[gnome-builder] libide/core: add IdeActionMuxer

[Christian Hergert <chergert src gnome org>]

commit fb29726b50e89bd75eb198f12aac93b04e30097b
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jul 26 16:25:49 2022 -0700

    libide/core: add IdeActionMuxer
    
    This is a fairly straightforward muxer of GActionGroups into a single,
    larger GActionGroup. Each action group may have a prefix associated with
    it. The prefix is suffixed by a dot (.) before using the names of the
    actions within it.

 src/libide/core/ide-action-muxer.c | 566 +++++++++++++++++++++++++++++++++++++
 src/libide/core/ide-action-muxer.h |  46 +++
 src/libide/core/meson.build        |   2 +
 3 files changed, 614 insertions(+)
---
diff --git a/src/libide/core/ide-action-muxer.c b/src/libide/core/ide-action-muxer.c
new file mode 100644
index 000000000..558fcff8c
--- /dev/null
+++ b/src/libide/core/ide-action-muxer.c
@@ -0,0 +1,566 @@
+/* ide-action-muxer.c
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define G_LOG_DOMAIN "ide-action-muxer"
+
+#include "config.h"
+
+#include "ide-action-muxer.h"
+#include "ide-macros.h"
+
+struct _IdeActionMuxer
+{
+  GObject    parent_instance;
+  GPtrArray *action_groups;
+  guint      n_recurse;
+};
+
+typedef struct
+{
+  IdeActionMuxer *backptr;
+  char           *prefix;
+  GActionGroup   *action_group;
+  GSignalGroup   *action_group_signals;
+} PrefixedActionGroup;
+
+static void action_group_iface_init (GActionGroupInterface *iface);
+
+G_DEFINE_FINAL_TYPE_WITH_CODE (IdeActionMuxer, ide_action_muxer, G_TYPE_OBJECT,
+                               G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_GROUP, action_group_iface_init))
+
+static void
+prefixed_action_group_finalize (gpointer data)
+{
+  PrefixedActionGroup *pag = data;
+
+  g_assert (pag->backptr == NULL);
+
+  g_clear_object (&pag->action_group_signals);
+  g_clear_object (&pag->action_group);
+  g_clear_pointer (&pag->prefix, g_free);
+}
+
+static void
+prefixed_action_group_unref (PrefixedActionGroup *pag)
+{
+  g_rc_box_release_full (pag, prefixed_action_group_finalize);
+}
+
+static void
+prefixed_action_group_drop (PrefixedActionGroup *pag)
+{
+  g_signal_group_set_target (pag->action_group_signals, NULL);
+  pag->backptr = NULL;
+  prefixed_action_group_unref (pag);
+}
+
+static PrefixedActionGroup *
+prefixed_action_group_ref (PrefixedActionGroup *pag)
+{
+  return g_rc_box_acquire (pag);
+}
+
+static void
+ide_action_muxer_dispose (GObject *object)
+{
+  IdeActionMuxer *self = (IdeActionMuxer *)object;
+
+  if (self->action_groups->len > 0)
+    g_ptr_array_remove_range (self->action_groups, 0, self->action_groups->len);
+
+  G_OBJECT_CLASS (ide_action_muxer_parent_class)->finalize (object);
+}
+
+static void
+ide_action_muxer_finalize (GObject *object)
+{
+  IdeActionMuxer *self = (IdeActionMuxer *)object;
+
+  g_clear_pointer (&self->action_groups, g_ptr_array_unref);
+
+  G_OBJECT_CLASS (ide_action_muxer_parent_class)->finalize (object);
+}
+
+static void
+ide_action_muxer_class_init (IdeActionMuxerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = ide_action_muxer_dispose;
+  object_class->finalize = ide_action_muxer_finalize;
+}
+
+static void
+ide_action_muxer_init (IdeActionMuxer *self)
+{
+  self->action_groups = g_ptr_array_new_with_free_func ((GDestroyNotify)prefixed_action_group_drop);
+}
+
+IdeActionMuxer *
+ide_action_muxer_new (void)
+{
+  g_return_val_if_fail (IDE_IS_MAIN_THREAD (), NULL);
+
+  return g_object_new (IDE_TYPE_ACTION_MUXER, NULL);
+}
+
+/**
+ * ide_action_muxer_list_groups:
+ * @self: a #IdeActionMuxer
+ *
+ * Gets a list of group names in the muxer.
+ *
+ * Returns: (transfer full) (array zero-terminated=1) (element-type utf8):
+ *   an array containing the names of groups within the muxer
+ */
+char **
+ide_action_muxer_list_groups (IdeActionMuxer *self)
+{
+  GArray *ar;
+
+  g_return_val_if_fail (IDE_IS_MAIN_THREAD (), NULL);
+  g_return_val_if_fail (IDE_IS_ACTION_MUXER (self), NULL);
+
+  ar = g_array_new (TRUE, FALSE, sizeof (char *));
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+      char *prefix = g_strdup (pag->prefix);
+
+      g_assert (prefix != NULL);
+      g_assert (g_str_has_suffix (prefix, "."));
+
+      *strrchr (prefix, '.') = 0;
+
+      g_array_append_val (ar, prefix);
+    }
+
+  return (char **)g_array_free (ar, FALSE);
+}
+
+static void
+ide_action_muxer_action_group_action_added_cb (GActionGroup        *action_group,
+                                               const char          *action_name,
