backend/libinput: rework tablet interface

The wlr_libinput_device owns its wlr_tablet and its associated wlr_tablet_tools

3 files changed, 106 insertions, 206 deletions

diff --git a/backend/libinput/backend.c b/backend/libinput/backend.c
index 2e26a269..111ebf3e 100644
--- a/backend/libinput/backend.c
+++ b/backend/libinput/backend.c
@@ -252,6 +252,9 @@ struct libinput_device *wlr_libinput_get_device_handle(
 	case WLR_INPUT_DEVICE_TOUCH:
 		dev = device_from_touch(wlr_dev->touch);
 		break;
+	case WLR_INPUT_DEVICE_TABLET_TOOL:
+		dev = device_from_tablet(wlr_dev->tablet);
+		break;
 	default:
 		dev = (struct wlr_libinput_input_device *)wlr_dev;
 		break;
diff --git a/backend/libinput/events.c b/backend/libinput/events.c
index 14678dbd..76e7709c 100644
--- a/backend/libinput/events.c
+++ b/backend/libinput/events.c
@@ -49,6 +49,9 @@ void destroy_libinput_input_device(struct wlr_libinput_input_device *dev)
 		if (dev->touch.impl) {
 			wlr_touch_destroy(&dev->touch);
 		}
+		if (dev->tablet.impl) {
+			wlr_tablet_destroy(&dev->tablet);
+		}
 	}
 
 	libinput_device_unref(dev->handle);
@@ -162,6 +165,14 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 		dev_used = true;
 	}
 
+	if (libinput_device_has_capability(libinput_dev,
+			LIBINPUT_DEVICE_CAP_TABLET_TOOL)) {
+		init_device_tablet(dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input,
+			&dev->tablet.base);
+		dev_used = true;
+	}
+
 	if (dev_used) {
 		wl_list_insert(&backend->devices, &dev->link);
 		return;
@@ -177,20 +188,6 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 	}
 	wl_list_init(wlr_devices);
 
-	if (libinput_device_has_capability(libinput_dev,
-			LIBINPUT_DEVICE_CAP_TABLET_TOOL)) {
-		struct wlr_input_device *wlr_dev = allocate_device(backend,
-				libinput_dev, wlr_devices, WLR_INPUT_DEVICE_TABLET_TOOL);
-		if (!wlr_dev) {
-			goto fail;
-		}
-		wlr_dev->tablet = create_libinput_tablet(libinput_dev);
-		if (!wlr_dev->tablet) {
-			free(wlr_dev);
-			goto fail;
-		}
-		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
-	}
 	if (libinput_device_has_capability(
 			libinput_dev, LIBINPUT_DEVICE_CAP_TABLET_PAD)) {
 		struct wlr_input_device *wlr_dev = allocate_device(backend,
@@ -316,16 +313,16 @@ void handle_libinput_event(struct wlr_libinput_backend *backend,
 		handle_touch_frame(event, &dev->touch);
 		break;
 	case LIBINPUT_EVENT_TABLET_TOOL_AXIS:
-		handle_tablet_tool_axis(event, libinput_dev);
+		handle_tablet_tool_axis(event, &dev->tablet);
 		break;
 	case LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY:
-		handle_tablet_tool_proximity(event, libinput_dev);
+		handle_tablet_tool_proximity(event, &dev->tablet);
 		break;
 	case LIBINPUT_EVENT_TABLET_TOOL_TIP:
-		handle_tablet_tool_tip(event, libinput_dev);
+		handle_tablet_tool_tip(event, &dev->tablet);
 		break;
 	case LIBINPUT_EVENT_TABLET_TOOL_BUTTON:
-		handle_tablet_tool_button(event, libinput_dev);
+		handle_tablet_tool_button(event, &dev->tablet);
 		break;
 	case LIBINPUT_EVENT_TABLET_PAD_BUTTON:
 		handle_tablet_pad_button(event, libinput_dev);
diff --git a/backend/libinput/tablet_tool.c b/backend/libinput/tablet_tool.c
index 373f87d7..af212218 100644
--- a/backend/libinput/tablet_tool.c
+++ b/backend/libinput/tablet_tool.c
@@ -1,92 +1,60 @@
-#ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200809L
-#endif
 #include <string.h>
 #include <assert.h>
 #include <libinput.h>
 #include <stdlib.h>
-#include <wayland-util.h>
-#include <wlr/backend/session.h>
 #include <wlr/interfaces/wlr_tablet_tool.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
-#include "util/array.h"
 #include "util/signal.h"
 
