implemented early keyboard grab for dmenu with a timeout for stdin data writers to prevent endless grabbings of the keyboard

3 files changed, 21 insertions, 4 deletions

diff --git a/config.arg.h b/config.arg.h
index a19e463..5b99a2c 100644
--- a/config.arg.h
+++ b/config.arg.h
@@ -8,3 +8,4 @@
 #define SELFGCOLOR              "#eeeeee"
 #define NORMBGCOLOR             "#333333"
 #define NORMFGCOLOR             "#dddddd"
+#define STDIN_TIMEOUT           3 /* seconds */
diff --git a/config.default.h b/config.default.h
index 1f66553..0bae3a1 100644
--- a/config.default.h
+++ b/config.default.h
@@ -8,3 +8,4 @@
 #define SELFGCOLOR              "#eeeeee"
 #define NORMBGCOLOR             "#333366"
 #define NORMFGCOLOR             "#cccccc"
+#define STDIN_TIMEOUT           3 /* seconds */
diff --git a/main.c b/main.c
index 6ca043d..03c8b1f 100644
--- a/main.c
+++ b/main.c
@@ -11,6 +11,8 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/select.h>
+#include <sys/time.h>
 #include <X11/cursorfont.h>
 #include <X11/Xutil.h>
 #include <X11/keysym.h>
@@ -290,6 +292,8 @@ int
 main(int argc, char *argv[])
 {
         char *maxname;
+        fd_set rd;
+        struct timeval timeout;
         Item *i;
         XEvent ev;
         XSetWindowAttributes wa;
@@ -307,13 +311,23 @@ main(int argc, char *argv[])
         screen = DefaultScreen(dpy);
         root = RootWindow(dpy, screen);
 
-        maxname = readstdin();
-
-        /* grab as early as possible, but after reading all items!!! */
+        /* Note, the select() construction allows to grab all keypresses as
+         * early as possible, to not loose them. But if there is no standard
+         * input supplied, we will make sure to exit after MAX_WAIT_STDIN
+         * seconds. This is convenience behavior for rapid typers.
+         */ 
         while(XGrabKeyboard(dpy, root, True, GrabModeAsync,
                          GrabModeAsync, CurrentTime) != GrabSuccess)
                 usleep(1000);
 
+        timeout.tv_usec = 0;
+        timeout.tv_sec = STDIN_TIMEOUT;
+        FD_ZERO(&rd);
+        FD_SET(STDIN_FILENO, &rd);
+        if(select(ConnectionNumber(dpy) + 1, &rd, NULL, NULL, &timeout) < 1)
+                goto UninitializedEnd;
+        maxname = readstdin();
+
         /* style */
         dc.sel[ColBG] = getcolor(SELBGCOLOR);
         dc.sel[ColFG] = getcolor(SELFGCOLOR);
@@ -366,7 +380,6 @@ main(int argc, char *argv[])
                 }
         }
 
-        XUngrabKeyboard(dpy, CurrentTime);
         while(allitems) {
                 i = allitems->next;
                 free(allitems->text);
@@ -380,6 +393,8 @@ main(int argc, char *argv[])
         XFreePixmap(dpy, dc.drawable);
         XFreeGC(dpy, dc.gc);
         XDestroyWindow(dpy, win);
+UninitializedEnd:
+        XUngrabKeyboard(dpy, CurrentTime);
         XCloseDisplay(dpy);
 
         return ret;