET)
-	$(INSTALL) -d -m 0755 $(DESTDIR)$(PREFIX)$(MANDIR)
-	$(INSTALL) -m 0755 $(TARGET) $(DESTDIR)$(PREFIX)/bin/$(TARGET)
-	$(INSTALL) -m 0644 xcape.1 $(DESTDIR)$(PREFIX)$(MANDIR)/xcape.1
 
 clean:
 	rm $(TARGET)
 
-.PHONY: all clean install
+.PHONY: clean

README.md

@@ -12,38 +12,24 @@ editor ;)
 Minimal building instructions
 -----------------------------
 
-First install the development dependencies. On Debian-based systems
+    $ sudo apt-get install git gcc make libx11-dev libxtst-dev pkg-config
-(including Ubuntu and Linux Mint), run:
+    $ mkdir xcape
-
-    $ sudo apt-get install git gcc make pkg-config libx11-dev libxtst-dev libxi-dev
-
-On Fedora-based systems, run:
-
-    $ sudo dnf install git gcc make pkgconfig libX11-devel libXtst-devel libXi-devel
-
-Then run:
-
-    $ git clone https://github.com/alols/xcape.git
     $ cd xcape
+    $ git clone https://github.com/alols/xcape.git .
     $ make
-    $ sudo make install
 
 Usage
 -----
-    $ xcape [-d] [-f] [-t <timeout ms>] [-e <map-expression>]
+    $ xcape [-d] [-t <timeout ms>] [-e <map-expression>]
 
 ### `-d`
 
-Debug mode. Does not fork into the background. Prints debug information.
+Debug mode. Does not fork into the background.
-
-### `-f`
-
-Foreground mode. Does not fork into the background.
 
 ### `-t <timeout ms>`
 
 If you hold a key longer than this timeout, xcape will not generate a key
-event. Default is 500 ms.
+event. Default is 50 ms.
 
 ### `-e <map-expression>`
 
@@ -56,44 +42,25 @@ the actual name of the character. For example to generate "{" the
 expression `'ModKey=Shift_L|bracketleft'` could be used (assuming that you
 have a key with "{" above "[").
 
-You can also specify keys in decimal (prefix `#`), octal (`#0`), or
+You can also specify ModKey in decimal (prefix `#`), octal (`#0`), or
-hexadecimal (`#0x`). They will be interpreted as keycodes unless no corresponding
+hexadecimal (`#0x`). It will be interpreted as a keycode unless no corresponding
 key name is found.
 
 #### Examples
 
-+   This will make Left Shift generate Escape when pressed and released on
+1.  This will make Left Shift generate Escape when pressed and released on
-    its own, and Left Control generate Ctrl-O combination when pressed and
+    it's own, and Left Control generate Ctrl-O combination when pressed and
-    released on its own.
+    released on it's own.
 
         xcape -e 'Shift_L=Escape;Control_L=Control_L|O'
 
-+   In conjunction with xmodmap it is possible to make an ordinary key act
+2.  If your `s` key has the code `42` and your `l` key `43` and you have set both
-    as an extra modifier. First map the key to the modifier with xmodmap
+    to `AltGr` (a.k.a. ISO_Level3_Shift) with xmodmap, then this will generate the
-    and then the modifier back to the key with xcape. However, this has
+    ordinary letters when pressed and released on their own. But pressed together
-    several limitations: the key will not work as ordinary until it is
+    with another key, the `s` or `l` key will produce `AltGr`. So, depending on your
-    released, and in particular, *it may act as a modifier unintentionally if
+    keyboard layout, you can compose e.g. `@`, `{` or `³` easily when touch-typing.
-    you type too fast.* This is not a bug in xcape, but an unavoidable
+
-    consequence of using these two tools together in this way.
+        xcape -e '#42=s;#43=l'
-    As an example, we can make the space bar work as an additional ctrl
-    key when held (similar to
-    [Space2ctrl](https://github.com/r0adrunner/Space2Ctrl)) with the
-    following sequence of commands.
-
-        # Map an unused modifier's keysym to the spacebar's keycode and make it a
-        # control modifier. It needs to be an existing key so that emacs won't
-        # spazz out when you press it. Hyper_L is a good candidate.
-        spare_modifier="Hyper_L"
-        xmodmap -e "keycode 65 = $spare_modifier"
-        xmodmap -e "remove mod4 = $spare_modifier" # hyper_l is mod4 by default
-        xmodmap -e "add Control = $spare_modifier"
-
-        # Map space to an unused keycode (to keep it around for xcape to
-        # use).
-        xmodmap -e "keycode any = space"
-
-        # Finally use xcape to cause the space bar to generate a space when tapped.
-        xcape -e "$spare_modifier=space"
 
