Values on resumed activity

If the user selects "resume" later, the Connect IQ data fields will be shut down. If you need to persist any data for an activity when your field is terminated prior to the activity completing, you can do so. A good place to do this may be in the AppBase.onStop() method. Saved values can be reloaded when the application is started back up. This could be done in AppBase.onStart() or in an initializer.

I was thinking about this problem and that's my thougths:
1) in function onTimerStop() I'll save to storage:
a) startTime from Activity.Info
b) total steps
c) array with steps per lap
I'll also save b and c to FitContributor.
2) in onTimerStart() I'll read data from storage
If startTime from storage and current activity are different: that's new activity and I set variables to 0's.
If both variables are same: that's same activity and I use values from storage.
3) in onTimerReset() I can clear persistent storage (but don't have to).

In order to "Resume later" user has to stop activity which will invoke onTimerStop(), so I don't have to use AppBase.onStop().
onTimerPause() and onTimerResume() are irrelevant to problem.

Did I missed anything?

This is a case where it can help to put together something really simple to see how things happen. Here's one I did that I can run on a watch (an f5 in this case) and log things. Like Brian said AppBase.onStop is the logical place to save things off, but it has to be smart enough to know if anything should be saved. If you do manual pause/resume you'll see more timer start/stops than in the log file I also attached. It gets more complex with manual and auto pause. (more timer events for start/stop/pause/resume)

//first file
using Toybox.Application;
using Toybox.System as Sys;

class dfstateApp extends Application.AppBase {

function initialize() {
AppBase.initialize();
}

// onStart() is called on application start up
function onStart(state) {
Sys.println("onStart");
}

// onStop() is called when your application is exiting
function onStop(state) {
Sys.println("onStop");
}

// Return the initial view of your application here
function getInitialView() {
return [ new dfstateView() ];
}

}

--------------------------------------------------------------------------------
//second file
using Toybox.WatchUi;
using Toybox.System as Sys;

class dfstateView extends WatchUi.SimpleDataField {
var state="??";

// Set the label of the data field here.
function initialize() {
SimpleDataField.initialize();
label = "timer state";
}

// The given info object contains all the current workout
// information. Calculate a value and return it in this method.
// Note that compute() and onUpdate() are asynchronous, and there is no
// guarantee that compute() will be called before onUpdate().
function compute(info) {
// See Activity.Info in the documentation for available information.
return state;
}

function onTimerLap() {
state="Timer Lap";
Sys.println(state);
}

function onTimerPause() {
state="Timer Pause";
Sys.println(state);
}

function onTimerReset() {
state="Timer Reset";
Sys.println(state);
}

function onTimerResume() {
state="Timer Resume";
Sys.println(state);
}

function onTimerStart() {
state="Timer Start";
Sys.println(state);
}

function onTimerStop() {
state="Timer Stop";
Sys.println(state);
}

}
--------------------------------------------------------------------------------------------
onStart <new activity
Timer Start
Timer Stop
onStop <recording discarded here
onStart
onStop <back to watchface

onStart <new activity
Timer Start
Timer Stop <resume later done here
onStop
onStart
Timer Start
Timer Stop
onStop <recording saved here


Try something simple like this to work out when/if to save anything, and when/if to use the saved data. I'm just showing the onTimer calls, so you'll want more logic based on the data itself I imagine.

I was thinking about this problem and that's my thougths:
1) in function onTimerStop() I'll save to storage:
a) startTime from Activity.Info
b) total steps
c) array with steps per lap
I'll also save b and c to FitContributor.
2) in onTimerStart() I'll read data from storage
If startTime from storage and current activity are different: that's new activity and I set variables to 0's.
If both variables are same: that's same activity and I use values from storage.
3) in onTimerReset() I can clear persistent storage (but don't have to).

In order to "Resume later" user has to stop activity which will invoke onTimerStop(), so I don't have to use AppBase.onStop().
onTimerPause() and onTimerResume() are irrelevant to problem.

Did I missed anything?

This seems reasonable to me, but you probably know better than I do how the device behaves when suspending an activity.