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feat(msg): add publisher-subscriber messaging

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This commit is contained in:
Gabor Kiss-Vamosi
2022-04-06 21:36:15 +02:00
parent 5977eeff3c
commit 79a29d749d
13 changed files with 853 additions and 2 deletions
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1
docs/others/index.md
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@@ -14,5 +14,6 @@
monkey monkey
gridnav gridnav
fragment fragment
msg
``` ```

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docs/others/msg.md Normal file
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```eval_rst
.. include:: /header.rst
:github_url: |github_link_base|/others/msg.md
```
# Messaging
Messaging (`lv_msg`) is a classic []publisher subscriber](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern) implementation for LVGL.
## IDs
Both the publishers and the subscribers needs to know the message identifiers.
In `lv_msg` these are simple `uint32_t` integers. For example:
```c
#define MSG_DOOR_OPENED 1
#define MSG_DOOR_CLOSED 2
#define MSG_USER_NAME_CHANGED 100
#define MSG_USER_AVATAR_CHANGED 101
```
You can orgnaize the message IDs as you wish.
Both parties also need to know about the format of teh payload. E.g. in the above example
`MSG_DOOR_OPENED` and `MSG_DOOR_CLOSED` has no payload but `MSG_USER_NAME_CHANGED` can have a `const char *` payload containing the user name, and `MSG_USER_AVATAR_CHANGED` a `const void *` image source with the new avatar image.
## Send message
Messages can be sent with `lv_msg_send(msg_id, payload)`. E.g.
```c
lv_msg_send(MSG_USER_DOOR_OPENED, NULL);
lv_msg_send(MSG_USER_NAME_CHANGED, "John Smith");
```
## Subscribe to a message
`lv_msg_subscribe(msg_id, callback, user_data)` can be used to subscribe to message.
The callback should look like this:
```c
static void user_name_subscriber_cb(void * s, lv_msg_t * m)
{
/*s: a subscriber obeject, can be used to unscubscribe*/
/*m: a message object with the msg_id, payload, and user_data (set durung subscription)*/
...do something...
}
```
From `lv_msg_t` the followings can be used to get some data:
- `lv_msg_get_id(m)`
- `lv_msg_get_payload(m)`
- `lv_msg_get_user_data(m)`
## Subscribe with an lv_obj
It's quite typical that an LVGL widget is interested in some messages.
To make it simpler `lv_msg_subsribe_obj(msg_id, obj, user_data)` can be used.
If a new message is published with `msg_id` an `LV_EVENT_MSG_RECEIVED` event will be sent to the object.
For example:
```c
lv_obj_add_event_cb(user_name_label, user_name_label_event_cb, LV_EVENT_MSG_RECEIVED, NULL);
lv_msg_subsribe_obj(MSG_USER_NAME_CHANGED, user_name_label, NULL);
...
void user_name_label_event_cb(lv_event_t * e)
{
lv_obj_t * label = lv_event_get_target(e);
lv_msg_t * m = lv_event_get_msg(e);
lv_label_set_text(label, lv_msg_get_payload(m));
}
```
### Unsubscribe
`lv_msg_subscribe` returns a pointer which can be used to unsubscribe:
```c
void * s1;
s1 = lv_msg_subscribe(MSG_USER_DOOR_OPENED, some_callback, NULL);
...
lv_msg_unsubscribe(s1);
```
## Example
```eval_rst
.. include:: ../../examples/others/msg/index.rst
```
## API
```eval_rst
.. doxygenfile:: lv_msg.h
:project: lvgl
```

20
examples/others/msg/index.rst Normal file
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Slider to label messaging
"""""""""""""""""""""""""
.. lv_example:: others/msg/lv_example_msg_1
:language: c
Handling login and its states
"""""""""""""""""""""""""""""
.. lv_example:: others/msg/lv_example_msg_2
:language: c
Setting the same value from many sources
""""""""""""""""""""""""""""""""""""""""
.. lv_example:: others/msg/lv_example_msg_3
:language: c

