CanShowPurgingSuggestions

AddSuggestion AddSuggestionsFromPurger MakeSuggestionsForDiscarding ResetSuggestionList ValidateSuggestionList

Attributes

CheckedSuggestionList ForOutOfMemory PurgingListView SuggestionList

Fields

Define Class CanShowPurgingSuggestions;
    mixes in with Object;
    
    attribute PurgingListView: CheckboxListView, readOnly, noGetter;
        // list view that holds the list of purging suggestions
        // subclass must provide implementation

    attribute SuggestionList: KeySortedList, readOnly;
        // getter returns list that stores suggestions for discarding
        // list is from PurgingListView(self)
        
    attribute CheckedSuggestionList: ObjectList, readOnly;
        // getter returns list that stores suggestions for discarding that user has selected
        // list is from PurgingListView(self)
        
    attribute ForOutOfMemory: Boolean, readOnly;
        // returns false
        // override occasionally to return true for subclasses that handle
        // the completely-out-of-memory scenario
        // called by system to make decisions about memory vs. performance tradeoffs
    
    operation AddSuggestion(discardable: Object);
        // called by overriders of SearchForSuggestion for each item to be suggested for discarding
        // adds <discardable> to suggestion list
        // sometimes override to update user interface as items are added, or to check for
        // user action that might interrupt lengthy search
        // sometimes called with nilObject as <discardable> to allow check for user action
        
    operation AddSuggestionsFromPurger(purger: CanOfferPurgingSuggestions; containerDevice: ContainerDevice; recommendedOnly: Boolean);
        // calls SearchForSuggestions
        // override sometimes to let user interface show progress

    operation MakeSuggestionsForDiscarding(containerDevice: ContainerDevice; recommendedOnly: Boolean);
        // iterates through iLowMemoryPurgers, calling AddSuggestionsFromPurger with each one
        // override rarely
        
    operation ResetSuggestionList();
        // clears out suggestionList and checkedSuggestionList
        // override rarely
        
    operation ValidateSuggestionList(): Boolean;
        // removes destroyed objects from suggestionList and checkedSuggestionList
        // returns true if there were any destroyed objects
        // override rarely
end class;