load configuration from xresources

Originally started as the xresources patch, but I ended up bringing
over the more configurable logic from the other suckless projects.

config.def.h

@@ -2,18 +2,34 @@ static const char *background_color = "#3e3e3e";
 static const char *border_color = "#ececec";
 static const char *font_color = "#ececec";
 static const char *font_pattern = "monospace:size=10";
-static const unsigned line_spacing = 5;
+static unsigned line_spacing = 5;
-static const unsigned int padding = 15;
+static unsigned int padding = 15;
 
-static const unsigned int width = 450;
+static unsigned int width = 450;
-static const unsigned int border_size = 2;
+static unsigned int border_size = 2;
-static const unsigned int pos_x = 30;
+static unsigned int pos_x = 30;
-static const unsigned int pos_y = 60;
+static unsigned int pos_y = 60;
 
 enum corners { TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT };
 enum corners corner = TOP_RIGHT;
 
-static const unsigned int duration = 5; /* in seconds */
+static unsigned int duration = 5; /* in seconds */
 
 #define DISMISS_BUTTON Button1
 #define ACTION_BUTTON Button3
+
+/* Xresources preferences to load at startup */
+ResourcePref resources[] = {
+	{ "bgcolor",      STRING,  &background_color },
+	{ "bordercolor",  STRING,  &border_color },
+	{ "fontcolor",    STRING,  &font_color },
+	{ "fontpattern",  STRING,  &font_pattern },
+	{ "line_spacing", INTEGER, &padding },
+	{ "padding",      INTEGER, &padding },
+	{ "width",        INTEGER, &width },
+	{ "border_size",  INTEGER, &border_size },
+	{ "pos_x",        INTEGER, &pos_x },
+	{ "pos_y",        INTEGER, &pos_y },
+	{ "corner",       INTEGER, &corner },
+	{ "duration",     INTEGER, &duration },
+};

herbe.c

@@ -1,5 +1,6 @@
 #include <X11/Xlib.h>
 #include <X11/Xft/Xft.h>
+#include <X11/Xresource.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
@@ -9,12 +10,27 @@
 #include <fcntl.h>
 #include <semaphore.h>
 
-#include "config.h"
-
 #define EXIT_ACTION 0
 #define EXIT_FAIL 1
 #define EXIT_DISMISS 2
 
+#define LEN(X)       (sizeof X / sizeof X[0])
+
+/* Xresources preferences */
+enum resource_type {
+	STRING = 0,
+	INTEGER = 1,
+	FLOAT = 2
+};
+
+typedef struct {
+	char *name;
+	enum resource_type type;
+	void *dst;
+} ResourcePref;
+
+#include "config.h"
+
 Display *display;
 Window window;
 int exit_code = EXIT_DISMISS;
@@ -79,6 +95,55 @@ void expire(int sig)
 	XFlush(display);
 }
 
+int resource_load(XrmDatabase db, char *name, enum resource_type rtype, void *dst)
+{
+	char **sdst = dst;
+	int *idst = dst;
+	float *fdst = dst;
+
+	char fullname[256];
+	char fullclass[256];
+	char *type;
+	XrmValue ret;
+
+	snprintf(fullname, sizeof(fullname), "%s.%s", "herbe", name);
+	snprintf(fullclass, sizeof(fullclass), "%s.%s", "Herbe", name);
+	fullname[sizeof(fullname) - 1] = fullclass[sizeof(fullclass) - 1] = '\0';
+
+	XrmGetResource(db, fullname, fullclass, &type, &ret);
+	if (ret.addr == NULL || strncmp("String", type, 64))
+		return 1;
+
+	switch (rtype) {
+	case STRING:
+		*sdst = ret.addr;
+		break;
+	case INTEGER:
+		*idst = strtoul(ret.addr, NULL, 10);
+		break;
+	case FLOAT:
+		*fdst = strtof(ret.addr, NULL);
+		break;
+	}
+	return 0;
+}
+
+void config_init(Display *dpy)
+{
+	char *resm;
+	XrmDatabase db;
+	ResourcePref *p;
+
+	XrmInitialize();
+	resm = XResourceManagerString(dpy);
+	if (!resm)
+		return;
+
+	db = XrmGetStringDatabase(resm);
+	for (p = resources; p < resources + LEN(resources); p++)
+		resource_load(db, p->name, p->type, p->dst);
+}
+
 int main(int argc, char *argv[])
 {
 	if (argc == 1)
@@ -107,6 +172,8 @@ int main(int argc, char *argv[])
 	if (!(display = XOpenDisplay(0)))
 		die("Cannot open display");
 
+	config_init(display);
+
 	int screen = DefaultScreen(display);
 	Visual *visual = DefaultVisual(display, screen);
 	Colormap colormap = DefaultColormap(display, screen);