-static bool tablet_is_libinput(struct wlr_tablet *tablet) {
-	return tablet->impl == &libinput_tablet_impl;
-}
-
-struct wlr_libinput_tablet_tool {
+struct tablet_tool {
 	struct wlr_tablet_tool wlr_tool;
-
-	struct libinput_tablet_tool *libinput_tool;
-
-	bool unique;
-	// Refcount for destroy + release
-	size_t pad_refs;
+	struct libinput_tablet_tool *handle;
+	struct wl_list link; // wlr_libinput_input_device::tablet_tools
 };
 
-struct wlr_libinput_tablet {
-	struct wlr_tablet wlr_tablet;
-	struct wl_array tools; // struct wlr_libinput_tablet_tool *
-};
-
-static void destroy_tool(struct wlr_libinput_tablet_tool *tool) {
+static void tool_destroy(struct tablet_tool *tool) {
 	wlr_signal_emit_safe(&tool->wlr_tool.events.destroy, &tool->wlr_tool);
-	libinput_tablet_tool_ref(tool->libinput_tool);
-	libinput_tablet_tool_set_user_data(tool->libinput_tool, NULL);
+	libinput_tablet_tool_unref(tool->handle);
+	libinput_tablet_tool_set_user_data(tool->handle, NULL);
+	wl_list_remove(&tool->link);
 	free(tool);
 }
 
-static void destroy_tablet(struct wlr_tablet *wlr_tablet) {
-	assert(tablet_is_libinput(wlr_tablet));
-	struct wlr_libinput_tablet *tablet =
-		wl_container_of(wlr_tablet, tablet, wlr_tablet);
-
-	struct wlr_libinput_tablet_tool **tool_ptr;
-	wl_array_for_each(tool_ptr, &tablet->tools) {
-		struct wlr_libinput_tablet_tool *tool = *tool_ptr;
-		if (--tool->pad_refs == 0) {
-			destroy_tool(tool);
-		}
+static void tablet_destroy(struct wlr_tablet *wlr_tablet) {
+	struct wlr_libinput_input_device *dev = device_from_tablet(wlr_tablet);
+	struct tablet_tool *tool, *tmp;
+	wl_list_for_each_safe(tool, tmp, &dev->tablet_tools, link) {
+		tool_destroy(tool);
 	}
-	wl_array_release(&tablet->tools);
-
-	free(tablet);
 }
 
 const struct wlr_tablet_impl libinput_tablet_impl = {
-	.destroy = destroy_tablet,
+	.destroy = tablet_destroy,
 };
 
-struct wlr_tablet *create_libinput_tablet(
-		struct libinput_device *libinput_dev) {
-	assert(libinput_dev);
-	struct wlr_libinput_tablet *libinput_tablet =
-		calloc(1, sizeof(struct wlr_libinput_tablet));
-	if (!libinput_tablet) {
-		wlr_log(WLR_ERROR, "Unable to allocate wlr_tablet_tool");
-		return NULL;
-	}
-
-	struct wlr_tablet *wlr_tablet = &libinput_tablet->wlr_tablet;
-	const char *name = libinput_device_get_name(libinput_dev);
-
+void init_device_tablet(struct wlr_libinput_input_device *dev) {
+	const char *name = libinput_device_get_name(dev->handle);
+	struct wlr_tablet *wlr_tablet = &dev->tablet;
 	wlr_tablet_init(wlr_tablet, &libinput_tablet_impl, name);
-	wlr_tablet->base.vendor = libinput_device_get_id_vendor(libinput_dev);
-	wlr_tablet->base.product = libinput_device_get_id_product(libinput_dev);
+	wlr_tablet->base.vendor = libinput_device_get_id_vendor(dev->handle);
+	wlr_tablet->base.product = libinput_device_get_id_product(dev->handle);
 
-	struct udev_device *udev = libinput_device_get_udev_device(libinput_dev);
+	struct udev_device *udev = libinput_device_get_udev_device(dev->handle);
 	char **dst = wl_array_add(&wlr_tablet->paths, sizeof(char *));
 	*dst = strdup(udev_device_get_syspath(udev));
 
-	wlr_tablet->name = strdup(libinput_device_get_name(libinput_dev));
+	wl_list_init(&dev->tablet_tools);
+}
 
-	wl_array_init(&libinput_tablet->tools);
+struct wlr_libinput_input_device *device_from_tablet(
+		struct wlr_tablet *wlr_tablet) {
+	assert(wlr_tablet->impl == &libinput_tablet_impl);
 
