Ecore Evas basics example

This example will illustrates the usage of some basic Ecore_Evas functions. This example will list the available evas engines, check which one we used to create our window and set some data on our Ecore_Evas. It also allows you to hide/show all windows in this process(we only have one, but if there were more they would be hidden), to hide the windows type 'h' and hit return, to show them, type 's' and hit return.

The very first thing we'll do is initialize ecore_evas:

if (ecore_evas_init() <= 0)
return 1;

Once inited we query which engines are available:

printf("Available engines:\n");
EINA_LIST_FOREACH(engines, l, data)
printf("%s\n", data);

We then create an Ecore_Evas(window) with the first available engine, on position 0,0 with size 200,200 and no especial flags, set it's title and show it:

ee = ecore_evas_new(NULL, 0, 0, 200, 200, NULL);
ecore_evas_title_set(ee, "Ecore Evas basics Example");

We now add some important data to our Ecore_Evas:

data = malloc(sizeof(char) * 6);
sprintf(data, "%s", "hello");
ecore_evas_data_set(ee, "key", data);

And since our data is dynamically allocated we'll need to free it when the Ecore_Evas dies:

static void
_on_delete(Ecore_Evas *ee)
{
free(ecore_evas_data_get(ee, "key"));
}

We now print which Evas engine is being used for our example:

printf("Using %s engine!\n", ecore_evas_engine_name_get(ee));

We are going to add a background to our window but before we can do that we'll need to get the canvas(Evas) on which to draw it:

canvas = ecore_evas_get(ee);

We then do a sanity check, verifying if the Ecore_Evas of the Evas is the Ecore_Evas from which we got the Evas:

if (ecore_evas_ecore_evas_get(canvas) == ee)
printf("Everything is sane!\n");

Now we can actually add the background:

evas_object_color_set(bg, 0, 0, 255, 255);
evas_object_resize(bg, 200, 200);
ecore_evas_object_associate(ee, bg, ECORE_EVAS_OBJECT_ASSOCIATE_BASE);

To hide and show the windows of this process when the user presses 'h' and 's' respectively we need to know when the user types something, so we register a callback for when we can read something from stdin:

ecore_main_fd_handler_add(STDIN_FILENO, ECORE_FD_READ, _stdin_cb, NULL, NULL, NULL);

The callback that actually does the hiding and showing is pretty simple, it does a scanf(which we know won't block since there is something to read on stdin) and if the character is an 'h' we iterate over all windows calling ecore_evas_hide on them, if the character is an 's' we call ecore_evas_show instead:

static Eina_Bool
_stdin_cb(void *data EINA_UNUSED, Ecore_Fd_Handler *handler EINA_UNUSED)
{
Ecore_Evas *ee;
char c;
int ret = scanf("%c", &c);
if (ret < 1) return ECORE_CALLBACK_RENEW;
if (c == 'h')
else if (c == 's')
}

Once all is done we run our main loop, and when that is done(application is exiting) we free our Ecore_Evas and shutdown the ecore_evas subsystem:

Here you have the full-source of the code:

