Add beginning of input capture API

This API aims to provide a way for users to capture input devices under
certain conditions, for example when a pointer crosses a specified
barrier.

So far only part of the API is implemented, specifially the session
management as well as zone advertisement, where a zone refers to a
region in the compositor which edges will eventually be made available
for barrier placement.

So far the remote access handle is created while the session is enable,
despite the input capturing isn't actually active yet. This will change
in the future once it can actually become active.

v2: Remove absolute/relative pointer, keep only pointer (ofourdan)

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2628>

src/tests/input-capture-test-client.c

@@ -0,0 +1,340 @@
+/*
+ * Copyright (C) 2022 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <stdio.h>
+
+#include "meta-dbus-input-capture.h"
+
+typedef struct
+{
+  unsigned int width;
+  unsigned int height;
+  int x;
+  int y;
+} Zone;
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Zone, g_free)
+
+typedef enum _Capabilities
+{
+  CAPABILITY_NONE = 0,
+  CAPABILITY_KEYBOARD = 1,
+  CAPABILITY_POINTER = 2,
+  CAPABILITY_TOUCH = 4,
+} Capabilities;
+
+typedef struct _InputCapture
+{
+  MetaDBusInputCapture *proxy;
+} InputCapture;
+
+typedef struct _InputCaptureSession
+{
+  MetaDBusInputCaptureSession *proxy;
+  unsigned int serial;
+} InputCaptureSession;
+
+static void
+ping_mutter (InputCaptureSession *session)
+{
+  GDBusProxy *proxy = G_DBUS_PROXY (session->proxy);
+  GError *error = NULL;
+
+  if (!g_dbus_connection_call_sync (g_dbus_proxy_get_connection (proxy),
+                                    "org.gnome.Mutter.InputCapture",
+                                    g_dbus_proxy_get_object_path (proxy),
+                                    "org.freedesktop.DBus.Peer",
+                                    "Ping",
+                                    NULL,
+                                    NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START, -1,
+                                    NULL, &error))
+    g_error ("Failed to ping D-Bus peer: %s", error->message);
+}
+
+static void
+write_state (InputCaptureSession *session,
+             const char          *state)
+{
+  ping_mutter (session);
+  fprintf (stdout, "%s\n", state);
+  fflush (stdout);
+}
+
+static InputCapture *
+input_capture_new (void)
+{
+  InputCapture *input_capture;
+  GError *error = NULL;
+
+  input_capture = g_new0 (InputCapture, 1);
+  input_capture->proxy = meta_dbus_input_capture_proxy_new_for_bus_sync (
+    G_BUS_TYPE_SESSION,
+    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+    "org.gnome.Mutter.InputCapture",
+    "/org/gnome/Mutter/InputCapture",
+    NULL,
+    &error);
+  if (!input_capture->proxy)
+    g_error ("Failed to acquire proxy: %s", error->message);
+
+  return input_capture;
+}
+
+static InputCaptureSession *
+input_capture_create_session (InputCapture *input_capture)
+{
+  GError *error = NULL;
+  InputCaptureSession *session;
+  g_autofree char *session_path = NULL;
+
+  if (!meta_dbus_input_capture_call_create_session_sync (input_capture->proxy,
+                                                         CAPABILITY_POINTER,
+                                                         &session_path,
+                                                         NULL,
+                                                         &error))
+    g_error ("Failed to create input capture session: %s", error->message);
+
+  session = g_new0 (InputCaptureSession, 1);
+  session->proxy = meta_dbus_input_capture_session_proxy_new_for_bus_sync (
+    G_BUS_TYPE_SESSION,
+    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+    "org.gnome.Mutter.InputCapture",
+    session_path,
+    NULL, &error);
+  if (!session->proxy)
+    g_error ("Failed to acquire proxy: %s", error->message);
+
+  return session;
+}
+
+static void
+input_capture_session_close (InputCaptureSession *session)
+{
+  GError *error = NULL;
+
+  if (!meta_dbus_input_capture_session_call_close_sync (session->proxy,
+                                                        NULL, &error))
+    g_error ("Failed to close session: %s", error->message);
+
+  g_object_unref (session->proxy);
+  g_free (session);
+}
+
+static GList *
+input_capture_session_get_zones (InputCaptureSession *session)
+{
+  GError *error = NULL;
+  g_autoptr (GVariant) zones_variant = NULL;
+  GVariantIter iter;
+  GList *zones = NULL;
+  unsigned int width, height;
+  int x, y;
+
+  if (!meta_dbus_input_capture_session_call_get_zones_sync (session->proxy,
+                                                            &session->serial,
+                                                            &zones_variant,
+                                                            NULL, &error))
+    g_error ("Failed to get zones: %s", error->message);
