Add libevdev_event_value_get_name() to resolve ABS_MT_TOOL_TYPE values

ABS_MT_TOOL_TYPE values are an enum, not a numerical value like all other
axes. So let's allow converting those values to string.

Fixes https://gitlab.freedesktop.org/libevdev/libevdev/issues/1

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

diff --git a/libevdev/libevdev-names.c b/libevdev/libevdev-names.c
index ad318de..6d06df3 100644 (file)
--- a/libevdev/libevdev-names.c
+++ b/libevdev/libevdev-names.c
@@ -143,6 +143,29 @@ libevdev_event_code_from_name_n(unsigned int type, const char *name, size_t len)
 }
 
 LIBEVDEV_EXPORT int
+libevdev_event_value_from_name(unsigned int type, unsigned int code, const char *name)
+{
+       return libevdev_event_value_from_name_n(type, code, name, strlen(name));
+}
+
+LIBEVDEV_EXPORT int
+libevdev_event_value_from_name_n(unsigned int type, unsigned int code, const char *name, size_t len)
+{
+       struct name_lookup lookup;
+       const struct name_entry *entry;
+
+       if (type != EV_ABS || code != ABS_MT_TOOL_TYPE)
+               return -1;
+
+       lookup.name = name;
+       lookup.len = len;
+
+       entry = lookup_name(tool_type_names, ARRAY_LENGTH(tool_type_names), &lookup);
+
+       return entry ? (int)entry->value : -1;
+}
+
+LIBEVDEV_EXPORT int
 libevdev_property_from_name(const char *name)
 {
        return libevdev_property_from_name_n(name, strlen(name));

diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
index c6ec114..fab87cf 100644 (file)
--- a/libevdev/libevdev.c
+++ b/libevdev/libevdev.c
@@ -1613,6 +1613,23 @@ libevdev_event_code_get_name(unsigned int type, unsigned int code)
        return event_type_map[type][code];
 }
 
+LIBEVDEV_EXPORT const char *
+libevdev_event_value_get_name(unsigned int type,
+                             unsigned int code,
+                             int value)
+{
+       /* This is a simplified version because nothing else
+          is an enum like ABS_MT_TOOL_TYPE so we don't need
+          a generic lookup */
+       if (type != EV_ABS || code != ABS_MT_TOOL_TYPE)
+               return NULL;
+
+       if (value > MT_TOOL_MAX)
+               return NULL;
+
+       return mt_tool_map[value];
+}
+
 LIBEVDEV_EXPORT const char*
 libevdev_property_get_name(unsigned int prop)
 {

