[gnome-builder/wip/gtk4-port] libide/sourceview: wire-up competion provider addins

[Christian Hergert <chergert src gnome org>]

commit 715d534ccc1a2c15f8f6d779905ea125b7301520
Author: Christian Hergert <chergert redhat com>
Date:   Mon Apr 18 13:08:47 2022 -0700

    libide/sourceview: wire-up competion provider addins
    
    This will cause issues now with GtkSourceView, but those need to be
    shaken out. Most likely due to various changes in GTK and how the
    assistants are being allocated.

 src/libide/sourceview/ide-source-view.c | 184 +++++++++++++++++++++++++++++---
 1 file changed, 171 insertions(+), 13 deletions(-)
---
diff --git a/src/libide/sourceview/ide-source-view.c b/src/libide/sourceview/ide-source-view.c
index 53bbaf05b..45ce60bd1 100644
--- a/src/libide/sourceview/ide-source-view.c
+++ b/src/libide/sourceview/ide-source-view.c
@@ -27,17 +27,22 @@
 
 #include <libide-code.h>
 #include <libide-gtk.h>
+#include <libide-plugins.h>
 
 #include "ide-source-view.h"
 
 struct _IdeSourceView
 {
-  GtkSourceView source_view;
-  GtkCssProvider *css_provider;
-  PangoFontDescription *font_desc;
-  int font_scale;
-  double line_height;
-  IdeJoinedMenu *joined_menu;
+  GtkSourceView            source_view;
+
+  IdeBuffer               *buffer;
+  GtkCssProvider          *css_provider;
+  PangoFontDescription    *font_desc;
+  IdeJoinedMenu           *joined_menu;
+  IdeExtensionSetAdapter  *completion_providers;
+
+  int                      font_scale;
+  double                   line_height;
 };
 
 G_DEFINE_TYPE (IdeSourceView, ide_source_view, GTK_SOURCE_TYPE_VIEW)
@@ -259,6 +264,152 @@ ide_source_view_buffer_request_scroll_to_insert_cb (IdeSourceView *self,
   IDE_EXIT;
 }
 
