path: root/dwl-patches/patches/tablet-input/tablet-input.patch

From 0659663b7eb9cafbd4f86779084765aa838e29cd Mon Sep 17 00:00:00 2001
From: A Frederick Christensen <dwl@ivories.org>
Date: Sat, 17 May 2025 23:26:15 -0500
Subject: [PATCH] Add tablet input

---
 Makefile     |   6 +-
 config.def.h |   1 +
 dwl.c        | 231 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 578194f..e0d1835 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,8 @@ dwl: dwl.o util.o
 	$(CC) dwl.o util.o $(DWLCFLAGS) $(LDFLAGS) $(LDLIBS) -o $@
 dwl.o: dwl.c client.h config.h config.mk cursor-shape-v1-protocol.h \
 	pointer-constraints-unstable-v1-protocol.h wlr-layer-shell-unstable-v1-protocol.h \
-	wlr-output-power-management-unstable-v1-protocol.h xdg-shell-protocol.h
+	wlr-output-power-management-unstable-v1-protocol.h xdg-shell-protocol.h \
+	tablet-v2-protocol.h
 util.o: util.c util.h
 
 # wayland-scanner is a tool which generates C headers and rigging for Wayland
@@ -45,6 +46,9 @@ wlr-output-power-management-unstable-v1-protocol.h:
 xdg-shell-protocol.h:
 	$(WAYLAND_SCANNER) server-header \
 		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
+tablet-v2-protocol.h:
+	$(WAYLAND_SCANNER) server-header \
+		$(WAYLAND_PROTOCOLS)/unstable/tablet/tablet-unstable-v2.xml $@
 
 config.h:
 	cp config.def.h $@
diff --git a/config.def.h b/config.def.h
index 22d2171..3ad98ef 100644
--- a/config.def.h
+++ b/config.def.h
@@ -4,6 +4,7 @@
                         ((hex >> 8) & 0xFF) / 255.0f, \
                         (hex & 0xFF) / 255.0f }
 /* appearance */
+static const int tabletmaptosurface        = 0;  /* map tablet input to surface(1) or monitor(0) */
 static const int sloppyfocus               = 1;  /* focus follows mouse */
 static const int bypass_surface_visibility = 0;  /* 1 means idle inhibitors will disable idle tracking even if it's surface isn't visible  */
 static const unsigned int borderpx         = 1;  /* border pixel of windows */
diff --git a/dwl.c b/dwl.c
index 4816159..e8d36ac 100644
--- a/dwl.c
+++ b/dwl.c
@@ -51,6 +51,9 @@
 #include <wlr/types/wlr_session_lock_v1.h>
 #include <wlr/types/wlr_single_pixel_buffer_v1.h>
 #include <wlr/types/wlr_subcompositor.h>
+#include <wlr/types/wlr_tablet_tool.h>
+#include <wlr/types/wlr_tablet_pad.h>
+#include <wlr/types/wlr_tablet_v2.h>
 #include <wlr/types/wlr_viewporter.h>
 #include <wlr/types/wlr_virtual_keyboard_v1.h>
 #include <wlr/types/wlr_virtual_pointer_v1.h>
@@ -268,6 +271,7 @@ static void createnotify(struct wl_listener *listener, void *data);
 static void createpointer(struct wlr_pointer *pointer);
 static void createpointerconstraint(struct wl_listener *listener, void *data);
 static void createpopup(struct wl_listener *listener, void *data);
+static void createtablet(struct wlr_input_device *device);
 static void cursorconstrain(struct wlr_pointer_constraint_v1 *constraint);
 static void cursorframe(struct wl_listener *listener, void *data);
 static void cursorwarptohint(void);
@@ -281,6 +285,9 @@ static void destroynotify(struct wl_listener *listener, void *data);
 static void destroypointerconstraint(struct wl_listener *listener, void *data);
 static void destroysessionlock(struct wl_listener *listener, void *data);
 static void destroykeyboardgroup(struct wl_listener *listener, void *data);
+static void destroytablet(struct wl_listener *listener, void *data);
+static void destroytabletsurfacenotify(struct wl_listener *listener, void *data);
+static void destroytablettool(struct wl_listener *listener, void *data);
 static Monitor *dirtomon(enum wlr_direction dir);
 static void focusclient(Client *c, int lift);
 static void focusmon(const Arg *arg);
@@ -333,6 +340,11 @@ static void spawn(const Arg *arg);
 static void startdrag(struct wl_listener *listener, void *data);
 static void tag(const Arg *arg);
 static void tagmon(const Arg *arg);
+static void tablettoolmotion(struct wlr_tablet_v2_tablet_tool *tool, bool change_x, bool change_y, double x, double y, double dx, double dy);
+static void tablettoolproximity(struct wl_listener *listener, void *data);
+static void tablettoolaxis(struct wl_listener *listener, void *data);
+static void tablettoolbutton(struct wl_listener *listener, void *data);
+static void tablettooltip(struct wl_listener *listener, void *data);
 static void tile(Monitor *m);
 static void togglefloating(const Arg *arg);
 static void togglefullscreen(const Arg *arg);
@@ -390,6 +402,13 @@ static struct wlr_pointer_constraint_v1 *active_constraint;
 static struct wlr_cursor *cursor;
 static struct wlr_xcursor_manager *cursor_mgr;
 
