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[lttv.git] / ltt / branches / poly / lttv / modules / gui / lttvwindow / lttvwindow / viewer.h

/* This file is part of the Linux Trace Toolkit Graphic User Interface
 * Copyright (C) 2003-2004 Xiangxiu Yang, Mathieu Desnoyers
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, 
 * MA 02111-1307, USA.
 */

/*
This file is what every viewer plugin writer should refer to.


Module Related API

A viewer plugin is, before anything, a plugin. As a dynamically loadable 
module, it thus has an init and a destroy function called whenever it is
loaded/initialized and unloaded/destroyed. A graphical module depends on
lttvwindow for construction of its viewer instances. In order to achieve this,
it must register its constructor function to the main window along with
button description or text menu entry description. A module keeps a list of
every viewer that currently sits in memory so it can destroy them before the
module gets unloaded/destroyed.


Main Window

The main window is a container that offers menus, buttons and a notebook. Some
of those menus and buttons are part of the core of the main window, others
are dynamically added and removed when modules are loaded/unloaded.

The notebook contains as much tabs as wanted. Each tab is linked with a
set of traces (traceset). Each trace contains many tracefiles (one per cpu).
A trace corresponds to a kernel being traced. A traceset corresponds to
many traces read together. The time span of a traceset goes from the
earliest start of all the traces to the latest end of all the traces.

Inside each tab are added the viewers. When they interact with the main
window through the lttvwindow API, they affect the other viewers located
in the same tab as they are.

The insertion of many viewers in a tab permits a quick look at all the
information wanted in a glance. The main window does merge the read requests
from all the viewers in the same tab in a way that every viewer will get exactly
the events it asked for, while the event reading loop and state update are
shared. It improves performance of events delivery to the viewers.



Viewer Instance Related API

The lifetime of a viewer is as follows. The viewer constructor function is
called each time an instance view is created (one subwindow of this viewer
type is created by the user either by clicking on the menu item or the button
corresponding to the viewer). Thereafter, the viewer gets hooks called for
different purposes by the window containing it. These hooks are detailed
below. It also has to deal with GTK Events. Finally, it can be destructed by
having its top level widget unreferenced by the main window or by any
GTK Event causing a "destroy-event" signal on the its top widget. Another
possible way for it do be destroyed is if the module gets unloaded. The module
unload function will have to emit a "destroy" signal on each top level widget
of all instances of its viewers.


Notices from Main Window

time_window : This is the time interval visible on the viewer's tab. Every
              viewer that cares about being synchronised by respect to the
              time with other viewers should register to this notification.
              They should redraw all or part of their display when this occurs.

traceset :    This notification is called whenever a trace is added/removed
              from the traceset. As it affects all the data displayed by the
              viewer, it sould redraw itself totally.

filter :      FIXME : describe..

current_time: Being able to zoom nearer a specific time or highlight a specific
              time on every viewer in synchronicity implies that the viewer
              has to shown a visual sign over the drawing or select an event
              when it receives this notice. It should also inform the main
              window with the appropriate report API function when a user
              selects a specific time as being the current time.

dividor :     This notice links the positions of the horizontal dividors
              between the graphic display zone of every viewer and their Y axis,
              typically showing processes, cpus, ...
              

FIXME : Add background computation explanation here
background_init: prepare for background computation (comes after show_end).
process_trace for background: done in small chunks in gtk_idle, hooks called.
background_end: remove the hooks and perhaps update the window.


Reporting Changes to the Main Window

In most cases, the enclosing window knows about updates such as described in the
Notification section higher. There are a few cases, however, where updates are
caused by actions known by a view instance. For example, clicking in a view may
update the current time; all viewers within the same window must be told about
the new current time to change the currently highlighted time point. A viewer
reports such events by calling lttvwindow_report_current_time on its lttvwindow.
The lttvwindow will consequently call current_time_notify for each of its 
contained viewers.


