backend/libinput: Manage tablet tool livetimes

This adds the management code to manage tablet tools lifetimes from
libinput.
It follows the suggestion made in the tablet-unstable-v2.xml to destroy
tablet_tools once all tablets that it got into contact with were removed
from the system. This is implemented via a refcount.

If a tool is *not* unique, it will be destroyed on proximity out. This
is libinput specific and mentioned in libinput docs that tools will not
be found again, so we shouldn't keep a reference to them.
Also they can't be on other tablets as well, because they cannot be
tracked.

The naming in this commit is a bit off (to not break things).
The wlr names stay the same, tablet_tool is the libinput_device with
capaiblity LIBINPUT_DEVICE_CAP_TABLET_TOOL which is more akin to
"tablet" in the tablet-unstable-v2 protocol.
The struct that corresponds to the tablet_tool in tablet-unstable-v2 is
called tablet_tool_tool, a rename should be done at some point in the
future.

2 files changed, 41 insertions, 0 deletions

diff --git a/include/backend/libinput.h b/include/backend/libinput.h
index f0928133..6ecdf44f 100644
--- a/include/backend/libinput.h
+++ b/include/backend/libinput.h
@@ -67,6 +67,7 @@ void handle_touch_cancel(struct libinput_event *event,
 
 struct wlr_tablet_tool *create_libinput_tablet_tool(
 		struct libinput_device *device);
+void wlr_libinput_tablet_tool_destroy(struct wlr_input_device *device);
 void handle_tablet_tool_axis(struct libinput_event *event,
 		struct libinput_device *device);
 void handle_tablet_tool_proximity(struct libinput_event *event,
diff --git a/include/wlr/types/wlr_tablet_tool.h b/include/wlr/types/wlr_tablet_tool.h
index 22bf2649..08d37f68 100644
--- a/include/wlr/types/wlr_tablet_tool.h
+++ b/include/wlr/types/wlr_tablet_tool.h
@@ -5,6 +5,41 @@
 #include <wayland-server.h>
 #include <wlr/types/wlr_input_device.h>
 
+/*
+ * Copy+Paste from libinput, but this should neither use libinput, nor
+ * tablet-unstable-v2 headers, so we can't include them
+ */
+enum wlr_tablet_tool_type {
+	WLR_TABLET_TOOL_TYPE_PEN = 1,	/**< A generic pen */
+	WLR_TABLET_TOOL_TYPE_ERASER,	/**< Eraser */
+	WLR_TABLET_TOOL_TYPE_BRUSH,	/**< A paintbrush-like tool */
+	WLR_TABLET_TOOL_TYPE_PENCIL,	/**< Physical drawing tool, e.g.
+				             Wacom Inking Pen */
+	WLR_TABLET_TOOL_TYPE_AIRBRUSH,	/**< An airbrush-like tool */
+	WLR_TABLET_TOOL_TYPE_MOUSE,	/**< A mouse bound to the tablet */
+	WLR_TABLET_TOOL_TYPE_LENS,		/**< A mouse tool with a lens */
+};
+
+struct wlr_tablet_tool_tool {
+	enum wlr_tablet_tool_type type;
+	uint64_t hardware_serial;
+	uint64_t hardware_wacom;
+
+	// Capabilities
+	bool tilt;
+	bool pressure;
+	bool distance;
+	bool rotation;
+	bool slider;
+	bool wheel;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+	
+	void *data;
+};
+
 struct wlr_tablet_tool_impl;
 
 struct wlr_tablet_tool {
@@ -34,6 +69,8 @@ enum wlr_tablet_tool_axes {
 
 struct wlr_event_tablet_tool_axis {
 	struct wlr_input_device *device;
+	struct wlr_tablet_tool_tool *tool;
+
 	uint32_t time_msec;
 	uint32_t updated_axes;
 	// From 0..1
@@ -53,6 +90,7 @@ enum wlr_tablet_tool_proximity_state {
 
 struct wlr_event_tablet_tool_proximity {
 	struct wlr_input_device *device;
+	struct wlr_tablet_tool_tool *tool;
 	uint32_t time_msec;
 	// From 0..1
 	double x, y;
@@ -66,6 +104,7 @@ enum wlr_tablet_tool_tip_state {
 
 struct wlr_event_tablet_tool_tip {
 	struct wlr_input_device *device;
+	struct wlr_tablet_tool_tool *tool;
 	uint32_t time_msec;
 	// From 0..1
 	double x, y;
@@ -74,6 +113,7 @@ struct wlr_event_tablet_tool_tip {
 
 struct wlr_event_tablet_tool_button {
 	struct wlr_input_device *device;
+	struct wlr_tablet_tool_tool *tool;
 	uint32_t time_msec;
 	uint32_t button;
 	enum wlr_button_state state;