/** 
@brief Ecore Library Public API Calls
 
These routines are used for Ecore Library interaction
*/

/**

@mainpage Ecore

@image latex ecore_big.eps width=5cm
@image html  ecore.png

@version 0.9.9.062
@author Carsten Haitzler <raster\@rasterman.com>
@author Tom Gilbert <tom\@linuxbrit.co.uk>
@author Burra <burra\@colorado.edu>
@author Chris Ross <chris\@darkrock.co.uk>
@author Term <term\@twistedpath.org>
@author Tilman Sauerbeck <tilman\@code-monkey.de>
@author Nathan Ingersoll <rbdpngn\@users.sourceforge.net>
@date 2000-2004

@section intro Introduction

Ecore is a library of convenience functions.

The Ecore library provides the following modules:
@li @link Ecore.h        Ecore - Main Loop Functions. @endlink
@li @link Ecore_Con.h    Ecore_Con - Connection functions. @endlink
@li @link Ecore_Config.h Ecore_Config - Configuration functions. @endlink
@li @link Ecore_Evas.h   Ecore_Evas - Evas convenience functions. @endlink
@li @link Ecore_Fb.h     Ecore_FB - Frame buffer convenience functions. @endlink
@li @link Ecore_Ipc.h    Ecore_IPC - Inter Process Communication functions. @endlink
@li @link Ecore_Job.h    Ecore_Job - Job functions, to be used in the Ecore main loop. @endlink
@li @link Ecore_Txt.h    Ecore_Txt - Text encoding conversion. @endlink
@li @link Ecore_X.h      Ecore_X - X Windows System wrapper. @endlink

@section compiling How to compile using Ecore?

This section has to be documented. Below is just a quick line to handle all
Ecore modules at once.

@verbatim
gcc *.c \
-I/usr/local/include -I/usr/X11R6/include \
-L/usr/local/lib -L/usr/X11R6/lib \
-lecore -lecore_evas -lecore_x -lecore_fb -lecore_job \
`pkg-config evas --cflags --libs`
@endverbatim

@section install How is it installed?

Suggested configure options for evas for a Linux desktop X display:

@verbatim
./configure \
--enable-ecore-x \
--enable-ecore-fb \
--enable-ecore-evas \
--enable-ecore-evas-gl \
--enable-ecore-job \
--enable-ecore-con \
--enable-ecore-ipc \
--enable-ecore-txt
make CFLAGS="-O9 -mpentiumpro -march=pentiumpro -mcpu=pentiumpro"
@endverbatim

@todo (1.0) Document API

*/

/*
@page Ecore_Main_Loop_Page The Ecore Main Loop

@section intro What is Ecore?

Ecore is a clean and tiny event loop library with many modules to do lots of
convenient things for a programmer, to save time and effort.

It's small and lean, designed to work on embedded systems all the way to
large and powerful multi-cpu workstations. It serialises all system signals,
events etc. into a single event queue, that is easily processed without
needing to worry about concurrency. A properly written, event-driven program
using this kind of programming doesn't need threads, nor has to worry about
concurrency. It turns a program into a state machine, and makes it very
robust and easy to follow.

Ecore gives you other handy primitives, such as timers to tick over for you
and call specified functions at particular times so the programmer can use
this to do things, like animate, or time out on connections or tasks that take
too long etc.

Idle handlers are provided too, as well as calls on entering an idle state
(often a very good time to update the state of the program). All events that
enter the system are passed to specific callback functions that the program
sets up to handle those events. Handling them is simple and other Ecore
modules produce more events on the queue, coming from other sources such as
file descriptors etc.

Ecore also lets you have functions called when file descriptors become active
for reading or writing, allowing for streamlined, non-blocking IO.

Here is an exmaple of a simple program and its basic event loop flow:

@image html  prog_flow.png



@section work How does Ecore work?

Ecore is very easy to learn and use. All the function calls are designed to
be easy to remember, explicit in describing what they do, and heavily
name-spaced. Ecore programs can start and be very simple.

For example:

@code
#include <Ecore.h>

int main(int argc, const char **argv)
{
  ecore_init();
  ecore_app_args_set(argc, argv);
  ecore_main_loop_begin();
  ecore_shutdown();
  return 0;
}
@endcode

This program is very simple and does't check for errors, but it does start up
and begin a main loop waiting for events or timers to tick off. This program
doesn't set up any, but now we can expand on this simple program a little
more by adding some event handlers and timers.

@code
#include <Ecore.h>

Ecore_Timer         *timer1     = NULL;
Ecore_Event_Handler *handler1   = NULL;
double               start_time = 0.0;

int timer_func(void *data)
{
  printf("Tick timer. Sec: %3.2f\n", ecore_time_get() - start_time);
  return 1;
}

int exit_func(void *data, int ev_type, void *ev)
{
  Ecore_Event_Signal_Exit *e;

  e = (Ecore_Event_Signal_Exit *)ev;
  if (e->interrupt)      printf("Exit: interrupt\n");
  else if (e->quit)      printf("Exit: quit\n");
  else if (e->terminate) printf("Exit: terminate\n");
  ecore_main_loop_quit();
  return 1;
}

int main(int argc, const char **argv)
{
  ecore_init();
  ecore_app_args_set(argc, argv);  
  start_time = ecore_time_get();
  handler1 = ecore_event_handler_add(ECORE_EVENT_SIGNAL_EXIT, exit_func, NULL);
  timer1 = ecore_timer_add(0.5, timer_func, NULL);  
  ecore_main_loop_begin();
  ecore_shutdown();
  return 0;
}
@endcode

In the previous example, we initialize our application and get the time at
which our program has started so we can calculate an offset. We set
up a timer to tick off in 0.5 seconds, and since it returns 1, will
keep ticking off every 0.5 seconds until it returns 0, or is deleted
by hand. An event handler is set up to call a function - exit_func(),
whenever an event of type ECORE_EVENT_SIGNAL_EXIT is received (CTRL-C
on the command line will cause such an event to happen). If this event
occurs it tells you what kind of exit signal was received, and asks
the main loop to quit when it is finished by calling
ecore_main_loop_quit().

