Ecore_Evas (image) buffer example

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Ecore_Evas (image) buffer example

In this example, we'll demonstrate the use of ecore_evas_object_image_new().

The idea is to have the same scene created for Ecore_Evas buffer example as the contents of an image object.

The canvas receiving this image object will have a white background, a red border image to delimit this image's boundaries and the image itself. After we create the special image, we set its "fill" property, place and resize it as we want. We have also to resize its underlying `Ecore_Evas` too, to the same dimensions:

img = ecore_evas_object_image_new(ee);
evas_object_image_filled_set(img, EINA_TRUE);
evas_object_image_size_set(
img, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
sub_ee = ecore_evas_object_ecore_evas_get(img);
sub_canvas = ecore_evas_object_evas_get(img);
evas_object_move(img, (WIDTH / 6) + 3, (HEIGHT / 6) + 3);
/* apply the same size on both! */
evas_object_resize(img, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
ecore_evas_resize(sub_ee, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
ecore_evas_resize
EAPI void ecore_evas_resize(Ecore_Evas *ee, int w, int h)
Resizes an Ecore_Evas.
Definition: ecore_evas.c:1324
ecore_evas_object_evas_get
EAPI Evas * ecore_evas_object_evas_get(Evas_Object *obj)
Retrieve the canvas bound to the internal Ecore_Evas handle of an image object created via ecore_evas...
Definition: ecore_evas.c:1120
ecore_evas_object_image_new
EAPI Evas_Object * ecore_evas_object_image_new(Ecore_Evas *ee_target)
Creates an Evas image object with image data bound to an own, internal Ecore_Evas canvas wrapper
Definition: ecore_evas_buffer.c:941
ecore_evas_object_ecore_evas_get
EAPI Ecore_Evas * ecore_evas_object_ecore_evas_get(Evas_Object *obj)
Retrieve the internal Ecore_Evas handle of an image object created via ecore_evas_object_image_new().
Definition: ecore_evas.c:1131
EINA_TRUE
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition: eina_types.h:539
evas_object_move
EVAS_API void evas_object_move(Evas_Object *obj, Evas_Coord x, Evas_Coord y)
Move the given Evas object to the given location inside its canvas' viewport.
Definition: evas_object_main.c:1171
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_image_size_set
EVAS_API void evas_object_image_size_set(Evas_Object *eo_obj, int w, int h)
Sets the size of the given image object.
Definition: evas_image_legacy.c:847
evas_object_image_filled_set
EVAS_API void evas_object_image_filled_set(Evas_Object *eo_obj, Eina_Bool value)
Set whether the image object's fill property should track the object's size.
Definition: evas_image_legacy.c:81

Now, we re-create the scene we cited, using the sub-canvas of our image to parent the objects in question. Because image objects are created with the alpha channel enabled, by default, we'll be seeing our white rectangle beneath the scene:

r0 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r0, 0, 0, 0, 255); /* 100% opaque black bg */
evas_object_move(r0, 0, 0);
evas_object_resize(r0, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
evas_object_show(r0);
r1 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r1, 255, 0, 0, 255); /* 100% opaque red */
evas_object_move(r1, 10, 10);
evas_object_resize(r1, 100, 100);
evas_object_show(r1);
r2 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r2, 0, 128, 0, 128); /* 50% opaque green */
evas_object_move(r2, 10, 10);
evas_object_resize(r2, 50, 50);
evas_object_show(r2);
r3 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r3, 0, 128, 0, 255); /* 100% opaque dark green */
evas_object_move(r3, 60, 60);
evas_object_resize(r3, 50, 50);
evas_object_show(r3);
evas_object_show(img);
ecore_main_loop_begin();
ecore_main_loop_begin
void ecore_main_loop_begin(void)
Runs the application main loop.
Definition: ecore_main.c:1311
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_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_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

And that's all. The contents of our image could be updated as one wished, and they would always be mirrored in the image's area.

Check that destination file for the result. The full example follows.

