[PATCH] Port of xbacklight to XCB

Jon Lund Steffensen jonlst at gmail.com
Sun Jan 29 06:02:30 PST 2012


I've ported xbacklight to XCB; patch below. I'm posting it here in
case anyone is interested.
Cheers,
Jon

---
 configure.ac |    2 +-
 xbacklight.c |  272 +++++++++++++++++++++++++++++++++++-----------------------
 2 files changed, 165 insertions(+), 109 deletions(-)

diff --git a/configure.ac b/configure.ac
index 2c67604..87c7b26 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,7 @@ XORG_DEFAULT_OPTIONS
 AC_CONFIG_HEADERS([config.h])

 # Checks for pkg-config packages
-PKG_CHECK_MODULES(XRANDR, xrandr >= 1.2.0 x11)
+PKG_CHECK_MODULES(XRANDR, [xcb-randr >= 1.2 xcb-atom xcb-aux xcb])

 AC_CONFIG_FILES([
 	Makefile
diff --git a/xbacklight.c b/xbacklight.c
index 9b68ce8..942fa3f 100644
--- a/xbacklight.c
+++ b/xbacklight.c
@@ -21,9 +21,11 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
-#include <X11/Xatom.h>
-#include <X11/Xlib.h>
-#include <X11/extensions/Xrandr.h>
+
+#include <xcb/xcb.h>
+#include <xcb/xcb_util.h>
+#include <xcb/xproto.h>
+#include <xcb/randr.h>

 #include <ctype.h>
 #include <string.h>
@@ -33,7 +35,7 @@ typedef enum { Get, Set, Inc, Dec } op_t;

 static char *program_name;

-static Atom backlight, backlight_new, backlight_legacy;
+static xcb_atom_t backlight, backlight_new, backlight_legacy;

 static void
 usage (void)
@@ -53,58 +55,75 @@ usage (void)
 }

 static long
-backlight_get (Display *dpy, RROutput output)
+backlight_get (xcb_connection_t *conn, xcb_randr_output_t output)
 {
-    unsigned long   nitems;
-    unsigned long   bytes_after;
-    unsigned char   *prop;
-    Atom	    actual_type;
-    int		    actual_format;
-    long	    value;
-
+    xcb_generic_error_t *error;
+    xcb_randr_get_output_property_reply_t *prop_reply = NULL;
+    xcb_randr_get_output_property_cookie_t prop_cookie;
+    long value;
+
     backlight = backlight_new;
-    if (!backlight ||
-	XRRGetOutputProperty (dpy, output, backlight,
-			      0, 4, False, False, None,
-			      &actual_type, &actual_format,
-			      &nitems, &bytes_after, &prop) != Success) {
-	backlight = backlight_legacy;
-	if (!backlight ||
-	    XRRGetOutputProperty (dpy, output, backlight,
-				  0, 4, False, False, None,
-				  &actual_type, &actual_format,
-				  &nitems, &bytes_after, &prop) != Success)
-	    return -1;
+    if (backlight != XCB_ATOM_NONE) {
+        prop_cookie = xcb_randr_get_output_property (conn, output,
+                                                     backlight, XCB_ATOM_NONE,
+                                                     0, 4, 0, 0);
+        prop_reply = xcb_randr_get_output_property_reply (conn,
prop_cookie, &error);
+        if (error != NULL || prop_reply == NULL) {
+            backlight = backlight_legacy;
+            if (backlight != XCB_ATOM_NONE) {
+                prop_cookie = xcb_randr_get_output_property (conn, output,
+
backlight, XCB_ATOM_NONE,
+                                                             0, 4, 0, 0);
+                prop_reply = xcb_randr_get_output_property_reply
(conn, prop_cookie, &error);
+                if (error != NULL || prop_reply == NULL) {
+                    return -1;
+                }
+            }
+        }
     }

