Storing state on exit in Symbian Web Runtime

Article Metadata

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Code Example

Source file: Media:StoreStateOnExit.zip

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Tested with

Devices(s): Nokia N97, Nokia N97 mini

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Compatibility

Platform(s): S60 5th edition

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Article

Keywords: widget.onexit

Created: User:Kbwiki (23 Dec 2009)

Last edited: hamishwillee (05 Jul 2012)

Overview

In some situations, it might be necessary to store the widget state on exit. One of these use cases is storing the last shown full screen view before the widget is minimised to the home screen by pressing the Exit key. The same view can then be shown to the user the next time the widget is maximised.

Solution

To implement this you will need to:

• detect when the widget has been closed
• store the state on exit and load state information when the widget is started.

The closing of a widget can be detected by defining an event handler for the widget.onexit event.

 widget.onexit = function() {
  // store current view
 }

widget.onexit is fired every time a widget is closed, just before the last onhide event.

For storing the state, setPreferenceForKey can be used. At startup, the last stored state can be loaded using preferenceForKey.

 var lastActiveFSView;
 
 widget.onexit = function() {
   if (lastActiveFSView) {
     widget.setPreferenceForKey(lastActiveFSView, "lastActiveFSView");
   }
 }
 
 window.onload = function() {
   lastActiveFSView = widget.preferenceForKey("lastActiveFSView");
 }

For a complete example, see: StoreStateOnExit.zip