backup

.gitignore

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+*.o
+*.swp
+xmousepasteblock

Makefile

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+TARGET = xmousepasteblock
+
+INSTALL = install
+PREFIX = /usr
+BINDIR = $(PREFIX)/bin
+
+CC = gcc
+CFLAGS += -std=gnu99
+CFLAGS += -Wall -Wundef -Wshadow -Wformat-security
+
+LD = $(CC)
+LDFLAGS += $(shell pkg-config --libs x11 xi)
+LDFLAGS += -lev
+
+.NOTPARALLEL:
+
+.PHONY: all
+all: clean $(TARGET)
+
+.PHONY: debug
+debug: clean
+debug: CFLAGS += -g -DDEBUG
+debug: $(TARGET)
+
+.PHONY: $(TARGET)
+$(TARGET): $(TARGET).o
+	$(LD) "$<" $(LDFLAGS) -o "$(TARGET)"
+
+$(TARGET).o: $(TARGET).c
+	$(CC) $(CFLAGS) -o "$@" -c "$<"
+
+.PHONY: install
+install: $(TARGET)
+	$(INSTALL) -Dm 0755 "$(TARGET)" "$(DESTDIR)$(BINDIR)/$(TARGET)"
+
+.PHONY: uninstall
+uninstall:
+	$(RM) "$(DESTDIR)$(BINDIR)/$(TARGET)"
+
+.PHONY: clean
+clean:
+	$(RM) $(TARGET) $(TARGET).o

README.md

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+# XMousePasteBlock
+
+Listens for middle mouse click events and clears the primary X selection/clipboard on detection to avoid accidentially pasting stuff all over the place.
+
+## About
+
+No need to disable your precious middle mouse button bindings, no clearing of visual selections nor performance losses because of emptying the primary X clipboard periodically.
+With the utilization of XInput and Xlibs this has _no_ measurable impact on performance whatsoever.
+No elevated privileges required. Just run within your regular users' X session.
+
+## Building
+````
+make
+sudo make install
+````
+
+## Running
+Just add `xmousepasteblock` to your startup script/config.
+
+## Known issues
+In case of devices which are configured with middle mouse button hold-to-scroll (e.g. Trackpoints), it may happen that the primary selection clear action gets fired too late on older and slower machines.
+You can observe the behavior by building with the DEBUG flag set (`make debug`), running `xmousepasteblock` in a shell and watching the debug output as you long press and hold the mouse buttons.
+
+This is due to the fact that the XI_RawButtonPress event only gets fired _after_ releasing the middle mouse button (in case the user wanted to execute a scroll action).
+The only option to work around this is to disable the middle mouse button hold-to-scroll functionality on Trackpoint devices (which is often not desirable).
+To do so (using _libinput_):
+`xinput set-prop <device id> 'libinput Button Scrolling Button' 0`

xmousepasteblock.c

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+/*
+ * Copyright (c) 2018 Micha LaQua <micha.laqua@gmail.com>
+ *
+ * Special thanks to Ingo Buerk (Airblader) for his work on the
+ * awesome unclutter-xfixes project, upon which the XInput eventcode
+ * is based on.
+ *
+ *
+ * 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
+ * the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ev.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xatom.h>
+#include <X11/extensions/XInput2.h>
+
+static Display *display;
+static struct ev_io *x_watcher;
+static struct ev_check *x_check;
+static int xi_opcode = -1;
+
+void errormsg(char *msg) {
+    printf("ERROR: %s\n", msg);
+    exit(1);
+}
+
+void init_xinput(void) {
+    int event, error;
+    if (!XQueryExtension(display, "XInputExtension", &xi_opcode, &event, &error)) {
+        errormsg("XInput extension not available");
+    }
+
+    int major_op = 2, minor_op = 2;
+    int result = XIQueryVersion(display, &major_op, &minor_op);
+    if (result == BadRequest) {
+        errormsg("XI2 is not supported in a sufficient version (>=2.2 required).");
+    } else if (result != Success) {
+        errormsg("Failed to query XI2");
+    }
+}
+
+void init_eventmask(void) {
+    XIEventMask masks[1];
+    unsigned char mask[(XI_LASTEVENT + 7)/8];
+
+    memset(mask, 0, sizeof(mask));
+    masks[0].deviceid = XIAllMasterDevices;
+    masks[0].mask_len = sizeof(mask);
+    masks[0].mask = mask;
+
+    XISetMask(mask, XI_RawButtonPress);
+
+    XISelectEvents(display, DefaultRootWindow(display), masks, 1);
+    XFlush(display);
+}
+
+void clear_primary(void) {
+    XSetSelectionOwner(display, XA_PRIMARY, None, CurrentTime);
+    XSync(display, False);
+#ifdef DEBUG
+    printf("primary selection cleared\n");
+#endif
+}
+
+void stub_cb(EV_P_ ev_io *w, int revents) {
+    /* STUB */
+}
+
+void check_cb(EV_P_ ev_check *w, int revents) {
+    XEvent ev;
+    while (XPending(display) > 0) {
+        XNextEvent(display, &ev);
+        XGenericEventCookie *cookie = &ev.xcookie;
+        if (cookie->type != GenericEvent || cookie->extension !=  xi_opcode || !XGetEventData(display, cookie)) {
+            continue;
+        }
+
+        const XIRawEvent *data = (const XIRawEvent *) cookie->data;
+#ifdef DEBUG
+        printf("button %i pressed\n", data->detail);
+#endif
+        if (data->detail == 2) {
+            clear_primary();
+        }
+
+        XFreeEventData(display, cookie);
+    }
+}
+
+int main(int argc, const char* argv[]) {
+    struct ev_loop *evloop;
+
+    display = XOpenDisplay(NULL);
+    if (display == NULL) {
+        errormsg("Failed to connect to the X server");
+        return 1;
+    }
+
+    init_xinput();
+    init_eventmask();
+
+    evloop = EV_DEFAULT;
+    
+    x_watcher = calloc(sizeof(struct ev_io), 1);
+    ev_io_init(x_watcher, stub_cb, XConnectionNumber(display), EV_READ);
+    ev_io_start(evloop, x_watcher);
+    
+    x_check = calloc(sizeof(struct ev_check), 1);
+    ev_check_init(x_check, check_cb);
+    ev_check_start(evloop, x_check);
+
+    ev_run(evloop, 0);
+
+    return 0;
+}