40
examples/others/msg/lv_example_msg.h Normal file
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/**
* @file lv_example_msg.h
*
*/
#ifndef LV_EXAMPLE_MSG_H
#define LV_EXAMPLE_MSG_H
#ifdef __cplusplus
extern "C" {
#endif
/*********************
* INCLUDES
*********************/
/*********************
* DEFINES
*********************/
/**********************
* TYPEDEFS
**********************/
/**********************
* GLOBAL PROTOTYPES
**********************/
void lv_example_msg_1(void);
void lv_example_msg_2(void);
void lv_example_msg_3(void);
/**********************
* MACROS
**********************/
#ifdef __cplusplus
} /*extern "C"*/
#endif
#endif /*LV_EXAMPLE_MSG_H*/

49
examples/others/msg/lv_example_msg_1.c Normal file
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#include "../../lv_examples.h"
#if LV_USE_MSG && LV_USE_SLIDER && LV_USE_LABEL && LV_BUILD_EXAMPLES
/*Define a message ID*/
#define MSG_NEW_TEMPERATURE 1
static void slider_event_cb(lv_event_t * e);
static void label_event_cb(lv_event_t * e);
/**
* A slider sends a message on value change and a label display's that value
*/
void lv_example_msg_1(void)
{
/*Create a slider in the center of the display*/
lv_obj_t * slider = lv_slider_create(lv_scr_act());
lv_obj_center(slider);
lv_obj_add_event_cb(slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
/*Create a label below the slider*/
lv_obj_t * label = lv_label_create(lv_scr_act());
lv_obj_add_event_cb(label, label_event_cb, LV_EVENT_MSG_RECEIVED, NULL);
lv_label_set_text(label, "0%");
lv_obj_align(label, LV_ALIGN_CENTER, 0, 30);
/*Subscribe the label to a message. Also use the user_data to set a format string here.*/
lv_msg_subsribe_obj(MSG_NEW_TEMPERATURE, label, "%d °C");
}
static void slider_event_cb(lv_event_t * e)
{
/*Notify all subscribers (only the label now) that the slider value has been changed*/
lv_obj_t * slider = lv_event_get_target(e);
int32_t v = lv_slider_get_value(slider);
lv_msg_send(MSG_NEW_TEMPERATURE, &v);
}
static void label_event_cb(lv_event_t * e)
{
lv_obj_t * label = lv_event_get_target(e);
lv_msg_t * m = lv_event_get_msg(e);
const char * fmt = lv_msg_get_user_data(m);
const int32_t * v = lv_msg_get_payload(m);
lv_label_set_text_fmt(label, fmt, *v);
}
#endif