Available report methods are :

lttvwindow_report_status : reports the text of the status bar.
lttvwindow_report_time_window : reports the new time window.
lttvwindow_report_current_time : reports the new current time.
lttvwindow_report_dividor : reports the new horizontal dividor's position.
lttvwindow_report_focus : One on the widgets in the viewer has the keyboard's
                          focus from GTK.



Requesting Events to Main Window

Events can be requested by passing a EventsRequest structure to the main window.
They will be delivered later when the next g_idle functions will be called.
Event delivery is done by calling the event hook for this event ID, or the 
main event hooks. A pointer to the EventsRequest structure is passed as 
hook_data to the event hooks of the viewers.

EventsRequest consists in 
- a pointer to the viewer specific data structure
- a start timestamp or position
- a stop_flag, ending the read process when set to TRUE
- a end timestamp and/or position and/or number of events to read
- hook lists to call for traceset/trace/tracefile begin and end, and for each
  event (event hooks and event_by_id hooks).
  
The main window will deliver events for every EventRequests it has pending
through an algorithm that guarantee that all events requested, and only them,
will be delivered to the viewer between the call of the tracefile_begin hooks
and the call of the tracefile_end hooks.

If a viewer wants to stop the event request at a certain point inside the event
hooks, it has to set the stop_flag to TRUE and return TRUE from the hook
function. Then return value will stop the process traceset. Then, the main
window will look for the stop_flag and remove the EventRequests from its lists,
calling the process_traceset_end for this request (it removes hooks from the
context and calls the after hooks).

It no stop_flag is rose, the end timestamp, end position or number of events to
read has to be reached to determine the end of the request. Otherwise,
the end of traceset does determine it.


GTK Events

Events and Signals

GTK is quite different from the other graphical toolkits around there. The main
difference resides in that there are many X Windows inside one GtkWindow,
instead of just one. That means that X events are delivered by the glib main 
loop directly to the widget corresponding to the GdkWindow affected by the X
event.

Event delivery to a widget emits a signal on that widget. Then, if a handler
is connected to this widget's signal, it will be executed. There are default
handlers for signals, connected at class instantiation time. There is also
the possibility to connect other handlers to these signals, which is what
should be done in most cases when a viewer needs to interact with X in any
way.



Signal emission and propagation is described there : 

http://www.gtk.org/tutorial/sec-signalemissionandpropagation.html

For further information on the GTK main loop (now a wrapper over glib main loop)
see :

http://developer.gnome.org/doc/API/2.0/gtk/gtk-General.html
http://developer.gnome.org/doc/API/2.0/glib/glib-The-Main-Event-Loop.html


For documentation on event handling in GTK/GDK, see :

http://developer.gnome.org/doc/API/2.0/gdk/gdk-Events.html
http://developer.gnome.org/doc/API/2.0/gdk/gdk-Event-Structures.html


Signals can be connected to handlers, emitted, propagated, blocked, 
stopped. See :

http://developer.gnome.org/doc/API/2.0/gobject/gobject-Signals.html




The "expose_event"

Provides the exposed region in the GdkEventExpose structure. 

There are two ways of dealing with exposures. The first one is to directly draw
on the screen and the second one is to draw in a pixmap buffer, and then to 
update the screen when necessary.

In the first case, the expose event will be responsible for registering hooks to
process_traceset and require time intervals to the main window. So, in this
scenario, if a part of the screen is damaged, the trace has to be read to
redraw the screen.

In the second case, with a pixmap buffer, the expose handler is only responsible
of showing the pixmap buffer on the screen. If the pixmap buffer has never
been filled with a drawing, the expose handler may ask for it to be filled.

The interest of using events request to the main window instead of reading the
events directly from the trace comes from the fact that the main window
does merge requests from the different viewers in the same tab so that the
read loop and the state update is shared. As viewers will, in the common
scenario, request the same events, only one pass through the trace that will
call the right hooks for the right intervals will be done.

