Ecore Evas Object example

This example creates an Ecore_Evas(a window) and associates a background and a custom cursor for it.

We'll start looking at the association, which is quite simple. We choose to associate using ECORE_EVAS_OBJECT_ASSOCIATE_BASE to have it be resized with the window, since for a background that is what's most useful:

ecore_evas_object_associate(ee, bg, ECORE_EVAS_OBJECT_ASSOCIATE_BASE);
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:223

Note
  If we didn't associate the background we'd need to listen to resize of Ecore_Evas and manually resize the background or have artifacts on our window.

We then check that the association worked:

evas_object_event_callback_add(bg, EVAS_CALLBACK_MOUSE_DOWN, _mouse_down_cb, ee);
if (bg == ecore_evas_object_associate_get(ee))
printf("Association worked!\n");
EVAS_CALLBACK_MOUSE_DOWN
@ EVAS_CALLBACK_MOUSE_DOWN
Mouse Button Down Event.
Definition Evas_Common.h:422
ecore_evas_object_associate_get
EAPI Evas_Object * ecore_evas_object_associate_get(const Ecore_Evas *ee)
Gets the object associated with ee.
Definition ecore_evas_util.c:283
evas_object_event_callback_add
EVAS_API void evas_object_event_callback_add(Evas_Object *eo_obj, Evas_Callback_Type type, Evas_Object_Event_Cb func, const void *data)
Add (register) a callback function to a given Evas object event.
Definition evas_callbacks.c:478

Next we are going to set a custom cursor, for our cursor we are going to use a small green rectangle. Our cursor is going to be on layer 0(any lower and it would be below the background and thus invisible) and clicks will be computed as happening on pixel 1, 1 of the image:

cursor = evas_object_rectangle_add(ecore_evas_get(ee));
evas_object_color_set(cursor, 0, 255, 0, 255);
evas_object_resize(cursor, 5, 10);
ecore_evas_object_cursor_set(ee, cursor, 0, 1, 1);
ecore_evas_object_cursor_set
EAPI void ecore_evas_object_cursor_set(Ecore_Evas *ee, Evas_Object *obj, int layer, int hot_x, int hot_y)
Sets the cursor for the default pointer device.
Definition ecore_evas.c:1845
ecore_evas_get
EAPI Evas * ecore_evas_get(const Ecore_Evas *ee)
Gets an Ecore_Evas's Evas.
Definition ecore_evas.c:1314
evas_object_color_set
EVAS_API 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:2024
evas_object_resize
EVAS_API void evas_object_resize(Evas_Object *obj, Evas_Coord w, Evas_Coord h)
Changes the size of the given Evas object.
Definition evas_object_main.c:1236
evas_object_rectangle_add
EVAS_API Evas_Object * evas_object_rectangle_add(Evas *e)
Adds a rectangle to the given evas.
Definition evas_object_rectangle.c:78

We then check every one of those parameters:

ecore_evas_cursor_get(ee, &obj, &layer, &x, &y);
if (obj == cursor && layer == 0 && x == 1 && y == 1)
printf("Set cursor worked!\n");
ecore_evas_cursor_get
EAPI void ecore_evas_cursor_get(const Ecore_Evas *ee, Evas_Object **obj, int *layer, int *hot_x, int *hot_y)
Gets information about an Ecore_Evas' default pointer device.
Definition ecore_evas.c:1902

Here you have the full-source of the code:

#include <Ecore.h>
#include <Ecore_Evas.h>
Evas_Object *cursor;
static void
_mouse_down_cb(void *data, Evas *evas EINA_UNUSED, Evas_Object *obj EINA_UNUSED, void *event_info EINA_UNUSED)
{
static Eina_Bool flag = EINA_FALSE;
if (!flag)
{
ecore_evas_cursor_unset(data);
ecore_evas_object_cursor_set(data, NULL, 0, 1, 1);
}
else
ecore_evas_object_cursor_set(data, cursor, 0, 1, 1);
flag = !flag;
}
int
main(void)
{
Ecore_Evas *ee;
Evas_Object *bg, *obj;
int layer, x, y;
ecore_evas_init();
ee = ecore_evas_new(NULL, 0, 0, 200, 200, NULL);
ecore_evas_title_set(ee, "Ecore Evas Object Example");
ecore_evas_show(ee);
bg = evas_object_rectangle_add(ecore_evas_get(ee));
evas_object_color_set(bg, 0, 0, 255, 255);
evas_object_resize(bg, 200, 200);
evas_object_show(bg);
ecore_evas_object_associate(ee, bg, ECORE_EVAS_OBJECT_ASSOCIATE_BASE);
evas_object_event_callback_add(bg, EVAS_CALLBACK_MOUSE_DOWN, _mouse_down_cb, ee);
if (bg == ecore_evas_object_associate_get(ee))
printf("Association worked!\n");
cursor = evas_object_rectangle_add(ecore_evas_get(ee));
evas_object_color_set(cursor, 0, 255, 0, 255);
evas_object_resize(cursor, 5, 10);
ecore_evas_object_cursor_set(ee, cursor, 0, 1, 1);
ecore_evas_cursor_get(ee, &obj, &layer, &x, &y);
if (obj == cursor && layer == 0 && x == 1 && y == 1)
printf("Set cursor worked!\n");
ecore_main_loop_begin();
ecore_evas_free(ee);
ecore_evas_shutdown();
return 0;
}
Ecore_Evas.h
Evas wrapper functions.
ecore_evas_init
EAPI int ecore_evas_init(void)
Inits the Ecore_Evas system.
Definition ecore_evas.c:608
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:1541
ecore_evas_show
EAPI void ecore_evas_show(Ecore_Evas *ee)
Shows an Ecore_Evas' window.
Definition ecore_evas.c:1494
ecore_evas_cursor_unset
EAPI Evas_Object * ecore_evas_cursor_unset(Ecore_Evas *ee)
Unsets the cursor of the default pointer device.
Definition ecore_evas.c:1942
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:1053
ecore_evas_shutdown
EAPI int ecore_evas_shutdown(void)
Shuts down the Ecore_Evas system.
Definition ecore_evas.c:672
ecore_evas_free
EAPI void ecore_evas_free(Ecore_Evas *ee)
Frees an Ecore_Evas.
Definition ecore_evas.c:1097
ecore_main_loop_begin
void ecore_main_loop_begin(void)
Runs the application main loop.
Definition ecore_main.c:1311
EINA_FALSE
#define EINA_FALSE
boolean value FALSE (numerical value 0)
Definition eina_types.h:533
Eina_Bool
unsigned char Eina_Bool
Type to mimic a boolean.
Definition eina_types.h:527
EINA_UNUSED
#define EINA_UNUSED
Used to indicate that a function parameter is purposely unused.
Definition eina_types.h:339
Evas
Eo Evas
An opaque handle to an Evas canvas.
Definition Evas_Common.h:163
evas_object_show
EVAS_API void evas_object_show(Evas_Object *eo_obj)
Makes the given Evas object visible.
Definition evas_object_main.c:1814
Evas_Object
Efl_Canvas_Object Evas_Object
An Evas Object handle.
Definition Evas_Common.h:185