core: Add a MetaToolActionMapper for tablet tools

This mapper hooks into CLUTTER_BUTTON_PRESS/RELEASE events with a
clutter button of zero but a nonzero evcode (e.g. BTN_STYLUS).
It then looks up the available button actions and implements
switch-monitor and keybindings using the MetaTabletActionMapper parent
class.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3649>

src/core/display-private.h

@@ -32,6 +32,7 @@
 #include "core/keybindings-private.h"
 #include "core/meta-gesture-tracker-private.h"
 #include "core/meta-pad-action-mapper.h"
+#include "core/meta-tool-action-mapper.h"
 #include "core/stack-tracker.h"
 #include "core/startup-notification-private.h"
 #include "meta/barrier.h"
@@ -141,6 +142,7 @@ struct _MetaDisplay
 
   ClutterActor *current_pad_osd;
   MetaPadActionMapper *pad_action_mapper;
+  MetaToolActionMapper *tool_action_mapper;
 
   MetaStartupNotification *startup_notification;
 

src/core/display.c

@@ -996,6 +996,7 @@ meta_display_new (MetaContext  *context,
                            display, G_CONNECT_SWAPPED);
 
   display->pad_action_mapper = meta_pad_action_mapper_new (monitor_manager);
+  display->tool_action_mapper = meta_tool_action_mapper_new (backend);
 
   input_capture = meta_backend_get_input_capture (backend);
   meta_input_capture_set_event_router (input_capture,

src/core/events.c

@@ -328,7 +328,10 @@ meta_display_handle_event (MetaDisplay        *display,
   else if (event_type == CLUTTER_BUTTON_PRESS ||
            event_type == CLUTTER_BUTTON_RELEASE)
     {
-      if (clutter_event_get_button (event) == 0)
+      mapper = META_TABLET_ACTION_MAPPER (display->tool_action_mapper);
+      if (((clutter_input_device_get_capabilities (device) & CLUTTER_INPUT_CAPABILITY_TABLET_TOOL) &&
+           meta_tablet_action_mapper_handle_event (mapper, event)) ||
+          clutter_event_get_button (event) == 0)
         return CLUTTER_EVENT_STOP;
     }
 

