1 files changed, 161 insertions(+), 0 deletions(-)

A randr_tail.c

@@ 0,0 1,161 @@
+#if 0
+# Copyright (c) 2014, Thomas Spurden <thomas@spurden.name>
+# 
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# Print a line to stdout whenever a XRandR diplay is plugged or unplugged
+# The line will be of the form:
+# + OUTPUTNAME
+# for plug, and
+# - OUTPUTNAME
+# for unplug
+
+# This file can be read by either GNU Make or a C99 compiler.
+# Easy way to compile is: make -f thisfile output
+# Which will produce a binary called output.
+
+# Dependencies: X11 with XRandR
+
+! := $(lastword $(MAKEFILE_LIST))
+%: $!
+	$(CC) -pedantic -Wall -O2 -std=c99 -lX11 -lXrandr -o $@ -xc $!
+
+define program
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xrandr.h>
+
+static int error_handler(void) 
+{
+	exit(EXIT_FAILURE);
+}
+
+char* strdup(char const* in)
+{
+	size_t len = strlen(in);
+	if(len > 256) {
+		return NULL;
+	}
+	char* to = malloc(len + 1);
+	strncpy(to, in, len);
+	to[len] = '\0';
+	return to;
+}
+
+char* connected_outputs[16] = {0};
+
+int set_connected(char const* name, int con)
+{
+	char** inspos = NULL;
+	for(unsigned int i = 0; i < sizeof(connected_outputs) / sizeof(connected_outputs[0]); i += 1) {
+		if(connected_outputs[i]) {
+			if(strcmp(connected_outputs[i], name) == 0) {
+				if(con) {
+					return 1;
+				} else {
+					free(connected_outputs[i]);
+					connected_outputs[i] = 0;
+					return 1;
+				}
+			}
+		} else {
+			inspos = &connected_outputs[i];
+		}
+	}
+	if(con && inspos) {
+		*inspos = strdup(name);
+		return (*inspos)? 0 : -1;
+	}
+
+	return -1;
+}
+
+int main(int argc, char **argv) 
+{
+	XEvent ev;
+	Display *dpy;
+	int eventBase, errorBase;
+
+	dpy = XOpenDisplay(NULL);
+
+	if(dpy == NULL) {
+		fprintf(stderr, "Could not open X11 display\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if(!XRRQueryExtension(dpy, &eventBase, &errorBase)) {
+		fprintf(stderr, "Could not query the XRandR extension\n");
+		exit(EXIT_FAILURE);
+	}
+
+	{
+		XRRScreenResources* res = XRRGetScreenResources(dpy, DefaultRootWindow(dpy));
+		for(int i = 0; i < res->noutput; i += 1) {
+			XRROutputInfo* info = XRRGetOutputInfo(dpy, res, res->outputs[i]);
+			set_connected(info->name, info->connection == 0);
+			XRRFreeOutputInfo(info);
+
+		}
+		XRRFreeScreenResources(res);
+	}
+
+	XRRSelectInput(dpy, DefaultRootWindow(dpy), RROutputChangeNotifyMask);
+	XSync(dpy, False);
+	XSetIOErrorHandler((XIOErrorHandler) error_handler);
+	while(1) {
+		if(!XNextEvent(dpy, &ev)) {
+			if(ev.type != eventBase + RRNotify_OutputChange) {
+				continue;
+			}
+
+			XRROutputChangeNotifyEvent* change = (XRROutputChangeNotifyEvent*)&ev;
+			XRRScreenResources* resources = XRRGetScreenResources(change->display, change->window);
+			if(resources == NULL) {
+				fprintf(stderr, "Could not get screen resources\n");
+				continue;
+			}
+
+			XRROutputInfo* info = XRRGetOutputInfo(change->display, resources, change->output);
+			if(info == NULL) {
+				XRRFreeScreenResources(resources);
+				fprintf(stderr, "Could not get output info\n");
+				continue;
+			}
+
+			if(info->connection == 0) {
+				if(set_connected(info->name, 1) == 0) {
+					printf("+ %s\n", info->name);
+					fflush(stdout);
+				}
+			}
+			else {
+				if(set_connected(info->name, 0) == 1) {
+					printf("- %s\n", info->name);
+					fflush(stdout);
+				}
+			}
+
+			XRRFreeScreenResources(resources);
+			XRRFreeOutputInfo(info);
+		}
+	}
+	return EXIT_SUCCESS;
+}
+
+#if 0
+endef
+#endif