Useful links

• USB Garmin on GNU/Linux
• onPartialUpdate
• eBook
• User interface Programmers Guide
• My question
• My second question

Lifecycles

Objects tend to be temporary, so be careful about storing things in member variables. For example, for a watch face, the AppBase and WatchFace objects will get destroyed whenever the watch face goes out of sight and recreated when it comes back. You can save data in AppBase’s onStop method (or as soon as you get it).

The approach that I found works for a watch face that gets data from the internet:

• Have a ServiceDelegate that will run in the background and fetch data.
  • It’s returned by AppBase.getServiceDelegate.
  • It calls Background.exit(data) when the network call returns.
• Have a WatchFace with a method like setData.
  • It’s returned by AppBase.getInitialView.
• Have AppBase that:
  • Calls Background.requestTemporalEvent in getInitialView to trigger the first request.
  • Calls Background.requestTemporalEvent in onBackgroundData for subsequent requests.
  • Stores the result of onBackgroundData in Application.Storage.
  • Passes the result of onBackgroundData to the WatchFace if it currently exists.
  • In getInitialView, call WatchFace.setData if we have a result stored in Application.Storage.

Graphics

Reference (src):

Fonts:

Graphics.FONT_XTINY     
Graphics.FONT_TINY      Graphics.FONT_NUMBER_MILD
Graphics.FONT_SMALL     Graphics.FONT_NUMBER_MEDIUM
Graphics.FONT_MEDIUM    Graphics.FONT_NUMBER_HOT
Graphics.FONT_LARGE     Graphics.FONT_NUMBER_THAI_HOT

You can also add _SYSTEM after FONT.

Colours:

Graphics.WHITE            Graphics.COLOR_LT_GRAY
Graphics.COLOR_DK_GRAY    Graphics.COLOR_BLACK
Graphics.COLOR_RED        Graphics.COLOR_DK_RED
Graphics.COLOR_YELLOW     Graphics.COLOR_ORANGE
Graphics.COLOR_GREEN      Graphics.COLOR_DK_GREEN
Graphics.COLOR_BLUE       Graphics.COLOR_DK_BLUE
Graphics.COLOR_PINK       Graphics.COLOR_PURPLE
Graphics.COLOR_TRANSPARENT

Table

GIMP palette for the colours a Garmin watch can display.

Installation

To get the Garmin SDK’s simulator running on Manjaro Linux:

• Try running bin/simulator to see what’s missing.
• sudo pacman -S libpng12
• Install webkitgtk2

The available colours for devices that support 16 bits can be found by searching for COLOR_ here. Or just here.

Installing GPSBabel got my device to mount.