src/core/meta-tool-action-mapper.c

@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2014-2020 Red Hat
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "config.h"
+
+#include <glib/gi18n-lib.h>
+#include <gsettings-desktop-schemas/gdesktop-enums.h>
+
+#ifdef HAVE_LIBWACOM
+#include <libwacom/libwacom.h>
+#endif
+
+#include "core/meta-tool-action-mapper.h"
+#include "backends/meta-input-device-private.h"
+#include "core/display-private.h"
+
+struct _MetaToolActionMapper
+{
+  GObject parent_class;
+  MetaInputSettings *input_settings;
+};
+
+G_DEFINE_TYPE (MetaToolActionMapper, meta_tool_action_mapper, META_TYPE_TABLET_ACTION_MAPPER);
+
+static gboolean
+meta_tool_action_mapper_handle_event (MetaTabletActionMapper *mapper,
+                                      const ClutterEvent     *event);
+
+static void
+meta_tool_action_mapper_finalize (GObject *object)
+{
+  MetaToolActionMapper *mapper = META_TOOL_ACTION_MAPPER (object);
+
+  g_clear_object (&mapper->input_settings);
+
+  G_OBJECT_CLASS (meta_tool_action_mapper_parent_class)->finalize (object);
+}
+
+static void
+meta_tool_action_mapper_class_init (MetaToolActionMapperClass *klass)
+{
+  G_OBJECT_CLASS (klass)->finalize = meta_tool_action_mapper_finalize;
+}
+
+static void
+meta_tool_action_mapper_init (MetaToolActionMapper *mapper)
+{
+  g_signal_connect (mapper, "input-event", G_CALLBACK (meta_tool_action_mapper_handle_event), NULL);
+}
+
+MetaToolActionMapper *
+meta_tool_action_mapper_new (MetaBackend *backend)
+{
+  MetaToolActionMapper *action_mapper;
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+
+  action_mapper = g_object_new (META_TYPE_TOOL_ACTION_MAPPER,
+                                "monitor-manager", monitor_manager,
+                                NULL);
+  action_mapper->input_settings = g_object_ref (meta_backend_get_input_settings (backend));
+
+  return action_mapper;
+}
+
+static gboolean
+meta_tool_action_mapper_handle_button (MetaToolActionMapper *mapper,
+                                       ClutterInputDevice   *device,
+                                       const ClutterEvent   *event)
+{
+  MetaTabletActionMapper *tablet_mapper = META_TABLET_ACTION_MAPPER (mapper);
+  MetaTabletActionMapperClass *tablet_klass = META_TABLET_ACTION_MAPPER_GET_CLASS (mapper);
+  GDesktopStylusButtonAction action;
+  gboolean is_press;
+  g_autofree char *accel = NULL;
+  uint32_t button, evcode;
+  ClutterInputDeviceTool *tool;
+
+  g_return_val_if_fail (clutter_event_type (event) == CLUTTER_BUTTON_PRESS ||
+                        clutter_event_type (event) == CLUTTER_BUTTON_RELEASE, FALSE);
+
+  if ((clutter_input_device_get_capabilities (device) & CLUTTER_INPUT_CAPABILITY_TABLET_TOOL) == 0)
+    return FALSE;
+
+  tool = clutter_event_get_device_tool (event);
+  evcode = clutter_event_get_event_code (event);
+  button = meta_evdev_tool_button_to_clutter (evcode);
+  is_press = clutter_event_type (event) == CLUTTER_BUTTON_PRESS;
+
+  action = meta_input_settings_get_tool_button_action (mapper->input_settings,
+                                                       device, tool, button, &accel);
+  switch (action)
+    {
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_DEFAULT:
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_MIDDLE:
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_RIGHT:
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_BACK:
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_FORWARD:
+      /* These are handled as normal button events, nothing to do here */
+      return FALSE;
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_SWITCH_MONITOR:
+      if (is_press)
+        tablet_klass->cycle_tablet_output (tablet_mapper, device);
+      return TRUE;
+    case G_DESKTOP_STYLUS_BUTTON_ACTION_KEYBINDING:
+      if (accel)
+        tablet_klass->emulate_keybinding (tablet_mapper, accel, is_press);
+      return TRUE;
+    default:
+      g_warn_if_reached ();
+      return FALSE;
+    }
+}
+
+gboolean
+meta_tool_action_mapper_handle_event (MetaTabletActionMapper *tablet_mapper,
+                                      const ClutterEvent     *event)
+{
+  MetaToolActionMapper *mapper = META_TOOL_ACTION_MAPPER (tablet_mapper);
+  ClutterInputDevice *tool;
+
+  tool = clutter_event_get_source_device ((ClutterEvent *) event);
+
+  switch (clutter_event_type (event))
+    {
+    case CLUTTER_BUTTON_PRESS:
+    case CLUTTER_BUTTON_RELEASE:
+      return meta_tool_action_mapper_handle_button (mapper, tool, event);
+    default:
+      break;
+    }
+
+  return CLUTTER_EVENT_PROPAGATE;
+}

src/core/meta-tool-action-mapper.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2020 Red Hat
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include "clutter/clutter.h"
+#include "meta/display.h"
+#include "meta/meta-monitor-manager.h"
+#include "core/meta-tablet-action-mapper.h"
+
+#define META_TYPE_TOOL_ACTION_MAPPER (meta_tool_action_mapper_get_type ())
+G_DECLARE_FINAL_TYPE (MetaToolActionMapper, meta_tool_action_mapper,
+                      META, TOOL_ACTION_MAPPER, MetaTabletActionMapper)
+
+MetaToolActionMapper *meta_tool_action_mapper_new (MetaBackend * backend);

src/meson.build

@@ -379,6 +379,7 @@ mutter_sources = [
   'core/meta-selection-source-memory.c',
   'core/meta-sound-player.c',
   'core/meta-tablet-action-mapper.c',
+  'core/meta-tool-action-mapper.c',
   'core/meta-workspace-manager.c',
   'core/meta-workspace-manager-private.h',
   'core/place.c',