When the traceset read is over for a events request, the traceset_end hook is
called. It has the responsibility of finishing the drawing if some parts
still need to be drawn and to show it on the screen (if the viewer uses a pixmap
buffer).

It can add dotted lines and such visual effects to enhance the user's
experience.


FIXME : explain other important events

*/




/*! \file viewer.h
 * \brief API used by the graphical viewers to interact with their top window.
 * 
 * Main window (lttvwindow module) is the place to contain and display viewers. 
 * Viewers (lttv plugins) interact with main window through this API.
 * This header file should be included in each graphic module.
 * 
 */

#include <gtk/gtk.h>
#include <ltt/ltt.h>
#include <ltt/time.h>
#include <lttv/hook.h>
#include <lttv/tracecontext.h>
#include <lttv/stats.h>
#include <lttvwindow/common.h>
//FIXME (not ready yet) #include <lttv/filter.h>


/* Module Related API */


/* constructor a the viewer */
//FIXME explain LttvTracesetSelector and key
typedef GtkWidget * (*lttvwindow_viewer_constructor)
                (MainWindow * main_window, LttvTracesetSelector * s, char *key);


/**
 * Function to register a view constructor so that main window can generate
 * a toolbar item for the viewer in order to generate a new instance easily. 
 * 
 * It should be called by init function of the module.
 * 
 * @param pixmap Image shown on the toolbar item.
 * @param tooltip tooltip of the toolbar item.
 * @param view_constructor constructor of the viewer. 
 */

void lttvwindow_register_toolbar
                            (char ** pixmap,
                             char *  tooltip,
                             lttvwindow_viewer_constructor view_constructor);


/**
 * Function to unregister the viewer's constructor, release the space 
 * occupied by pixmap, tooltip and constructor of the viewer.
 * 
 * It will be called when a module is unloaded.
 * 
 * @param view_constructor constructor of the viewer.
 */

void lttvwindow_unregister_toolbar
                            (lttvwindow_viewer_constructor view_constructor);


/**
 * Function to register a view constructor so that main window can generate
 * a menu item for the viewer in order to generate a new instance easily.
 * 
 * It will be called by init function of the module.
 * 
 * @param menu_path path of the menu item.
 * @param menu_text text of the menu item.
 * @param view_constructor constructor of the viewer. 
 */

void lttvwindow_register_menu(char *menu_path, 
                              char *menu_text,
                              lttvwindow_viewer_constructor view_constructor);


/**
 * Function to unregister the viewer's constructor, release the space 
 * occupied by menu_path, menu_text and constructor of the viewer.
 * 
 * It will be called when a module is unloaded.
 * 
 * @param view_constructor constructor of the viewer.
 */

void lttvwindow_unregister_menu(lttvwindow_viewer_constructor view_constructor);



/* Viewer Instance Related API */

/**
 * Structure used as hook_data for the time_window_notify hook.
 */
typedef struct _TimeWindowNotifyData {
  TimeWindow *new_time_window;
  TimeWindow *old_time_window;
} TimeWindowNotifyData;


/**
 * Function to register a hook function that will be called by the main window
 * when the time interval needs to be updated.
 * 
 * This register function is typically called by the constructor of the viewer.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook that sould be called by the main window when the time
 *             interval changes. This hook function takes a
 *             TimeWindowNotifyData* as call_data.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_register_time_window_notify(MainWindow *main_win,
                                            LttvHook    hook,
                                            gpointer    hook_data);


/**
 * Function to unregister the time_window notification hook.
 * 
 * This unregister function is typically called by the destructor of the viewer.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook that sould be called by the main window when the time
 *             interval changes. This hook function takes a
 *             TimeWindowNotifyData* as call_data.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_unregister_time_window_notify(MainWindow *main_win,
                                              LttvHook    hook, 
                                              gpointer    hook_data);