diff --git a/libevdev/libevdev.h b/libevdev/libevdev.h
index 4c516ad..f0f34bb 100644 (file)
--- a/libevdev/libevdev.h
+++ b/libevdev/libevdev.h
@@ -2022,6 +2022,29 @@ const char * libevdev_event_code_get_name(unsigned int type, unsigned int code);
 /**
  * @ingroup misc
  *
+ * This function resolves the event value for a code.
+ *
+ * For almost all event codes this will return NULL as the value is just a
+ * numerical value. As of kernel 4.17, the only event code that will return
+ * a non-NULL value is EV_ABS/ABS_MT_TOOL_TYPE.
+ *
+ * @param type The event type for the value to query (EV_ABS, etc.)
+ * @param code The event code for the value to query (e.g. ABS_MT_TOOL_TYPE)
+ * @param value The event value to return the name for (e.g. MT_TOOL_PALM)
+ *
+ * @return The name of the given event value (e.g. MT_TOOL_PALM) or NULL for
+ * an invalid type or code or NULL for an axis that has numerical values
+ * only.
+ *
+ * @note The list of names is compiled into libevdev. If the kernel adds new
+ * defines for new event values, libevdev will not automatically pick these up.
+ */
+const char * libevdev_event_value_get_name(unsigned int type,
+                                          unsigned int code,
+                                          int value);
+/**
+ * @ingroup misc
+ *
  * @param prop The input prop to return the name for (e.g. INPUT_PROP_BUTTONPAD)
  *
  * @return The name of the given input prop (e.g. INPUT_PROP_BUTTONPAD) or NULL for an
@@ -2130,6 +2153,56 @@ int libevdev_event_code_from_name_n(unsigned int type, const char *name,
 /**
  * @ingroup misc
  *
+ * Look up an event value by its type, code and name. Event values start
+ * with a fixed prefix followed by their name (eg., "MT_TOOL_PALM"). The
+ * prefix must be included in the name. It returns the constant assigned
+ * to the event code or -1 if not found.
+ *
+ * You have to pass the event type and code where to look for the name. For
+ * instance, to resolve "MT_TOOL_PALM" you need to pass EV_ABS as type,
+ * ABS_MT_TOOL_TYPE as code and "MT_TOOL_PALM" as string.
+ *
+ * As of kernel 4.17, only EV_ABS/ABS_MT_TOOL_TYPE support name resolution.
+ *
+ * @param type The event type (EV_* constant) where to look for the name.
+ * @param code The event code (ABS_* constant) where to look for the name.
+ * @param name A non-NULL string describing an input-event value
+ * ("MT_TOOL_TYPE", ...)
+ *
+ * @return The given value constant for the name or -1 if not found.
+ */
+int libevdev_event_value_from_name(unsigned int type, unsigned int code,
+                                  const char *name);
+
+/**
+ * @ingroup misc
+ *
+ * Look up an event value by its type, code and name. Event values start
+ * with a fixed prefix followed by their name (eg., "MT_TOOL_PALM"). The
+ * prefix must be included in the name. It returns the constant assigned
+ * to the event code or -1 if not found.
+ *
+ * You have to pass the event type and code where to look for the name. For
+ * instance, to resolve "MT_TOOL_PALM" you need to pass EV_ABS as type,
+ * ABS_MT_TOOL_TYPE as code and "MT_TOOL_PALM" as string.
+ *
+ * As of kernel 4.17, only EV_ABS/ABS_MT_TOOL_TYPE support name resolution.
+ *
+ * @param type The event type (EV_* constant) where to look for the name.
+ * @param code The event code (ABS_* constant) where to look for the name.
+ * @param name A non-NULL string describing an input-event value
+ * ("MT_TOOL_TYPE", ...)
+ * @param len The length of the string in @p name excluding any terminating 0
+ * character.
+ *
+ * @return The given value constant for the name or -1 if not found.
+ */
+int libevdev_event_value_from_name_n(unsigned int type, unsigned int code,
+                                    const char *name, size_t len);
+
+/**
+ * @ingroup misc
+ *
  * Look up an input property by its name. Properties start with the fixed
  * prefix "INPUT_PROP_" followed by their name (eg., "INPUT_PROP_POINTER").
  * The prefix must be included in the name. It returns the constant assigned

diff --git a/libevdev/libevdev.sym b/libevdev/libevdev.sym
index 374712f..7dd0c20 100644 (file)
--- a/libevdev/libevdev.sym
+++ b/libevdev/libevdev.sym
@@ -112,3 +112,12 @@ global:
 local:
        *;
 } LIBEVDEV_1;
+
+LIBEVDEV_1_6 {
+global:
+       libevdev_event_value_get_name;
+       libevdev_event_value_from_name;
+       libevdev_event_value_from_name_n;
+local:
+       *;
+} LIBEVDEV_1_3;

diff --git a/libevdev/make-event-names.py b/libevdev/make-event-names.py
index 38b44cf..8d572d0 100755 (executable)
--- a/libevdev/make-event-names.py
+++ b/libevdev/make-event-names.py
@@ -26,6 +26,7 @@ prefixes = [
                "SYN_",
                "REP_",
                "INPUT_PROP_",
+               "MT_TOOL_",
 ]
 
 duplicates = [
@@ -39,6 +40,7 @@ duplicates = [
                "BTN_TRIGGER_HAPPY",
                "SW_MAX",
                "REP_MAX",
+               "MT_TOOL_MAX",
 ]
 
 btn_additional = [
@@ -78,7 +80,7 @@ def print_map(bits):
        print("static const char * const * const event_type_map[EV_MAX + 1] = {")
 
        for prefix in prefixes:
-               if prefix in ["BTN_", "EV_", "INPUT_PROP_"]:
+               if prefix in ["BTN_", "EV_", "INPUT_PROP_", "MT_TOOL_"]:
                        continue
                print(" [EV_%s] = %s_map," % (prefix[:-1], prefix[:-1].lower()))
 
@@ -95,7 +97,7 @@ def print_map(bits):
        print("static const int ev_max[EV_MAX + 1] = {")
        print(" [0 ... EV_MAX] = -1,")
        for prefix in prefixes:
-               if prefix in ["BTN_", "EV_", "INPUT_PROP_"]:
+               if prefix in ["BTN_", "EV_", "INPUT_PROP_", "MT_TOOL_"]:
                        continue
                print(" [EV_%s] = %s_MAX," % (prefix[:-1], prefix[:-1]))
        print("};")
@@ -129,6 +131,10 @@ def print_lookup_table(bits):
        print(" unsigned int value;")
        print("};")
        print("")
+       print("static const struct name_entry tool_type_names[] = {")
+       print_lookup(bits, "mt_tool")
+       print("};")
+       print("")
        print("static const struct name_entry ev_names[] = {")
        print_lookup(bits, "ev")
        print("};")

diff --git a/test/test-event-codes.c b/test/test-event-codes.c
index 8b587d9..643b537 100644 (file)
--- a/test/test-event-codes.c
+++ b/test/test-event-codes.c
@@ -114,6 +114,28 @@ START_TEST(test_code_names_max)
 }
 END_TEST
 
