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Tizen Native API
4.0
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Functions to tell Evas that input events happened and should be processed.
As explained in intro_not_evas, Evas does not know how to poll for input events, so the developer should do it and then feed such events to the canvas to be processed. This is only required if operating Evas directly. Modules such as Ecore_Evas do that for you.
Some of the functions in this group are exemplified here.
Functions | |
| Evas_Device * | evas_device_add (Evas *e) |
| void | evas_device_del (Evas_Device *dev) |
| void | evas_device_push (Evas *e, Evas_Device *dev) |
| void | evas_device_pop (Evas *e) |
| const Eina_List * | evas_device_list (Evas *e, const Evas_Device *dev) |
| void | evas_device_name_set (Evas_Device *dev, const char *name) |
| const char * | evas_device_name_get (const Evas_Device *dev) |
| void | evas_device_description_set (Evas_Device *dev, const char *desc) |
| const char * | evas_device_description_get (const Evas_Device *dev) |
| void | evas_device_parent_set (Evas_Device *dev, Evas_Device *parent) |
| const Evas_Device * | evas_device_parent_get (const Evas_Device *dev) |
| void | evas_device_class_set (Evas_Device *dev, Evas_Device_Class clas) |
| Evas_Device_Class | evas_device_class_get (const Evas_Device *dev) |
| void | evas_device_subclass_set (Evas_Device *dev, Evas_Device_Subclass clas) |
| Evas_Device_Subclass | evas_device_subclass_get (const Evas_Device *dev) |
| void | evas_device_emulation_source_set (Evas_Device *dev, Evas_Device *src) |
| const Evas_Device * | evas_device_emulation_source_get (const Evas_Device *dev) |
| Evas_Device* evas_device_add | ( | Evas * | e | ) |
Add a new device type
| e | The canvas to create the device node for. |
Adds a new device node to the given canvas e. All devices created as part of the canvas e will automatically be deleted when the canvas is freed.
| Evas_Device_Class evas_device_class_get | ( | const Evas_Device * | dev | ) |
Get the major class of a device
| dev | The devise to query |
This sets the device class set by evas_device_class_set().
| void evas_device_class_set | ( | Evas_Device * | dev, |
| Evas_Device_Class | clas | ||
| ) |
Set the major class of device
| dev | The device whose class to set |
| clas | The class to set it to |
This sets the "primary" class of device (a broad thing like mouse, keyboard, touch, pen etc.).
| void evas_device_del | ( | Evas_Device * | dev | ) |
Delete a new device type
| dev | The device node you want to delete. |
| const char* evas_device_description_get | ( | const Evas_Device * | dev | ) |
Get the description of a device
dev The device to query
This gets the description set by evas_device_description_set(). This is a readable UTF8 C string, or NULL if no description is set.
A description is meant to be a longer string describing the device so a human may make sense of it. For example "Wireless 6 button mouse in Black with red buttons" would be a good description, so a user may identify precisely which device is being talked about.
| void evas_device_description_set | ( | Evas_Device * | dev, |
| const char * | desc | ||
| ) |
Set the description of a device as a string
dev The device to set the description of name The description string as a readable C UTF8 string
| const Evas_Device* evas_device_emulation_source_get | ( | const Evas_Device * | dev | ) |
Get the emulation source device
| dev | The device to query |
| void evas_device_emulation_source_set | ( | Evas_Device * | dev, |
| Evas_Device * | src | ||
| ) |
Set the emulation source device
| dev | The device being emulated |
| src | The primary source device producing events in the emulated device |
Devices may not be real, but may be emulated by listening to input on other devices and modifying or interpeting it to generate output on an emulated device (example a fingeron a touchscreen will often emulate a mouse when it presses). This allows you to set which device primarily emulates dev so the user can choose to ignore events from emulated devices if they also pay attention to source device events for example.
| const Eina_List* evas_device_list | ( | Evas * | e, |
| const Evas_Device * | dev | ||
| ) |
List all current devices attached to the given canvas and/or device
| e | The canvas to query for a device list |
| dev | A specific device inside the canvas to query for child devices or NULL if just querying the base canvas devices |
This will list all devices belonging to a specific evas canvas e, at the top-level in the device tree if dev passed in is NULL. If dev is a valid device for the given canvas e, then a list of child devices of dev will be returned, allowing you to walk the device tree.
The list returned is only valid so long as no changes are made to the device tree in the given canvas e. If there are no devices or children then NULL is returned.
| const char* evas_device_name_get | ( | const Evas_Device * | dev | ) |
Get the name of a device
dev The device to query
This gets the name set by evas_device_name_set(). This is a readable UTF8 C string, or NULL if no name is set.