+static struct wlr_tablet_manager_v2 *tablet_mgr;
+static struct wlr_tablet_v2_tablet *tablet = NULL;
+static struct wlr_tablet_v2_tablet_tool *tablet_tool = NULL;
+static struct wlr_tablet_v2_tablet_pad *tablet_pad = NULL;
+static struct wlr_surface *tablet_curr_surface = NULL;
+static struct wl_listener destroy_tablet_surface_listener = {.notify = destroytabletsurfacenotify};
+
 static struct wlr_scene_rect *root_bg;
 static struct wlr_session_lock_manager_v1 *session_lock_mgr;
 static struct wlr_scene_rect *locked_bg;
@@ -412,6 +431,12 @@ static struct wl_listener cursor_button = {.notify = buttonpress};
 static struct wl_listener cursor_frame = {.notify = cursorframe};
 static struct wl_listener cursor_motion = {.notify = motionrelative};
 static struct wl_listener cursor_motion_absolute = {.notify = motionabsolute};
+static struct wl_listener tablet_device_destroy = {.notify = destroytablet};
+static struct wl_listener tablet_tool_axis = {.notify = tablettoolaxis};
+static struct wl_listener tablet_tool_button = {.notify = tablettoolbutton};
+static struct wl_listener tablet_tool_destroy = {.notify = destroytablettool};
+static struct wl_listener tablet_tool_proximity = {.notify = tablettoolproximity};
+static struct wl_listener tablet_tool_tip = {.notify = tablettooltip};
 static struct wl_listener gpu_reset = {.notify = gpureset};
 static struct wl_listener layout_change = {.notify = updatemons};
 static struct wl_listener new_idle_inhibitor = {.notify = createidleinhibitor};
@@ -1196,6 +1221,28 @@ createpopup(struct wl_listener *listener, void *data)
 	LISTEN_STATIC(&popup->base->surface->events.commit, commitpopup);
 }
 
+void
+createtablet(struct wlr_input_device *device)
+{
+	if (!tablet) {
+		struct libinput_device *device_handle = NULL;
+		if (!wlr_input_device_is_libinput(device) ||
+				!(device_handle = wlr_libinput_get_device_handle(device)))
+			return;
+
+		tablet = wlr_tablet_create(tablet_mgr, seat, device);
+		wl_signal_add(&tablet->wlr_device->events.destroy, &tablet_device_destroy);
+		if (libinput_device_config_send_events_get_modes(device_handle)) {
+			libinput_device_config_send_events_set_mode(device_handle, send_events_mode);
+			wlr_cursor_attach_input_device(cursor, device);
+		}
+	} else if (device == tablet->wlr_device) {
+		wlr_log(WLR_ERROR, "createtablet: duplicate device");
+	} else {
+		wlr_log(WLR_ERROR, "createtablet: already have one tablet");
+	}
+}
+
 void
 cursorconstrain(struct wlr_pointer_constraint_v1 *constraint)
 {
@@ -1380,6 +1427,27 @@ destroykeyboardgroup(struct wl_listener *listener, void *data)
 	free(group);
 }
 
+void
+destroytablet(struct wl_listener *listener, void *data)
+{
+	tablet = NULL;
+}
+
+void
+destroytabletsurfacenotify(struct wl_listener *listener, void *data)
+{
+	if (tablet_curr_surface)
+		wl_list_remove(&destroy_tablet_surface_listener.link);
+	tablet_curr_surface = NULL;
+}
+
+void
+destroytablettool(struct wl_listener *listener, void *data)
+{
+	destroytabletsurfacenotify(NULL, NULL);
+	tablet_tool = NULL;
+}
+
 Monitor *
 dirtomon(enum wlr_direction dir)
 {
@@ -1587,6 +1655,12 @@ inputdevice(struct wl_listener *listener, void *data)
 	case WLR_INPUT_DEVICE_POINTER:
 		createpointer(wlr_pointer_from_input_device(device));
 		break;
+        case WLR_INPUT_DEVICE_TABLET:
+		createtablet(device);
+		break;
+	case WLR_INPUT_DEVICE_TABLET_PAD:
+	        tablet_pad = wlr_tablet_pad_create(tablet_mgr, seat, device);
+		break;
 	default:
 		/* TODO handle other input device types */
 		break;
@@ -2580,6 +2654,8 @@ setup(void)
 
 	relative_pointer_mgr = wlr_relative_pointer_manager_v1_create(dpy);
 