-    if (actual_type != XA_INTEGER || nitems != 1 || actual_format != 32)
+    if (prop_reply == NULL ||
+        prop_reply->type != XCB_ATOM_INTEGER ||
+        prop_reply->num_items != 1 ||
+        prop_reply->format != 32) {
 	value = -1;
-    else
-	value = *((long *) prop);
-    XFree (prop);
+    } else {
+	value = *((long *) xcb_randr_get_output_property_data (prop_reply));
+    }
+
+    free (prop_reply);
     return value;
 }

 static void
-backlight_set (Display *dpy, RROutput output, long value)
+backlight_set (xcb_connection_t *conn, xcb_randr_output_t output, long value)
 {
-    XRRChangeOutputProperty (dpy, output, backlight, XA_INTEGER, 32,
-			     PropModeReplace, (unsigned char *) &value, 1);
+    xcb_randr_change_output_property (conn, output, backlight,
XCB_ATOM_INTEGER,
+                                      32, XCB_PROP_MODE_REPLACE,
+                                      1, (unsigned char *)&value);
 }

 int
 main (int argc, char **argv)
 {
     char    *dpy_name = NULL;
-    Display *dpy;
-    int	    screen;
-    int	    major, minor;
     op_t    op = Get;
     int	    value = 0;
     int	    i;
     int	    total_time = 200;	/* ms */
     int	    steps = 20;

+    xcb_connection_t *conn;
+    xcb_generic_error_t *error;
+
+    xcb_randr_query_version_cookie_t ver_cookie;
+    xcb_randr_query_version_reply_t *ver_reply;
+
+    xcb_intern_atom_cookie_t backlight_cookie[2];
+    xcb_intern_atom_reply_t *backlight_reply;
+
+    xcb_screen_iterator_t iter;
+
     program_name = argv[0];

     for (i = 1; i < argc; i++)
@@ -177,97 +196,134 @@ main (int argc, char **argv)
 	}
 	usage ();
     }
-    dpy = XOpenDisplay (dpy_name);
-    if (!dpy)
-    {
-	fprintf (stderr, "Cannot open display \"%s\"\n",
-		 XDisplayName (dpy_name));
-	exit (1);
+    conn = xcb_connect (dpy_name, NULL);
+    ver_cookie = xcb_randr_query_version (conn, 1, 2);
+    ver_reply = xcb_randr_query_version_reply (conn, ver_cookie, &error);
+    if (error != NULL || ver_reply == NULL) {
+        int ec = error ? error->error_code : -1;
+        fprintf (stderr, "RANDR Query Version returned error %d\n", ec);
+        exit (1);
     }
-    if (!XRRQueryVersion (dpy, &major, &minor))
-    {
-	fprintf (stderr, "RandR extension missing\n");
-	exit (1);
+    if (ver_reply->major_version != 1 ||
+        ver_reply->minor_version < 2) {
+        fprintf (stderr, "RandR version %d.%d too old\n",
+                 ver_reply->major_version, ver_reply->minor_version);
+        exit (1);
     }
-    if (major < 1 || (major == 1 && minor < 2))
-    {
-	fprintf (stderr, "RandR version %d.%d too old\n", major, minor);
-	exit (1);
+    free (ver_reply);
+
+    backlight_cookie[0] = xcb_intern_atom (conn, 1,
strlen("Backlight"), "Backlight");
+    backlight_cookie[1] = xcb_intern_atom (conn, 1,
strlen("BACKLIGHT"), "BACKLIGHT");
+
+    backlight_reply = xcb_intern_atom_reply (conn,
backlight_cookie[0], &error);
+    if (error != NULL || backlight_reply == NULL) {
+        int ec = error ? error->error_code : -1;
+        fprintf (stderr, "Intern Atom returned error %d\n", ec);
+        exit (1);
     }

