Add the libinput_tool object

This will be used to represent a tool in use on a drawing tablet.

Signed-off-by: Stephen Chandler Paul <thatslyude@gmail.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

src/libinput-private.h

@@ -85,6 +85,13 @@ struct libinput_device {
 	int refcount;
 };
 
+struct libinput_tool {
+	struct list link;
+	uint32_t serial;
+	enum libinput_tool_type type;
+	int refcount;
+};
+
 typedef void (*libinput_source_dispatch_t)(void *data);
 
 

src/libinput.c

@@ -515,6 +515,35 @@ libinput_event_tablet_get_time(struct libinput_event_tablet *event)
 	return event->time;
 }
 
+LIBINPUT_EXPORT enum libinput_tool_type
+libinput_tool_get_type(struct libinput_tool *tool)
+{
+	return tool->type;
+}
+
+LIBINPUT_EXPORT uint32_t
+libinput_tool_get_serial(struct libinput_tool *tool)
+{
+	return tool->serial;
+}
+
+LIBINPUT_EXPORT void
+libinput_tool_ref(struct libinput_tool *tool)
+{
+	tool->refcount++;
+}
+
+LIBINPUT_EXPORT void
+libinput_tool_unref(struct libinput_tool *tool)
+{
+	assert(tool->refcount > 0);
+
+	if (--tool->refcount == 0) {
+		list_remove(&tool->link);
+		free(tool);
+	}
+}
+
 struct libinput_source *
 libinput_add_fd(struct libinput *libinput,
 		int fd,

src/libinput.h

@@ -182,6 +182,32 @@ enum libinput_tablet_axis {
 	LIBINPUT_TABLET_AXIS_CNT = LIBINPUT_TABLET_AXIS_Y + 1
 };
 
+/**
+ * @ingroup device
+ *
+ * An object representing a tool being used by the device. It must have the @ref
+ * LIBINPUT_DEVICE_CAP_TABLET capability.
+ */
+struct libinput_tool;
+
+/**
+ * @ingroup device
+ *
+ * Available tool types for a device. It must have the @ref
+ * LIBINPUT_DEVICE_CAP_TABLET capability.
+ */
+enum libinput_tool_type {
+	LIBINPUT_TOOL_NONE = -1,
+	LIBINPUT_TOOL_PEN = 0x140, /* Matches BTN_TOOL_PEN */
+	LIBINPUT_TOOL_ERASER,
+	LIBINPUT_TOOL_BRUSH,
+	LIBINPUT_TOOL_PENCIL,
+	LIBINPUT_TOOL_AIRBRUSH,
+	LIBINPUT_TOOL_FINGER,
+	LIBINPUT_TOOL_MOUSE,
+	LIBINPUT_TOOL_LENS
+};
+
 /**
  * @ingroup base
  *
@@ -874,6 +900,53 @@ libinput_event_tablet_get_y_transformed(struct libinput_event_tablet *event,
 uint32_t
 libinput_event_tablet_get_time(struct libinput_event_tablet *event);
 
+/**
+ * @ingroup event_tablet
+ *
+ * Return the type of tool type for a tool object
+ *
+ * @param tool The libinput tool
+ * @return The tool type for this tool object
+ */
+enum libinput_tool_type
+libinput_tool_get_type(struct libinput_tool *tool);
+
+/**
+ * @ingroup event_tablet
+ *
+ * Increment the ref count of tool by one
+ *
+ * @param tool The tool to increment the ref count of
+ */
+void
+libinput_tool_ref(struct libinput_tool *tool);
+
+/**
+ * @ingroup event_tablet
+ *
+ * Decrement the ref count of tool by one. When the ref count of tool reaches 0,
+ * the memory allocated for tool will be freed.
+ *
+ * @param tool The tool to decrement the ref count of
+ */
+void
+libinput_tool_unref(struct libinput_tool *tool);
+
+/**
+ * @ingroup event_tablet
+ *
+ * Return the serial number of a tool
+ *
+ * @note Not all tablets report a serial number along with the type of tool
+ * being used. If the hardware does not provide a unique serial number, the
+ * serial number is always 0.
+ *
+ * @param tool The libinput tool
+ * @return The new tool serial triggering this event
+ */
+uint32_t
+libinput_tool_get_serial(struct libinput_tool *tool);
+
 /**
  * @defgroup base Initialization and manipulation of libinput contexts
  */