Added SelectionListener handling selection changing events

src/gui/widgets/timeline/timeline-ibeam-tool.cpp

@@ -49,7 +49,8 @@ IBeamTool::IBeamTool(TimelineBody &timeline_body) :
   scrollSlideRate(0)
 {
   // Connect the timlinebody selection to the selectionControl
-  this->get_state()->setSelection (selectionControl, false);
+  // TODO: Create a virtual initialize function in the base class
+  get_state()->set_selection_control(selectionControl);
 }
 
 IBeamTool::~IBeamTool()

src/gui/widgets/timeline/timeline-state.cpp

@@ -24,6 +24,7 @@
 #include "gui/widgets/timeline/timeline-state.hpp"
 #include "lib/time/timevalue.hpp"
 #include "lib/time/mutation.hpp"
+#include "lib/time/control.hpp"
 
 using namespace Gtk;
 using namespace sigc;
@@ -36,14 +37,15 @@ using lib::time::FSecs;
 using lib::time::Offset;
 using lib::time::Duration;
 using lib::time::Mutation;
+using lib::time::Control;
 using std::tr1::shared_ptr;
 
 
-
 TimelineState::TimelineState (shared_ptr<model::Sequence> source_sequence)
   : sequence(source_sequence)
   , viewWindow(Offset(Time::ZERO), 1)
   , selection_(Time::ZERO, Duration::NIL)
+  , selectionListener()
   , playbackPeriod_(Time::ZERO, Duration::NIL)
   , playbackPoint_(Time::ZERO)
   , isPlayback_(false)
@@ -55,6 +57,9 @@ TimelineState::TimelineState (shared_ptr<model::Sequence> source_sequence)
   
   viewWindow.set_time_scale(DEFAULT_TIMELINE_SCALE);
 
+  selectionListener.connect(
+      mem_fun(*this, &TimelineState::on_selection_changed));
+
   setSelection (Mutation::changeTime (Time(FSecs(2))));
   setSelection (Mutation::changeDuration(Duration(FSecs(2))));
   //////////////////////////////////////////////////////TICKET #797 : this is cheesy. Should provide a single Mutation to change all
@@ -97,6 +102,14 @@ TimelineState::setPlaybackPoint (Time newPosition)
   playbackChangedSignal.emit();
 }
 
+void
+TimelineState::set_selection_control (SelectionControl &control)
+{
+  control.disconnect();
+  selection_.accept (control);
+  control.connectChangeNotification (selectionListener);
+}
+
 sigc::signal<void>
 TimelineState::selection_changed_signal() const
 {
@@ -109,6 +122,12 @@ TimelineState::playback_changed_signal() const
   return playbackChangedSignal;
 }
 
+void
+TimelineState::on_selection_changed()
+{
+  selectionChangedSignal.emit();
+}
+
 }   // namespace timeline
 }   // namespace widgets
 }   // namespace gui

src/gui/widgets/timeline/timeline-state.hpp

@@ -28,6 +28,7 @@
 
 #include "gui/widgets/timeline/timeline-view-window.hpp"
 #include "lib/time/mutation.hpp"
+#include "lib/time/control.hpp"
 
 
 namespace gui {
@@ -39,8 +40,41 @@ class Sequence;
 namespace widgets { 
 namespace timeline {
 
+using lib::time::Control;
 using lib::time::Mutation;
 
+typedef Control<TimeSpan> SelectionControl;
+
+/**
+ * SelectionListener is a template class which emits a signal when
+ * the value is changed by it's associated time::Control object.
+ */
+template<class TI>
+class SelectionListener
+  : boost::noncopyable
+  {
+    sigc::signal<void> valueChangedSignal;
+  public:
+    SelectionListener()
+      {
+
+      }
+
+
+    void
+    operator() (TI const& changeValue)  const
+      {
+        valueChangedSignal.emit();
+      }
+
+
+    void connect (const sigc::slot<void> &connection)
+      {
+        valueChangedSignal.connect (connection);
+      }
+
+  };
+
 /**
  * TimelineState is a container for the state data for TimelineWidget.
  * @remarks TimelineState s can be swapped out so that TimelineWidget
@@ -70,7 +104,11 @@ public:
    */
   timeline::TimelineViewWindow& get_view_window();
   
-  TimeSpan get_selection()      const { return selection_; }
+  TimeSpan& get_selection()           { return selection_; }
+
+  SelectionListener<TimeSpan>&
+  get_selection_listener()            { return selectionListener; }
+
   Time getSelectionStart()      const { return selection_.start();}
   Time getSelectionEnd()        const { return selection_.end();  }
   Time getPlaybackPeriodStart() const { return selection_.start();}
@@ -83,6 +121,7 @@ public:
    *  Otherwise the #getPlaybackPoint is meaningless */
   bool isPlaying() const { return isPlayback_; }
   
+  void set_selection_control (SelectionControl &control);
   
   /**
    * Sets the period of the selection.
@@ -114,6 +153,15 @@ public:
    */
   sigc::signal<void> playback_changed_signal() const; 
 
+private:
+
+  /* ========= Event Handlers ========== */
+
+  /**
+   * Event handler for when the selection is changed
+   */
+  void on_selection_changed();
+  
 private:
 
   /**
@@ -134,6 +182,9 @@ private:
   /** currently selected time period. */
   TimeSpan selection_;
   
+  /** listens for a selection change */
+  SelectionListener<TimeSpan> selectionListener;
+
   /** current playback period. */
   TimeSpan playbackPeriod_;