Pebble Pre-Builder

Update resources media by scanning Pebble resources folder and generate C header file based on application keys.

Usage

There are two ways to use Pebble Pre-Builder :

• Run ppb -gALL to the folder where your appinfo.json file is.
• Modify the wscript file of your pebble project.

For the second case, you have to import ruby in the top of your wscript :

import os.path
from sh import ruby

Then, define the pre-build function :

def prebuild(ctx):
    ruby('path to the ppb script', g='ALL')

Finally, just put to following line into the build function :

def build(ctx):
    prebuild(ctx)
    ...

Tap pebble build and watch the magic happen in your appinfo.json file and src/generated folder.

Installation

Pebble Pre-Builder use a ruby script to scan your folder and update your appinfo.json.
If ppb doesn't work properly, tap this following lines in a terminal :

# For mac users
brew install ruby && gem install json
# For unix users
sudo apt-get install ruby && gem install json

Images

Just put your images into the resources/images and build the watchapp with the pebble tool. Pebble Pre-Builder takes the name of your image files to update the appinfo.json.
Example is always better than a bunch of words so let's take a look to the following lines :

# Folder tree
resources
|- images
|  |- cross-pbi.png
|  |- logo~color.png
|  |- logo~bw.png
|  |- timeline-pbi8.png

# Updated appinfo.json file
...
"resources": {
	"media": [
		{
			"type": "png",
			"file": "images/logo.png",
			"name": "IMAGE_LOGO"
		},
		{
			"type": "pbi",
			"file": "images/cross-pbi.png",
			"name": "IMAGE_CROSS"
		},
		{
			"type": "pbi8",
			"file": "images/timeline-pbi8.png",
			"name": "IMAGE_TIMELINE"
		}
	]
}
...

Pebble Pre-Builder is a tool to increase speed development but it's not increase the Pebble SDK so do not forget png is the only image format supported by the watch.
To set the menu icon of your app, name your image file menu_icon(-*).png.
The image types values can be :

• pbi
• pbi8
• png-trans

Fonts

Generate font resources is not that easy than generate image resources. Like your images, put your font files into the resources/fonts and now pay attention. Pebble Pre-Builder should know which size and which allowed characters you want for each font files. Like the previous section, Example is friendly to understand new concept :

# Folder tree
resources
|- fonts
|  |- main-ascii-12-18.ttf
|  |- second-date-time.ttf

# Updated appinfo.json file
...
"resources": {
	"media": [
		{
		    "characterRegex": "[ -~]",
			"type": "font",
			"file": "fonts/man-ascii-12-18.ttf",
			"name": "FONT_MAIN_ASCII_12"
		},
		{
		    "characterRegex": "[ -~]",
			"type": "font",
			"file": "fonts/man-ascii-12-18.ttf",
			"name": "FONT_MAIN_ASCII_18"
		},
				{
		    "characterRegex": "[0-9a-zA-Z ]",
			"type": "font",
			"file": "fonts/second-date-time.ttf"
			"name": "FONT_SECOND_DATE_14"
		},
				{
		    "characterRegex": "[0-9APM ]",
			"type": "font",
			"file": "fonts/second-date-time.ttf"
			"name": "FONT_SECOND_TIME_14"
		}
	]
}
...

If you don't provide size after allowed characters, the default font size is 14.
The allowed characters values can be :

• ascii
• number
• letter
• alphanumeric
• time
• date
• temperature

Raw & Animation

The resource files doesn't need treatment like image or font resources.
Simply add your animation (do not forget only apng format is supported by Pebble watch and only on Basalt platform) into resources/animations and your other resource files into resources.
There are no restrictions here so do what you want !

C generation

To communicate between your watch application and your smartphone, Pebble use keys store in appinfo.json. Pebble Pre-Builder generate a C file named pebble-keys.h into src/generated folder based on appinfo.json.

# appinfo.json
...
"appKeys": {
    "dummy": 0,
    "foo bar": 42 
},
...

# generated pebble-keys.h
#ifndef PEBBLE_KEYS.H
#define PEBBLE_KEYS.H

typedef enum {
    PEBBLE_KEYS_DUMMY = 0,
    PEBBLE_KEYS_FOO_BAR = 42
} PebbleKeys;

#endif

Warning

Pebble Pre-Builder introduce a bunch of rules. If you respect this the following lines, everything should be ok :

• Do not forget to rebuild the watchapp each time you modify the resources folder.
• Do not add or modify by hand the resources section of your appinfo.json.
• Do not put your resources files into nested folder.
• Only the supported images (png, pbi, pbi8, png-trans) and fonts () are generated.
• Do not name several files with the same name - without extension part of course.
• Resources file starting by a dot character is skipped.

Licence

Copyright (c) 2015 Alexis Le Provost
Licensed under the MIT license.