Bangle.js Code Guidelines

For general information on making apps try this page

This a list of suggestions and things that we'd like apps submitted to the App Loader to do, to make sure everything works together well.

General

• If you need settings, try and use an myapp.settings.js file
• If you need to run code at boot time, use a file called myapp.boot.js
• Try and use the same code style as the rest of Bangle.js
• Where possible, store large chunks of data in functions as this will avoid using RAM
• Once in the App store, keep a ChangeLog file in your app's folder and increment the version whenever you submit a change to the App Loader.
• Try and use the locale module to format dates/distances/etc in a way that is correct for multiple countries.
• Please don't include editor config/settings files and things that are not relevant to your application
• Please test your app! Ideally in your own copy of the App Loader

Apps

• Add widgets with Bangle.loadWidgets() then Bangle.drawWidgets() if at all possible.
• Don't use widgets with any screen modes other than the normal, unbuffered screen mode.
• If using Widgets:
  • Don't render in the top or bottom 24px of the screen (reserved for Widgets)
  • Avoid clearing the whole screen with g.clear(), but if you do, call Bangle.drawWidgets() right after
• Give your app an icon (icons from icons8.com are fine)
• Where possible, use "allow_emulator":true in metadata.json to allow your app to be previewed online in the emulator.

Widgets

• Render inside the box this.x, this.y, this.x + this.width-1, this.y + 23
• Call g.reset() before rendering to ensure that everything is in a known state
• Don't call g.clear (which will clear the whole screen)
• Only call g.flip() if you want your widget's update to wake the screen
• Be aware that you're running in a constrained environment alongside other widgets and apps - try not to use any more RAM than required.