sp_object_invoke_release -> SPObject::releaseReferences, plus the introduction of sigc++ signals for "release" and "modified" which will eventually replace their GObject signal counterparts

(bzr r1447)

3 files changed, 57 insertions, 28 deletions

diff --git a/src/document.cpp b/src/document.cpp
index 44e13b4f2..3077198cf 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -131,7 +131,7 @@ SPDocument::~SPDocument() {
         sp_document_clear_undo(this);
 
         if (root) {
-            sp_object_invoke_release(root);
+            root->releaseReferences();
             sp_object_unref(root);
             root = NULL;
         }
diff --git a/src/sp-object.cpp b/src/sp-object.cpp
index 8a96258e8..43611e9ed 100644
--- a/src/sp-object.cpp
+++ b/src/sp-object.cpp
@@ -195,6 +195,8 @@ sp_object_init(SPObject *object)
 
     object->_collection_policy = SPObject::COLLECT_WITH_PARENT;
 
+    new (&object->_release_signal) sigc::signal<void, SPObject *>();
+    new (&object->_modified_signal) sigc::signal<void, SPObject *, unsigned int>();
     new (&object->_delete_signal) sigc::signal<void, SPObject *>();
     new (&object->_position_changed_signal) sigc::signal<void, SPObject *>();
     object->_successor = NULL;
@@ -225,6 +227,8 @@ sp_object_finalize(GObject *object)
         (* ((GObjectClass *) (parent_class))->finalize)(object);
     }
 
+    spobject->_release_signal.~signal();
+    spobject->_modified_signal.~signal();
     spobject->_delete_signal.~signal();
     spobject->_position_changed_signal.~signal();
 }
@@ -653,7 +657,7 @@ sp_object_detach(SPObject *parent, SPObject *object) {
     g_return_if_fail(SP_IS_OBJECT(object));
     g_return_if_fail(object->parent == parent);
 
-    sp_object_invoke_release(object);
+    object->releaseReferences();
 
     SPObject *prev=NULL;
     for ( SPObject *child = parent->children ; child && child != object ;
@@ -859,45 +863,41 @@ sp_object_invoke_build(SPObject *object, SPDocument *document, Inkscape::XML::No
     sp_repr_add_listener(repr, &object_event_vector, object);
 }
 
-void
-sp_object_invoke_release(SPObject *object)
-{
-    g_assert(object != NULL);
-    g_assert(SP_IS_OBJECT(object));
-
-    g_assert(object->document);
-    g_assert(object->repr);
+void SPObject::releaseReferences() {
+    g_assert(this->document);
+    g_assert(this->repr);
 
-    sp_repr_remove_listener_by_data(object->repr, object);
+    sp_repr_remove_listener_by_data(this->repr, this);
 
-    g_signal_emit(G_OBJECT(object), object_signals[RELEASE], 0);
+    g_signal_emit(G_OBJECT(this), object_signals[RELEASE], 0);
+    this->_release_signal.emit(this);
 
     /* all hrefs should be released by the "release" handlers */
-    g_assert(object->hrefcount == 0);
+    g_assert(this->hrefcount == 0);
 
-    if (!SP_OBJECT_IS_CLONED(object)) {
-        if (object->id) {
-            object->document->bindObjectToId(object->id, NULL);
+    if (!SP_OBJECT_IS_CLONED(this)) {
+        if (this->id) {
+            this->document->bindObjectToId(this->id, NULL);
         }
-        g_free(object->id);
-        object->id = NULL;
+        g_free(this->id);
+        this->id = NULL;
 
-        g_free(object->_default_label);
-        object->_default_label = NULL;
+        g_free(this->_default_label);
+        this->_default_label = NULL;
 
-        object->document->bindObjectToRepr(object->repr, NULL);
+        this->document->bindObjectToRepr(this->repr, NULL);
     } else {
-        g_assert(!object->id);
+        g_assert(!this->id);
     }
 
-    if (object->style) {
-        object->style = sp_style_unref(object->style);
+    if (this->style) {
+        this->style = sp_style_unref(this->style);
     }
 
-    Inkscape::GC::release(object->repr);
+    Inkscape::GC::release(this->repr);
 
-    object->document = NULL;
-    object->repr = NULL;
+    this->document = NULL;
+    this->repr = NULL;
 }
 
 /**
@@ -1303,6 +1303,7 @@ SPObject::emitModified(unsigned int flags)
 
     g_object_ref(G_OBJECT(this));
     g_signal_emit(G_OBJECT(this), object_signals[MODIFIED], 0, flags);
+    _modified_signal.emit(this, flags);
     g_object_unref(G_OBJECT(this));
 }
 
diff --git a/src/sp-object.h b/src/sp-object.h
index 054fb6c7a..b563d8d3b 100644
--- a/src/sp-object.h
+++ b/src/sp-object.h
@@ -158,6 +158,21 @@ struct SPObject : public GObject {
     Inkscape::XML::Node *repr; /* Our xml representation */
     gchar *id; /* Our very own unique id */
 
+    /** @brief cleans up an SPObject, releasing its references and
+     *         requesting that references to it be released
+     */
+    void releaseReferences();
+
+    /** @brief connects to the release request signal
+     *
+     *  @param slot the slot to connect
+     *
+     *  @returns the sigc::connection formed
+     */
+    sigc::connection connectRelease(sigc::slot<void, SPObject *> slot) {
+        return _release_signal.connect(slot);
+    }
+
     /**
      * Represents the style properties, whether from presentation attributes, the <tt>style</tt>
      * attribute, or inherited.
@@ -445,6 +460,18 @@ struct SPObject : public GObject {
      */
     void emitModified(unsigned int flags);
 
+    /** @brief Connects to the modification notification signal
+     *
+     *  @param slot the slot to connect
+     *
+     *  @returns the connection formed thereby
+     */
+    sigc::connection connectModified(
+      sigc::slot<void, SPObject *, unsigned int> slot
+    ) {
+        return _modified_signal.connect(slot);
+    }
+
     void _sendDeleteSignalRecursive();
     void _updateTotalHRefCount(int increment);
 
@@ -453,8 +480,10 @@ struct SPObject : public GObject {
     }
     void _requireSVGVersion(Inkscape::Version version);
 
+    sigc::signal<void, SPObject *> _release_signal;
     sigc::signal<void, SPObject *> _delete_signal;
     sigc::signal<void, SPObject *> _position_changed_signal;
+    sigc::signal<void, SPObject *, unsigned int> _modified_signal;
     SPObject *_successor;
     CollectionPolicy _collection_policy;
     gchar *_label;
@@ -501,7 +530,6 @@ inline SPObject *sp_object_first_child(SPObject *parent) {
 SPObject *sp_object_get_child_by_repr(SPObject *object, Inkscape::XML::Node *repr);
 
 void sp_object_invoke_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr, unsigned int cloned);
-void sp_object_invoke_release(SPObject *object);
 
 void sp_object_set(SPObject *object, unsigned int key, gchar const *value);