#include <Ecore.h>
#include <Ecore_Evas.h>
#include <unistd.h>
static Eina_Bool
_stdin_cb(void *data EINA_UNUSED, Ecore_Fd_Handler *handler EINA_UNUSED)
{
Ecore_Evas *ee;
char c;
int ret = scanf("%c", &c);
if (ret < 1) return ECORE_CALLBACK_RENEW;
if (c == 'h')
else if (c == 's')
}
static void
_on_delete(Ecore_Evas *ee)
{
free(ecore_evas_data_get(ee, "key"));
}
int
main(void)
{
Ecore_Evas *ee;
Evas *canvas;
Eina_List *engines, *l;
char *data;
if (ecore_evas_init() <= 0)
return 1;
printf("Available engines:\n");
EINA_LIST_FOREACH(engines, l, data)
printf("%s\n", data);
ee = ecore_evas_new(NULL, 0, 0, 200, 200, NULL);
ecore_evas_title_set(ee, "Ecore Evas basics Example");
data = malloc(sizeof(char) * 6);
sprintf(data, "%s", "hello");
ecore_evas_data_set(ee, "key", data);
printf("Using %s engine!\n", ecore_evas_engine_name_get(ee));
canvas = ecore_evas_get(ee);
if (ecore_evas_ecore_evas_get(canvas) == ee)
printf("Everything is sane!\n");
evas_object_color_set(bg, 0, 0, 255, 255);
evas_object_resize(bg, 200, 200);
ecore_evas_object_associate(ee, bg, ECORE_EVAS_OBJECT_ASSOCIATE_BASE);
ecore_main_fd_handler_add(STDIN_FILENO, ECORE_FD_READ, _stdin_cb, NULL, NULL, NULL);
return 0;
}
ecore_evas_object_associate
EAPI Eina_Bool ecore_evas_object_associate(Ecore_Evas *ee, Evas_Object *obj, Ecore_Evas_Object_Associate_Flags flags)
Associates the given object to this ecore evas.
Definition: ecore_evas_util.c:222
ecore_evas_new
EAPI Ecore_Evas * ecore_evas_new(const char *engine_name, int x, int y, int w, int h, const char *extra_options)
Creates a new Ecore_Evas based on engine name and common parameters.
Definition: ecore_evas.c:1059
ecore_evas_shutdown
EAPI int ecore_evas_shutdown(void)
Shuts down the Ecore_Evas system.
Definition: ecore_evas.c:668
ecore_evas_engines_free
EAPI void ecore_evas_engines_free(Eina_List *engines)
Free list returned by ecore_evas_engines_get()
Definition: ecore_evas.c:1032
ecore_main_loop_quit
void ecore_main_loop_quit(void)
Quits the main loop once all the events currently on the queue have been processed.
Definition: ecore_main.c:1289
Ecore_Fd_Handler
struct _Ecore_Fd_Handler Ecore_Fd_Handler
A handle for Fd handlers.
Definition: Ecore_Common.h:1380
EINA_LIST_FOREACH
#define EINA_LIST_FOREACH(list, l, _data)
Definition for the macro to iterate over a list.
Definition: eina_list.h:1427
EINA_UNUSED
#define EINA_UNUSED
Definition: eina_types.h:321
ecore_evas_free
EAPI void ecore_evas_free(Ecore_Evas *ee)
Frees an Ecore_Evas.
Definition: ecore_evas.c:1103
ecore_evas_title_set
EAPI void ecore_evas_title_set(Ecore_Evas *ee, const char *t)
Sets the title of an Ecore_Evas' window.
Definition: ecore_evas.c:1547
ecore_evas_init
EAPI int ecore_evas_init(void)
Inits the Ecore_Evas system.
Definition: ecore_evas.c:604
ecore_main_fd_handler_add
Ecore_Fd_Handler * ecore_main_fd_handler_add(int fd, Ecore_Fd_Handler_Flags flags, Ecore_Fd_Cb func, const void *data, Ecore_Fd_Cb buf_func, const void *buf_data)
Adds a callback for activity on the given file descriptor.
Definition: ecore_main.c:1417
ecore_evas_engines_get
EAPI Eina_List * ecore_evas_engines_get(void)
Returns a list of supported engine names.
Definition: ecore_evas.c:1026
ECORE_FD_READ
Fd Read mask.
Definition: Ecore_Common.h:1388
Evas_Object
Efl_Canvas_Object Evas_Object
Definition: Evas_Common.h:180
ecore_evas_engine_name_get
const EAPI char * ecore_evas_engine_name_get(const Ecore_Evas *ee)
Gets the engine name used by this Ecore_Evas(window).
Definition: ecore_evas.c:1086
ecore_evas_ecore_evas_list_get
EAPI Eina_List * ecore_evas_ecore_evas_list_get(void)
Gets a list of all the ecore_evases.
Definition: ecore_evas.c:3837
ecore_evas_callback_delete_request_set
EAPI void ecore_evas_callback_delete_request_set(Ecore_Evas *ee, Ecore_Evas_Event_Cb func)
Sets a callback for Ecore_Evas delete request events.
Definition: ecore_evas.c:1196
ECORE_CALLBACK_RENEW
#define ECORE_CALLBACK_RENEW
Return value to keep a callback.
Definition: Ecore_Common.h:153
Ecore_Evas.h
Evas wrapper functions.
ecore_evas_get
EAPI Evas * ecore_evas_get(const Ecore_Evas *ee)
Gets an Ecore_Evas's Evas.
Definition: ecore_evas.c:1320
ecore_evas_data_get
EAPI void * ecore_evas_data_get(const Ecore_Evas *ee, const char *key)
Retrieves user data associated with an Ecore_Evas.
Definition: ecore_evas.c:1112
ecore_main_loop_begin
void ecore_main_loop_begin(void)
Runs the application main loop.
Definition: ecore_main.c:1279
evas_object_show
void evas_object_show(Evas_Object *eo_obj)
Makes the given Evas object visible.
Definition: evas_object_main.c:1853
Evas
Eo Evas
Definition: Evas_Common.h:158
Eina_Bool
unsigned char Eina_Bool
Definition: eina_types.h:496
evas_object_rectangle_add
Evas_Object * evas_object_rectangle_add(Evas *e)
Adds a rectangle to the given evas.
Definition: evas_object_rectangle.c:78
_Eina_List
Definition: eina_list.h:326
ecore_evas_hide
EAPI void ecore_evas_hide(Ecore_Evas *ee)
Hides an Ecore_Evas' window.
Definition: ecore_evas.c:1508
ecore_evas_ecore_evas_get
EAPI Ecore_Evas * ecore_evas_ecore_evas_get(const Evas *e)
Returns the Ecore_Evas for this Evas.
Definition: ecore_evas.c:1094
ecore_evas_data_set
EAPI void ecore_evas_data_set(Ecore_Evas *ee, const char *key, const void *data)
Stores user data in an Ecore_Evas structure.
Definition: ecore_evas.c:1123
ecore_evas_show
EAPI void ecore_evas_show(Ecore_Evas *ee)
Shows an Ecore_Evas' window.
Definition: ecore_evas.c:1500
evas_object_color_set
void evas_object_color_set(Evas_Object *obj, int r, int g, int b, int a)
Sets the general/main color of the given Evas object to the given one.
Definition: evas_object_main.c:2063