 
 Note regarding xmodmap

xcape.1

@@ -1,96 +0,0 @@
-.TH XCAPE 1 2017-07-03 "John Hill" "xcape Manual"
-
-.SH NAME
-xcape \- use a modifier key as another key
-
-.SH SYNOPSIS
-.B xcape
-[\fB-d\fR]
-[\fB-f\fR]
-[\fB-t\fR \fItimeout\fR]
-[\fB-e\fR \fImap-expression\fR]
-
-.SH DESCRIPTION
-\fBxcape\fR allows a modifier key to be used as another key when it is pressed
-and released on its own. The default behaviour is to generate the \fIEscape\fR
-key in place of \fIControl_L\fR (Left Control).
-
-.SH OPTIONS
-.TP
-.BR \-d
-Debug mode.  Will run as a foreground process and print debug information.
-.TP
-.BR \-f
-Foreground mode.  Will run as a foreground process.
-.TP
-.BR \-t " " \fItimeout\fR
-Give a \fItimeout\fR in milliseconds.  If you hold a key longer than
-\fItimeout\fR a key event will not be generated.
-.TP
-.BR \-e " " \fImap-expression\fR
-Use \fImap-expression\fR as the expression(s).
-
-.SH EXPRESSION SYNTAX
-Expression syntax is \'\fBModKey\fR=\fBKey\fR[|\fBOtherKey\fR]\'.  Multiple
-expressions can be passed, delimited by semi-colons (;).
-.PP
-A list of keysyms can be found in the header file <\fIX11/keysymdef.h\fR>
-(without the \fIXK_\fR prefix).
-.PP
-Note that shifted keys must be specified as a shift key followed by the key to
-be pressed rather than the actual name of the character. For example to
-generate "\fI{\fR" the expression
-\'\fIModKey\fR=\fIShift_L\fR|\fIbracketleft\fR\' could be used
-(assuming that you have a key with \'{\' above \'[\').
-.PP
-You can also specify \fBModKey\fR in decimal (prefix \fI#\fR), octal
-(\fI#0\fR), or hexadecimal (\fI#0x\fR). It will be interpreted as a keycode
-unless no corresponding key name is
-found.
-
-.SH EXAMPLES
-.PP
-Make Left Shift generate Escape when pressed and released on it's own, and Left
-Control generate Ctrl\-O combination when pressed and released on it's own:
-.RS
-\fBxcape\fR \fB-e\fR '\fIShift_L\fR=\fIEscape\fR;\fIControl_L\fR=\fIControl_L\fR|\fIO\fR'
-.RE
-.PP
-In conjugation with xmodmap it is possible to make an ordinary key act as an
-extra modifier. First map the key to the modifier with xmodmap and then the
-modifier back to the key with \fBxcape\fR. As an example, we can make the space
-bar work as an additional ctrl key when held with the following sequence of
-commands:
-.PP
-First, map an unused modifier's keysym to the spacebar's keycode and make it a
-control modifier. It needs to be an existing key so that emacs won't spazz out
-when you press it. Hyper_L is a good candidate.
-.PP
-.RS
-.nf
-\fBspare_modifier\fR="\fIHyper_L\fR"
-\fBxmodmap\fR \fB-e\fR "\fBkeycode\fR \fI65\fR = \fI$spare_modifier\fR"
-\fBxmodmap\fR \fB-e\fR "\fBremove\fR \fImod4\fR = \fI$spare_modifier\fR"
-# hyper_l is mod4 by default
-\fBxmodmap\fR \fB-e\fR "\fBadd\fR \fIControl\fR = \fI$spare_modifier\fR"
-.fi
-.RE
-.PP
-Next, map space to an unused keycode (to keep it around for \fBxcape\fR to use).
-.PP
-.RS
-\fBxmodmap\fR \fR-e\fR "\fBkeycode\fR \fIany\fR = \fIspace\fR"
-.RE
-.PP
-Finally use \fBxcape\fR to cause the space bar to generate a space when tapped.
-.PP
-.RS
-\fBxcape\fR \fB-e\fR "\fI$spare_modifier\fR=\fIspace\fR"
-.RE
-
-.SH SEE ALSO
-\fBxmodmap\fR(1), \fBxev\fR(1)
-
-.SH AUTHOR
-\fBxcape\fR was written by Albin Olsson
-(albin dot olsson at gmail dot com)

