[gnome-builder] xml: use EggSignalGroup

[Christian Hergert <chergert src gnome org>]

commit 9050968de1c0db6574474ba04b0f05de910e2e70
Author: Christian Hergert <christian hergert me>
Date:   Thu May 14 02:24:39 2015 -0700

    xml: use EggSignalGroup
    
    This fixes a couple of things.
    
     - ide_xml_highlighter_on_buffer_set() thought param 3 was an IdeBuffer.
       It is really an IdeHighlightEngine which we can use to get the
       IdeBuffer. This was the main point of assertion failure.
     - Switch to EggSignalGroup so that tracking weak pointers is not
       required by us. We can just grab the buffer instance from the
       target property of the signal group. (Yay, less things to manage)
     - Use G_SOURCE_REMOVE instead of FALSE. More readable.
     - We can use bitfields for booleans in the struct
     - Short circuit in the timeout if we cant find our buffer
    
    The stashing of the iter in the instance struct doesn't look safe at
    first, but by all accounts I can't prove that it isn't. So fine by me.

 libide/xml/ide-xml-highlighter.c |  121 ++++++++++++++++++-------------------
 1 files changed, 59 insertions(+), 62 deletions(-)
---
diff --git a/libide/xml/ide-xml-highlighter.c b/libide/xml/ide-xml-highlighter.c
index 0404d2f..625c8a2 100644
--- a/libide/xml/ide-xml-highlighter.c
+++ b/libide/xml/ide-xml-highlighter.c
@@ -18,6 +18,8 @@
 
 #include <glib/gi18n.h>
 
+#include "egg-signal-group.h"
+
 #include "ide-xml-highlighter.h"
 #include "ide-context.h"
 #include "ide-buffer.h"
@@ -31,10 +33,10 @@ struct _IdeXmlHighlighter
 {
   IdeHighlighter  parent_instance;
 
-  gboolean        has_tags;
-  guint           highlight_timeout;
+  EggSignalGroup *signal_group;
   GtkTextIter     iter;
-  IdeBuffer      *buffer;
+  guint           highlight_timeout;
+  guint           has_tags : 1;
 };
 
 G_DEFINE_TYPE (IdeXmlHighlighter, ide_xml_highlighter, IDE_TYPE_HIGHLIGHTER)
@@ -51,15 +53,20 @@ ide_xml_highlighter_highlight_timeout_handler (gpointer data)
 
   g_assert (IDE_IS_XML_HIGHLIGHTER (self));
 
+  /*
+   * If we lost our buffer handle, nothing we can do!
+   */
+  buffer = egg_signal_group_get_target (self->signal_group);
+  if (!GTK_IS_TEXT_BUFFER (buffer))
+    goto finished;
+
   engine = ide_highlighter_get_highlight_engine (IDE_HIGHLIGHTER (self));
   tag = ide_highlight_engine_get_style (engine, XML_TAG_MATCH_STYLE_NAME);
 
-  buffer = GTK_TEXT_BUFFER (self->buffer);
-
   /*
-   * Clear previous tags.We could save the previous
+   * Clear previous tags. We could save the previous
    * iters and clear only those locations but for
-   * now this should be ok
+   * now this should be ok.
    */
   if (self->has_tags)
     {
@@ -114,8 +121,9 @@ ide_xml_highlighter_highlight_timeout_handler (gpointer data)
         }
     }
 
+finished:
   self->highlight_timeout = 0;
-  return FALSE;
+  return G_SOURCE_REMOVE;
 }
 
 static void
@@ -125,19 +133,15 @@ ide_xml_highlighter_cursor_moved_cb (GtkTextBuffer     *buffer,
 {
   g_assert (IDE_IS_HIGHLIGHTER (self));
 
-  if (self->highlight_timeout != 0)
-    {
-      g_source_remove (self->highlight_timeout);
-      self->highlight_timeout = 0;
-    }
-
   self->iter = *iter;
+
+  if (self->highlight_timeout != 0)
+    g_source_remove (self->highlight_timeout);
   self->highlight_timeout = g_timeout_add (HIGHLIGH_TIMEOUT_MSEC,
                                            ide_xml_highlighter_highlight_timeout_handler,
                                            self);
 }
 
-
 static void
 ide_xml_highlighter_set_buffer (IdeXmlHighlighter *highlighter,
                                 IdeBuffer         *buffer)
@@ -147,38 +151,21 @@ ide_xml_highlighter_set_buffer (IdeXmlHighlighter *highlighter,
   g_assert (IDE_IS_HIGHLIGHTER (self));
   g_assert (!buffer || IDE_IS_BUFFER (buffer));
 
