+/**
+ * Function to set the focused pane (viewer).
+ * It will be called by a viewer's signal handle associated with
+ * the grab_focus signal
+ * @param main_win the main window the viewer belongs to.
+ * @param paned a pointer to a pane where the viewer is contained.
+ */
+
+void set_focused_pane(MainWindow *main_win, gpointer paned);
+
+
+/**
+ * Function to register a hook function for a viewer to set/update the
+ * dividor of the hpane.
+ * It will be called by the constructor of the viewer.
+ * @param hook hook function of the viewer.
+ * @param hook_data hook data associated with the hook function.
+ * @param main_win the main window the viewer belongs to.
+ */
+
+void reg_update_dividor(LttvHook hook, gpointer hook_data,
+ MainWindow *main_win);
+
+
+/**
+ * Function to unregister a viewer's hook function which is used to
+ * set/update hpane's dividor of the viewer.
+ * It will be called by the destructor of the viewer.
+ * @param hook hook function of the viewer.
+ * @param hook_data hook data associated with the hook function.
+ * @param main_win the main window the viewer belongs to.
+ */
+
+void unreg_update_dividor(LttvHook hook, gpointer hook_data,
+ MainWindow *main_win);
+
+
+/**
+ * Function to set the position of the hpane's dividor (viewer).
+ * It will be called by a viewer's signal handle associated with
+ * the motion_notify_event event/signal
+ * @param main_win the main window the viewer belongs to.
+ * @param position position of the hpane's dividor.
+ */
+
+void set_hpane_dividor(MainWindow *main_win, gint position);
+
+
+/**
+ * Function to process traceset. It will call lttv_process_trace,
+ * each view will call this api to get events.
+ * @param main_win the main window the viewer belongs to.
+ * @param start the start time of the first event to be processed.
+ * @param end the end time of the last event to be processed.
+ */
+
+void process_traceset_api(MainWindow *main_win, LttTime start,
+ LttTime end, unsigned maxNumEvents);
+
+
+/**
+ * Function to add hooks into the context of a traceset,
+ * before reading events from traceset, viewer will call this api to
+ * register hooks
+ * @param main_win the main window the viewer belongs to.
+ * @param LttvHooks hooks to be registered.
+ */
+
+void context_add_hooks_api(MainWindow *main_win ,
+ LttvHooks *before_traceset,
+ LttvHooks *after_traceset,
+ LttvHooks *check_trace,
+ LttvHooks *before_trace,
+ LttvHooks *after_trace,
+ LttvHooks *check_tracefile,
+ LttvHooks *before_tracefile,
+ LttvHooks *after_tracefile,
+ LttvHooks *check_event,
+ LttvHooks *before_event,
+ LttvHooks *after_event);
+
+
+/**
+ * Function to remove hooks from the context of a traceset,
+ * before reading events from traceset, viewer will call this api to
+ * unregister hooks
+ * @param main_win the main window the viewer belongs to.
+ * @param LttvHooks hooks to be registered.
+ */
+
+void context_remove_hooks_api(MainWindow *main_win ,
+ LttvHooks *before_traceset,
+ LttvHooks *after_traceset,
+ LttvHooks *check_trace,
+ LttvHooks *before_trace,
+ LttvHooks *after_trace,
+ LttvHooks *check_tracefile,
+ LttvHooks *before_tracefile,
+ LttvHooks *after_tracefile,
+ LttvHooks *check_event,
+ LttvHooks *before_event,
+ LttvHooks *after_event);
+
+
+/**
+ * Function to get the life span of the traceset
+ * @param main_win the main window the viewer belongs to.
+ * @param start start time of the traceset.
+ * @param end end time of the traceset.
+ */
+
+void get_traceset_time_span(MainWindow *main_win, TimeInterval *time_span);
+
+
+/**
+ * Function to add/remove event hooks for state
+ * @param main_win the main window the viewer belongs to.
+ */
+
+void state_add_event_hooks_api(MainWindow *main_win );
+void state_remove_event_hooks_api(MainWindow *main_win );
+
+
+/**
+ * Function to add/remove event hooks for stats
+ * @param main_win the main window the viewer belongs to.
+ */
+
+void stats_add_event_hooks_api(MainWindow *main_win );
+void stats_remove_event_hooks_api(MainWindow *main_win );
+
+
+/**
+ * Function to get the stats of the traceset
+ * @param main_win the main window the viewer belongs to.
+ */
+
+LttvTracesetStats* get_traceset_stats_api(MainWindow *main_win);