[gstreamermm: 54/167] fixed query class

[Murray Cumming <murrayc src gnome org>]

commit 518421ab76b08eaba65b40ef29b75268479c2865
Author: Marcin Kolny at Flytronic <marcin kolny flytronic pl>
Date:   Fri Jul 26 13:54:12 2013 +0200

    fixed query class

 gstreamer/src/query.ccg |   60 +++++++++-------------------------------------
 gstreamer/src/query.hg  |   22 ++++++++++-------
 2 files changed, 25 insertions(+), 57 deletions(-)
---
diff --git a/gstreamer/src/query.ccg b/gstreamer/src/query.ccg
index 0b106ae..5b1f07f 100644
--- a/gstreamer/src/query.ccg
+++ b/gstreamer/src/query.ccg
@@ -46,30 +46,22 @@ Glib::RefPtr<Gst::Query> Query::create_writable()
   return Glib::wrap(gst_query_make_writable(gobj()));
 }
 
-QueryApplication::QueryApplication(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryApplication>
   QueryApplication::create(QueryType type, Gst::Structure& structure)
 {
   // Create copy because query takes ownership of structure:
   GstStructure* copy_struct = gst_structure_copy(structure.gobj());
-  GstQuery* query = gst_query_new_application(GstQueryType(type),
+  GstQuery* query = gst_query_new_custom(GstQueryType(type),
     copy_struct); 
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryApplication>(query);
 }
 
-QueryConvert::QueryConvert(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryConvert>
   QueryConvert::create(Format src_format, gint64 value, Format dest_format)
 {
   GstQuery* query = gst_query_new_convert(GstFormat(src_format), value,
     GstFormat(dest_format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryConvert>(query);
 }
 
 void QueryConvert::set(Format src_format, gint64 src_value, Format dest_format, gint64 dest_value)
@@ -122,14 +114,10 @@ gint64 QueryConvert::parse_dest_value() const
   return dest_value;
 }
 
-QueryPosition::QueryPosition(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryPosition> QueryPosition::create(Format format)
 {
   GstQuery* query = gst_query_new_position(GstFormat(format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryPosition>(query);
 }
 
 void QueryPosition::set(Format format, gint64 position)
@@ -158,14 +146,10 @@ Format QueryPosition::parse_format() const
   return format;
 }
 
-QueryDuration::QueryDuration(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryDuration> QueryDuration::create(Format format)
 {
   GstQuery* query = gst_query_new_duration(GstFormat(format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryDuration>(query);
 }
 
 void QueryDuration::set(Format format, gint64 duration)
@@ -194,14 +178,10 @@ Format QueryDuration::parse_format() const
   return format;
 }
 
-QueryLatency::QueryLatency(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryLatency> QueryLatency::create()
 {
   GstQuery* query = gst_query_new_latency();
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryLatency>(query);
 }
 
 void QueryLatency::set(bool live, ClockTime min_latency, ClockTime max_latency)
@@ -241,14 +221,10 @@ ClockTime QueryLatency::parse_max() const
   return max;
 }
 
-QuerySeeking::QuerySeeking(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QuerySeeking> QuerySeeking::create(Format format)
 {
   GstQuery* query = gst_query_new_seeking(GstFormat(format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QuerySeeking>(query);
 }
 
 void QuerySeeking::set(Format format, bool seekable, gint64 segment_start, gint64 segment_end)
@@ -297,14 +273,10 @@ gint64 QuerySeeking::parse_end() const
   return end;
 }
 
-QueryFormats::QueryFormats(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryFormats> QueryFormats::create()
 {
   GstQuery* query = gst_query_new_formats();
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryFormats>(query);
 }
 
 void QueryFormats::set(const Glib::ArrayHandle<Format>& formats)
@@ -322,26 +294,22 @@ void QueryFormats::set(int n_formats, const Glib::ArrayHandle<Format>& formats)
 guint QueryFormats::parse_length() const
 {
   guint n_formats = 0;
-  gst_query_parse_formats_length(const_cast<GstQuery*>(gobj()), &n_formats);
+  gst_query_parse_n_formats(const_cast<GstQuery*>(gobj()), &n_formats);
   return n_formats;
 }
 