-  if (self->buffer != buffer)
-    {
-      if (self->buffer != NULL)
-        {
-          g_signal_handlers_disconnect_by_func (self->buffer,
-                                                G_CALLBACK (ide_xml_highlighter_cursor_moved_cb),
-                                                self);
-          ide_clear_weak_pointer (&self->buffer);
-        }
-
-      if (buffer != NULL)
-        {
-          g_signal_connect (buffer,
-                            "cursor-moved",
-                            G_CALLBACK (ide_xml_highlighter_cursor_moved_cb),
-                            self);
-          ide_set_weak_pointer (&self->buffer, buffer);
-        }
-
-    }
+  egg_signal_group_set_target (self->signal_group, buffer);
 }
 
 static void
-ide_xml_highlighter_on_buffer_set (IdeHighlighter *self,
-                                   GParamSpec     *pspec,
-                                   IdeBuffer      *buffer)
+ide_xml_highlighter_on_buffer_set (IdeXmlHighlighter  *self,
+                                   GParamSpec         *pspec,
+                                   IdeHighlightEngine *engine)
 {
-  IdeXmlHighlighter *highlighter = IDE_XML_HIGHLIGHTER (self);
+  IdeBuffer *buffer;
 
-  g_assert (IDE_IS_XML_HIGHLIGHTER (highlighter));
+  g_assert (IDE_IS_XML_HIGHLIGHTER (self));
+  g_assert (IDE_IS_HIGHLIGHT_ENGINE (engine));
 
-  ide_xml_highlighter_set_buffer (highlighter, buffer);
+  buffer = ide_highlight_engine_get_buffer (engine);
+  ide_xml_highlighter_set_buffer (self, buffer);
 }
 
 static void
@@ -186,29 +173,28 @@ ide_xml_highlighter_on_highlight_engine_set (IdeHighlighter  *self,
                                              GParamSpec      *pspec,
                                              gpointer        *data)
 {
-  IdeXmlHighlighter *highlighter = IDE_XML_HIGHLIGHTER (self);
-  IdeHighlightEngine *engine = ide_highlighter_get_highlight_engine (self);
+  IdeXmlHighlighter *highlighter = (IdeXmlHighlighter *)self;
+  IdeHighlightEngine *engine;
+  IdeBuffer *buffer = NULL;
 
   g_assert (IDE_IS_XML_HIGHLIGHTER (highlighter));
-  g_assert (engine != NULL);
-
-  ide_xml_highlighter_set_buffer (highlighter, ide_highlight_engine_get_buffer (engine));
-  g_signal_connect_object (engine,
-                           "notify::buffer",
-                           G_CALLBACK (ide_xml_highlighter_on_buffer_set),
-                           self,
-                           G_CONNECT_SWAPPED);
-}
 
-static void
-ide_xml_highlighter_constructed (GObject *object)
-{
-  IdeXmlHighlighter *self = (IdeXmlHighlighter *)object;
+  if ((engine = ide_highlighter_get_highlight_engine (self)))
+    {
+      buffer = ide_highlight_engine_get_buffer (engine);
+      /*
+       * TODO: technically we should connect/disconnect when the
+       *       highlighter changes. but in practice, it is set only
+       *       once.
+       */
+      g_signal_connect_object (engine,
+                               "notify::buffer",
+                               G_CALLBACK (ide_xml_highlighter_on_buffer_set),
+                               self,
+                               G_CONNECT_SWAPPED);
+    }
 
-  g_signal_connect (self,
-                    "notify::highlight-engine",
-                    G_CALLBACK (ide_xml_highlighter_on_highlight_engine_set),
-                    NULL);
+  ide_xml_highlighter_set_buffer (highlighter, buffer);
 }
 
 static void
@@ -221,7 +207,8 @@ ide_xml_highlighter_engine_dispose (GObject *object)
       g_source_remove (self->highlight_timeout);
       self->highlight_timeout = 0;
     }
-  ide_clear_weak_pointer (&self->buffer);
+
+  g_clear_object (&self->signal_group);
 
   G_OBJECT_CLASS (ide_xml_highlighter_parent_class)->dispose (object);
 }
@@ -232,10 +219,20 @@ ide_xml_highlighter_class_init (IdeXmlHighlighterClass *klass)
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
   object_class->dispose = ide_xml_highlighter_engine_dispose;
-  object_class->constructed = ide_xml_highlighter_constructed;
 }
 
 static void
 ide_xml_highlighter_init (IdeXmlHighlighter *self)
 {
+  g_signal_connect (self,
+                    "notify::highlight-engine",
+                    G_CALLBACK (ide_xml_highlighter_on_highlight_engine_set),
+                    NULL);
+
+  self->signal_group = egg_signal_group_new (IDE_TYPE_BUFFER);
+  egg_signal_group_connect_object (self->signal_group,
+                                   "cursor-moved",
+                                   G_CALLBACK (ide_xml_highlighter_cursor_moved_cb),
+                                   self,
+                                   0);
 }