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examples/others/msg/lv_example_msg_2.c Normal file
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#include "../../lv_examples.h"
#if LV_USE_MSG && LV_USE_SLIDER && LV_USE_LABEL && LV_BUILD_EXAMPLES
/*Define a message ID*/
#define MSG_LOGIN_ATTEMPT 1
#define MSG_LOG_OUT 2
#define MSG_LOGIN_ERROR 3
#define MSG_LOGIN_OK 4
static void auth_manager(void * s, lv_msg_t * m);
static void textarea_event_cb(lv_event_t * e);
static void log_out_event_cb(lv_event_t * e);
static void start_engine_msg_event_cb(lv_event_t * e);
static void info_label_msg_event_cb(lv_event_t * e);
/**
* Simple PIN login screen.
* No global variables are used, all state changes are communicated via messages.
*/
void lv_example_msg_2(void)
{
lv_msg_subsribe(MSG_LOGIN_ATTEMPT, auth_manager, "hello");
/*Create a slider in the center of the display*/
lv_obj_t * ta = lv_textarea_create(lv_scr_act());
lv_obj_set_pos(ta, 10, 10);
lv_obj_set_width(ta, 200);
lv_textarea_set_one_line(ta, true);
lv_textarea_set_password_mode(ta, true);
lv_textarea_set_placeholder_text(ta, "The password is: hello");
lv_obj_add_event_cb(ta, textarea_event_cb, LV_EVENT_ALL, NULL);
lv_msg_subsribe_obj(MSG_LOGIN_ERROR, ta, NULL);
lv_msg_subsribe_obj(MSG_LOGIN_OK, ta, NULL);
lv_msg_subsribe_obj(MSG_LOG_OUT, ta, NULL);
lv_obj_t * kb = lv_keyboard_create(lv_scr_act());
lv_keyboard_set_textarea(kb, ta);
lv_obj_t * btn;
lv_obj_t * label;
/*Create a log out button which will be active only when logged in*/
btn = lv_btn_create(lv_scr_act());
lv_obj_set_pos(btn, 240, 10);
lv_obj_add_event_cb(btn, log_out_event_cb, LV_EVENT_ALL, NULL);
lv_msg_subsribe_obj(MSG_LOGIN_OK, btn, NULL);
lv_msg_subsribe_obj(MSG_LOG_OUT, btn, NULL);
label = lv_label_create(btn);
lv_label_set_text(label, "LOG OUT");
/*Create a label to show info*/
label = lv_label_create(lv_scr_act());
lv_label_set_text(label, "");
lv_obj_add_event_cb(label, info_label_msg_event_cb, LV_EVENT_MSG_RECEIVED, NULL);
lv_obj_set_pos(label, 10, 60);
lv_msg_subsribe_obj(MSG_LOGIN_ERROR, label, NULL);
lv_msg_subsribe_obj(MSG_LOGIN_OK, label, NULL);
lv_msg_subsribe_obj(MSG_LOG_OUT, label, NULL);
/*Create button which will be active only when logged in*/
btn = lv_btn_create(lv_scr_act());
lv_obj_set_pos(btn, 10, 80);
lv_obj_add_event_cb(btn, start_engine_msg_event_cb, LV_EVENT_MSG_RECEIVED, NULL);
lv_obj_add_flag(btn, LV_OBJ_FLAG_CHECKABLE);
lv_msg_subsribe_obj(MSG_LOGIN_OK, btn, NULL);
lv_msg_subsribe_obj(MSG_LOG_OUT, btn, NULL);
label = lv_label_create(btn);
lv_label_set_text(label, "START ENGINE");
lv_msg_send(MSG_LOG_OUT, NULL);
}
static void auth_manager(void * s, lv_msg_t * m)
{
LV_UNUSED(s);
const char * pin_act = lv_msg_get_payload(m);
const char * pin_expexted = lv_msg_get_user_data(m);
if(strcmp(pin_act, pin_expexted) == 0) {
lv_msg_send(MSG_LOGIN_OK, NULL);
} else {
lv_msg_send(MSG_LOGIN_ERROR, "Incorrect PIN");
}
}
static void textarea_event_cb(lv_event_t * e)
{
lv_obj_t * ta = lv_event_get_target(e);
lv_event_code_t code = lv_event_get_code(e);
if(code == LV_EVENT_READY) {
lv_msg_send(MSG_LOGIN_ATTEMPT, lv_textarea_get_text(ta));
} else if (code == LV_EVENT_MSG_RECEIVED) {
lv_msg_t * m = lv_event_get_msg(e);
switch(lv_msg_get_id(m)) {
case MSG_LOGIN_ERROR:
/*If there was an error, clean the text area*/
if(strlen(lv_msg_get_payload(m))) lv_textarea_set_text(ta, "");
break;
case MSG_LOGIN_OK:
lv_obj_add_state(ta, LV_STATE_DISABLED);
lv_obj_clear_state(ta, LV_STATE_FOCUSED | LV_STATE_FOCUS_KEY);
break;
case MSG_LOG_OUT:
lv_textarea_set_text(ta, "");
lv_obj_clear_state(ta, LV_STATE_DISABLED);
break;
}
}
}
static void log_out_event_cb(lv_event_t * e)
{
lv_event_code_t code = lv_event_get_code(e);
if(code == LV_EVENT_CLICKED) {
lv_msg_send(MSG_LOG_OUT, NULL);
} else if (code == LV_EVENT_MSG_RECEIVED) {
lv_msg_t * m = lv_event_get_msg(e);
lv_obj_t * btn = lv_event_get_target(e);
switch(lv_msg_get_id(m)) {
case MSG_LOGIN_OK:
lv_obj_clear_state(btn, LV_STATE_DISABLED);
break;
case MSG_LOG_OUT:
lv_obj_add_state(btn, LV_STATE_DISABLED);
break;
}
}
}
static void start_engine_msg_event_cb(lv_event_t * e)
{
lv_msg_t * m = lv_event_get_msg(e);
lv_obj_t * btn = lv_event_get_target(e);
switch(lv_msg_get_id(m)) {
case MSG_LOGIN_OK:
lv_obj_clear_state(btn, LV_STATE_DISABLED);
break;
case MSG_LOG_OUT:
lv_obj_add_state(btn, LV_STATE_DISABLED);
break;
}
}
static void info_label_msg_event_cb(lv_event_t * e)
{
lv_obj_t * label = lv_event_get_target(e);
lv_msg_t * m = lv_event_get_msg(e);
switch(lv_msg_get_id(m)) {
case MSG_LOGIN_ERROR:
lv_label_set_text(label, lv_msg_get_payload(m));
lv_obj_set_style_text_color(label, lv_palette_main(LV_PALETTE_RED), 0);
break;
case MSG_LOGIN_OK:
lv_label_set_text(label, "Login successful");
lv_obj_set_style_text_color(label, lv_palette_main(LV_PALETTE_GREEN), 0);
break;
case MSG_LOG_OUT:
lv_label_set_text(label, "Logged out");
lv_obj_set_style_text_color(label, lv_palette_main(LV_PALETTE_GREY), 0);
break;
default:
break;
}
}
#endif