+                                               PrefixedActionGroup *pag)
+{
+  g_autofree char *full_name = NULL;
+
+  g_assert (IDE_IS_MAIN_THREAD ());
+  g_assert (G_IS_ACTION_GROUP (action_group));
+  g_assert (action_name != NULL);
+  g_assert (pag != NULL);
+  g_assert (pag->backptr != NULL);
+  g_assert (IDE_IS_ACTION_MUXER (pag->backptr));
+
+  full_name = g_strconcat (pag->prefix, action_name, NULL);
+  g_action_group_action_added (G_ACTION_GROUP (pag->backptr), full_name);
+}
+
+static void
+ide_action_muxer_action_group_action_removed_cb (GActionGroup        *action_group,
+                                                 const char          *action_name,
+                                                 PrefixedActionGroup *pag)
+{
+  g_autofree char *full_name = NULL;
+
+  g_assert (IDE_IS_MAIN_THREAD ());
+  g_assert (G_IS_ACTION_GROUP (action_group));
+  g_assert (action_name != NULL);
+  g_assert (pag != NULL);
+  g_assert (pag->backptr != NULL);
+  g_assert (IDE_IS_ACTION_MUXER (pag->backptr));
+
+  full_name = g_strconcat (pag->prefix, action_name, NULL);
+  g_action_group_action_removed (G_ACTION_GROUP (pag->backptr), full_name);
+}
+
+static void
+ide_action_muxer_action_group_action_enabled_changed_cb (GActionGroup        *action_group,
+                                                         const char          *action_name,
+                                                         gboolean             enabled,
+                                                         PrefixedActionGroup *pag)
+{
+  g_autofree char *full_name = NULL;
+
+  g_assert (IDE_IS_MAIN_THREAD ());
+  g_assert (G_IS_ACTION_GROUP (action_group));
+  g_assert (action_name != NULL);
+  g_assert (pag != NULL);
+  g_assert (pag->backptr != NULL);
+  g_assert (IDE_IS_ACTION_MUXER (pag->backptr));
+
+  full_name = g_strconcat (pag->prefix, action_name, NULL);
+  g_action_group_action_enabled_changed (G_ACTION_GROUP (pag->backptr), full_name, enabled);
+}
+
+static void
+ide_action_muxer_action_group_action_state_changed_cb (GActionGroup        *action_group,
+                                                       const char          *action_name,
+                                                       GVariant            *value,
+                                                       PrefixedActionGroup *pag)
+{
+  g_autofree char *full_name = NULL;
+
+  g_assert (IDE_IS_MAIN_THREAD ());
+  g_assert (G_IS_ACTION_GROUP (action_group));
+  g_assert (action_name != NULL);
+  g_assert (pag != NULL);
+  g_assert (pag->backptr != NULL);
+  g_assert (IDE_IS_ACTION_MUXER (pag->backptr));
+
+  full_name = g_strconcat (pag->prefix, action_name, NULL);
+  g_action_group_action_state_changed (G_ACTION_GROUP (pag->backptr), full_name, value);
+}
+
+void
+ide_action_muxer_insert_action_group (IdeActionMuxer *self,
+                                      const char     *prefix,
+                                      GActionGroup   *action_group)
+{
+  g_autofree char *prefix_dot = NULL;
+
+  g_return_if_fail (IDE_IS_MAIN_THREAD ());
+  g_return_if_fail (IDE_IS_ACTION_MUXER (self));
+  g_return_if_fail (self->n_recurse == 0);
+  g_return_if_fail (prefix != NULL);
+  g_return_if_fail (!action_group || G_IS_ACTION_GROUP (action_group));
+
+  /* Protect against recursion via signal emission. We don't want anything to
+   * mess with our GArray while we are actively processing actions. To do so is
+   * invalid API use.
+   */
+  self->n_recurse++;
+
+  /* Precalculate with a dot suffix so we can simplify lookups */
+  prefix_dot = g_strconcat (prefix, ".", NULL);
+
+  /* Find our matching action group by prefix, and then notify it has been
+   * removed from our known actions.
+   */
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+      g_auto(GStrv) action_names = NULL;
+
+      g_assert (pag->prefix != NULL);
+      g_assert (G_IS_ACTION_GROUP (pag->action_group));
+
+      if (g_strcmp0 (pag->prefix, prefix_dot) != 0)
+        continue;
+
+      /* Clear signal group first, since it has weak pointers */
+      g_signal_group_set_target (pag->action_group_signals, NULL);
+
+      /* Retrieve list of all the action names so we can drop references */
+      action_names = g_action_group_list_actions (pag->action_group);
+
+      /* Remove this entry from our knowledge, clear pag because it now
+       * points to potentially invalid memory.
+       */
+      pag = NULL;
+      g_ptr_array_remove_index_fast (self->action_groups, i);
+
+      /* Notify any actiongroup listeners of removed actions */