-	return wlr_tablet;
+	struct wlr_libinput_input_device *dev =
+		wl_container_of(wlr_tablet, dev, tablet);
+	return dev;
 }
 
 static enum wlr_tablet_tool_type wlr_type_from_libinput_type(
@@ -112,87 +80,55 @@ static enum wlr_tablet_tool_type wlr_type_from_libinput_type(
 	abort(); // unreachable
 }
 
-static struct wlr_libinput_tablet_tool *get_wlr_tablet_tool(
-		struct libinput_tablet_tool *tool) {
-	struct wlr_libinput_tablet_tool *ret =
-		libinput_tablet_tool_get_user_data(tool);
-
-	if (ret) {
-		return ret;
+static struct tablet_tool *get_tablet_tool(
+		struct wlr_libinput_input_device *dev,
+		struct libinput_tablet_tool *libinput_tool) {
+	struct tablet_tool *tool =
+		libinput_tablet_tool_get_user_data(libinput_tool);
+	if (tool) {
+		return tool;
 	}
 
-	ret = calloc(1, sizeof(struct wlr_libinput_tablet_tool));
-	if (!ret) {
+	tool = calloc(1, sizeof(struct tablet_tool));
+	if (tool == NULL) {
+		wlr_log_errno(WLR_ERROR, "failed to allocate wlr_libinput_tablet_tool");
 		return NULL;
 	}
 
-	ret->libinput_tool = libinput_tablet_tool_ref(tool);
-	ret->wlr_tool.pressure = libinput_tablet_tool_has_pressure(tool);
-	ret->wlr_tool.distance = libinput_tablet_tool_has_distance(tool);
-	ret->wlr_tool.tilt = libinput_tablet_tool_has_tilt(tool);
-	ret->wlr_tool.rotation = libinput_tablet_tool_has_rotation(tool);
-	ret->wlr_tool.slider = libinput_tablet_tool_has_slider(tool);
-	ret->wlr_tool.wheel = libinput_tablet_tool_has_wheel(tool);
+	tool->wlr_tool.type = wlr_type_from_libinput_type(
+		libinput_tablet_tool_get_type(libinput_tool));
+	tool->wlr_tool.hardware_serial =
+		libinput_tablet_tool_get_serial(libinput_tool);
+	tool->wlr_tool.hardware_wacom =
+		libinput_tablet_tool_get_tool_id(libinput_tool);
 
-	ret->wlr_tool.hardware_serial = libinput_tablet_tool_get_serial(tool);
-	ret->wlr_tool.hardware_wacom = libinput_tablet_tool_get_tool_id(tool);
-	ret->wlr_tool.type = wlr_type_from_libinput_type(
-		libinput_tablet_tool_get_type(tool));
+	tool->wlr_tool.pressure = libinput_tablet_tool_has_pressure(libinput_tool);
+	tool->wlr_tool.distance = libinput_tablet_tool_has_distance(libinput_tool);
+	tool->wlr_tool.tilt = libinput_tablet_tool_has_tilt(libinput_tool);
+	tool->wlr_tool.rotation = libinput_tablet_tool_has_rotation(libinput_tool);
+	tool->wlr_tool.slider = libinput_tablet_tool_has_slider(libinput_tool);
+	tool->wlr_tool.wheel = libinput_tablet_tool_has_wheel(libinput_tool);
 
-	ret->unique = libinput_tablet_tool_is_unique(tool);
+	wl_signal_init(&tool->wlr_tool.events.destroy);
 
-	wl_signal_init(&ret->wlr_tool.events.destroy);
+	tool->handle = libinput_tablet_tool_ref(libinput_tool);
+	libinput_tablet_tool_set_user_data(libinput_tool, tool);
 
-	libinput_tablet_tool_set_user_data(tool, ret);
-	return ret;
-}
-
-static void ensure_tool_reference(struct wlr_libinput_tablet_tool *tool,
-		struct wlr_tablet *wlr_dev) {
-	assert(tablet_is_libinput(wlr_dev));
-	struct wlr_libinput_tablet *tablet =
-		wl_container_of(wlr_dev, tablet, wlr_tablet);
-
-	struct wlr_libinput_tablet_tool **tool_ptr;
-	wl_array_for_each(tool_ptr, &tablet->tools) {
-		if (*tool_ptr == tool) { // We already have a ref
-			// XXX: We *could* optimize the tool to the front of
-			// the list here, since we will probably get the next
-			// couple of events from the same tool.
-			// BUT the list should always be rather short (probably
-			// single digit amount of tools) so it might be more
-			// work than it saves
-			return;
-		}
-	}
-
-	struct wlr_libinput_tablet_tool **dst =
-		wl_array_add(&tablet->tools, sizeof(tool));
-	if (!dst) {
-		wlr_log(WLR_ERROR, "Failed to allocate memory for tracking tablet tool");
-		return;
-	}
-	*dst = tool;
-	++tool->pad_refs;
+	wl_list_insert(&dev->tablet_tools, &tool->link);
+	return tool;
 }
 