152
examples/others/msg/lv_example_msg_3.c Normal file
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#include "../../lv_examples.h"
#if LV_USE_MSG && LV_USE_SLIDER && LV_USE_LABEL && LV_BUILD_EXAMPLES
/*Define a message ID*/
#define MSG_INC 1
#define MSG_DEC 2
#define MSG_SET 3
#define MSG_UPDATE 4
#define MSG_UPDATE_REQUEST 5
static void value_handler(void * s, lv_msg_t * m);
static void value_handler(void * s, lv_msg_t * m);
static void btn_event_cb(lv_event_t * e);
static void label_event_cb(lv_event_t * e);
static void slider_event_cb(lv_event_t * e);
/**
* Show how an increment button, a decrement button, as slider can set a value
* and a label display it.
* The current value (i.e. the system's state) is stored only in one static variable in a function
* and no global variables are required.
*/
void lv_example_msg_3(void)
{
lv_msg_subsribe(MSG_INC, value_handler, NULL);
lv_msg_subsribe(MSG_DEC, value_handler, NULL);
lv_msg_subsribe(MSG_SET, value_handler, NULL);
lv_msg_subsribe(MSG_UPDATE, value_handler, NULL);
lv_msg_subsribe(MSG_UPDATE_REQUEST, value_handler, NULL);
lv_obj_t * panel = lv_obj_create(lv_scr_act());
lv_obj_set_size(panel, 250, LV_SIZE_CONTENT);
lv_obj_center(panel);
lv_obj_set_flex_flow(panel, LV_FLEX_FLOW_ROW);
lv_obj_set_flex_align(panel, LV_FLEX_ALIGN_SPACE_BETWEEN, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_START);
lv_obj_t * btn;
lv_obj_t * label;
/*Up button*/
btn = lv_btn_create(panel);
lv_obj_set_flex_grow(btn, 1);
lv_obj_add_event_cb(btn, btn_event_cb, LV_EVENT_ALL, NULL);
label = lv_label_create(btn);
lv_label_set_text(label, LV_SYMBOL_LEFT);
lv_obj_center(label);
/*Current value*/
label = lv_label_create(panel);
lv_obj_set_flex_grow(label, 2);
lv_obj_set_style_text_align(label, LV_TEXT_ALIGN_CENTER, 0);
lv_label_set_text(label, "?");
lv_msg_subsribe_obj(MSG_UPDATE, label, NULL);
lv_obj_add_event_cb(label, label_event_cb, LV_EVENT_MSG_RECEIVED, NULL);
/*Down button*/
btn = lv_btn_create(panel);
lv_obj_set_flex_grow(btn, 1);
lv_obj_add_event_cb(btn, btn_event_cb, LV_EVENT_ALL, NULL);
label = lv_label_create(btn);
lv_label_set_text(label, LV_SYMBOL_RIGHT);
lv_obj_center(label);
/*Slider*/
lv_obj_t * slider = lv_slider_create(panel);
lv_obj_set_flex_grow(slider, 1);
lv_obj_add_flag(slider, LV_OBJ_FLAG_FLEX_IN_NEW_TRACK);
lv_obj_add_event_cb(slider, slider_event_cb, LV_EVENT_ALL, NULL);
lv_msg_subsribe_obj(MSG_UPDATE, slider, NULL);
/* As there are new UI elements that don't know the system's state
* send an UPDATE REQUEST message which will trigger an UPDATE message with the current value*/
lv_msg_send(MSG_UPDATE_REQUEST, NULL);
}
static void value_handler(void * s, lv_msg_t * m)
{
LV_UNUSED(s);
static int32_t value = 10;
int32_t old_value = value;
switch(lv_msg_get_id(m)) {
case MSG_INC:
if(value < 100) value++;
break;
case MSG_DEC:
if(value > 0) value--;
break;
case MSG_SET: {
const int32_t * new_value = lv_msg_get_payload(m);
value = *new_value;
}
break;
case MSG_UPDATE_REQUEST:
lv_msg_send(MSG_UPDATE, &value);
break;
default:
break;
}
if(value != old_value) {
lv_msg_send(MSG_UPDATE, &value);
}
}
static void btn_event_cb(lv_event_t * e)
{
lv_obj_t * btn = lv_event_get_target(e);
lv_event_code_t code = lv_event_get_code(e);
if(code == LV_EVENT_CLICKED || code == LV_EVENT_LONG_PRESSED_REPEAT) {
if(lv_obj_get_index(btn) == 0) { /*First object is the dec. button*/
lv_msg_send(MSG_DEC, NULL);
} else {
lv_msg_send(MSG_INC, NULL);
}
}
}
static void label_event_cb(lv_event_t * e)
{
lv_obj_t * label = lv_event_get_target(e);
lv_event_code_t code = lv_event_get_code(e);
if (code == LV_EVENT_MSG_RECEIVED) {
lv_msg_t * m = lv_event_get_msg(e);
if(lv_msg_get_id(m) == MSG_UPDATE) {
const int32_t *v = lv_msg_get_payload(m);
lv_label_set_text_fmt(label, "%d %%", *v);
}
}
}
static void slider_event_cb(lv_event_t * e)
{
lv_obj_t * slider = lv_event_get_target(e);
lv_event_code_t code = lv_event_get_code(e);
if(code == LV_EVENT_VALUE_CHANGED) {
int32_t v = lv_slider_get_value(slider);
lv_msg_send(MSG_SET, &v);
} else if (code == LV_EVENT_MSG_RECEIVED) {
lv_msg_t * m = lv_event_get_msg(e);
if(lv_msg_get_id(m) == MSG_UPDATE) {
const int32_t *v = lv_msg_get_payload(m);
lv_slider_set_value(slider, *v, LV_ANIM_OFF);
}
}
}
#endif

