Normally a homescreen widget can only update itself every 30 minutes. A lower value is not possible in the ConfigureHomeWidget() call.
But what if you want to create something like a clock which needs to be updated every minute?
This is possible too but I experienced some problems handling the widgetservice correctly in this case. If it is not handled correctly the service will run forever even if no widget is visible on the homescreen anymore. I will explain it in this tutorial on a simple clock widget example.
We configure our widget in Service_Create(). The update interval can be set to 0 here. It really shouldn't matter because we update the widget ourself. I used a value of 120 because I wanted to be sure that the clock will restart at least after 2 hours when an unexpected problem occurs.
To handle the service correctly we have to react correctly on the Intent actions. The commets should explain everything here enough.
If a widget (not the last one) is removed from the homescreen nothing has to be done so we just return.
If the Events are handled by HandleWidgetEvents() then we don't need to do anything special. Otherwise we just update the widget.
At last we have to reschedule our service at the next full minute. Attention: We have to be sure that we don't reschedule our service when the last widget is removed from homescreen. Otherwise our service won't stop correctly!
If the last widget is removed we have to cancel the last schedule and completely stop the service.
The other subs in the program are trivial. Look at the example code.
PS: I'm always amazed how simple and fast it is to create apps with B4A!
But what if you want to create something like a clock which needs to be updated every minute?
This is possible too but I experienced some problems handling the widgetservice correctly in this case. If it is not handled correctly the service will run forever even if no widget is visible on the homescreen anymore. I will explain it in this tutorial on a simple clock widget example.
B4X:
Sub Service_Create
rv = ConfigureHomeWidget("l2x1", "rv", 120, "AmberHome Minimalistic Clock")
End SubWe configure our widget in Service_Create(). The update interval can be set to 0 here. It really shouldn't matter because we update the widget ourself. I used a value of 120 because I wanted to be sure that the clock will restart at least after 2 hours when an unexpected problem occurs.
B4X:
Sub Service_Start (StartingIntent As Intent)
' If a widget is removed from homescreen we don't need to do anything
If StartingIntent.Action = "android.appwidget.action.APPWIDGET_DELETED" Then Return
' Handle the widget events
If rv.HandleWidgetEvents(StartingIntent) = False Then
' If the action is not handled by HandleWidgetEvents() then we
' probably were called by StartService() or StartServiceAt().
' So just update the widget.
rv_RequestUpdate
End If
' We have to be sure that we do not start the service
' again if all widgets are removed from homescreen
If StartingIntent.Action <> "android.appwidget.action.APPWIDGET_DISABLED" Then
StartServiceAt("", TimeToNextMinute, False)
End If
End SubTo handle the service correctly we have to react correctly on the Intent actions. The commets should explain everything here enough.
If a widget (not the last one) is removed from the homescreen nothing has to be done so we just return.
If the Events are handled by HandleWidgetEvents() then we don't need to do anything special. Otherwise we just update the widget.
At last we have to reschedule our service at the next full minute. Attention: We have to be sure that we don't reschedule our service when the last widget is removed from homescreen. Otherwise our service won't stop correctly!
B4X:
Sub rv_Disabled
CancelScheduledService("")
StopService("")
End SubIf the last widget is removed we have to cancel the last schedule and completely stop the service.
The other subs in the program are trivial. Look at the example code.
PS: I'm always amazed how simple and fast it is to create apps with B4A!
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