This example shows how to manipulate a dragable part through the edje_object_part_drag API.
First, in the edc code, we are declaring a part which will be our movable part, called "knob". It is a normal rectangle, which contains a block called "dragable", that will define the area where this rectangle can be moved, and in which axis it can be moved.
This is our part:
part {
name: "example/knob";
type: RECT;
mouse_events: 1;
dragable {
confine: "drag_area";
x: 0 0 0;
y: 1 1 0;
}
description {
state: "default" 0.0;
min: 10 10;
color: 255 0 0 200;
}
} // example/knob
Notice that it defines, through its "x:"
and "y:'
properties, that the part will be only moved on the y axis (vertical). Check the edc reference docs for more info about this.
Now, in our example C code, we just do the same as on the other examples, setting some global data on a structure, load the edje file and so:
static const char *PARTNAME = "example/knob";
We want to use the drag_page and drag_step functions, and in order to do so we need to define the step size and page size of our dragable part. They are defined as float values which represent a portion of the entire size of the dragable area:
We are going to use the keyboard to move the knob
part, through the key down callback _bg_key_down
, but we also want to know when the user has moved the knob by using the mouse (which is possible, since we defined that this part will receive mouse events). Thus, we set a callback for the signal "drag", which comes from the dragable part:
Now, let's take a look at our key down callback:
{
Ecore_Evas *ee;
ee = (Ecore_Evas *)data;
if (!strcmp(ev->
key,
"h"))
{
printf(commands);
return;
}
else if (!strcmp(ev->
key,
"Down"))
{
}
else if (!strcmp(ev->
key,
"Up"))
{
}
else if (!strcmp(ev->
key,
"m"))
{
}
else if (!strcmp(ev->
key,
"Prior"))
{
}
else if (!strcmp(ev->
key,
"Next"))
{
}
else if (!strcmp(ev->
key,
"Escape"))
else
{
printf(
"unhandled key: %s\n", ev->
key);
printf(commands);
}
}
On this callback we define that the user will use the "up" and "down" arrows to move the dragable part, respectively, -1.0 and 1.0 times the step size. And that the "Page Up" (Prior) and "Page Down" (Next) keys will move -1.0 and 1.0 times the page size. Both of these will occur on the vertical axis, since we pass 0.0 as value to the respective horizontal axis parameters. And our dragable part also only supports being moved in the vertical axis (defined in the edc).
We also define that the "m" key will be used to explicitly position the knob part in the middle of the dragable area.
And here is the callback for the "drag"
signal that is received from the theme:
{
double val;
printf("value changed to: %0.3f\n", val);
}
The example's window should look like this picture:
The full source code follows:
#ifdef HAVE_CONFIG_H
# include "config.h"
#else
# define EINA_UNUSED
#endif
#ifndef PACKAGE_DATA_DIR
#define PACKAGE_DATA_DIR "."
#endif
#include <Ecore.h>
#define WIDTH 300
#define HEIGHT 300
static const char commands[] = \
"commands are:\n"
"\tDown - set drag step to 1\n"
"\tUp - set drag step to -1\n"
"\tm - set drag value to 0.5\n"
"\tPrior - set drag page to -1\n"
"\tNext - set drag page to -1\n"
"\tEsc - exit\n"
"\th - print help\n";
static const char *PARTNAME = "example/knob";
static void
{
}
static void
_on_canvas_resize(Ecore_Evas *ee)
{
int w;
int h;
}
static void
{
Ecore_Evas *ee;
ee = (Ecore_Evas *)data;
if (!strcmp(ev->
key,
"h"))
{
printf(commands);
return;
}
else if (!strcmp(ev->
key,
"Down"))
{
}
else if (!strcmp(ev->
key,
"Up"))
{
}
else if (!strcmp(ev->
key,
"m"))
{
}
else if (!strcmp(ev->
key,
"Prior"))
{
}
else if (!strcmp(ev->
key,
"Next"))
{
}
else if (!strcmp(ev->
key,
"Escape"))
else
{
printf(
"unhandled key: %s\n", ev->
key);
printf(commands);
}
}
static void
{
double val;
printf("value changed to: %0.3f\n", val);
}
int
{
const char *edje_file = PACKAGE_DATA_DIR"/drag.edj";
Ecore_Evas *ee;
return EXIT_FAILURE;
goto shutdown_ecore_evas;
if (!ee) goto shutdown_edje;
printf("failed to set file %s.\n", edje_file);
printf("error when setting drag step size.\n");
printf("error when setting drag page step size.\n");
printf(commands);
return EXIT_SUCCESS;
shutdown_edje:
shutdown_ecore_evas:
return EXIT_FAILURE;
}
To compile use this command:
* gcc -o edje-drag edje-drag.c -DPACKAGE_BIN_DIR=\"/Where/enlightenment/is/installed/bin\" -DPACKAGE_LIB_DIR=\"/Where/enlightenment/is/installed/lib\"
* -DPACKAGE_DATA_DIR=\"/Where/enlightenment/is/installed/share\"
* `pkg-config --cflags --libs evas ecore ecore-evas edje`
*
* edje_cc drag.edc
*
int edje_init(void)
Initializes the Edje library.