+START_TEST(test_value_names)
+{
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_PALM"), MT_TOOL_PALM);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_FINGER"), MT_TOOL_FINGER);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_PEN"), MT_TOOL_PEN);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_MAX"), MT_TOOL_MAX);
+}
+END_TEST
+
+START_TEST(test_value_names_invalid)
+{
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_SYN, REL_X, "MT_TOOL_PALM"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_REL, REL_X, "MT_TOOL_PALM"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_X, "MT_TOOL_PALM"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "MT_TOOL_PALMA"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, ""), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "EV_ABS"), -1);
+       ck_assert_int_eq(libevdev_event_value_from_name(EV_ABS, ABS_MT_TOOL_TYPE, "ABS_X"), -1);
+}
+END_TEST
+
 START_TEST(test_properties)
 {
        struct prop {
@@ -161,6 +183,11 @@ TEST_SUITE(event_code_suite)
        tcase_add_test(tc, test_code_names_max);
        suite_add_tcase(s, tc);
 
+       tc = tcase_create("value tests");
+       tcase_add_test(tc, test_value_names);
+       tcase_add_test(tc, test_value_names_invalid);
+       suite_add_tcase(s, tc);
+
        tc = tcase_create("property tests");
        tcase_add_test(tc, test_properties);
        tcase_add_test(tc, test_properties_invalid);

diff --git a/test/test-event-names.c b/test/test-event-names.c
index 9ed23d0..0116fab 100644 (file)
--- a/test/test-event-names.c
+++ b/test/test-event-names.c
@@ -36,6 +36,7 @@ START_TEST(test_limits)
        ck_assert(libevdev_event_code_get_name(EV_REP, REP_MAX + 1) == NULL);
        ck_assert(libevdev_event_code_get_name(EV_FF, FF_MAX + 1) == NULL);
        ck_assert(libevdev_event_code_get_name(EV_MAX + 1, 0) == NULL);
+       ck_assert(libevdev_event_value_get_name(EV_ABS, ABS_MT_TOOL_TYPE, MT_TOOL_MAX + 1) == NULL);
 }
 END_TEST
 
@@ -201,6 +202,35 @@ START_TEST(test_code_syn_name)
 }
 END_TEST
 
+START_TEST(test_value_name)
+{
+       unsigned int type, code;
+       int value;
+
+       for (type = 0; type < EV_MAX; type++) {
+               int max = libevdev_event_type_get_max(type);
+
+               if (max == -1)
+                       continue;
+
+               for (code = 0; code < (unsigned int)max; code++) {
+                       if (type == EV_ABS && code == ABS_MT_TOOL_TYPE)
+                               continue;
+
+                       for (value = 0; value < 0xff; value++) {
+                               ck_assert(libevdev_event_value_get_name(type, code, value) == NULL);
+                       }
+               }
+       }
+
+       ck_assert_str_eq(libevdev_event_value_get_name(EV_ABS, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER), "MT_TOOL_FINGER");
+       ck_assert_str_eq(libevdev_event_value_get_name(EV_ABS, ABS_MT_TOOL_TYPE, MT_TOOL_PALM), "MT_TOOL_PALM");
+       ck_assert_str_eq(libevdev_event_value_get_name(EV_ABS, ABS_MT_TOOL_TYPE, MT_TOOL_PEN), "MT_TOOL_PEN");
+       /* overlapping value */
+       ck_assert_str_eq(libevdev_event_value_get_name(EV_ABS, ABS_MT_TOOL_TYPE, MT_TOOL_MAX), "MT_TOOL_PALM");
+}
+END_TEST
+
 START_TEST(test_prop_name)
 {
        ck_assert_str_eq(libevdev_property_get_name(INPUT_PROP_POINTER), "INPUT_PROP_POINTER");
@@ -297,6 +327,10 @@ TEST_SUITE(event_name_suite)
        tcase_add_test(tc, test_code_syn_name);
        suite_add_tcase(s, tc);
 
+       tc = tcase_create("value names");
+       tcase_add_test(tc, test_value_name);
+       suite_add_tcase(s, tc);
+
        tc = tcase_create("prop names");
        tcase_add_test(tc, test_prop_name);
        suite_add_tcase(s, tc);