+static void
+ide_source_view_completion_provider_added_cb (IdeExtensionSetAdapter *adapter,
+                                              PeasPluginInfo         *plugin_info,
+                                              PeasExtension          *exten,
+                                              gpointer                user_data)
+{
+  GtkSourceCompletionProvider *provider = (GtkSourceCompletionProvider *)exten;
+  IdeSourceView *self = user_data;
+  GtkSourceCompletion *completion;
+
+  IDE_ENTRY;
+
+  g_assert (IDE_IS_EXTENSION_SET_ADAPTER (adapter));
+  g_assert (plugin_info != NULL);
+  g_assert (GTK_SOURCE_IS_COMPLETION_PROVIDER (provider));
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  g_debug ("Adding completion provider %s from module %s\n",
+           G_OBJECT_TYPE_NAME (provider),
+           peas_plugin_info_get_module_name (plugin_info));
+
+  completion = gtk_source_view_get_completion (GTK_SOURCE_VIEW (self));
+  gtk_source_completion_add_provider (completion, provider);
+
+  IDE_EXIT;
+}
+
+static void
+ide_source_view_completion_provider_removed_cb (IdeExtensionSetAdapter *adapter,
+                                                PeasPluginInfo         *plugin_info,
+                                                PeasExtension          *exten,
+                                                gpointer                user_data)
+{
+  GtkSourceCompletionProvider *provider = (GtkSourceCompletionProvider *)exten;
+  IdeSourceView *self = user_data;
+  GtkSourceCompletion *completion;
+
+  IDE_ENTRY;
+
+  g_assert (IDE_IS_EXTENSION_SET_ADAPTER (adapter));
+  g_assert (plugin_info != NULL);
+  g_assert (GTK_SOURCE_IS_COMPLETION_PROVIDER (provider));
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  g_debug ("Removing completion provider %s from module %s\n",
+           G_OBJECT_TYPE_NAME (provider),
+           peas_plugin_info_get_module_name (plugin_info));
+
+  completion = gtk_source_view_get_completion (GTK_SOURCE_VIEW (self));
+  gtk_source_completion_remove_provider (completion, provider);
+
+  IDE_EXIT;
+}
+
+static void
+ide_source_view_buffer_notify_language_cb (IdeSourceView *self,
+                                           GParamSpec    *pspec,
+                                           IdeBuffer     *buffer)
+{
+  GtkSourceLanguage *language;
+  const char *language_id = NULL;
+
+  IDE_ENTRY;
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+  g_assert (IDE_IS_BUFFER (buffer));
+
+  if ((language = gtk_source_buffer_get_language (GTK_SOURCE_BUFFER (buffer))))
+    language_id = gtk_source_language_get_id (language);
+
+  if (self->completion_providers != NULL)
+    ide_extension_set_adapter_set_value (self->completion_providers, language_id);
+
+  IDE_EXIT;
+}
+
+static void
+ide_source_view_connect_buffer (IdeSourceView *self,
+                                IdeBuffer     *buffer)
+{
+  GtkSourceLanguage *language;
+  const char *language_id = NULL;
+  IdeObjectBox *parent;
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+  g_assert (IDE_IS_BUFFER (buffer));
+  g_assert (self->buffer == NULL);
+
+  g_set_object (&self->buffer, buffer);
+
+  /* Get a handle to the buffers "Box" on the object tree */
+  parent = ide_object_box_from_object (G_OBJECT (buffer));
+
+  /* There are cases where we need to force a scroll to insert
+   * from just an IdeBuffer pointer. Respond to that appropriately
+   * (which generally just happens on load).
+   */
+  g_signal_connect_object (buffer,
+                           "request-scroll-to-insert",
+                           G_CALLBACK (ide_source_view_buffer_request_scroll_to_insert_cb),
+                           self,
+                           G_CONNECT_SWAPPED);
+
+  /* Get the current language for the buffer and be notified of
+   * changes in the future so that we can update providers.
+   */
+  g_signal_connect_object (buffer,
+                           "notify::language",
+                           G_CALLBACK (ide_source_view_buffer_notify_language_cb),
+                           self,
+                           G_CONNECT_SWAPPED);
+  if ((language = gtk_source_buffer_get_language (GTK_SOURCE_BUFFER (buffer))))
+    language_id = gtk_source_language_get_id (language);
+
+  /* Create our completion providers and attach them */
+  self->completion_providers =
+    ide_extension_set_adapter_new (IDE_OBJECT (parent),
+                                   peas_engine_get_default (),
+                                   GTK_SOURCE_TYPE_COMPLETION_PROVIDER,
+                                   "Completion-Provider-Languages",
+                                   language_id);
+  g_signal_connect (self->completion_providers,
+                    "extension-added",
+                    G_CALLBACK (ide_source_view_completion_provider_added_cb),
+                    self);
+  g_signal_connect (self->completion_providers,
+                    "extension-removed",
+                    G_CALLBACK (ide_source_view_completion_provider_removed_cb),
+                    self);
+  ide_extension_set_adapter_foreach (self->completion_providers,
+                                     ide_source_view_completion_provider_added_cb,
+                                     self);
+}
+
+static void
+ide_source_view_disconnect_buffer (IdeSourceView *self)
+{
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  if (self->buffer == NULL)
+    return;
+
+  g_clear_object (&self->completion_providers);
+  g_clear_object (&self->buffer);
+}
+
 static void
 ide_source_view_notify_buffer_cb (IdeSourceView *self,
                                   GParamSpec    *pspec,
@@ -266,18 +417,21 @@ ide_source_view_notify_buffer_cb (IdeSourceView *self,
 {
   GtkTextBuffer *buffer;
 
+  IDE_ENTRY;
+
   g_assert (IDE_IS_SOURCE_VIEW (self));
+  g_assert (user_data == NULL);
 
   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (self));
+  if (buffer == GTK_TEXT_BUFFER (self->buffer))
+    IDE_EXIT;
+
+  ide_source_view_disconnect_buffer (self);
 
   if (IDE_IS_BUFFER (buffer))
-    {
-      g_signal_connect_object (buffer,
-                               "request-scroll-to-insert",
-                               G_CALLBACK (ide_source_view_buffer_request_scroll_to_insert_cb),
-                               self,
-                               G_CONNECT_SWAPPED);
-    }
+    ide_source_view_connect_buffer (self, IDE_BUFFER (buffer));
+
+  IDE_EXIT;
 }
 
 static gboolean
@@ -327,10 +481,14 @@ ide_source_view_dispose (GObject *object)
 
   IDE_ENTRY;
 
+  ide_source_view_disconnect_buffer (self);
+
   g_clear_object (&self->joined_menu);
   g_clear_object (&self->css_provider);
   g_clear_pointer (&self->font_desc, pango_font_description_free);
 
+  g_assert (self->completion_providers == NULL);
+
   G_OBJECT_CLASS (ide_source_view_parent_class)->dispose (object);
 
   IDE_EXIT;