data: add a new Keys/KeyCodes entry to the tablet files

This is parsed but not exported by libwacom itself beyond the number of
available keys. We can add other bits once we know what potential
callers want.

It is used however to determine if a device has a pad and thus used to
set the ID_INPUT_TABLET_PAD property through the hwdb. This fixes the
issue with some devices without buttons (but with keys) to not get
labelled as pads, e.g. the Cintiq Pro 13.

Fixes #585

data/cintiq-pro-13.tablet

@@ -43,3 +43,7 @@ Stylus=true
 Reversible=false
 Touch=true
 Ring=false
+
+[Keys]
+# first key is in-kernel display toggle
+KeyCodes=0;KEY_CONTROLPANEL;KEY_ONSCREEN_KEYBOARD;KEY_BUTTONCONFIG;SW_MUTE_DEVICE

data/wacom.example

@@ -210,3 +210,10 @@ Touchstrip2=J
 # We assume the same number of modes for each of the touchstrips
 # if there is more than one
 StripsNumModes=4
+
+
+# Metadata about the keys on the tablet
+[Keys]
+# The evdev codes for the keys (if any) in order from left to right.
+# Keys that have a code of zero do not produce any events.
+KeyCodes=0;KEY_CONTROLPANEL;KEY_ONSCREEN_KEYBOARD;KEY_BUTTONCONFIG;SW_MUTE_DEVICE

libwacom/libwacom-database.c

@@ -45,6 +45,7 @@
 #define FEATURES_GROUP "Features"
 #define DEVICE_GROUP "Device"
 #define BUTTONS_GROUP "Buttons"
+#define KEYS_GROUP "Keys"
 
 static WacomClass
 libwacom_class_string_to_enum(const char *class)
@@ -493,6 +494,50 @@ set_button_codes_from_string(WacomDevice *device, char **strvals)
 	return success;
 }
 
+static inline bool
+set_key_codes_from_string(WacomDevice *device, char **strvals)
+{
+	bool success = false;
+	assert(strvals);
+
+	for (unsigned int idx = 0; strvals[idx]; idx++) {
+		const char *str = strvals[idx];
+		int code = -1;
+		int type = -1;
+
+		if (!str) {
+			g_error("%s: Missing KeyCode for key %d, ignoring all codes\n",
+				device->name, idx);
+			goto out;
+		} else if (g_str_has_prefix(str, "KEY")) {
+			type = EV_KEY;
+			code = libevdev_event_code_from_code_name(str);
+		} else if (g_str_has_prefix(str, "SW")) {
+			type = EV_SW;
+			code = libevdev_event_code_from_code_name(str);
+		} else {
+			if (safe_atoi_base (strvals[idx], &code, 16))
+				type = EV_KEY;
+		}
+
+		if (code == -1 || type == -1) {
+			g_warning ("%s: Invalid KeyCode %s, ignoring all codes\n", device->name, str);
+			goto out;
+		}
+
+		device->keycodes[idx].type = type;
+		device->keycodes[idx].code = code;
+		device->num_keycodes = idx + 1;
+	}
+
+	success = true;
+out:
+	if (!success) {
+		memset(device->keycodes, 0, sizeof(device->keycodes));
+	}
+	return success;
+}
+
 static inline void
 set_button_codes_from_heuristics(WacomDevice *device)
 {
@@ -604,6 +649,30 @@ libwacom_parse_buttons(WacomDevice *device,
 	device->strips_num_modes = libwacom_parse_num_modes(device, keyfile, "StripsNumModes", WACOM_BUTTON_TOUCHSTRIP_MODESWITCH);
 }
 
+static void
+libwacom_parse_key_codes(WacomDevice *device,
+			 GKeyFile    *keyfile)
+{
+	char **vals;
+
+	vals = g_key_file_get_string_list(keyfile, KEYS_GROUP, "KeyCodes", NULL, NULL);
+	if (vals)
+		set_key_codes_from_string(device, vals);
+
+	g_strfreev (vals);
+}
+
+static void
+libwacom_parse_keys(WacomDevice *device,
+		    GKeyFile    *keyfile)
+{
+	if (!g_key_file_has_group(keyfile, KEYS_GROUP))
+		return;
+
+	libwacom_parse_key_codes(device, keyfile);
+}
+
+
 static int
 styli_id_sort(gconstpointer pa, gconstpointer pb)
 {
@@ -829,6 +898,7 @@ libwacom_parse_tablet_keyfile(WacomDeviceDatabase *db,
 
