make wlroots libinput backend optional

src/input/cursor.c

@@ -3,7 +3,7 @@
 #include "input/cursor.h"
 #include <assert.h>
 #include <time.h>
-#include <wlr/backend/libinput.h>
+#include <wlr/config.h>
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_cursor_shape_v1.h>
 #include <wlr/types/wlr_data_device.h>
@@ -38,6 +38,10 @@
 #include "view.h"
 #include "xwayland.h"
 
+#if WLR_HAS_LIBINPUT_BACKEND
+	#include <wlr/backend/libinput.h>
+#endif
+
 #define LAB_CURSOR_SHAPE_V1_VERSION 1
 
 struct constraint {
@@ -898,6 +902,7 @@ preprocess_cursor_motion(struct seat *seat, struct wlr_pointer *pointer,
 
 static double get_natural_scroll_factor(struct wlr_input_device *wlr_input_device)
 {
+#if WLR_HAS_LIBINPUT_BACKEND
 	if (wlr_input_device_is_libinput(wlr_input_device)) {
 		struct libinput_device *libinput_device =
 			wlr_libinput_get_device_handle(wlr_input_device);
@@ -905,7 +910,7 @@ static double get_natural_scroll_factor(struct wlr_input_device *wlr_input_devic
 			return -1.0;
 		}
 	}
-
+#endif
 	return 1.0;
 }
 

src/input/tablet-pad.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include "input/tablet-pad.h"
 #include <stdlib.h>
-#include <wlr/backend/libinput.h>
+#include <wlr/config.h>
 #include <wlr/types/wlr_compositor.h>
 #include <wlr/types/wlr_tablet_pad.h>
 #include <wlr/types/wlr_tablet_v2.h>
@@ -14,6 +14,12 @@
 #include "input/tablet.h"
 #include "labwc.h"
 
+#if WLR_HAS_LIBINPUT_BACKEND
+	#include <wlr/backend/libinput.h>
+#else
+	#define wlr_input_device_is_libinput(device) (false)
+#endif
+
 void
 tablet_pad_attach_tablet(struct seat *seat)
 {
@@ -34,7 +40,7 @@ tablet_pad_attach_tablet(struct seat *seat)
 			 */
 			continue;
 		}
-
+#if WLR_HAS_LIBINPUT_BACKEND
 		struct libinput_device *tablet_device =
 			wlr_libinput_get_device_handle(tablet->wlr_input_device);
 		struct libinput_device_group *tablet_group =
@@ -55,6 +61,7 @@ tablet_pad_attach_tablet(struct seat *seat)
 				pad->tablet = tablet;
 			}
 		}
+#endif
 	}
 }
 

src/input/tablet.c

@@ -2,7 +2,7 @@
 #include "input/tablet.h"
 #include <stdlib.h>
 #include <linux/input-event-codes.h>
-#include "wlr/backend/libinput.h"
+#include <wlr/config.h>
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_tablet_tool.h>
 #include <wlr/types/wlr_tablet_v2.h>
@@ -22,6 +22,10 @@
 #include "action.h"
 #include "view.h"
 
+#if WLR_HAS_LIBINPUT_BACKEND
+	#include <wlr/backend/libinput.h>
+#endif
+
 bool
 tablet_tool_has_focused_surface(struct seat *seat)
 {
@@ -338,6 +342,7 @@ handle_tablet_tool_proximity(struct wl_listener *listener, void *data)
 		tool = tablet_tool_create(tablet->seat, ev->tool);
 	}
 
+#if WLR_HAS_LIBINPUT_BACKEND
 	struct libinput_tablet_tool *libinput_tool =
 		wlr_libinput_get_tablet_tool_handle(tool->tool_v2->wlr_tool);
 
@@ -358,6 +363,7 @@ handle_tablet_tool_proximity(struct wl_listener *listener, void *data)
 				rc.tablet_tool.min_pressure, rc.tablet_tool.max_pressure);
 		}
 	}
+#endif
 
 	/*
 	 * Enforce mouse emulation when the current tool is a tablet mouse.

src/seat.c

@@ -2,7 +2,7 @@
 #include <assert.h>
 #include <stdbool.h>
 #include <strings.h>
-#include <wlr/backend/libinput.h>
+#include <wlr/config.h>
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_input_device.h>
 #include <wlr/types/wlr_keyboard.h>
@@ -31,6 +31,12 @@
 #include "session-lock.h"
 #include "view.h"
 
+#if WLR_HAS_LIBINPUT_BACKEND
+	#include <wlr/backend/libinput.h>
+#else
+	#define wlr_input_device_is_libinput(device) (false)
+#endif
+
 static void
 input_device_destroy(struct wl_listener *listener, void *data)
 {
@@ -48,6 +54,7 @@ input_device_destroy(struct wl_listener *listener, void *data)
 	free(input);
 }
 
+#if WLR_HAS_LIBINPUT_BACKEND
 static enum lab_libinput_device_type
 device_type_from_wlr_device(struct wlr_input_device *wlr_input_device)
 {
@@ -101,6 +108,7 @@ get_category(struct wlr_input_device *device)
 	/* Use default profile as a fallback */
 	return libinput_category_get_default();
 }
+#endif
 
 static void
 configure_libinput(struct wlr_input_device *wlr_input_device)
@@ -135,7 +143,7 @@ configure_libinput(struct wlr_input_device *wlr_input_device)
 		input->scroll_factor = 1.0;
 		return;
 	}
-
+#if WLR_HAS_LIBINPUT_BACKEND
 	struct libinput_device *libinput_dev =
 		wlr_libinput_get_device_handle(wlr_input_device);
 	if (!libinput_dev) {
@@ -347,6 +355,7 @@ configure_libinput(struct wlr_input_device *wlr_input_device)
 
 	wlr_log(WLR_INFO, "scroll factor configured (%g)", dc->scroll_factor);
 	input->scroll_factor = dc->scroll_factor;
+#endif
 }
 
 static struct wlr_output *