The handles returned by ecore_timer_add() and ecore_event_handler_add() are 
only stored here as an example. If you don't need to address the timer or 
event handler again you don't need to store the result, so just call the 
function, and don't assign the result to any variable.

This program looks slightly more complex than needed to do these simple
things, but in principle, programs don't get any more complex. You add more
event handlers, for more events, will have more timers and such, BUT it all
follows the same principles as shown in this example.

*/

/**
@page Ecore_Config_Page The Enlightened Property Library

The Enlightened Property Library (Ecore_Config) is an adbstraction
from the complexities of writing your own configuration. It provides
many features using the Enlightenment 17 development libraries.

To use the library, you:
@li Set the default values of your properties.
@li Load the configuration from a file.  You must set the default values
    first, so that the library knows the correct type of each argument.

The following examples show how to use the Enlightened Property Library:
@li @link config_basic_example.c config_basic_example.c @endlink
@li @link config_listener_example.c config_listener_example.c @endlink

*/

/**
@page Ecore_ADT_Page Ecore Abstract Data Types

This page briefly describes the different abstract data types
that are provided by the Ecore library for general usage.  You need to
include the @link Ecore_Data.h Ecore_Data.h @endlink to use them.

@section Ecore_ADT_List List

A list is a simple data type where one each piece of data points to
another piece of data.

Associated modules that describe the List ADT include:
@li @ref Ecore_Data_List_Creation_Group
@li @ref Ecore_Data_List_Add_Item_Group
@li @ref Ecore_Data_List_Remove_Item_Group
@li @ref Ecore_Data_List_Traverse_Group
@li @ref Ecore_Data_List_Node_Group

Examples involving lists include:
@li @link list_example.c list_example.c @endlink

@section Ecore_ADT_DList Doubly Linked List

A doubly linked list is like a linked list, only each piece of data
can also point to the piece before it.  In other words, you can traverse
a doubly linked list in both directions.

Associated modules that describe the DList ADT include:
@li @ref Ecore_Data_DList_Creation_Group
@li @ref Ecore_Data_DList_Add_Item_Group
@li @ref Ecore_Data_DList_Remove_Item_Group

@section Ecore_ADT_Hash Hash

A hash is an abstract data type where one value is associated with another
value.  Instead of each element of the group being accessible using a
number, each element is accessed using another object.

Associated modules that describe the Hash ADT include:
@li @ref Ecore_Data_Hash_ADT_Creation_Group
@li @ref Ecore_Data_Hash_ADT_Destruction_Group
@li @ref Ecore_Data_Hash_ADT_Data_Group

@todo Finish this.
*/

/**
@page X_Window_System_Page X Window System

The Ecore library includes a wrapper for handling the X window system.
This page briefly explains what the X window system is and various terms
that are used.
*/

// GROUP DEFINITIONS

/**
@defgroup Ecore_Timer_Group Ecore Timer

The timer allows callbacks to be called at specific intervals.
 */

/**
@defgroup Ecore_Job_Group Ecore Jobs

You can queue jobs that are to be done by the main loop when the current
event is dealt with.
*/

/**
@defgroup Idle_Group Idle Handlers

Callbacks that are called when the program enters or exits an idle state.

The ecore main loop enters an idle state when it is waiting for timers
to time out, data to come in on a file descriptor or any other event
to occur.  You can set callbacks to be called when the main loop
enters an idle state, during an idle state or just after the program
wakes up.

Enterer callbacks are good for updating your program's state, if it
has a state engine.  Once all of the enterer handlers are called, the
program will enter a "sleeping" state.

Idler callbacks are called when the main loop has called all enterer
handlers.  They are useful for interfaces that require polling and
timers would be too slow to use.

If no idler callbacks are specified, then the process literally goes
to sleep.  Otherwise, the idler callbacks are called continuously
while the loop is "idle", using as much CPU as is available to the
process.

Exiter callbacks are called when the main loop wakes up from an idle
state.

*/

/**
@defgroup Ecore_Config_Create_Group Ecore Config Create Functions

Convenience functions that set default values, bounds, option values and
descriptions in one call.
*/

/**
@defgroup Ecore_Config_File_Group Ecore Config File Functions

Functions that are used to load and save properties from and to files.
*/

// EXAMPLES

/**
@example args_example.c
Shows how to set and retrieve the program arguments.
*/

/**
@example con_server_example.c
Shows how to write a simple server using the Ecore_Con library.
*/

/**
@example con_client_example.c
Shows how to write a simple client, that connects to the example server.
*/

/**
@example event_handler_example.c
Shows how to use event handlers.
*/

/**
@example timer_example.c
Demonstrates use of the ecore_timer.
*/

/**
@example config_basic_example.c
Provides an example of how to use the basic configuration functions.
See the file Ecore_Config.h for the full list of available functions.
*/

/**
@example config_listener_example.c
Shows how to set up a listener to listen for configuration changes.
*/

/**
@example list_example.c
Provides a basic example of how to append to and traverse a list.
*/

/**
@example list_destroy_example.c
Shows how to set and use a destructor for an Ecore_List.
*/

/**
@example x_window_example.c
Shows the basics of using the X Windows system through Ecore functions.
*/