+      for (guint j = 0; action_names[j]; j++)
+        {
+          g_autofree char *action_name = g_strconcat (prefix_dot, action_names[j], NULL);
+          g_action_group_action_removed (G_ACTION_GROUP (self), action_name);
+        }
+
+      break;
+    }
+
+  /* If we got a new action group to replace it, setup tracking of the
+   * action group and then notify of all the current actions.
+   */
+  if (action_group != NULL)
+    {
+      g_auto(GStrv) action_names = g_action_group_list_actions (action_group);
+      PrefixedActionGroup *new_pag = g_rc_box_new0 (PrefixedActionGroup);
+
+      new_pag->backptr = self;
+      new_pag->prefix = g_strdup (prefix_dot);
+      new_pag->action_group = g_object_ref (action_group);
+      new_pag->action_group_signals = g_signal_group_new (G_TYPE_ACTION_GROUP);
+      g_ptr_array_add (self->action_groups, new_pag);
+
+      g_signal_group_connect_data (new_pag->action_group_signals,
+                                   "action-added",
+                                   G_CALLBACK (ide_action_muxer_action_group_action_added_cb),
+                                   prefixed_action_group_ref (new_pag),
+                                   (GClosureNotify)prefixed_action_group_unref,
+                                   0);
+      g_signal_group_connect_data (new_pag->action_group_signals,
+                                   "action-removed",
+                                   G_CALLBACK (ide_action_muxer_action_group_action_removed_cb),
+                                   prefixed_action_group_ref (new_pag),
+                                   (GClosureNotify)prefixed_action_group_unref,
+                                   0);
+      g_signal_group_connect_data (new_pag->action_group_signals,
+                                   "action-enabled-changed",
+                                   G_CALLBACK (ide_action_muxer_action_group_action_enabled_changed_cb),
+                                   prefixed_action_group_ref (new_pag),
+                                   (GClosureNotify)prefixed_action_group_unref,
+                                   0);
+      g_signal_group_connect_data (new_pag->action_group_signals,
+                                   "action-state-changed",
+                                   G_CALLBACK (ide_action_muxer_action_group_action_state_changed_cb),
+                                   prefixed_action_group_ref (new_pag),
+                                   (GClosureNotify)prefixed_action_group_unref,
+                                   0);
+
+      g_signal_group_set_target (new_pag->action_group_signals, action_group);
+
+      for (guint j = 0; action_names[j]; j++)
+        {
+          g_autofree char *action_name = g_strconcat (prefix_dot, action_names[j], NULL);
+          g_action_group_action_added (G_ACTION_GROUP (self), action_name);
+        }
+    }
+
+  self->n_recurse--;
+}
+
+void
+ide_action_muxer_remove_action_group (IdeActionMuxer *self,
+                                      const char     *prefix)
+{
+  g_return_if_fail (IDE_IS_MAIN_THREAD ());
+  g_return_if_fail (IDE_IS_ACTION_MUXER (self));
+  g_return_if_fail (prefix != NULL);
+
+  ide_action_muxer_insert_action_group (self, prefix, NULL);
+}
+
+static gboolean
+ide_action_muxer_has_action (GActionGroup *group,
+                             const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+static char **
+ide_action_muxer_list_actions (GActionGroup *group)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+  GArray *ar = g_array_new (TRUE, FALSE, sizeof (char *));
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+      g_auto(GStrv) action_names = g_action_group_list_actions (pag->action_group);
+
+      for (guint j = 0; action_names[j]; j++)
+        {
+          char *full_action_name = g_strconcat (pag->prefix, action_names[j], NULL);
+          g_array_append_val (ar, full_action_name);
+        }
+    }
+
+  return (char **)g_array_free (ar, FALSE);
+}
+
+static gboolean
+ide_action_muxer_get_action_enabled (GActionGroup *group,
+                                     const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return g_action_group_get_action_enabled (pag->action_group, short_name);
+        }
+    }
+
+  return FALSE;
+}
+
+static GVariant *
+ide_action_muxer_get_action_state (GActionGroup *group,
+                                   const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return g_action_group_get_action_state (pag->action_group, short_name);
+        }