#ifdef HAVE_CONFIG_H
#include "config.h"
#else
#define EINA_UNUSED
#define PACKAGE_EXAMPLES_DIR "."
#endif
#include <Ecore.h>
#include <Ecore_Evas.h>
#include <stdio.h>
#define WIDTH (320)
#define HEIGHT (240)
static Ecore_Evas *ee;
static const char *border_img_path = PACKAGE_EXAMPLES_DIR "/red.png";
static void
_on_destroy(Ecore_Evas *ee_ EINA_UNUSED)
{
ecore_main_loop_quit();
}
int
main(void)
{
Evas *canvas, *sub_canvas;
Evas_Object *bg, *r0, *r1, *r2, *r3; /* "sub" canvas objects */
Evas_Object *border, *img; /* canvas objects */
Ecore_Evas *sub_ee;
ecore_evas_init();
/* this will give you a window with an Evas canvas under the first
* engine available */
ee = ecore_evas_new(NULL, 0, 0, WIDTH, HEIGHT, NULL);
if (!ee) goto error;
ecore_evas_size_min_set(ee, WIDTH, HEIGHT);
ecore_evas_size_max_set(ee, WIDTH, HEIGHT);
ecore_evas_callback_delete_request_set(ee, _on_destroy);
ecore_evas_title_set(ee, "Ecore_Evas buffer (image) example");
ecore_evas_show(ee);
canvas = ecore_evas_get(ee);
bg = evas_object_rectangle_add(canvas);
evas_object_color_set(bg, 255, 255, 255, 255); /* white bg */
evas_object_move(bg, 0, 0); /* at origin */
evas_object_resize(bg, WIDTH, HEIGHT); /* covers full canvas */
evas_object_show(bg);
/* this is a border around the image containing a scene of another
* canvas */
border = evas_object_image_filled_add(canvas);
evas_object_image_file_set(border, border_img_path, NULL);
evas_object_image_border_set(border, 3, 3, 3, 3);
evas_object_image_border_center_fill_set(border, EVAS_BORDER_FILL_NONE);
evas_object_move(border, WIDTH / 6, HEIGHT / 6);
evas_object_resize(border, (2 * WIDTH) / 3, (2 * HEIGHT) / 3);
evas_object_show(border);
img = ecore_evas_object_image_new(ee);
evas_object_image_filled_set(img, EINA_TRUE);
evas_object_image_size_set(
img, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
sub_ee = ecore_evas_object_ecore_evas_get(img);
sub_canvas = ecore_evas_object_evas_get(img);
evas_object_move(img, (WIDTH / 6) + 3, (HEIGHT / 6) + 3);
/* apply the same size on both! */
evas_object_resize(img, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
ecore_evas_resize(sub_ee, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
r0 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r0, 0, 0, 0, 255); /* 100% opaque black bg */
evas_object_move(r0, 0, 0);
evas_object_resize(r0, ((2 * WIDTH) / 3) - 6, ((2 * HEIGHT) / 3) - 6);
evas_object_show(r0);
r1 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r1, 255, 0, 0, 255); /* 100% opaque red */
evas_object_move(r1, 10, 10);
evas_object_resize(r1, 100, 100);
evas_object_show(r1);
r2 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r2, 0, 128, 0, 128); /* 50% opaque green */
evas_object_move(r2, 10, 10);
evas_object_resize(r2, 50, 50);
evas_object_show(r2);
r3 = evas_object_rectangle_add(sub_canvas);
evas_object_color_set(r3, 0, 128, 0, 255); /* 100% opaque dark green */
evas_object_move(r3, 60, 60);
evas_object_resize(r3, 50, 50);
evas_object_show(r3);
evas_object_show(img);
ecore_main_loop_begin();
ecore_evas_free(ee);
ecore_evas_shutdown();
return 0;
error:
fprintf(stderr, "error: Requires at least one Evas engine built"
" and linked to ecore-evas for this example to run"
" properly.\n");
ecore_evas_shutdown();
return -1;
}
Ecore_Evas.h
Evas wrapper functions.
ecore_evas_init
EAPI int ecore_evas_init(void)
Inits the Ecore_Evas system.
Definition: ecore_evas.c:602
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:1527
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:1176
ecore_evas_show
EAPI void ecore_evas_show(Ecore_Evas *ee)
Shows an Ecore_Evas' window.
Definition: ecore_evas.c:1480
ecore_evas_size_min_set
EAPI void ecore_evas_size_min_set(Ecore_Evas *ee, int w, int h)
Sets the minimum size of a given Ecore_Evas window.
Definition: ecore_evas.c:1560
ecore_evas_get
EAPI Evas * ecore_evas_get(const Ecore_Evas *ee)
Gets an Ecore_Evas's Evas.
Definition: ecore_evas.c:1300
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:1039
ecore_evas_shutdown
EAPI int ecore_evas_shutdown(void)
Shuts down the Ecore_Evas system.
Definition: ecore_evas.c:666
ecore_evas_size_max_set
EAPI void ecore_evas_size_max_set(Ecore_Evas *ee, int w, int h)
Sets the maximum size of a given Ecore_Evas window.
Definition: ecore_evas.c:1596
ecore_evas_free
EAPI void ecore_evas_free(Ecore_Evas *ee)
Frees an Ecore_Evas.
Definition: ecore_evas.c:1083
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:1321
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
Efl_Canvas_Object Evas_Object
An Evas Object handle.
Definition: Evas_Common.h:185
evas_object_image_border_set
EVAS_API void evas_object_image_border_set(Evas_Object *obj, int l, int r, int t, int b)
Dimensions of this image's border, a region that does not scale with the center area.
Definition: evas_image_legacy.c:117
evas_object_image_border_center_fill_set
EVAS_API void evas_object_image_border_center_fill_set(Evas_Object *obj, Evas_Border_Fill_Mode fill)
Specifies how the center part of the object (not the borders) should be drawn when EFL is rendering i...
Definition: evas_image_legacy.c:145
evas_object_image_file_set
EVAS_API void evas_object_image_file_set(Evas_Object *obj, const char *file, const char *key)
Set the source file from where an image object must fetch the real image data (it may be an Eet file,...
Definition: evas_image_legacy.c:194
evas_object_image_filled_add
EVAS_API Evas_Object * evas_object_image_filled_add(Evas *eo_e)
Creates a new image object that automatically scales its bound image to the object's area,...
Definition: evas_image_legacy.c:35
EVAS_BORDER_FILL_NONE
@ EVAS_BORDER_FILL_NONE
Image's center region is not to be rendered.
Definition: Evas_Legacy.h:5721