+
+  g_variant_iter_init (&iter, zones_variant);
+  while (g_variant_iter_next (&iter, "(uuii)", &width, &height, &x, &y))
+    {
+      Zone *zone;
+
+      zone = g_new0 (Zone, 1);
+      *zone = (Zone) {
+        .width = width,
+        .height = height,
+        .x = x,
+        .y = y,
+      };
+      zones = g_list_append (zones, zone);
+    }
+
+  return zones;
+}
+
+static void
+input_capture_session_enable (InputCaptureSession *session)
+{
+  g_autoptr (GError) error = NULL;
+
+  if (!meta_dbus_input_capture_session_call_enable_sync (session->proxy,
+                                                         NULL, &error))
+    g_warning ("Failed to enable session: %s", error->message);
+}
+
+static void
+input_capture_session_disable (InputCaptureSession *session)
+{
+  g_autoptr (GError) error = NULL;
+
+  if (!meta_dbus_input_capture_session_call_disable_sync (session->proxy,
+                                                          NULL, &error))
+    g_warning ("Failed to disable session: %s", error->message);
+}
+
+static void
+test_sanity (void)
+{
+  InputCapture *input_capture;
+  InputCaptureSession *session;
+
+  input_capture = input_capture_new ();
+  session = input_capture_create_session (input_capture);
+
+  g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING,
+                         "*org.freedesktop.DBus.Error.Failed: Session not enabled*");
+  input_capture_session_disable (session);
+  g_test_assert_expected_messages ();
+
+  input_capture_session_enable (session);
+
+  g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING,
+                         "*org.freedesktop.DBus.Error.Failed: Already enabled*");
+  input_capture_session_enable (session);
+  g_test_assert_expected_messages ();
+
+  input_capture_session_disable (session);
+
+  g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING,
+                         "*org.freedesktop.DBus.Error.Failed: Session not enabled*");
+  input_capture_session_disable (session);
+  g_test_assert_expected_messages ();
+
+  input_capture_session_close (session);
+}
+
+static void
+on_zones_changed (MetaDBusInputCaptureSession *proxy,
+                  int                         *zones_changed_count)
+{
+  *zones_changed_count += 1;
+}
+
+static void
+assert_zones (GList       *zones,
+              const Zone  *expected_zones,
+              int          n_expected_zones)
+{
+  GList *l;
+  int i;
+
+  g_assert_cmpuint (g_list_length (zones), ==, n_expected_zones);
+
+  for (l = zones, i = 0; l; l = l->next, i++)
+    {
+      Zone *zone = l->data;
+
+      g_assert_cmpint (zone->width, ==, expected_zones[i].width);
+      g_assert_cmpint (zone->height, ==, expected_zones[i].height);
+      g_assert_cmpint (zone->x, ==, expected_zones[i].x);
+      g_assert_cmpint (zone->y, ==, expected_zones[i].y);
+    }
+}
+
+static void
+test_zones (void)
+{
+  InputCapture *input_capture;
+  InputCaptureSession *session;
+  static const Zone expected_zones1[] = {
+    { .width = 800, .height = 600, .x = 0, .y = 0 },
+    { .width = 1024, .height = 768, .x = 800, .y = 0 },
+  };
+  static const Zone expected_zones2[] = {
+    { .width = 1024, .height = 768, .x = 0, .y = 0 },
+  };
+  GList *zones;
+  int zones_changed_count = 0;
+  unsigned int serial;
+
+  input_capture = input_capture_new ();
+  session = input_capture_create_session (input_capture);
+
+  g_signal_connect (session->proxy, "zones-changed",
+                    G_CALLBACK (on_zones_changed),
+                    &zones_changed_count);
+
+  zones = input_capture_session_get_zones (session);
+  assert_zones (zones, expected_zones1, G_N_ELEMENTS (expected_zones1));
+  g_clear_list (&zones, g_free);
+
+  write_state (session, "1");
+
+  while (zones_changed_count == 0)
+    g_main_context_iteration (NULL, TRUE);
+
+  serial = session->serial;
+  g_clear_list (&zones, g_free);
+
+  zones = input_capture_session_get_zones (session);
+  g_assert_cmpuint (session->serial, >, serial);
+  assert_zones (zones, expected_zones2, G_N_ELEMENTS (expected_zones2));
+  g_clear_list (&zones, g_free);
+
+  input_capture_session_close (session);
+}
+
+static const struct
+{
+  const char *name;
+  void (* func) (void);
+} test_cases[] = {
+  { "sanity", test_sanity, },
+  { "zones", test_zones, },
+};
+
+static void
+print_to_stderr (const char *text)
+{
+  fputs (text, stderr);
+  fflush (stderr);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  const char *test_case;
+  int i;
+
+  g_assert_cmpint (argc, ==, 2);
+
+  test_case = argv[1];
+
+  g_set_print_handler (print_to_stderr);
+  g_test_init (&argc, &argv, NULL);
+
+  for (i = 0; i < G_N_ELEMENTS (test_cases); i++)
+    {
+      if (g_strcmp0 (test_cases[i].name, test_case) == 0)
+        {
+          test_cases[i].func ();
+          return EXIT_SUCCESS;
+        }
+    }
+
+  g_warning ("Invalid test case '%s'", test_case);
+  return EXIT_FAILURE;
+}