/**
 * Function to register a hook function that will be called by the main window
 * when the traceset is changed. That means that the viewer must redraw
 * itself completely or check if it's affected by the particular change to the
 * traceset.
 *
 * This register function is typically called by the constructor of the viewer.
 *
 * @param main_win the main window the viewer belongs to.
 * @param hook hook that should be called whenever a change to the traceset
 *             occurs. The call_data of this hook is a NULL pointer.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_register_traceset_notify(MainWindow *main_win,
                                         LttvHook    hook,
                                         gpointer    hook_data);


/**
 * Function to unregister the traceset_notify hook.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook that should be called whenever a change to the traceset
 *             occurs. The call_data of this hook is a NULL pointer.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_unregister_traceset_notify(MainWindow *main_win,
                                           LttvHook    hook,
                                           gpointer    hook_data);


/**
 * Function to register a hook function for a viewer to set/update its 
 * filter. 
 *
 * FIXME : Add information about what a filter is as seen from a viewer and how
 * to use it.
 *
 * This register function is typically called by the constructor of the viewer.
 *
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function called by the main window when a filter change
 *             occurs.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_register_filter_notify(MainWindow *main_win,
                                       LttvHook    hook,
                                       gpointer    hook_data);


/**
 * Function to unregister a viewer's hook function which is used to 
 * set/update the filter of the viewer.
 * 
 * This unregistration is called by the destructor of the viewer.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function called by the main window when a filter change
 *             occurs.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_unregister_filter_notify(MainWindow * main_win,
                                         LttvHook     hook,
                                         gpointer     hook_data);


/**
 * Function to register a hook function for a viewer to set/update its 
 * current time.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function of the viewer that updates the current time. The
 *             call_data is a LttTime* representing the new current time.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_register_current_time_notify(MainWindow *main_win,
                                             LttvHook    hook,
                                             gpointer    hook_data);


/**
 * Function to unregister a viewer's hook function which is used to 
 * set/update the current time of the viewer.
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function of the viewer that updates the current time. The
 *             call_data is a LttTime* representing the new current time.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_unregister_current_time_notify(MainWindow *main_win,
                                               LttvHook    hook,
                                               gpointer    hook_data);


/**
 * Function to register a hook function for a viewer to set/update the 
 * dividor of the hpane. It provides a way to make the horizontal
 * dividors of all the viewers linked together.
 *
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function of the viewer that will be called whenever a
 *             dividor changes in another viewer. The call_data of this hook
 *             is a gint*. The value of the integer is the new position of the
 *             hpane dividor.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_register_dividor(MainWindow *main_win,
                                 LttvHook    hook,
                                 gpointer    hook_data);


/**
 * Function to unregister a viewer's hook function which is used to 
 * set/update hpane's dividor of the viewer.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param hook hook function of the viewer that will be called whenever a
 *             dividor changes in another viewer. The call_data of this hook
 *             is a gint*. The value of the integer is the new position of the
 *             hpane dividor.
 * @param hook_data hook data associated with the hook function. It will
 *                  be typically a pointer to the viewer's data structure.
 */

void lttvwindow_unregister_dividor(MainWindow *main_win,
                                   LttvHook    hook,
                                   gpointer    hook_data);



/**
 * This method reports the information to show on the status bar in the
 * main window.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param info the message which will be shown in the status bar.
 */

void lttvwindow_report_status(MainWindow *main_win, const char *info);


/**
 * Function to set the time interval of the current tab.a
 *
 * @param main_win the main window the viewer belongs to.
 * @param time_interval pointer to the time interval value.
 */

void lttvwindow_report_time_window(MainWindow       *main_win,
                                   const TimeWindow *time_window);

/**
 * Function to set the current time/event of the current tab.
 * It will be called by a viewer's signal handle associated with 
 * the button-release-event signal
 * @param main_win the main window the viewer belongs to.
 * @param time a pointer where time is stored.
 */

void lttvwindow_report_current_time(MainWindow    *main_win, 
                                    const LttTime *time);