+	tablet_mgr = wlr_tablet_v2_create(dpy);
+
 	/*
 	 * Creates a cursor, which is a wlroots utility for tracking the cursor
 	 * image shown on screen.
@@ -2609,6 +2685,11 @@ setup(void)
 	wl_signal_add(&cursor->events.button, &cursor_button);
 	wl_signal_add(&cursor->events.axis, &cursor_axis);
 	wl_signal_add(&cursor->events.frame, &cursor_frame);
+	wl_signal_add(&cursor->events.tablet_tool_proximity, &tablet_tool_proximity);
+	wl_signal_add(&cursor->events.tablet_tool_axis, &tablet_tool_axis);
+	wl_signal_add(&cursor->events.tablet_tool_button, &tablet_tool_button);
+	wl_signal_add(&cursor->events.tablet_tool_tip, &tablet_tool_tip);
+
 
 	cursor_shape_mgr = wlr_cursor_shape_manager_v1_create(dpy, 1);
 	wl_signal_add(&cursor_shape_mgr->events.request_set_shape, &request_set_cursor_shape);
@@ -2704,6 +2785,159 @@ tagmon(const Arg *arg)
 		setmon(sel, dirtomon(arg->i), 0);
 }
 
+void
+tabletapplymap(double x, double y, struct wlr_input_device *dev)
+{
+	Client *p;
+	struct wlr_box geom = {0};
+	if (tabletmaptosurface && tablet_curr_surface) {
+		toplevel_from_wlr_surface(tablet_curr_surface, &p, NULL);
+		if (p) {
+			for (; client_get_parent(p); p = client_get_parent(p));
+			geom.x = p->geom.x + p->bw;
+			geom.y = p->geom.y + p->bw;
+			geom.width = p->geom.width - 2 * p->bw;
+			geom.height = p->geom.height - 2 * p->bw;
+		}
+	}
+	wlr_cursor_map_input_to_region(cursor, dev, &geom);
+	wlr_cursor_map_input_to_output(cursor, dev, selmon->wlr_output);
+}
+
+void
+tablettoolmotion(struct wlr_tablet_v2_tablet_tool *tool, bool change_x, bool change_y,
+		double x, double y, double dx, double dy)
+{
+	struct wlr_surface *surface = NULL;
+	double sx, sy;
+
+	if (!change_x && !change_y)
+		return;
+
+	tabletapplymap(x, y, tablet->wlr_device);
+
+	// TODO: apply constraints
+	switch (tablet_tool->wlr_tool->type) {
+	case WLR_TABLET_TOOL_TYPE_LENS:
+	case WLR_TABLET_TOOL_TYPE_MOUSE:
+		wlr_cursor_move(cursor, tablet->wlr_device, dx, dy);
+		break;
+	default:
+		wlr_cursor_warp_absolute(cursor, tablet->wlr_device, change_x ? x : NAN, change_y ? y : NAN);
+		break;
+	}
+
+	motionnotify(0, NULL, 0, 0, 0, 0);
+
+	xytonode(cursor->x, cursor->y, &surface, NULL, NULL, &sx, &sy);
+	if (surface && !wlr_surface_accepts_tablet_v2(surface, tablet))
+		surface = NULL;
+
+	if (surface != tablet_curr_surface) {
+		if (tablet_curr_surface) {
+			// TODO: wait until all buttons released before leaving
+			if (tablet_tool)
+				wlr_tablet_v2_tablet_tool_notify_proximity_out(tablet_tool);
+			if (tablet_pad)
+				wlr_tablet_v2_tablet_pad_notify_leave(tablet_pad, tablet_curr_surface);
+			wl_list_remove(&destroy_tablet_surface_listener.link);
+		}
+		if (surface) {
+			if (tablet_pad)
+				wlr_tablet_v2_tablet_pad_notify_enter(tablet_pad, tablet, surface);
+			if (tablet_tool)
+				wlr_tablet_v2_tablet_tool_notify_proximity_in(tablet_tool, tablet, surface);
+			wl_signal_add(&surface->events.destroy, &destroy_tablet_surface_listener);
+		}
+		tablet_curr_surface = surface;
+	}