5
lv_conf_template.h
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@@ -663,9 +663,12 @@
/*1: Enable lv_obj fragment*/ /*1: Enable lv_obj fragment*/
#define LV_USE_FRAGMENT 0 #define LV_USE_FRAGMENT 0
/*draw img in label or span obj */ /*1: Support using images as font in label or span widgets */
#define LV_USE_IMGFONT 0 #define LV_USE_IMGFONT 0
/*1: Enable a published subscriber based messaging system */
#define LV_USE_MSG 0
/*================== /*==================
* EXAMPLES * EXAMPLES
*==================*/ *==================*/

4
src/extra/lv_extra.c
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@@ -42,6 +42,10 @@ void lv_extra_init(void)
lv_grid_init(); lv_grid_init();
#endif #endif
#if LV_USE_MSG
lv_msg_init();
#endif
#if LV_USE_FS_FATFS != '\0' #if LV_USE_FS_FATFS != '\0'
lv_fs_fatfs_init(); lv_fs_fatfs_init();
#endif #endif

1
src/extra/others/lv_others.h
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@@ -18,6 +18,7 @@ extern "C" {
#include "gridnav/lv_gridnav.h" #include "gridnav/lv_gridnav.h"
#include "fragment/lv_fragment.h" #include "fragment/lv_fragment.h"
#include "imgfont/lv_imgfont.h" #include "imgfont/lv_imgfont.h"
#include "msg/lv_msg.h"
/********************* /*********************
* DEFINES * DEFINES