xcape.c

@@ -1,7 +1,7 @@
 /************************************************************************
  * xcape.c
  *
- * Copyright 2015 Albin Olsson
+ * Copyright 2012 Albin Olsson
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -44,7 +44,7 @@ typedef struct _Key_t
 
 typedef struct _KeyMap_t
 {
-    Bool UseKeyCode;        /* (for from) instead of KeySym; ignore latter */
+    Bool UseKeyCode;        // (for from) instead of KeySym; ignore latter
     KeySym from_ks;
     KeyCode from_kc;
     Key_t *to_keys;
@@ -62,11 +62,11 @@ typedef struct _XCape_t
     XRecordContext record_ctx;
     pthread_t sigwait_thread;
     sigset_t sigset;
-    Bool foreground;
     Bool debug;
     KeyMap_t *map;
     Key_t *generated;
     struct timeval timeout;
+    Bool timeout_valid;
 } XCape_t;
 
 /************************************************************************
@@ -78,47 +78,29 @@ void intercept (XPointer user_data, XRecordInterceptData *data);
 
 KeyMap_t *parse_mapping (Display *ctrl_conn, char *mapping, Bool debug);
 
-void delete_mapping (KeyMap_t *map);
-
 Key_t *key_add_key (Key_t *keys, KeyCode key);
 
-void delete_keys (Key_t *keys);
-
-void print_usage (const char *program_name);
-
 /************************************************************************
  * Main function
  ***********************************************************************/
 int main (int argc, char **argv)
 {
     XCape_t *self = malloc (sizeof (XCape_t));
-
     int dummy, ch;
-
     static char default_mapping[] = "Control_L=Escape";
     char *mapping = default_mapping;
-
-    XRecordRange *rec_range = XRecordAllocRange();
-    XRecordClientSpec client_spec = XRecordAllClients;
-
-    self->foreground = False;
     self->debug = False;
     self->timeout.tv_sec = 0;
     self->timeout.tv_usec = 500000;
+    self->timeout_valid = True;
     self->generated = NULL;
 
-    rec_range->device_events.first = KeyPress;
+    while ((ch = getopt (argc, argv, "de:t:")) != -1)
-    rec_range->device_events.last = ButtonRelease;
-
-    while ((ch = getopt (argc, argv, "dfe:t:")) != -1)
     {
         switch (ch)
         {
         case 'd':
             self->debug = True;
-            /* imply -f (no break) */
-        case 'f':
-            self->foreground = True;
             break;
         case 'e':
             mapping = optarg;
@@ -128,36 +110,24 @@ int main (int argc, char **argv)
                 int ms = atoi (optarg);
                 if (ms > 0)
                 {
+                    self->timeout_valid = True;
                     self->timeout.tv_sec = ms / 1000;
                     self->timeout.tv_usec = (ms % 1000) * 1000;
                 }
                 else
                 {
-                    fprintf (stderr, "Invalid argument for '-t': %s.\n", optarg);
+                    self->timeout_valid = False;
-                    print_usage (argv[0]);
-                    return EXIT_FAILURE;
                 }
             }
             break;
         default:
-            print_usage (argv[0]);
+            fprintf (stdout, "Usage: %s [-d] [-t timeout_ms] [-e <mapping>]\n", argv[0]);
+            fprintf (stdout,
+                    "Runs as a daemon unless -d flag is set\n");
             return EXIT_SUCCESS;
         }
     }
 
-    if (optind < argc)
-    {
-        fprintf (stderr, "Not a command line option: '%s'\n", argv[optind]);
-        print_usage (argv[0]);
-        return EXIT_SUCCESS;
-    }
-
-    if (!XInitThreads ())
-    {
-        fprintf (stderr, "Failed to initialize threads.\n");
-        exit (EXIT_FAILURE);
-    }
-
     self->data_conn = XOpenDisplay (NULL);
     self->ctrl_conn = XOpenDisplay (NULL);
 
@@ -187,12 +157,9 @@ int main (int argc, char **argv)
     self->map = parse_mapping (self->ctrl_conn, mapping, self->debug);
 
     if (self->map == NULL)
-    {
-        fprintf (stderr, "Failed to parse_mapping\n");
         exit (EXIT_FAILURE);
-    }
 