/**
 * Function to set the position of the hpane's dividor (viewer).
 * It will typically 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 lttvwindow_report_dividor(MainWindow *main_win, gint position);

/**
 * Function to set the focused viewer of the tab.
 * It will be called by a viewer's signal handle associated with 
 * the grab_focus signal of all widgets in the viewer.
 *
 * @param main_win the main window the viewer belongs to.
 * @param top_widget the top widget containing all the other widgets of the
 *                   viewer.
 */
void lttvwindow_report_focus(MainWindow *main_win, 
                             GtkWidget  *top_widget);



/* Structure sent to the time request hook */
                                                /* Value considered as empty */
typedef struct _EventsRequest {
  LttTime                     start_time,       /* Unset : { 0, 0 }         */
  LttvTracesetContextPosition start_position,   /* Unset : num_traces = 0   */
  gboolean                    stop_flag,        /* Continue:TRUE Stop:FALSE */
  LttTime                     end_time,         /* Unset : { 0, 0 }         */
  guint                       num_events,       /* Unset : G_MAXUINT        */
  LttvTracesetContextPosition end_position,     /* Unset : num_traces = 0   */
  LttvHooks                  *before_traceset,  /* Unset : NULL             */
  LttvHooks                  *before_trace,     /* Unset : NULL             */
  LttvHooks                  *before_tracefile, /* Unset : NULL             */
  LttvHooks                  *event,            /* Unset : NULL             */
  LttvHooksById              *event_by_id,      /* Unset : NULL             */
  LttvHooks                  *after_tracefile,  /* Unset : NULL             */
  LttvHooks                  *after_trace,      /* Unset : NULL             */
  LttvHooks                  *after_traceset    /* Unset : NULL             */
} EventsRequest;


/**
 * Function to request data in a specific time interval to the main window. The
 * time request servicing is differed until the glib idle functions are
 * called.
 *
 * The viewer has to provide hooks that should be associated with the event
 * request.
 *
 * Either start time or start position must be defined in a EventRequest
 * structure for it to be valid.
 *
 * end_time, end_position and num_events can all be defined. The first one
 * to occur will be used as end criterion.
 * 
 * @param main_win the main window the viewer belongs to.
 * @param events_requested the structure of request from.
 */

void lttvwindow_events_request(MainWindow    *main_win,
                               EventsRequest  events_request);

/**
 * Function to get the current time window of the current tab.
 * 
 * @param main_win the main window the viewer belongs to.
 * @return a pointer to the current tab's time interval.
 */

const TimeWindow *lttvwindow_get_time_window(MainWindow *main_win);


/**
 * Function to get the current time of the current tab.
 *
 * @param main_win the main window the viewer belongs to.
 * @return a pointer to the current tab's current time.
 */

const LttTime *lttvwindow_get_current_time(MainWindow *main_win);


/**
 * Function to get the filter of the current tab.
 * @param main_win, the main window the viewer belongs to.
 * @param filter, a pointer to a filter.
 */

//FIXME
typedef void lttv_filter;
//FIXME
const lttv_filter *lttvwindow_get_filter(MainWindow *main_win);


/**
 * Function to get the stats of the traceset 
 * It must be non const so the viewer can modify it.
 * FIXME : a set/get pair of functions would be more appropriate here.
 * @param main_win the main window the viewer belongs to.
 * @return A pointer to Traceset statistics.
 */

LttvTracesetStats* lttvwindow_get_traceset_stats(MainWindow *main_win);

/**
 * Function to get the context of the traceset 
 * It must be non const so the viewer can add and remove hooks from it.
 * @param main_win the main window the viewer belongs to.
 * @return Context of the current tab.
 */


LttvTracesetContext* lttvwindow_get_traceset_context(MainWindow *main_win);