179
src/extra/others/msg/lv_msg.c Normal file
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@@ -0,0 +1,179 @@
/**
* @file lv_msg.c
*
*/
/*********************
* INCLUDES
*********************/
#include "lv_msg.h"
#if LV_USE_MSG
#include "../../../misc/lv_assert.h"
#include "../../../misc/lv_ll.h"
/*********************
* DEFINES
*********************/
/**********************
* TYPEDEFS
**********************/
typedef struct {
uint32_t msg_id;
lv_msg_subscribe_cb_t callback;
void * user_data;
void * _priv_data; /*Internal: used only store 'obj' in lv_obj_subscribe*/
} sub_dsc_t;
/**********************
* STATIC PROTOTYPES
**********************/
static void notify(lv_msg_t * m);
static void obj_notify_cb(void * s, lv_msg_t * m);
static void obj_delete_event_cb(lv_event_t * e);
/**********************
* STATIC VARIABLES
**********************/
static lv_ll_t subs_ll;
static lv_ll_t reqs_ll;
/**********************
* GLOBAL VARIABLES
**********************/
lv_event_code_t LV_EVENT_MSG_RECEIVED;
/**********************
* MACROS
**********************/
/**********************
* GLOBAL FUNCTIONS
**********************/
void lv_msg_init(void)
{
LV_EVENT_MSG_RECEIVED = lv_event_register_id();
_lv_ll_init(&subs_ll, sizeof(sub_dsc_t));
}
void * lv_msg_subsribe(uint32_t msg_id, lv_msg_subscribe_cb_t cb, void * user_data)
{
sub_dsc_t * s = _lv_ll_ins_tail(&subs_ll);
LV_ASSERT_MALLOC(s);
if(s == NULL) return NULL;
lv_memset_00(s, sizeof(*s));
s->msg_id = msg_id;
s->callback = cb;
s->user_data = user_data;
return s;
}
void * lv_msg_subsribe_obj(uint32_t msg_id, lv_obj_t * obj, void * user_data)
{
sub_dsc_t * s = lv_msg_subsribe(msg_id, obj_notify_cb, user_data);
if(s == NULL) return NULL;
s->_priv_data = obj;
/*If not added yet, add a delete event cb which automatically unsubcribes the object*/
sub_dsc_t * s_first = lv_obj_get_event_user_data(obj, obj_delete_event_cb);
if(s_first == NULL) {
lv_obj_add_event_cb(obj, obj_delete_event_cb, LV_EVENT_DELETE, s);
}
return s;
}
void lv_msg_unsubscribe(void * s)
{
LV_ASSERT_NULL(s);
_lv_ll_remove(&subs_ll, s);
lv_mem_free(s);
}
uint32_t lv_msg_id_range(uint32_t start, uint32_t end)
{
if(start == end) return start;
else return start + (end << 16);
}
void lv_msg_send(uint32_t msg_id, const void * payload)
{
lv_msg_t m;
lv_memset_00(&m, sizeof(m));
m.id = msg_id;
m.payload = payload;
notify(&m);
}
uint32_t lv_msg_get_id(lv_msg_t * m)
{
return m->id;
}
const void * lv_msg_get_payload(lv_msg_t * m)
{
return m->payload;
}
void * lv_msg_get_user_data(lv_msg_t * m)
{
return m->user_data;
}
lv_msg_t * lv_event_get_msg(lv_event_t * e)
{
if(e->code == LV_EVENT_MSG_RECEIVED) {
return lv_event_get_param(e);
}
else {
LV_LOG_WARN("Not interpreted with this event code");
return NULL;
}
}
/**********************
* STATIC FUNCTIONS
**********************/
static void notify(lv_msg_t * m)
{
sub_dsc_t * s;
_LV_LL_READ(&subs_ll, s) {
if(s->msg_id == m->id && s->callback) {
m->user_data = s->user_data;
m->_priv_data = s->_priv_data;
s->callback(s, m);
}
}
}
static void obj_notify_cb(void * s, lv_msg_t * m)
{
LV_UNUSED(s);
lv_event_send(m->_priv_data, LV_EVENT_MSG_RECEIVED, m);
}
static void obj_delete_event_cb(lv_event_t * e)
{
lv_obj_t * obj = lv_event_get_target(e);
sub_dsc_t * s = _lv_ll_get_head(&subs_ll);
sub_dsc_t * s_next;
while(s) {
/*On unsubscribe the list changes s becomes invalid so get next item while it's surely valid*/
s_next = _lv_ll_get_next(&subs_ll, s);
if(s->_priv_data == obj) {
lv_msg_unsubscribe(s);
}
s = s_next;
}
}
#endif /*LV_USE_MSG*/

