initial import

1 files changed, 257 insertions, 0 deletions

diff --git a/x11.c b/x11.c
new file mode 100644
index 0000000..3b8bcdc
--- /dev/null
+++ b/x11.c
@@ -0,0 +1,257 @@
+#include <ctype.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xatom.h>
+#include <X11/Xutil.h>
+#include <X11/extensions/XInput.h>
+#include <X11/extensions/XInput2.h>
+#include <glib-unix.h>
+
+#include "x11.h"
+#include "key.h"
+
+#define ONLY_SURFACE_COVER 1
+
+static Display *display;
+
+static int xi_opcode;
+static int xi_event;
+static int xi_error;
+
+static Atom product_id;
+static Atom button_horiz_wheel_left;
+
+static bool is_keyboard(const XIDeviceInfo *info)
+{
+	if (!info->enabled)
+		return false;
+
+	// Surface keyboard appears as a SlavePointer sometimes
+	if (info->use != XISlaveKeyboard && info->use != XISlavePointer)
+		return false;
+
+	for (int i = 0; i < info->num_classes; i++) {
+		if (info->classes[i]->type != KeyClass)
+			continue;
+
+		const XIKeyClassInfo *key_info = (XIKeyClassInfo *)info->classes[i];
+		if (key_info->num_keycodes > 40) {
+			// If it has more than 40 keys, it is a keyboard
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static bool is_surface_touch_cover(const XIDeviceInfo *info)
+{
+	Atom act_type;
+	int act_format;
+	unsigned long nitems, bytes_after;
+	unsigned char *data;
+	Status status;
+
+	// First test: product_id
+	status = XIGetProperty(display, info->deviceid, product_id, 0, 2, False, XA_INTEGER,
+	                       &act_type, &act_format, &nitems, &bytes_after, &data);
+
+	if (status != Success) {
+		return false;
+	}
+
+	if (act_type != XA_INTEGER || act_format != 32) {
+		XFree(data);
+		return false;
+	}
+
+	int32_t *int_data = (int32_t*)data;
+	int vendor_id = int_data[0];
+	int product_id = int_data[1];
+	XFree(data);
+
+	if (vendor_id == MICROSOFT_VENDOR_ID) {
+		if (product_id != MICROSOFT_TOUCH_COVER_1_PRODUCT_ID &&
+		        product_id != MICROSOFT_TOUCH_COVER_2_PRODUCT_ID) {
+			return false;
+		}
+		// TODO: Touch cover 2
+	} else {
+		return false;
+	}
+
+	// Second test: check if it has a horizontal wheel (all Surface covers 'have' one)
+	// This way we ignore the device with the volume buttons.
+	for (int i = 0; i < info->num_classes; i++) {
+		if (info->classes[i]->type != ButtonClass)
+			continue;
+
+		const XIButtonClassInfo *btn_info = (XIButtonClassInfo *)info->classes[i];
+		for (int j = 0; j < btn_info->num_buttons; j++) {
+			if (btn_info->labels[j] == button_horiz_wheel_left) {
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+
+static bool find_and_select_devices()
+{
+	int ndevices;
+	XIDeviceInfo *info = XIQueryDevice(display, XIAllDevices, &ndevices);
+
+	if (!info) return false;
+
+	for (int i = 0; i < ndevices; i++) {
+		// Looking for keyboards only currently
+		if (!is_keyboard(&info[i])) continue;
+#if ONLY_SURFACE_COVER
+		if (!is_surface_touch_cover(&info[i])) continue;
+#endif
+
+		g_debug("Capturing events from '%s'", info[i].name);
+
+		// Subscribe to this device's events
+		XIEventMask mask;
+		mask.deviceid = info[i].deviceid;
+		mask.mask_len = XIMaskLen(XI_LASTEVENT);
+		mask.mask = calloc(mask.mask_len, 1);