+    }
+
+  return NULL;
+}
+
+static GVariant *
+ide_action_muxer_get_action_state_hint (GActionGroup *group,
+                                        const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return g_action_group_get_action_state_hint (pag->action_group, short_name);
+        }
+    }
+
+  return NULL;
+}
+
+static void
+ide_action_muxer_change_action_state (GActionGroup *group,
+                                      const char   *action_name,
+                                      GVariant     *value)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            {
+              g_action_group_change_action_state (pag->action_group, short_name, value);
+              break;
+            }
+        }
+    }
+}
+
+static const GVariantType *
+ide_action_muxer_get_action_state_type (GActionGroup *group,
+                                        const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return g_action_group_get_action_state_type (pag->action_group, short_name);
+        }
+    }
+
+  return NULL;
+}
+
+static void
+ide_action_muxer_activate_action (GActionGroup *group,
+                                  const char   *action_name,
+                                  GVariant     *parameter)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            {
+              g_action_group_activate_action (pag->action_group, short_name, parameter);
+              break;
+            }
+        }
+    }
+}
+
+static const GVariantType *
+ide_action_muxer_get_action_parameter_type (GActionGroup *group,
+                                            const char   *action_name)
+{
+  IdeActionMuxer *self = IDE_ACTION_MUXER (group);
+
+  for (guint i = 0; i < self->action_groups->len; i++)
+    {
+      const PrefixedActionGroup *pag = g_ptr_array_index (self->action_groups, i);
+
+      if (g_str_has_prefix (action_name, pag->prefix))
+        {
+          const char *short_name = action_name + strlen (pag->prefix);
+
+          if (g_action_group_has_action (pag->action_group, short_name))
+            return g_action_group_get_action_parameter_type (pag->action_group, short_name);
+        }
+    }
+
+  return NULL;
+}
+
+static void
+action_group_iface_init (GActionGroupInterface *iface)
+{
+  iface->has_action = ide_action_muxer_has_action;
+  iface->list_actions = ide_action_muxer_list_actions;
+  iface->get_action_parameter_type = ide_action_muxer_get_action_parameter_type;
+  iface->get_action_enabled = ide_action_muxer_get_action_enabled;
+  iface->get_action_state = ide_action_muxer_get_action_state;
+  iface->get_action_state_hint = ide_action_muxer_get_action_state_hint;
+  iface->get_action_state_type = ide_action_muxer_get_action_state_type;
+  iface->change_action_state = ide_action_muxer_change_action_state;
+  iface->activate_action = ide_action_muxer_activate_action;
+}
diff --git a/src/libide/core/ide-action-muxer.h b/src/libide/core/ide-action-muxer.h
new file mode 100644
index 000000000..2cf5c284c
--- /dev/null
+++ b/src/libide/core/ide-action-muxer.h
@@ -0,0 +1,46 @@
+/* ide-action-muxer.h
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gio/gio.h>
+
+#include "ide-version-macros.h"
+
+G_BEGIN_DECLS
+
+#define IDE_TYPE_ACTION_MUXER (ide_action_muxer_get_type())
+
+IDE_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (IdeActionMuxer, ide_action_muxer, IDE, ACTION_MUXER, GObject)
+
+IDE_AVAILABLE_IN_ALL
+IdeActionMuxer  *ide_action_muxer_new                 (void);
+IDE_AVAILABLE_IN_ALL
+void             ide_action_muxer_insert_action_group (IdeActionMuxer *self,
+                                                       const char     *prefix,
+                                                       GActionGroup   *action_group);
+IDE_AVAILABLE_IN_ALL
+void             ide_action_muxer_remove_action_group (IdeActionMuxer *self,
+                                                       const char     *prefix);
+IDE_AVAILABLE_IN_ALL
+char           **ide_action_muxer_list_groups         (IdeActionMuxer *self);
+
+G_END_DECLS
diff --git a/src/libide/core/meson.build b/src/libide/core/meson.build
index 751b0cb64..8f2ca16ab 100644
--- a/src/libide/core/meson.build
+++ b/src/libide/core/meson.build
@@ -73,6 +73,7 @@ libide_core_public_headers = [
 ]
 
 libide_core_private_headers = [
+  'ide-action-muxer.h',
   'ide-layered-settings-private.h',
   'ide-transfer-manager-private.h',
 ]
@@ -101,6 +102,7 @@ libide_core_public_sources = [
 ]
 
 libide_core_private_sources = [
+  'ide-action-muxer.c',
   'ide-layered-settings.c',
 ]