Enamel is a python script that generates C helpers from a [Clay](https://github.com/pebble/clay) configuration file to easily get the value of your settings.
npm install enamelEnamel is a python script that generates C helpers from a Clay configuration file to easily get the value of your settings.
Enamel will :
* handle AppMessages automatically (app_message_open, handler registration, ...)
* save/load the value of the settings in the persistant storage automatically
* provide a getter for each of your settings
* notify subscribers when settings are received from Clay
You can focus on your watchapp/face, Enamel will do the rest !
---
src/js/config.json (see https://github.com/pebble/clay)pebble package install enamelwscript : python
import sys
sys.path.append('node_modules')
from enamel.enamel import enamel
`
4. Change the of your wscript from
` python
ctx.pbl_program(source=ctx.path.ant_glob('src/*/.c'), target=app_elf)
`
to
python
ctx(rule = enamel, source='src/js/config.json', target=['enamel.c', 'enamel.h'])
ctx.pbl_program(source=ctx.path.ant_glob('src/*/.c') + ['enamel.c'], target=app_elf)
`
5. Launch your Pebble build : 2 files (enamel.c and enamel.h) should be generated in and compiled>:warning:
>The first time you launch a build, you will get an error message because Jinja2 module is missing.
>Just follow the instructions to fix your environment.
Getting Started (CloudPebble)
In the CloudPebble environment, you can't modify the wscript so you need to call directly the python script.1. Under Dependencies in the project navigation, enter
enamel as the Package Name and ^1.0.0 for the Version. You may use any specific version you like, however using ^1.0.0 will ensure you receive all minor version updates.2. Copy the content of your Clay's
config.js file into a local file (local_config.js)3. Install the python dependencies for the code generation
`
pip install -r requirements.txt
4. Call the script to generate the enamel files
python enamel.py --config /path/to/local_config.js
5. Copy the 2 generated files in your CloudPebble project
---
Using Enamel
1. Setup your project correctly for Clay : https://github.com/pebble/clay
2. Include in your c file :
` c
#include "enamel.h"
#include
`
3. Initialize enamel in your function and call events_app_message_open() after any other libraries you need to init.
` c
static void init(void) {
// Initialize Enamel to register App Message handlers and restores settings
enamel_init();
// call pebble-events app_message_open function
events_app_message_open();
...
}
`
4. Deinitialize enamel in your function :
` c
static void deinit(void) {
...
// Deinit Enamel to unregister App Message handlers and save settings
enamel_deinit();
}
`
5. (Optional) Subscribe with a handler after that will be automatically called when the settings are received. Multiple subscribers are supported. Do not forget to unsubscribe before calling enamel_deinit!
` c
static EventHandle s_window_event_handle;
static EventHandle s_text_layer_event_handle; ...
static void enamel_settings_received_window_handler(void *context){
APP_LOG(0, "Settings received %d", enamel_get_myinteger());
Window window = (Window ) context;
window_set_background_color(window, enamel_get_background());
}
static void enamel_settings_received_text_layer_handler(void *context){
APP_LOG(0, "Settings received %d", enamel_get_myinteger());
TextLayer text_layer = (TextLayer ) context;
text_layer_set_text_color(text_layer, enamel_get_foreground());
}
...
static void init(void) {
// Initialize Enamel to register App Message handlers and restores settings
enamel_init();
// Subscribe a handler for a window
s_window_event_handle = enamel_settings_received_subscribe(enamel_settings_received_window_handler, window);
// Subscribe a handler for a text layer
s_text_layer_event_handle = enamel_settings_received_subscribe(enamel_settings_received_text_layer_handler, text_layer);
// call pebble-events app_message_open function
events_app_message_open();
...
}
static void deinit(void) {
// Unsubscribe from Enamel events
enamel_settings_received_unsubscribe(s_window_event_handle);
enamel_settings_received_unsubscribe(s_text_layer_event_handle);
enamel_deinit();
...
}
`
6. Get the value of your setting with :
c
enamel_get_Mysetting(); // where 'Mysetting' is a messageKey in your configuration file
`
---Enamel API
Methods
| Method | Description |
|--------|---------|
|
| Initialize Enamel and read settings from persistant storage |
| void enamel_deinit() | Deinitialize Enamel and save the settings in the persistant storage |
| | Return the value for the setting messageKeyId |
| bool enamel_get_ | Only relevant for checkboxgroup.
Return the value at given index for the setting messageKeyId |Type mapping
| Clay Type | Type returned by the getter |
|--------|---------|
|
input | char* |
| toggle | bool |
| color | GColor |
| select/radiogroup | char* or enum |
| checkboxgroup | bool |
| slider | int32_t |$3
If the value of the options are
string in the config.json, Enamel will generate a char* getterIf the value of the options are
integer, Enamel will generate an enum mapping all the possible values for this setting and the getter will return this enumFor the given setting :
json
{
"type": "radiogroup",
"messageKey": "favorite_food",
"label": "Favorite Food",
"defaultValue": "1",
"options": [
{
"label": "Sushi",
"value": 0
},
{
"label": "Pizza",
"value": 1
},
{
"label": "Burgers",
"value": 2
}
]
}
`Enamel will generate
c
typedef enum {
FAVORITE_FOOD_SUSHI = 0,
FAVORITE_FOOD_PIZZA = 1,
FAVORITE_FOOD_BURGER = 2,
} FAVORITE_FOODValue;
FAVORITE_FOODValue enamel_get_favorite_food();
`You can then easily code switch case for this setting
c
switch(enamel_get_favorite_food()){
case FAVORITE_FOOD_SUSHI : break; //do something
case FAVORITE_FOOD_PIZZA : break; //do something
case FAVORITE_FOOD_BURGER : break; //do something
}
`$3
Enamel will also generate a constant for your slider containing the 'precision' of your slider, e.g.
#define MY_SLIDER_PRECISION 100