+		XISetMask(mask.mask, XI_KeyPress);
+		XISelectEvents(display, DefaultRootWindow(display), &mask, 1);
+		free(mask.mask);
+	}
+
+	XIFreeDeviceInfo(info);
+	return true;
+}
+
+static void handle_key_press(const XIDeviceEvent *event)
+{
+	// Convert into an XKeyEvent
+	XKeyEvent kevent;
+	kevent.serial = event->serial;
+	kevent.send_event = event->send_event;
+	kevent.display = event->display;
+	kevent.same_screen = True;
+	kevent.window = event->event;
+	kevent.root = event->root;
+	kevent.subwindow = event->child;
+	kevent.time = event->time;
+	kevent.x = event->event_x;
+	kevent.y = event->event_y;
+	kevent.x_root = event->root_x;
+	kevent.y_root = event->root_y;
+	kevent.state = event->mods.effective;
+	kevent.keycode = event->detail;
+
+	char buf[4];
+	KeySym sym;
+
+	int len = XLookupString(&kevent, buf, sizeof(buf), &sym, NULL);
+
+	bool is_dead_key;
+	switch (len) {
+	case 0:
+		is_dead_key = true;
+		break;
+	case 1:
+		is_dead_key = iscntrl(buf[0]) || isblank(buf[0]);
+		break;
+	default:
+		is_dead_key = false;
+		break;
+	}
+
+	handle_keypress(is_dead_key);
+}
+
+static void handle_xi_event(const XGenericEventCookie *event)
+{
+	switch (event->evtype) {
+	case XI_HierarchyChanged:
+		g_debug("Hierarchy changed event");
+		find_and_select_devices();
+		break;
+	case XI_KeyPress:
+		handle_key_press(event->data);
+		break;
+	case XI_RawKeyPress:
+		g_debug("Raw key press");
+		break;
+	}
+}
+
+static gboolean handle_x11_fd(gint fd, GIOCondition condition, gpointer data)
+{
+	while (XPending(display)) {
+		XEvent event;
+		XNextEvent(display, &event);
+
+		switch (event.type) {
+		case GenericEvent:
+			if (XGetEventData(display, &event.xcookie)) {
+				if (event.xcookie.extension == xi_opcode) {
+					handle_xi_event(&event.xcookie);
+				}
+				XFreeEventData(display, &event.xcookie);
+			}
+			break;
+		}
+
+		// Ignoring events
+	}
+
+	return G_SOURCE_CONTINUE;
+}
+
+bool x11_init()
+{
+	display = XOpenDisplay(NULL);
+	if (!display) {
+		g_warning("Cannot connect to X display");
+		return false;
+	}
+
+	if (!XQueryExtension(display, INAME, &xi_opcode, &xi_event, &xi_error)) {
+        g_warning("X Input extension not available");
+        return false;
+    }
+
+	int major = 2;
+	int minor = 0;
+	if (XIQueryVersion(display, &major, &minor) != Success) {
+		g_warning("X Input 2.0 not available");
+        return false;
+	}
+
+	product_id = XInternAtom(display, "Device Product ID", False);
+	button_horiz_wheel_left = XInternAtom(display, "Button Horiz Wheel Left", False);
+
+	// Setup a mask for hierarchy changed events
+	XIEventMask mask;
+	mask.deviceid = XIAllDevices;
+	mask.mask_len = XIMaskLen(XI_LASTEVENT);
+	mask.mask = calloc(mask.mask_len, 1);
+	XISetMask(mask.mask, XI_HierarchyChanged);
+	XISelectEvents(display, DefaultRootWindow(display), &mask, 1);
+	free(mask.mask);
+
+	if (!find_and_select_devices()) {
+		return false;
+	}
+
+	// Prepare integration with glib event loop
+	g_unix_fd_add(ConnectionNumber(display), G_IO_IN,
+	              handle_x11_fd, NULL);
+	XFlush(display);
+
+	return true;
+}
+
+void x11_close()
+{
+	XCloseDisplay(display);
+}