+
+	if (surface)
+		wlr_tablet_v2_tablet_tool_notify_motion(tablet_tool, sx, sy);
+}
+
+void
+tablettoolproximity(struct wl_listener *listener, void *data)
+{
+	struct wlr_tablet_tool_proximity_event *event = data;
+	struct wlr_tablet_tool *tool = event->tool;
+
+	if (!tablet_tool) {
+		tablet_tool = wlr_tablet_tool_create(tablet_mgr, seat, tool);
+		wl_signal_add(&tablet_tool->wlr_tool->events.destroy, &tablet_tool_destroy);
+		wl_signal_add(&tablet_tool->events.set_cursor, &request_cursor);
+	}
+
+	switch (event->state) {
+	case WLR_TABLET_TOOL_PROXIMITY_OUT:
+		wlr_tablet_v2_tablet_tool_notify_proximity_out(tablet_tool);
+		destroytabletsurfacenotify(NULL, NULL);
+		break;
+	case WLR_TABLET_TOOL_PROXIMITY_IN:
+		tablettoolmotion(tablet_tool, true, true, event->x, event->y, 0, 0);
+		break;
+	}
+}
+
+void
+tablettoolaxis(struct wl_listener *listener, void *data)
+{
+	struct wlr_tablet_tool_axis_event *event = data;
+
+	tablettoolmotion(tablet_tool,
+		event->updated_axes & WLR_TABLET_TOOL_AXIS_X,
+		event->updated_axes & WLR_TABLET_TOOL_AXIS_Y,
+		event->x, event->y, event->dx, event->dy);
+
+	if (event->updated_axes & WLR_TABLET_TOOL_AXIS_PRESSURE)
+		wlr_tablet_v2_tablet_tool_notify_pressure(tablet_tool, event->pressure);
+	if (event->updated_axes & WLR_TABLET_TOOL_AXIS_DISTANCE)
+		wlr_tablet_v2_tablet_tool_notify_distance(tablet_tool, event->distance);
+	if (event->updated_axes & (WLR_TABLET_TOOL_AXIS_TILT_X | WLR_TABLET_TOOL_AXIS_TILT_Y))
+       {
+       printf("DEBUGGING: In axis event handling\n");
+		wlr_tablet_v2_tablet_tool_notify_tilt(tablet_tool, event->tilt_x, event->tilt_y);
+       }
+	if (event->updated_axes & WLR_TABLET_TOOL_AXIS_ROTATION)
+		wlr_tablet_v2_tablet_tool_notify_rotation(tablet_tool, event->rotation);
+	if (event->updated_axes & WLR_TABLET_TOOL_AXIS_SLIDER)
+		wlr_tablet_v2_tablet_tool_notify_slider(tablet_tool, event->slider);
+	if (event->updated_axes & WLR_TABLET_TOOL_AXIS_WHEEL)
+		wlr_tablet_v2_tablet_tool_notify_wheel(tablet_tool, event->wheel_delta, 0);
+}
+
+void
+tablettoolbutton(struct wl_listener *listener, void *data)
+{
+	struct wlr_tablet_tool_button_event *event = data;
+	wlr_tablet_v2_tablet_tool_notify_button(tablet_tool, event->button,
+		(enum zwp_tablet_pad_v2_button_state)event->state);
+}
+
+void
+tablettooltip(struct wl_listener *listener, void *data)
+{
+	struct wlr_tablet_tool_tip_event *event = data;
+
+	if (!tablet_curr_surface) {
+		struct wlr_pointer_button_event fakeptrbtnevent = {
+			.button = BTN_LEFT,
+			.state = event->state == WLR_TABLET_TOOL_TIP_UP ?
+				WL_POINTER_BUTTON_STATE_RELEASED : WL_POINTER_BUTTON_STATE_PRESSED,
+			.time_msec = event->time_msec,
+		};
+		buttonpress(NULL, (void *)&fakeptrbtnevent);
+	}
+
+	if (event->state == WLR_TABLET_TOOL_TIP_UP) {
+		wlr_tablet_v2_tablet_tool_notify_up(tablet_tool);
+		return;
+	}
+
+	wlr_tablet_v2_tablet_tool_notify_down(tablet_tool);
+	wlr_tablet_tool_v2_start_implicit_grab(tablet_tool);
+}
+
 void
 tile(Monitor *m)
 {
-- 
2.49.0