Definition: edje_main.c:35
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:1065
EAPI int ecore_evas_shutdown(void)
Shuts down the Ecore_Evas system.
Definition: ecore_evas.c:674
Eina_Bool edje_object_file_set(Evas_Object *obj, const char *file, const char *group)
Sets the EDJ file (and group within it) to load an Edje object's contents from.
Definition: edje_smart.c:467
EAPI void ecore_evas_geometry_get(const Ecore_Evas *ee, int *x, int *y, int *w, int *h)
Gets the geometry of an Ecore_Evas.
Definition: ecore_evas.c:1388
Eina_Bool edje_object_part_drag_step_set(Evas_Object *obj, const char *part, double dx, double dy)
Sets the drag step increment.
Definition: edje_legacy.c:252
EAPI void ecore_evas_callback_resize_set(Ecore_Evas *ee, Ecore_Evas_Event_Cb func)
Sets a callback for Ecore_Evas resize events.
Definition: ecore_evas.c:1166
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:1308
Key press event.
Definition: Evas_Legacy.h:313
#define EINA_UNUSED
Definition: eina_types.h:339
EAPI void ecore_evas_free(Ecore_Evas *ee)
Frees an Ecore_Evas.
Definition: ecore_evas.c:1109
EAPI void ecore_evas_title_set(Ecore_Evas *ee, const char *t)
Sets the title of an Ecore_Evas' window.
Definition: ecore_evas.c:1553
EAPI int ecore_evas_init(void)
Inits the Ecore_Evas system.
Definition: ecore_evas.c:606
void edje_object_signal_callback_add(Evas_Object *obj, const char *emission, const char *source, Edje_Signal_Cb func, void *data)
Adds a callback for an arriving Edje signal, emitted by a given Edje object.
Definition: edje_legacy.c:85
Efl_Canvas_Object Evas_Object
Definition: Evas_Common.h:185
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
Edje Graphical Design Library.
Eina_Bool edje_object_part_drag_page(Evas_Object *obj, const char *part, double dx, double dy)
Pages x,y steps.
Definition: edje_legacy.c:282
EAPI Evas * ecore_evas_get(const Ecore_Evas *ee)
Gets an Ecore_Evas's Evas.
Definition: ecore_evas.c:1326
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:1118
Evas_Object * edje_object_add(Evas *evas)
Instantiates a new Edje object.
Definition: edje_smart.c:22
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
@ EVAS_CALLBACK_KEY_DOWN
Key Press Event.
Definition: Evas_Common.h:430
const char * key
The logical key : (eg shift+1 == exclamation)
Definition: Evas_Legacy.h:320
void ecore_main_loop_begin(void)
Runs the application main loop.
Definition: ecore_main.c:1298
void evas_object_focus_set(Efl_Canvas_Object *obj, Eina_Bool focus)
Indicates that this object is the keyboard event receiver on its canvas.
Definition: efl_canvas_object_eo.legacy.c:39
void evas_object_show(Evas_Object *eo_obj)
Makes the given Evas object visible.
Definition: evas_object_main.c:1814
Eo Evas
Definition: Evas_Common.h:163
#define EINA_TRUE
Definition: eina_types.h:539
Eina_Bool edje_object_part_drag_size_set(Evas_Object *obj, const char *part, double dw, double dh)
Sets the dragable object size.
Definition: edje_legacy.c:240
Evas_Object * evas_object_rectangle_add(Evas *e)
Adds a rectangle to the given evas.
Definition: evas_object_rectangle.c:78
Eina_Bool edje_object_part_drag_value_get(const Evas_Object *obj, const char *part, double *dx, double *dy)
Gets the dragable object location.
Definition: edje_legacy.c:234
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
Eina_Bool edje_object_part_drag_step(Evas_Object *obj, const char *part, double dx, double dy)
Steps the dragable x,y steps.
Definition: edje_legacy.c:276
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:1129
EAPI void ecore_evas_callback_destroy_set(Ecore_Evas *ee, Ecore_Evas_Event_Cb func)
Sets a callback for Ecore_Evas destroy events.
Definition: ecore_evas.c:1211
Eina_Bool edje_object_part_drag_value_set(Evas_Object *obj, const char *part, double dx, double dy)
Sets the dragable object location.
Definition: edje_legacy.c:228
EAPI void ecore_evas_show(Ecore_Evas *ee)
Shows an Ecore_Evas' window.
Definition: ecore_evas.c:1506
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
int edje_shutdown(void)
Shuts down the Edje library.
Definition: edje_main.c:264
Eina_Bool edje_object_part_drag_page_set(Evas_Object *obj, const char *part, double dx, double dy)
Sets the page step increments.
Definition: edje_legacy.c:264