 void handle_tablet_tool_axis(struct libinput_event *event,
-		struct libinput_device *libinput_dev) {
-	struct wlr_input_device *wlr_dev =
-		get_appropriate_device(WLR_INPUT_DEVICE_TABLET_TOOL, libinput_dev);
-	if (!wlr_dev) {
-		wlr_log(WLR_DEBUG,
-			"Got a tablet tool event for a device with no tablet tools?");
-		return;
-	}
+		struct wlr_tablet *wlr_tablet) {
 	struct libinput_event_tablet_tool *tevent =
 		libinput_event_get_tablet_tool_event(event);
+	struct wlr_libinput_input_device *dev = device_from_tablet(wlr_tablet);
+	struct tablet_tool *tool =
+		get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));
+
 	struct wlr_event_tablet_tool_axis wlr_event = { 0 };
-	struct wlr_libinput_tablet_tool *tool = get_wlr_tablet_tool(
-		libinput_event_tablet_tool_get_tool(tevent));
-	ensure_tool_reference(tool, wlr_dev->tablet);
 
-	wlr_event.device = wlr_dev;
+	wlr_event.device = &wlr_tablet->base;
 	wlr_event.tool = &tool->wlr_tool;
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent));
@@ -234,27 +170,20 @@ void handle_tablet_tool_axis(struct libinput_event *event,
 		wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_WHEEL;
 		wlr_event.wheel_delta = libinput_event_tablet_tool_get_wheel_delta(tevent);
 	}
-	wlr_signal_emit_safe(&wlr_dev->tablet->events.axis, &wlr_event);
+	wlr_signal_emit_safe(&wlr_tablet->events.axis, &wlr_event);
 }
 
 void handle_tablet_tool_proximity(struct libinput_event *event,
-		struct libinput_device *libinput_dev) {
-	struct wlr_input_device *wlr_dev =
-		get_appropriate_device(WLR_INPUT_DEVICE_TABLET_TOOL, libinput_dev);
-	if (!wlr_dev) {
-		wlr_log(WLR_DEBUG,
-			"Got a tablet tool event for a device with no tablet tools?");
-		return;
-	}
+		struct wlr_tablet *wlr_tablet) {
 	struct libinput_event_tablet_tool *tevent =
 		libinput_event_get_tablet_tool_event(event);
-	struct wlr_event_tablet_tool_proximity wlr_event = { 0 };
-	struct wlr_libinput_tablet_tool *tool = get_wlr_tablet_tool(
-		libinput_event_tablet_tool_get_tool(tevent));
-	ensure_tool_reference(tool, wlr_dev->tablet);
+	struct wlr_libinput_input_device *dev = device_from_tablet(wlr_tablet);
+	struct tablet_tool *tool =
+		get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));
 
+	struct wlr_event_tablet_tool_proximity wlr_event = { 0 };
 	wlr_event.tool = &tool->wlr_tool;
-	wlr_event.device = wlr_dev;
+	wlr_event.device = &wlr_tablet->base;
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent));
 	wlr_event.x = libinput_event_tablet_tool_get_x_transformed(tevent, 1);
@@ -268,56 +197,34 @@ void handle_tablet_tool_proximity(struct libinput_event *event,
 		wlr_event.state = WLR_TABLET_TOOL_PROXIMITY_IN;
 		break;
 	}
-	wlr_signal_emit_safe(&wlr_dev->tablet->events.proximity, &wlr_event);
+	wlr_signal_emit_safe(&wlr_tablet->events.proximity, &wlr_event);
 
 	if (libinput_event_tablet_tool_get_proximity_state(tevent) ==
 			LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN) {
-		handle_tablet_tool_axis(event, libinput_dev);
+		handle_tablet_tool_axis(event, wlr_tablet);
 	}
 