124
src/extra/others/msg/lv_msg.h Normal file
View File

@@ -0,0 +1,124 @@
/**
* @file lv_msg.h
*
*/
#ifndef LV_MSG_H
#define LV_MSG_H
#ifdef __cplusplus
extern "C" {
#endif
/*********************
* INCLUDES
*********************/
#include "../../../core/lv_obj.h"
#if LV_USE_MSG
/*********************
* DEFINES
*********************/
/**********************
* TYPEDEFS
**********************/
typedef struct {
uint32_t id; /*Identifier of the message*/
void * user_data; /*Set the the user_data set in `lv_msg_subscribe`*/
void * _priv_data; /*Used internally*/
const void * payload; /*Pointer to the data of the message*/
} lv_msg_t;
typedef void (*lv_msg_subscribe_cb_t)(void * s, lv_msg_t * msg);
typedef void (*lv_msg_request_cb_t)(void * r, uint32_t msg_id);
/**********************
* GLOBAL PROTOTYPES
**********************/
/**
* Called internally to initialize the message module
*/
void lv_msg_init(void);
/**
* Subscribe to an `msg_id`
* @param msg_id the message ID to listen to
* @param cb callback to call if a message with `msg_id` was sent
* @param user_data arbitrary data which will be available in `cb` too
* @return pointer to a "subscribe object". It can be used the unsubscribe.
*/
void * lv_msg_subsribe(uint32_t msg_id, lv_msg_subscribe_cb_t cb, void * user_data);
/**
* Subscribe an `lv_obj` to a message.
* `LV_EVENT_MSG_RECEIVED` will be triggered if a message with matching ID was sent
* @param msg_id the message ID to listen to
* @param obj pointer to an `lv_obj`
* @param user_data arbitrary data which will be available in `cb` too
* @return pointer to a "subscribe object". It can be used the unsubscribe.
*/
void * lv_msg_subsribe_obj(uint32_t msg_id, lv_obj_t * obj, void * user_data);
/**
* Cancel a previous subscription
* @param s pointer to a "subscibe object".
* Return value of `lv_msg_subsribe` or `lv_msg_subsribe_obj`
*/
void lv_msg_unsubscribe(void * s);
/**
* Send a message with a given ID and payload
* @param msg_id ID of the message to send
* @param data pointer to the data to send
*/
void lv_msg_send(uint32_t msg_id, const void * payload);
/**
* Get the ID of a message object. Typically used in the subscriber callback.
* @param m pointer to a message object
* @return the ID of the message
*/
uint32_t lv_msg_get_id(lv_msg_t * m);
/**
* Get the payload of a message object. Typically used in the subscriber callback.
* @param m pointer to a message object
* @return the payload of the message
*/
const void * lv_msg_get_payload(lv_msg_t * m);
/**
* Get the user data of a message object. Typically used in the subscriber callback.
* @param m pointer to a message object
* @return the user data of the message
*/
void * lv_msg_get_user_data(lv_msg_t * m);
/**
* Get the message object from an event object. Can be used in `LV_EVENT_MSG_RECEIVED` events.
* @param e pointer to an event object
* @return the message object or NULL if called with unrelated event code.
*/
lv_msg_t * lv_event_get_msg(lv_event_t * e);
/**********************
* GLOBAL VARIABLES
**********************/
extern lv_event_code_t LV_EVENT_MSG_RECEIVED;
/**********************
* MACROS
**********************/
#endif /*LV_USE_MSG*/
#ifdef __cplusplus
} /*extern "C"*/
#endif
#endif /*LV_MSG_H*/

11
src/lv_conf_internal.h
View File

@@ -2167,7 +2167,7 @@
#endif #endif
#endif #endif
/*draw img in label or span obj */ /*1: Support using images as font in label or span widgets */
#ifndef LV_USE_IMGFONT #ifndef LV_USE_IMGFONT
#ifdef CONFIG_LV_USE_IMGFONT #ifdef CONFIG_LV_USE_IMGFONT
#define LV_USE_IMGFONT CONFIG_LV_USE_IMGFONT #define LV_USE_IMGFONT CONFIG_LV_USE_IMGFONT
@@ -2176,6 +2176,15 @@
#endif #endif
#endif #endif
/*1: Enable a published subscriber based messaging system */
#ifndef LV_USE_MSG
#ifdef CONFIG_LV_USE_MSG
#define LV_USE_MSG CONFIG_LV_USE_MSG
#else
#define LV_USE_MSG 0
#endif
#endif
/*================== /*==================
* EXAMPLES * EXAMPLES
*==================*/ *==================*/