src/tests/input-capture-tests.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2022 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <gio/gio.h>
+
+#include "meta-test/meta-context-test.h"
+#include "tests/meta-test-utils.h"
+
+typedef struct _InputCaptureTestClient
+{
+  GSubprocess *subprocess;
+  char *path;
+  GMainLoop *main_loop;
+  GDataInputStream *line_reader;
+} InputCaptureTestClient;
+
+static MetaContext *test_context;
+
+static InputCaptureTestClient *
+input_capture_test_client_new (const char *test_case)
+{
+  g_autofree char *test_client_path = NULL;
+  g_autoptr (GSubprocessLauncher) launcher = NULL;
+  GSubprocess *subprocess;
+  GError *error = NULL;
+  InputCaptureTestClient *test_client;
+  GInputStream *stdout_stream;
+  GDataInputStream *line_reader;
+
+  test_client_path = g_test_build_filename (G_TEST_BUILT,
+                                            "src",
+                                            "tests",
+                                            "mutter-input-capture-test-client",
+                                            NULL);
+  launcher = g_subprocess_launcher_new (G_SUBPROCESS_FLAGS_STDOUT_PIPE);
+  subprocess = g_subprocess_launcher_spawn (launcher,
+                                            &error,
+                                            test_client_path,
+                                            test_case,
+                                            NULL);
+  if (!subprocess)
+    g_error ("Failed to launch input capture test client: %s", error->message);
+
+  stdout_stream = g_subprocess_get_stdout_pipe (subprocess);
+  line_reader = g_data_input_stream_new (stdout_stream);
+
+  test_client = g_new0 (InputCaptureTestClient, 1);
+  test_client->subprocess = subprocess;
+  test_client->main_loop = g_main_loop_new (NULL, FALSE);
+  test_client->line_reader = line_reader;
+
+  return test_client;
+}
+
+typedef struct
+{
+  GMainLoop *loop;
+  const char *expected_state;
+} WaitData;
+
+static void
+on_line_read (GObject      *source_object,
+              GAsyncResult *res,
+              gpointer      user_data)
+{
+  WaitData *data = user_data;
+  g_autofree char *line = NULL;
+  g_autoptr (GError) error = NULL;
+
+  line =
+    g_data_input_stream_read_line_finish (G_DATA_INPUT_STREAM (source_object),
+                                          res, NULL, &error);
+  if (error)
+    g_error ("Failed to read line from test client: %s", error->message);
+  if (!line)
+    g_error ("Unexpected EOF");
+
+  g_assert_cmpstr (data->expected_state, ==, line);
+
+  g_main_loop_quit (data->loop);
+}
+
+static void
+input_capture_test_client_wait_for_state (InputCaptureTestClient *test_client,
+                                          const char             *expected_state)
+{
+  WaitData data;
+
+  data.loop = g_main_loop_new (NULL, FALSE);
+  data.expected_state = expected_state;
+
+  g_data_input_stream_read_line_async (test_client->line_reader,
+                                       G_PRIORITY_DEFAULT,
+                                       NULL,
+                                       on_line_read,
+                                       &data);
+
+  g_main_loop_run (data.loop);
+  g_main_loop_unref (data.loop);
+}
+
+static void
+input_capture_test_client_finished (GObject      *source_object,
+                                    GAsyncResult *res,
+                                    gpointer      user_data)
+{
+  InputCaptureTestClient *test_client = user_data;
+  GError *error = NULL;
+
+  if (!g_subprocess_wait_finish (test_client->subprocess,
+                                 res,
+                                 &error))
+    {
+      g_error ("Failed to wait for input capture test client: %s",
+               error->message);
+    }
+
+  g_main_loop_quit (test_client->main_loop);
+}
+
+static void
+input_capture_test_client_finish (InputCaptureTestClient *test_client)
+{
+  g_subprocess_wait_async (test_client->subprocess, NULL,
+                           input_capture_test_client_finished, test_client);
+
+  g_main_loop_run (test_client->main_loop);
+
+  g_assert_true (g_subprocess_get_successful (test_client->subprocess));
+
+  g_main_loop_unref (test_client->main_loop);
+  g_object_unref (test_client->line_reader);
+  g_object_unref (test_client->subprocess);
+  g_free (test_client);
+}
+
+static void
+meta_test_input_capture_sanity (void)
+{
+  InputCaptureTestClient *test_client;
+
+  test_client = input_capture_test_client_new ("sanity");
+  input_capture_test_client_finish (test_client);
+}
+
+static void
+meta_test_input_capture_zones (void)
+{
+  g_autoptr (MetaVirtualMonitor) virtual_monitor1 = NULL;
+  g_autoptr (MetaVirtualMonitor) virtual_monitor2 = NULL;
+  InputCaptureTestClient *test_client;
+
+  virtual_monitor1 = meta_create_test_monitor (test_context, 800, 600, 20.0);
+  virtual_monitor2 = meta_create_test_monitor (test_context, 1024, 768, 20.0);
+
+  test_client = input_capture_test_client_new ("zones");
+
+  input_capture_test_client_wait_for_state (test_client, "1");
+
+  g_clear_object (&virtual_monitor1);
+
+  input_capture_test_client_finish (test_client);
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/backends/native/input-capture/sanity",
+                   meta_test_input_capture_sanity);
+  g_test_add_func ("/backends/native/input-capture/zones",
+                   meta_test_input_capture_zones);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  g_autoptr (MetaContext) context = NULL;
+  g_autoptr (GError) error = NULL;
+
+  context = test_context =
+    meta_create_test_context (META_CONTEXT_TEST_TYPE_HEADLESS,
+                              META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert (meta_context_configure (context, &argc, &argv, NULL));
+
+  init_tests ();
+
+  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
+                                      META_TEST_RUN_FLAG_NONE);
+}