-    backlight_new    = XInternAtom (dpy, "Backlight", True);
-    backlight_legacy = XInternAtom (dpy, "BACKLIGHT", True);
-    if (backlight_new == None && backlight_legacy == None)
-    {
+    backlight_new = backlight_reply->atom;
+    free (backlight_reply);
+
+    backlight_reply = xcb_intern_atom_reply (conn,
backlight_cookie[1], &error);
+    if (error != NULL || backlight_reply == NULL) {
+        int ec = error ? error->error_code : -1;
+        fprintf (stderr, "Intern Atom returned error %d\n", ec);
+        exit (1);
+    }
+
+    backlight_legacy = backlight_reply->atom;
+    free (backlight_reply);
+
+    if (backlight_new == XCB_NONE && backlight_legacy == XCB_NONE) {
 	fprintf (stderr, "No outputs have backlight property\n");
 	exit (1);
     }
-    for (screen = 0; screen < ScreenCount (dpy); screen++)
-    {
-	Window		    root = RootWindow (dpy, screen);
-	XRRScreenResources  *resources = XRRGetScreenResources (dpy, root);
-	int		    o;
-	
-	if (!resources) continue;
-	for (o = 0; o < resources->noutput; o++)
+
+    iter = xcb_setup_roots_iterator (xcb_get_setup (conn));
+    while (iter.rem) {
+        xcb_screen_t *screen = iter.data;
+        xcb_window_t root = screen->root;
+        xcb_randr_output_t *outputs;
+
+        xcb_randr_get_screen_resources_cookie_t resources_cookie;
+        xcb_randr_get_screen_resources_reply_t *resources_reply;
+
+        resources_cookie = xcb_randr_get_screen_resources (conn, root);
+        resources_reply = xcb_randr_get_screen_resources_reply (conn,
resources_cookie, &error);
+        if (error != NULL || resources_reply == NULL) {
+            int ec = error ? error->error_code : -1;
+            fprintf (stderr, "RANDR Get Screen Resources returned
error %d\n", ec);
+            continue;
+        }
+
+        outputs = xcb_randr_get_screen_resources_outputs (resources_reply);
+	for (int o = 0; o < resources_reply->num_outputs; o++)
 	{
-	    RROutput	output = resources->outputs[o];
-	    XRRPropertyInfo *info;
+	    xcb_randr_output_t output = outputs[o];
 	    double    	cur, new, step;
 	    double	min, max;
 	    double	set;

-	    cur = backlight_get (dpy, output);
+	    cur = backlight_get (conn, output);
 	    if (cur != -1)
 	    {
-		info = XRRQueryOutputProperty (dpy, output, backlight);
-		if (info)
-		{
-		    if (info->range && info->num_values == 2)
-		    {
-			min = info->values[0];
-			max = info->values[1];
-			if (op == Get) {
-			    printf ("%f\n", (cur - min) * 100 / (max - min));
-			} else {
-			    set = value * (max - min) / 100;
-			    switch (op) {
-			    case Set:
-				new = min + set;
-				break;
-			    case Inc:
-				new = cur + set;
-				break;
-			    case Dec:
-				new = cur - set;
-				break;
-			    default:
-				XSync (dpy, False);
-				return 1;
-			    }
-			    if (new > max) new = max;
-			    if (new < min) new = min;
-			    step = (new - cur) / steps;
-			    for (i = 0; i < steps && step != 0; i++)
-			    {
-				if (i == steps - 1)
-				    cur = new;
-				else
-				    cur += step;
-				backlight_set (dpy, output, (long) cur);
-				XFlush (dpy);
-				usleep (total_time * 1000 / steps);
-			    }
-			}
-		    }
-		    XFree (info);
-		}
+                xcb_randr_query_output_property_cookie_t prop_cookie;
+                xcb_randr_query_output_property_reply_t *prop_reply;
+
+                prop_cookie = xcb_randr_query_output_property (conn,
output, backlight);
+                prop_reply = xcb_randr_query_output_property_reply
(conn, prop_cookie, &error);
+
+                if (error != NULL || prop_reply == NULL) continue;
+
+                if (prop_reply->range &&
+
xcb_randr_query_output_property_valid_values_length (prop_reply) == 2)
{
+                    int32_t *values =
xcb_randr_query_output_property_valid_values (prop_reply);
+                    min = values[0];
+                    max = values[1];
+
+                    if (op == Get) {
+                        printf ("%f\n", (cur - min) * 100 / (max - min));
+                    } else {
+                        set = value * (max - min) / 100;
+                        switch (op) {
+                        case Set:
+                            new = min + set;
+                            break;
+                        case Inc:
+                            new = cur + set;
+                            break;
+                        case Dec:
+                            new = cur - set;
+                            break;
+                        default:
+                            xcb_aux_sync (conn);
+                            return 1;
+                        }
+                        if (new > max) new = max;
+                        if (new < min) new = min;
+                        step = (new - cur) / steps;
+                        for (i = 0; i < steps && step != 0; i++)
+                        {
+                            if (i == steps - 1)
+                                cur = new;
+                            else
+                                cur += step;
+                            backlight_set (conn, output, (long) cur);
+                            xcb_flush (conn);
+                            usleep (total_time * 1000 / steps);
+                        }
+                    }
+                }
+                free (prop_reply);
 	    }
 	}
-							
-	XRRFreeScreenResources (resources);
+
+        free (resources_reply);
+        xcb_screen_next (&iter);
     }
-    XSync (dpy, False);
+
+    xcb_aux_sync (conn);

     return 0;
 }
-- 
1.7.5.4


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