Clear oneshot on click

This patch passively monitors mouse events and passes them
through to the active keyboard in order to facilitate
clearing oneshot modifiers on click.

A byproduct of this is an increase the number of spurious wakeups
(caused by mouse movement since we can't exclusively monitor click
events) , but this seems to have an minimal performance impact
in practice.

Author: rvaiya

src/device.c

@@ -21,49 +21,61 @@
 #include <linux/input.h>
 #include <sys/inotify.h>
 
-/* 
- * Abstract away evdev and inotify. 
- * 
+/*
+ * Abstract away evdev and inotify.
+ *
  * We could make this cleaner by creating a single file descriptor via epoll
  * but this would break FreeBSD compatibility without a dedicated kqueue
- * implementation. A thread based approach was also considered,
- * but inter-thread communication adds too much overhead (~100us).
+ * implementation. A thread based approach was also considered, but
+ * inter-thread communication adds too much overhead (~100us).
  *
  * Overview:
- * 
+ *
  * A 'devmon' is a file descriptor which can be created with devmon_create()
  * and subsequently monitored for new devices read with devmon_read_device().
- * 
- * A 'device' always corresponds to a keyboard from which activity can be
- * monitored with device->fd and events subsequently read using
+ *
+ * A 'device' always corresponds to a keyboard or mouse from which activity can
+ * be monitored with device->fd and events subsequently read using
  * device_read_event().
  *
  * If the event returned by device_read_event() is of type DEV_REMOVED then the
  * corresponding device should be considered invalid by the caller.
  */
 
-static int is_keyboard(int fd)
+/*
+ * returns 1 if keyboard, 2 if mouse, and 0 if neither.
+ */
+static int device_type(int fd)
 {
-	uint32_t keymask;
+	uint32_t mask[BTN_LEFT/32+1] = {0};
 
-	if (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof keymask), &keymask) < 0) {
+	if (ioctl(fd, EVIOCGBIT(EV_KEY, (BTN_LEFT/32+1)*4), mask) < 0) {
 		perror("ioctl");
 		return 0;
 	}
 
 	/* The first 31 bits correspond to [KEY_ESC-KEY_S] */
-	return keymask == 0xFFFFFFFE;
+	if (mask[0] == 0xFFFFFFFE)
+		return 1;
+	else if (mask[BTN_LEFT/32] >> BTN_LEFT%32)
+		return 2;
+	else
+		return 0;
 }
 
 static int device_init(const char *path, struct device *dev)
 {
 	int fd;
+	int type;
+
 	if ((fd = open(path, O_RDONLY | O_NONBLOCK, 0600)) < 0) {
 		fprintf(stderr, "failed to open %s\n", path);
 		return -1;
 	}
 
-	if (is_keyboard(fd)) {
+	type = device_type(fd);
+
+	if (type) {
 		struct input_id info;
 
 		if (ioctl(fd, EVIOCGNAME(sizeof(dev->name)), dev->name) == -1) {
@@ -80,6 +92,7 @@ static int device_init(const char *path, struct device *dev)
 		dev->path[sizeof(dev->path)-1] = 0;
 
 		dev->fd = fd;
+		dev->is_keyboard = type == 1;
 		dev->vendor_id = info.vendor;
 		dev->product_id = info.product;
 
@@ -143,7 +156,7 @@ int device_scan(struct device devices[MAX_DEVICES])
 	return ndevs;
 }
 
-/* 
+/*
  * NOTE: Only a single devmon fd may exist. Implementing this properly
  * would involve bookkeeping state for each fd, but this is
  * unnecessary for our use.
@@ -169,7 +182,7 @@ int devmon_create()
 	return fd;
 }
 
-/* 
+/*
  * A non blocking call which returns any devices available on the provided
  * monitor descriptor. The return value should not be freed or modified by the calling
  * code. Returns NULL if no devices are available.
@@ -215,7 +228,7 @@ int device_ungrab(struct device *dev)
 	return ioctl(dev->fd, EVIOCGRAB, (void *) 0);
 }
 
-/* 
+/*
  * Read a device event from the given device or return
  * NULL if none are available (may happen in the
  * case of a spurious wakeup).
@@ -254,6 +267,8 @@ struct device_event *device_read_event(struct device *dev)
 			ev.code = KEYD_MOUSE_2;
 		else if (ev.code == KEY_FN)
 			ev.code = KEYD_FN;
+		else if (ev.code >= BTN_DIGI && ev.code <= BTN_TOOL_QUADTAP)
+			;
 		else {
 			fprintf(stderr, "ERROR: unsupported evdev code: 0x%x\n", ev.code);
 			return NULL;

src/device.h

@@ -21,6 +21,7 @@ struct device {
 	 */
 	int fd;
 
