input: map pointer to output if possible

This is needed in order for wlroots to interpret some values (mostly
coords of absolute input events) correctly. It for example fixes how the
pointer behaves with WLR_WL_OUTPUTS=2.

In order to also map the pointer/output pair when the pointer is created
before the output, a list of pointers has to be managed, which wasn't
needed until now.

include/input/input.h

@@ -12,6 +12,7 @@
 
 struct kiwmi_input {
     struct wl_list keyboards; // struct kiwmi_keyboard::link
+    struct wl_list pointers;  // struct kiwmi_pointer::link
     struct wl_listener new_input;
     struct kiwmi_cursor *cursor;
     struct kiwmi_seat *seat;

include/input/pointer.h

@@ -0,0 +1,27 @@
+/* Copyright (c), Charlotte Meyer <dev@buffet.sh>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef KIWMI_INPUT_POINTER_H
+#define KIWMI_INPUT_POINTER_H
+
+#include <wayland-server.h>
+#include <wlr/types/wlr_input_device.h>
+
+#include "server.h"
+
+struct kiwmi_pointer {
+    struct wlr_input_device *device;
+    struct wl_list link;
+
+    struct wl_listener device_destroy;
+};
+
+struct kiwmi_pointer *
+pointer_create(struct kiwmi_server *server, struct wlr_input_device *device);
+void pointer_destroy(struct kiwmi_pointer *pointer);
+
+#endif /* KIWMI_INPUT_POINTER_H */

kiwmi/desktop/output.c

@@ -27,6 +27,7 @@
 #include "desktop/view.h"
 #include "input/cursor.h"
 #include "input/input.h"
+#include "input/pointer.h"
 #include "server.h"
 
 static void
@@ -355,9 +356,17 @@ new_output_notify(struct wl_listener *listener, void *data)
     wlr_output->data = output;
 
     struct kiwmi_cursor *cursor = server->input.cursor;
-
     wlr_xcursor_manager_load(cursor->xcursor_manager, wlr_output->scale);
 
+    struct kiwmi_pointer *pointer;
+    wl_list_for_each (pointer, &server->input.pointers, link) {
+        if (pointer->device->output_name
+            && strcmp(pointer->device->output_name, wlr_output->name) == 0) {
+            wlr_cursor_map_input_to_output(
+                cursor->cursor, pointer->device, wlr_output);
+        }
+    }
+
     wl_list_insert(&desktop->outputs, &output->link);
 
     wlr_output_layout_add_auto(desktop->output_layout, wlr_output);

kiwmi/input/input.c

@@ -19,13 +19,21 @@
 #include "desktop/desktop.h"
 #include "input/cursor.h"
 #include "input/keyboard.h"
+#include "input/pointer.h"
 #include "input/seat.h"
 #include "server.h"
 
 static void
 new_pointer(struct kiwmi_input *input, struct wlr_input_device *device)
 {
-    wlr_cursor_attach_input_device(input->cursor->cursor, device);
+    struct kiwmi_server *server = wl_container_of(input, server, input);
+
+    struct kiwmi_pointer *pointer = pointer_create(server, device);
+    if (!pointer) {
+        return;
+    }
+
+    wl_list_insert(&input->pointers, &pointer->link);
 }
 
 static void
@@ -86,6 +94,7 @@ input_init(struct kiwmi_input *input)
     }
 
     wl_list_init(&input->keyboards);
+    wl_list_init(&input->pointers);
 
     input->new_input.notify = new_input_notify;
     wl_signal_add(&server->backend->events.new_input, &input->new_input);
@@ -99,11 +108,17 @@ void
 input_fini(struct kiwmi_input *input)
 {
     struct kiwmi_keyboard *keyboard;
-    struct kiwmi_keyboard *tmp;
-    wl_list_for_each_safe (keyboard, tmp, &input->keyboards, link) {
+    struct kiwmi_keyboard *tmp_keyboard;
+    wl_list_for_each_safe (keyboard, tmp_keyboard, &input->keyboards, link) {
         keyboard_destroy(keyboard);
     }
 
+    struct kiwmi_pointer *pointer;
+    struct kiwmi_pointer *tmp_pointer;
+    wl_list_for_each_safe (pointer, tmp_pointer, &input->pointers, link) {
+        pointer_destroy(pointer);
+    }
+
     seat_destroy(input->seat);
 
     cursor_destroy(input->cursor);

kiwmi/input/pointer.c

@@ -0,0 +1,67 @@
+/* Copyright (c), Charlotte Meyer <dev@buffet.sh>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "input/pointer.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <wayland-server.h>
+#include <wlr/types/wlr_cursor.h>
+#include <wlr/types/wlr_input_device.h>
+
+#include "desktop/output.h"
+#include "input/cursor.h"
+#include "input/input.h"
+#include "server.h"
+
+static void
+pointer_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_pointer *pointer =
+        wl_container_of(listener, pointer, device_destroy);
+
+    pointer_destroy(pointer);
+}
+
+struct kiwmi_pointer *
+pointer_create(struct kiwmi_server *server, struct wlr_input_device *device)
+{
+    wlr_cursor_attach_input_device(server->input.cursor->cursor, device);
+
+    struct kiwmi_pointer *pointer = malloc(sizeof(*pointer));
+    if (!pointer) {
+        return NULL;
+    }
+
+    pointer->device = device;
+
+    pointer->device_destroy.notify = pointer_destroy_notify;
+    wl_signal_add(&device->events.destroy, &pointer->device_destroy);
+
+    if (device->output_name) {
+        struct kiwmi_output *output;
+        wl_list_for_each (output, &server->desktop.outputs, link) {
+            if (strcmp(device->output_name, output->wlr_output->name) == 0) {
+                wlr_cursor_map_input_to_output(
+                    server->input.cursor->cursor, device, output->wlr_output);
+                break;
+            }
+        }
+    }
+
+    return pointer;
+}
+
+void
+pointer_destroy(struct kiwmi_pointer *pointer)
+{
+    wl_list_remove(&pointer->device_destroy.link);
+    wl_list_remove(&pointer->link);
+
+    free(pointer);
+}

kiwmi/meson.build

@@ -10,6 +10,7 @@ kiwmi_sources = files(
   'input/cursor.c',
   'input/input.c',
   'input/keyboard.c',
+  'input/pointer.c',
   'input/seat.c',
   'luak/ipc.c',
   'luak/kiwmi_cursor.c',