 	// If the tool is not unique, libinput will not find it again after the
 	// proximity out, so we should destroy it
-	if (!tool->unique &&
-			libinput_event_tablet_tool_get_proximity_state(tevent) ==
+	if (!libinput_tablet_tool_is_unique(tool->handle)
+			&& libinput_event_tablet_tool_get_proximity_state(tevent) ==
 			LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT) {
 		// The tool isn't unique, it can't be on multiple tablets
-		assert(tool->pad_refs == 1);
-		assert(tablet_is_libinput(wlr_dev->tablet));
-		struct wlr_libinput_tablet *tablet =
-			wl_container_of(wlr_dev->tablet, tablet, wlr_tablet);
-
-		size_t i = 0;
-		struct wlr_libinput_tablet_tool **tool_ptr;
-		wl_array_for_each(tool_ptr, &tablet->tools) {
-			if (*tool_ptr == tool) {
-				array_remove_at(&tablet->tools, i * sizeof(tool), sizeof(tool));
-				break;
-			}
-			i++;
-		}
-
-		destroy_tool(tool);
+		tool_destroy(tool);
 	}
 }
 
 void handle_tablet_tool_tip(struct libinput_event *event,
-		struct libinput_device *libinput_dev) {
-	struct wlr_input_device *wlr_dev =
-		get_appropriate_device(WLR_INPUT_DEVICE_TABLET_TOOL, libinput_dev);
-	if (!wlr_dev) {
-		wlr_log(WLR_DEBUG,
-			"Got a tablet tool event for a device with no tablet tools?");
-		return;
-	}
-	handle_tablet_tool_axis(event, libinput_dev);
+		struct wlr_tablet *wlr_tablet) {
+	handle_tablet_tool_axis(event, wlr_tablet);
 	struct libinput_event_tablet_tool *tevent =
 		libinput_event_get_tablet_tool_event(event);
-	struct wlr_event_tablet_tool_tip wlr_event = { 0 };
-	struct wlr_libinput_tablet_tool *tool = get_wlr_tablet_tool(
-		libinput_event_tablet_tool_get_tool(tevent));
-	ensure_tool_reference(tool, wlr_dev->tablet);
+	struct wlr_libinput_input_device *dev = device_from_tablet(wlr_tablet);
+	struct tablet_tool *tool =
+		get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));
 
-	wlr_event.device = wlr_dev;
+	struct wlr_event_tablet_tool_tip wlr_event = { 0 };
+	wlr_event.device = &wlr_tablet->base;
 	wlr_event.tool = &tool->wlr_tool;
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent));
@@ -332,27 +239,20 @@ void handle_tablet_tool_tip(struct libinput_event *event,
 		wlr_event.state = WLR_TABLET_TOOL_TIP_DOWN;
 		break;
 	}
-	wlr_signal_emit_safe(&wlr_dev->tablet->events.tip, &wlr_event);
+	wlr_signal_emit_safe(&wlr_tablet->events.tip, &wlr_event);
 }
 
 void handle_tablet_tool_button(struct libinput_event *event,
-		struct libinput_device *libinput_dev) {
-	struct wlr_input_device *wlr_dev =
-		get_appropriate_device(WLR_INPUT_DEVICE_TABLET_TOOL, libinput_dev);
-	if (!wlr_dev) {
-		wlr_log(WLR_DEBUG,
-			"Got a tablet tool event for a device with no tablet tools?");
-		return;
-	}
-	handle_tablet_tool_axis(event, libinput_dev);
+		struct wlr_tablet *wlr_tablet) {
+	handle_tablet_tool_axis(event, wlr_tablet);
 	struct libinput_event_tablet_tool *tevent =
 		libinput_event_get_tablet_tool_event(event);
-	struct wlr_event_tablet_tool_button wlr_event = { 0 };
-	struct wlr_libinput_tablet_tool *tool = get_wlr_tablet_tool(
-		libinput_event_tablet_tool_get_tool(tevent));
-	ensure_tool_reference(tool, wlr_dev->tablet);
+	struct wlr_libinput_input_device *dev = device_from_tablet(wlr_tablet);
+	struct tablet_tool *tool =
+		get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));
 
-	wlr_event.device = wlr_dev;
+	struct wlr_event_tablet_tool_button wlr_event = { 0 };
+	wlr_event.device = &wlr_tablet->base;
 	wlr_event.tool = &tool->wlr_tool;
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent));
@@ -365,5 +265,5 @@ void handle_tablet_tool_button(struct libinput_event *event,
 		wlr_event.state = WLR_BUTTON_PRESSED;
 		break;
 	}
-	wlr_signal_emit_safe(&wlr_dev->tablet->events.button, &wlr_event);
+	wlr_signal_emit_safe(&wlr_tablet->events.button, &wlr_event);
 }