+	uint8_t is_keyboard;
 	uint16_t product_id;
 	uint16_t vendor_id;
 	char name[64];

src/keyboard.c

@@ -30,7 +30,7 @@ static long get_time()
 
 static void kbd_send_key(struct keyboard *kbd, uint8_t code, uint8_t pressed)
 {
-	if (code == KEYD_NOOP)
+	if (code == KEYD_NOOP || code == KEYD_EXTERNAL_MOUSE_BUTTON)
 		return;
 
 	if (pressed)
@@ -377,10 +377,10 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code, struct descri
 		} else {
 			kbd_send_key(kbd, d->args[0].code, 0);
 			send_mods(kbd, descriptor_layer_mods, 1);
+			clear_oneshot = 1;
 		}
 
 		oneshot_latch = 0;
-		clear_oneshot = 1;
 		break;
 	case OP_LAYER:
 		layer = &layers[d->args[0].idx];

src/keyd.c

@@ -55,6 +55,16 @@ static void daemon_add_cb(struct device *dev)
 
 	dev->data = NULL;
 
+	/*
+	 * NOTE: Some mice can emit keys and consequently appear as keyboards.
+	 * Conversely, some keyboards with a builtin trackpad can emit mouse
+	 * events. There doesn't appear to be a reliable way to distinguish
+	 * between these two, so we take a permissive approach and leave it up to
+	 * the user to blacklist mice which emit key events.
+	 */
+	if (!dev->is_keyboard)
+		return;
+
 	printf("device added: %04x:%04x %s (%s)\n",
 	       dev->vendor_id,
 	       dev->product_id,
@@ -106,7 +116,18 @@ static void panic_check(uint8_t code, uint8_t pressed)
 
 static int daemon_event_cb(struct device *dev, uint8_t code, uint8_t pressed)
 {
-	struct keyboard *kbd = dev ? dev->data : active_kbd;
+	struct keyboard *kbd = NULL;
+
+	if (!dev) {
+		/* timeout */
+		kbd = active_kbd;
+	} else if (dev->data) {
+		kbd = dev->data;
+	} else if (code >= KEYD_LEFT_MOUSE && code <= KEYD_MOUSE_2) {
+		code = KEYD_EXTERNAL_MOUSE_BUTTON;
+
+		kbd = active_kbd;
+	}
 
 	if (!kbd)
 		return 0;

src/keys.h

@@ -281,13 +281,15 @@ struct modifier_table_ent {
 
 /* These deviate from uinput codes. */
 
-#define  KEYD_NOOP             195
-#define  KEYD_LEFT_MOUSE       249
-#define  KEYD_RIGHT_MOUSE      250
-#define  KEYD_MIDDLE_MOUSE     251
-#define  KEYD_MOUSE_1          252
-#define  KEYD_MOUSE_2          253
-#define  KEYD_FN               254
+#define  KEYD_EXTERNAL_MOUSE_BUTTON     196
+
+#define  KEYD_NOOP             		195
+#define  KEYD_LEFT_MOUSE       		249
+#define  KEYD_MIDDLE_MOUSE     		250
+#define  KEYD_RIGHT_MOUSE		251
+#define  KEYD_MOUSE_1          		252
+#define  KEYD_MOUSE_2          		253
+#define  KEYD_FN               		254
 
 extern const struct modifier_table_ent modifier_table[MAX_MOD];
 extern const struct keycode_table_ent keycode_table[256];

t/oneshot.t

@@ -5,5 +5,5 @@ b up
 
 control down
 b down
-control up
 b up
+control up

t/oneshot11.t

@@ -9,7 +9,7 @@ a up
 
 control down
 j down
-control up
 j up
+control up
 a down
 a up

t/oneshot14.t

@@ -11,5 +11,7 @@ shift down
 shift up
 a down
 a up
+shift down
+shift up
 b down
 b up

t/oneshot5.t

@@ -8,6 +8,6 @@ i up
 shift down
 control down
 i down
+i up
 control up
 shift up
-i up

t/oneshot6.t

@@ -8,6 +8,6 @@ i up
 shift down
 control down
 i down
+i up
 control up
 shift up
-i up