Android Question Once more, timers...

[Troberg]

OK, here we go again: Timers.

My problem:

I want to show various bits of information on screen. Most of the time, none will be shown, and at most, maybe a handful, but there will be dozens of such items stored in a map that will occasionally be shown. Now, when I show them, I want them to stay a few seconds, then disappear, and I want some central handling of that, so that it won't have to be re-invented in every class.

Now, I see two main ways of doing it.

* Creating one timer for each class. Well, could be done, but hardly neat.

* Set a "death time" on each item as it is shown. Then, using a single timer, check every 200 ms or so if any of them has passed their "death time". Only one timer, but iteration hundreds of items every second seems wasteful, and will make debugging a pain in the ass.

Is there any good way of doing it? I'd like some kind of "Get back to me at this time" scheduler, though, of course, not something as Heavy as starting services or lobbing intents around. However, any solution that works better is good.

Some pseudocode to try to explain what I'm doing:

Sub Globals()
  Dim NfMap as Map
End Sub

Sub Setup()
  NfMap.Initialize
  'Note: Different types
  Dim nf as NewsFlash1: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash2: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash3: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash4: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash5: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash6: nf.Initialize: AddNfToMap(nf)
  Dim nf as NewsFlash7: nf.Initialize: AddNfToMap(nf)
  ...
End Sub

Sub AddNfToMap(nf as object)
  NfMap.Put(nf.Key, nf)
End Sub

Sub ShowInfo(Key as string, Message as string)
  dim nf as object= NfMap.Get(Key, Message)
  nf.Show(Message, 3000) 'Hide after 3000 ms
End Sub

'Something to hide nf after the time has passed???

Edit: In other words, what I need is something like "Fire an event at these times", where I can add times dynamically.

 

[sorex]

I wrote a tween class that works kind of what you want.

The class has it's own timer and you feed it with objects from other classes.

I just use a timer where I update the map elements or remove items if a certain condition is met.


Edit: add 2 extra ints to your cutom types and store the current ticks in it and the delay.

in you timer you check if abs(typetick-currentticks)>delaytick if so remove the element from the map and the panel.

 

[Troberg]

That's more or less my second solution. The main problem is that it'll have to fire events pretty often, which makes stepping through code when debugging a nightmare.

 

[JordiCP]

To minimize the number of events and use only one timer, you can manage a DeathList with the active messages and their remaining time.

Something like this

type mItem(msg as string, remainingTime as long)

Sub Show(msg as string ,timeToShow as long)
  Dim I as mItem
  I.msg=msg
  I.remainingTime=TimeToShow
  DeathList.Add(I)
  'If the timer isn't active, activate it with that interval.

sub Timer_Tick
  'stop the timer
  'for each item as mItem in Deathlist, Item.remainingTime -= Timer.Interval
  'remove those elements which have a remaining time <=0 and update the rest
  'if DeathList not empty, activate Timer with the minimum remainingTime
end sub

 

[Troberg]

Actually, I just did it using more or less exactly that method. Some intelligent disabling of the timer when the list is empty made it much neater.