-    if (self->foreground != True)
+    if (self->debug != True)
         daemon (0, 0);
 
     sigemptyset (&self->sigset);
@@ -203,6 +170,11 @@ int main (int argc, char **argv)
     pthread_create (&self->sigwait_thread,
             NULL, sig_handler, self);
 
+    XRecordRange *rec_range = XRecordAllocRange();
+    rec_range->device_events.first = KeyPress;
+    rec_range->device_events.last = ButtonRelease;
+    XRecordClientSpec client_spec = XRecordAllClients;
+
     self->record_ctx = XRecordCreateContext (self->ctrl_conn,
             0, &client_spec, 1, &rec_range, 1);
 
@@ -221,23 +193,15 @@ int main (int argc, char **argv)
         exit (EXIT_FAILURE);
     }
 
-    pthread_join (self->sigwait_thread, NULL);
-
     if (!XRecordFreeContext (self->ctrl_conn, self->record_ctx))
     {
         fprintf (stderr, "Failed to free xrecord context\n");
     }
 
-    if (self->debug) fprintf (stdout, "main exiting\n");
-
-    XFree (rec_range);
-
     XCloseDisplay (self->ctrl_conn);
     XCloseDisplay (self->data_conn);
 
-    delete_mapping (self->map);
+    if (self->debug) fprintf (stdout, "main exiting\n");
-
-    free (self);
 
     return EXIT_SUCCESS;
 }
@@ -257,8 +221,6 @@ void *sig_handler (void *user_data)
 
     if (self->debug) fprintf (stdout, "Caught signal %d!\n", sig);
 
-    XLockDisplay (self->ctrl_conn);
-
     if (!XRecordDisableContext (self->ctrl_conn,
                 self->record_ctx))
     {
@@ -268,8 +230,6 @@ void *sig_handler (void *user_data)
 
     XSync (self->ctrl_conn, False);
 
-    XUnlockDisplay (self->ctrl_conn);
-
     if (self->debug) fprintf (stdout, "sig_handler exiting...\n");
 
     return NULL;
@@ -307,6 +267,7 @@ void handle_key (XCape_t *self, KeyMap_t *key,
 
         key->pressed = True;
 
+        if (self->timeout_valid)
             gettimeofday (&key->down_at, NULL);
 
         if (mouse_pressed)
@@ -320,10 +281,13 @@ void handle_key (XCape_t *self, KeyMap_t *key,
         if (key->used == False)
         {
             struct timeval timev = self->timeout;
+            if (self->timeout_valid)
+            {
                 gettimeofday (&timev, NULL);
                 timersub (&timev, &key->down_at, &timev);
+            }
 
-            if (timercmp (&timev, &self->timeout, <))
+            if (!self->timeout_valid || timercmp (&timev, &self->timeout, <))
             {
                 for (k = key->to_keys; k != NULL; k = k->next)
                 {
@@ -355,8 +319,6 @@ void intercept (XPointer user_data, XRecordInterceptData *data)
     static Bool mouse_pressed = False;
     KeyMap_t *km;
 
-    XLockDisplay (self->ctrl_conn);
-
     if (data->category == XRecordFromServer)
     {
         int     key_event = data->data[0];
@@ -395,13 +357,9 @@ void intercept (XPointer user_data, XRecordInterceptData *data)
         {
             mouse_pressed = False;
         }
-        for (km = self->map; km != NULL; km = km->next)
+        else
         {
-            if ((km->UseKeyCode == False
+            for (km = self->map; km != NULL; km = km->next)
-                    && XkbKeycodeToKeysym (self->ctrl_conn, key_code, 0, 0)
-                        == km->from_ks)
-                || (km->UseKeyCode == True
-                    && key_code == km->from_kc))
             {
                 if ((km->UseKeyCode == False
                         && XkbKeycodeToKeysym (self->ctrl_conn, key_code, 0, 0)
@@ -411,7 +369,7 @@ void intercept (XPointer user_data, XRecordInterceptData *data)
                 {
                     handle_key (self, km, mouse_pressed, key_event);
                 }
-                else if (km->pressed && (key_event == KeyPress || key_event == ButtonPress))
+                else if (km->pressed && key_event == KeyPress) 
                 {
 		    /* We should check if the pressed key is a modifier before marking the key as used. */
 		    if (key_code != 50)  /* hack; try if it works */
@@ -424,7 +382,6 @@ void intercept (XPointer user_data, XRecordInterceptData *data)
     }
 