The name should be a short name like "Wireless Mouse", "Joystick", "Finger", "Keyboard" or "Numberpad" etc.
| void evas_device_name_set | ( | Evas_Device * | dev, |
| const char * | name | ||
| ) |
Set the name of a device as a string
dev The device to set the name of name The name string as a readable C UTF8 string
| const Evas_Device* evas_device_parent_get | ( | const Evas_Device * | dev | ) |
Get the parent of a device
| dev | The device to query |
This returns the parent device of any given device entry, or NULL if no parent device exists (is a toplevel device).
| void evas_device_parent_set | ( | Evas_Device * | dev, |
| Evas_Device * | parent | ||
| ) |
Set the parent of a device
dev The device to set the parent of parent The new parent device
This sets the parent of a device dev to the parent given by parent. If the device already has a parent, it is removed from that parent's list. If parent is NULL then the device is unparented and placed back as a root device in the canvas.
When a device is deleted with evas_device_del(), all children are also deleted along with it.
| void evas_device_pop | ( | Evas * | e | ) |
This pops the top of the device stack for the canvas
| e | The canvas to pop the device stack from |
This pops the top of the device stack making the current device context used for device events being what is now at the top of the stack after popping.
| void evas_device_push | ( | Evas * | e, |
| Evas_Device * | dev | ||
| ) |
Push the current context device onto the device stack
| e | The canvas to push the device on to |
| dev | The device to push. |
This pushes the given device dev onto the stack for the canvas e resulting in the dev pointer in all events that get fed to the canvas being the device at the top of the device stack for that canvas.
If a device is pushed onto the device stack, it will not be deleted until a canvas free OR until it has been popped from the stack even if evas_device_del() is called.
The device dev must have been created as a device for the canvas it is pushed onto (and not another canvas).
Example:
evas_device_push(canvas, dev); evas_event_feed_mouse_move(canvas, 20, 30, 0, NULL); evas_device_pop(canvas);
| Evas_Device_Subclass evas_device_subclass_get | ( | const Evas_Device * | dev | ) |
Get the device sub-class
| dev | The device to query |
| void evas_device_subclass_set | ( | Evas_Device * | dev, |
| Evas_Device_Subclass | clas | ||
| ) |
Set the sub-class of a device
| dev | The device to modify |
| clas | The sub-class to set |
This sets the sub-class of a device which gives much more detailed usage within a broader category.
| void evas_event_freeze | ( | Evas * | e | ) |
Freeze all input events processing.
| e | The canvas to freeze input events processing on. |
This function will indicate to Evas that the canvas e is to have all input event processing frozen until a matching evas_event_thaw() function is called on the same canvas. All events of this kind during the freeze will get discarded. Every freeze call must be matched by a thaw call in order to completely thaw out a canvas (i.e. these calls may be nested). The most common use is when you don't want the user to interact with your user interface when you're populating a view or changing the layout.
Example:
"\tf - freeze input for 3 seconds\n" "\tp - toggle precise point collision detection on image\n" "\tControl + o - add an obscured rectangle\n" "\th - print help\n"; struct test_data { Ecore_Evas *ee; Evas *canvas; Evas_Object *img, *bg; Ecore_Timer *resize_timer, *freeze_timer; Eina_Bool obscured, focus; };
/* let's have our events back */ static Eina_Bool _thaw_cb(void *data EINA_UNUSED) { fprintf(stdout, "Canvas was frozen %d times, now thawing.\n", evas_event_freeze_get(d.canvas)); evas_event_thaw(d.canvas); return EINA_FALSE; /* do not re-issue the timer */ }
See the full example.
If you run that example, you'll see the canvas ignoring all input events for 3 seconds, when the "f" key is pressed. In a more realistic code we would be freezing while a toolkit or Edje was doing some UI changes, thawing it back afterwards.
| int evas_event_freeze_get | ( | const Evas * | e | ) |
Return the freeze count on input events of a given canvas.
| e | The canvas to fetch the freeze count from. |
This returns the number of times the canvas has been told to freeze input events. It is possible to call evas_event_freeze() multiple times, and these must be matched by evas_event_thaw() calls. This call allows the program to discover just how many times things have been frozen in case it may want to break out of a deep freeze state where the count is high.
Example:
extern Evas *evas; while (evas_event_freeze_get(evas) > 0) evas_event_thaw(evas);
| void evas_event_thaw | ( | Evas * | e | ) |
Thaw a canvas out after freezing (for input events).
| e | The canvas to thaw out. |
This will thaw out a canvas after a matching evas_event_freeze() call. If this call completely thaws out a canvas, i.e., there's no other unbalanced call to evas_event_freeze(), events will start to be processed again, but any "missed" events will not be evaluated.
See evas_event_freeze() for an example.
| void evas_event_thaw_eval | ( | Evas * | e | ) |
After thaw of a canvas, re-evaluate the state of objects and call callbacks
| e | The canvas to evaluate after a thaw |
This is normally called after evas_event_thaw() to re-evaluate mouse containment and other states and thus also call callbacks for mouse in and out on new objects if the state change demands it.