 	libwacom_parse_features(device, keyfile);
 	libwacom_parse_buttons(device, keyfile);
+	libwacom_parse_keys(device, keyfile);
 
 	success = TRUE;
 

libwacom/libwacom.c

@@ -379,6 +379,10 @@ libwacom_copy(const WacomDevice *device)
 		WacomButton *b = g_memdup2(a, sizeof(WacomButton));
 		g_hash_table_insert(d->buttons, k, b);
 	}
+
+	d->num_keycodes = device->num_keycodes;
+	memcpy(d->keycodes, device->keycodes, sizeof(device->keycodes));
+
 	return d;
 }
 
@@ -1120,6 +1124,12 @@ libwacom_get_num_buttons(const WacomDevice *device)
 	return g_hash_table_size(device->buttons);
 }
 
+LIBWACOM_EXPORT int
+libwacom_get_num_keys(const WacomDevice *device)
+{
+	return device->num_keycodes;
+}
+
 LIBWACOM_EXPORT const int *
 libwacom_get_supported_styli(const WacomDevice *device, int *num_styli)
 {

libwacom/libwacom.h

@@ -594,6 +594,16 @@ int libwacom_has_touch(const WacomDevice *device);
  */
 int libwacom_get_num_buttons(const WacomDevice *device);
 
+/**
+ * Tablet keys indices are numbered from zero
+ *
+ * @param device The tablet to query
+ * @return The number of keys on the tablet
+ *
+ * @ingroup devices
+ */
+int libwacom_get_num_keys(const WacomDevice *device);
+
 /**
  * @param device The tablet to query
  * @param num_styli Return location for the number of listed styli

libwacom/libwacom.sym

@@ -68,3 +68,7 @@ global:
 local:
         *;
 };
+
+LIBWACOM_2.9 {
+    libwacom_get_num_keys;
+} LIBWACOM_2.0;

libwacom/libwacomint.h

@@ -67,6 +67,11 @@ typedef struct _WacomButton {
 	int code;
 } WacomButton;
 
+typedef struct _WacomKeycode {
+	unsigned int type;
+	unsigned int code;
+} WacomKeycode;
+
 /* WARNING: When adding new members to this struct
  * make sure to update libwacom_copy() and
  * libwacom_print_device_description() ! */
@@ -92,6 +97,8 @@ struct _WacomDevice {
 
 	GArray *styli;
 	GHashTable *buttons; /* 'A' : WacomButton */
+	WacomKeycode keycodes[32];
+	size_t num_keycodes;
 
 	GArray *status_leds;
 

test/test-load.c

@@ -226,6 +226,16 @@ test_cintiq13hd(struct fixture *f, gconstpointer user_data)
 	libwacom_destroy(device);
 }
 
+static void
+test_cintiqpro13(struct fixture *f, gconstpointer user_data)
+{
+	WacomDevice *device = libwacom_new_from_name(f->db, "Wacom Cintiq Pro 13", NULL);
+	g_assert_nonnull(device);
+	g_assert_cmpint(libwacom_get_num_keys(device), ==, 5);
+
+	libwacom_destroy(device);
+}
+
 static void
 test_bamboopen(struct fixture *f, gconstpointer user_data)
 {
@@ -294,6 +304,9 @@ int main(int argc, char **argv)
 	g_test_add("/load/056a:0304", struct fixture, NULL,
 		   fixture_setup, test_cintiq13hd,
 		   fixture_teardown);
+	g_test_add("/load/056a:034f", struct fixture, NULL,
+		   fixture_setup, test_cintiqpro13,
+		   fixture_teardown);
 	g_test_add("/load/056a:0065", struct fixture, NULL,
 		   fixture_setup, test_bamboopen,
 		   fixture_teardown);

tools/libwacom-update-db.py

@@ -147,7 +147,7 @@ def _load(self, path):
                         )
                 except KeyError:
                     pass
-                t.has_pad = config.has_section("Buttons")
+                t.has_pad = any(config.has_section(s) for s in ["Buttons", "Keys"])
                 yield t