 exit:
-    XUnlockDisplay (self->ctrl_conn);
     XRecordFreeData (data);
 }
 
@@ -434,8 +391,8 @@ KeyMap_t *parse_token (Display *dpy, char *token, Bool debug)
     KeyMap_t *km = NULL;
     KeySym    ks;
     char      *from, *to, *key;
-    KeyCode   code;           /* keycode */
+    KeyCode   code;        // keycode (to)
-    long      parsed_code;    /* parsed keycode value */
+    long      fromcode;    // keycode (from)
 
     to = token;
     from = strsep (&to, "=");
@@ -447,17 +404,17 @@ KeyMap_t *parse_token (Display *dpy, char *token, Bool debug)
                && strsep (&from, "#") != NULL)
         {
             errno = 0;
-            parsed_code = strtoul (from, NULL, 0); /* dec, oct, hex automatically */
+            fromcode = strtoul (from, NULL, 0); // dec, oct, hex automatically
             if (errno == 0
-                   && parsed_code <=255
+                   && fromcode <=255
-                   && XkbKeycodeToKeysym (dpy, (KeyCode) parsed_code, 0, 0) != NoSymbol)
+                   && XkbKeycodeToKeysym (dpy, (KeyCode) fromcode, 0, 0) != NoSymbol)
             {
                 km->UseKeyCode = True;
-                km->from_kc = (KeyCode) parsed_code;
+                km->from_kc = (KeyCode) fromcode;
                 if (debug)
                 {
-                  KeySym ks_temp = XkbKeycodeToKeysym (dpy, (KeyCode) parsed_code, 0, 0);
+                  KeySym ks_temp = XkbKeycodeToKeysym (dpy, (KeyCode) fromcode, 0, 0);
-                  fprintf(stderr, "Assigned mapping from \"%s\" ( keysym 0x%x, "
+                  fprintf(stderr, "Assigned mapping from from \"%s\" ( keysym 0x%x, "
                           "key code %d)\n",
                           XKeysymToString(ks_temp),
                           (unsigned) ks_temp,
@@ -498,23 +455,6 @@ KeyMap_t *parse_token (Display *dpy, char *token, Bool debug)
             if (key == NULL)
                 break;
 
-            if (!strncmp (key, "#", 1)
-                   && strsep (&key, "#") != NULL)
-            {
-                errno = 0;
-                parsed_code = strtoul (key, NULL, 0); /* dec, oct, hex automatically */
-                if (!(errno == 0
-                      && parsed_code <=255
-                      && XkbKeycodeToKeysym (dpy, (KeyCode) parsed_code, 0, 0) != NoSymbol))
-                {
-                    fprintf (stderr, "Invalid keycode: %s\n", key);
-                    return NULL;
-                }
-
-                code = (KeyCode) parsed_code;
-            }
-            else
-            {
             if ((ks = XStringToKeysym (key)) == NoSymbol)
             {
                 fprintf (stderr, "Invalid key: %s\n", key);
@@ -529,15 +469,13 @@ KeyMap_t *parse_token (Display *dpy, char *token, Bool debug)
                         "mapping.\n", key, (unsigned int)ks, token);
                 return NULL;
             }
-            }
-
             km->to_keys = key_add_key (km->to_keys, code);
+
             if (debug)
             {
-              KeySym ks_temp = XkbKeycodeToKeysym (dpy, code, 0, 0);
               fprintf(stderr, "to \"%s\" (keysym 0x%x, key code %d)\n",
-                  XKeysymToString(ks_temp),
+                      key,
-                  (unsigned) ks_temp,
+                      (unsigned) XStringToKeysym (key),
                       (unsigned) code);
             }
         }
@@ -578,28 +516,3 @@ KeyMap_t *parse_mapping (Display *ctrl_conn, char *mapping, Bool debug)
 
     return rval;
 }
-
-void delete_mapping (KeyMap_t *map)
-{
-    while (map != NULL) {
-        KeyMap_t *next = map->next;
-        delete_keys (map->to_keys);
-        free (map);
-        map = next;
-    }
-}
-
-void delete_keys (Key_t *keys)
-{
-    while (keys != NULL) {
-        Key_t *next = keys->next;
-        free (keys);
-        keys = next;
-    }
-}
-
-void print_usage (const char *program_name)
-{
-    fprintf (stdout, "Usage: %s [-d] [-f] [-t timeout_ms] [-e <mapping>]\n", program_name);
-    fprintf (stdout, "Runs as a daemon unless -d or -f flag is set\n");
-}