src/tests/meson.build

@@ -308,6 +308,23 @@ if have_native_tests
     install_rpath: pkglibdir,
   )
 
+  input_capture_client = executable('mutter-input-capture-test-client',
+    sources: [
+      'input-capture-test-client.c',
+      dbus_input_capture_built_sources,
+    ],
+    include_directories: tests_includes,
+    c_args: [
+      tests_c_args,
+      '-DG_LOG_DOMAIN="mutter-input-capture-test-client"',
+    ],
+    dependencies: [
+      gio_unix_dep,
+    ],
+    install: have_installed_tests,
+    install_dir: mutter_installed_tests_libexecdir,
+  )
+
   # Native backend tests
   test_cases += [
     {
@@ -345,6 +362,11 @@ if have_native_tests
       'suite': 'backends/native',
       'sources': [ 'native-persistent-virtual-monitor.c' ],
     },
+    {
+      'name': 'input-capture',
+      'suite': 'backends/native',
+      'sources': [ 'input-capture-tests.c' ],
+    },
   ]
 
   # KMS tests

src/tests/meta-test-utils.h

@@ -25,6 +25,7 @@
 #include <X11/extensions/sync.h>
 
 #include "backends/meta-backend-types.h"
+#include "backends/meta-virtual-monitor.h"
 #include "meta/window.h"
 
 #define META_TEST_CLIENT_ERROR meta_test_client_error_quark ()