 Format QueryFormats::parse(guint nth) const
 {
   Format format = Gst::FORMAT_UNDEFINED;
-  gst_query_parse_formats_nth(const_cast<GstQuery*>(gobj()), nth,
+  gst_query_parse_nth_format(const_cast<GstQuery*>(gobj()), nth,
     reinterpret_cast<GstFormat*>(&format));
   return format;
 }
 
-QuerySegment::QuerySegment(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QuerySegment> QuerySegment::create(Format format)
 {
   GstQuery* query = gst_query_new_segment(GstFormat(format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QuerySegment>(query);
 }
 
 void QuerySegment::set(double rate, Format format, gint64 start_value, gint64 stop_value)
@@ -388,14 +356,10 @@ gint64 QuerySegment::parse_stop() const
   return stop;
 }
 
-QueryBuffering::QueryBuffering(GstQuery* castitem) :
-Query(castitem)
-{}
-
 Glib::RefPtr<Gst::QueryBuffering> QueryBuffering::create(Format format)
 {
   GstQuery* query = gst_query_new_buffering(GstFormat(format));
-  return Glib::wrap(query);
+  return Glib::wrap_query_derived<Gst::QueryBuffering>(query);
 }
 
 void QueryBuffering::set(bool busy, int percent)
diff --git a/gstreamer/src/query.hg b/gstreamer/src/query.hg
index ac6f79d..01a83e3 100644
--- a/gstreamer/src/query.hg
+++ b/gstreamer/src/query.hg
@@ -25,6 +25,19 @@
 
 _DEFS(gstreamermm,gst)
 
+namespace Glib
+{
+    template<typename T>
+    Glib::RefPtr<T> wrap_query_derived(GstQuery* object, bool take_copy = false)
+    {
+      if(take_copy && object)
+        gst_query_ref(object);
+
+      // See the comment at the top of this file, if you want to know why the cast works.
+      return Glib::RefPtr<T>(reinterpret_cast<T*>(object));
+    }
+}
+
 namespace Gst
 {
 
@@ -141,7 +154,6 @@ protected:
 class QueryApplication : public Query
 {
 public:
-  explicit QueryApplication(GstQuery* query);
 
   /** Constructs a new custom application query object.  The Gst::Query may be
    * used by applications in their own way.  Please note that a custom
@@ -160,7 +172,6 @@ public:
 class QueryConvert : public Query
 {
 public:
-  explicit QueryConvert(GstQuery* query);
 
   /** Constructs a new convert query object.  A convert query is used to ask
    * for a conversion between one format and another.
@@ -225,7 +236,6 @@ public:
 class QueryPosition : public Query
 {
 public:
-  explicit QueryPosition(GstQuery* query);
 
   /** Constructs a new query stream position query object. A position query is
    * used to query the current position of playback in the streams, in some
@@ -266,7 +276,6 @@ public:
 class QueryDuration : public Query
 {
 public:
-  explicit QueryDuration(GstQuery* query);
 
   /** Constructs a new stream duration query object to query in the given
    * format. A duration query will give the total length of the stream.
@@ -306,7 +315,6 @@ public:
 class QueryLatency : public Query
 {
 public:
-  explicit QueryLatency(GstQuery* query);
 
   /** Constructs a new latency query object. A latency query is usually
    * performed by sinks to compensate for additional latency introduced by
@@ -352,7 +360,6 @@ public:
 class QuerySeeking : public Query
 {
 public:
-  explicit QuerySeeking(GstQuery* query);
 
   /** Constructs a new query object for querying seeking properties of the
    * stream.
@@ -406,7 +413,6 @@ public:
 class QueryFormats : public Query
 {
 public:
-  explicit QueryFormats(GstQuery* query);
 
   /** Constructs a new query object for querying formats of the stream.
    * @return The new Gst::QueryFormats.
@@ -447,7 +453,6 @@ public:
 class QuerySegment : public Query
 {
 public:
-  explicit QuerySegment(GstQuery* query);
 
   /** Constructs a new segment query object. A segment query is used to
    * discover information about the currently configured segment for playback.
@@ -516,7 +521,6 @@ public:
 class QueryBuffering : public Query
 {
 public:
-  explicit QueryBuffering(GstQuery* query);
 
   /** Constructs a new query object for querying the buffering status of a
    * stream.