/*

* Copyright (c) 2003-2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  The CMIDChoiceGroup listbox model

*

*/

#ifndef CMIDCHOICEGROUPMODEL_H

#define CMIDCHOICEGROUPMODEL_H

#include <lcdui.h>

#include <coecntrl.h>

#include <eikenv.h>

// CAknFilteredTextListBoxModel inheritance in declaration

#include <AknUtils.h>

// using CMIDChoiceGroupElement for array of elements

#include "CMIDChoiceGroupElement.h"

// 3 seems like a reasonable default amount of elements in a choice

const TInt KCGElementArrayGranularity = 3;

// Forward declaration for the observer interface

class CMIDChoiceGroupModel;

// Choicegroup listbox model observer interface. The observer

// is notified about element addition, removal and modification

class MMIDChoiceGroupModelObserver

{

public:

    enum TChoiceGroupModelEvent

    {

        EElementAdded,

        EElementDeleted,

        EElementModified,

        EElementSelected,

        EUpdateStarted,

        EUpdateEnded

    };

public:

    virtual void HandleChoiceGroupModelEventL(

        CMIDChoiceGroupModel* aModel,

        TChoiceGroupModelEvent aEvent) = 0;

};

/**

 * ChoiceGroup listbox model. Contains ChoiceGroup elements.

 * Figures out and provides strings with correct indices to the

 * listbox, and creates an image array for the column listbox data

 */

NONSHARABLE_CLASS(CMIDChoiceGroupModel) : public CAknFilteredTextListBoxModel

{

public:

    // Default constructor & destructor

    CMIDChoiceGroupModel(MMIDChoiceGroup::TChoiceType aType);

    virtual ~CMIDChoiceGroupModel();

public:

    // Two-phase constructor, initialises member arrays and stuff

    virtual void ConstructL(CEikonEnv* aEikonEnv);

public: // Base class overrides

    // The model contains more than just the strings - need to override

    // number of items query

    virtual TInt NumberOfItems() const;

    // Provides a string with correct indices to images

    virtual TPtrC ItemText(TInt aItemIndex) const;

    // Initialises the element array with given strings

    void SetItemTextArray(MDesCArray* aItemTextArray);

    // Returns a pointer to the item text array (needs to create one

    // first, really. Actually this is not needed, and should be

    // overridden, if only to return NULL.

    MDesCArray* ItemTextArray() const;

public:  // New functions

    // Add an element to the end of the array

    void AppendElementL(CMIDChoiceGroupElement* aElement);

    // Insert an element at <aIndex>. Space must be reserved.

    void InsertElementL(TInt aIndex, CMIDChoiceGroupElement* aElement);

    // Delete element at <anIndex>.

    void DeleteElementL(TInt aIndex);

    // Delete all elements

    void DeleteAllL();

    // Set properties of element at <aIndex>

    void SetElementL(

        TInt aIndex,

        const TDesC& aText,

        CFbsBitmap* aBitmap,

        CFbsBitmap* aMask);

    // Get element at position <aIndex>

    CMIDChoiceGroupElement* ElementAt(TInt aIndex) const;

    // Reserve space for <aCount> elements

    void SetReserveL(TInt aCount);

    // Get icon array, recreate if requested

    CArrayPtr<CGulIcon>* IconArray(TBool aReCreate = EFalse);

    // Set model observer associated with this model

    void SetObserver(MMIDChoiceGroupModelObserver* aObserver)

    {

        iObserver = aObserver;

    }

    // Get control associated with this model

    MMIDChoiceGroupModelObserver* Observer()

    {

        return iObserver;

    }

    // Set selection state of item at <index>.

    // If an item is set selected in an exclusive type choice, also

    // deselects other items.

    // Deselection of an item in an exlusive choice has no effect.

    // NOTE: Currently does not leave, but the name was 'L' in Choice interface

    void SelectElementL(TInt aIndex, TBool aSelected);

    // Begin model update. During the update the icon array will not be

    // updated nor the observer notified of element actions.

    // Once EndUpdate() is called, icon array is rebuilt and notification

    // will occur.

    void BeginUpdate();

    // End a model update. At the end the icon array will be

    // recreated, and the associated observer notified.

    void EndUpdate();

    // Returns the index of the selected element in an exclusive

    // choice, or -1

    TInt SelectedElement();

    //Constructs radio or checkbox on and off icons

    void ReConstructSelectionIconsL();

    // Create an icon array to be given to the lbox column data

    // This should be done every time the contents of the model are changed,

    // or icon array is retrieved with create flag set.

    // NOTE that the indices in the array and the item strings should

    // be synchronised. The selection icon is always at index

    // 0 (selected) and 1 (not selected)

    void UpdateIconArrayL();

    // Returns true if there is at least one item that has icon

    TBool HasIcons() const;

private:  // Utility functions

    // Clears all selections

    void ClearSelection();

    // Report choicegroup event to observer

    void ReportEventL(

        MMIDChoiceGroupModelObserver::TChoiceGroupModelEvent aEvent);

private:

    // Type of the choicegroup

    // (model is only really interested in selection type)

    MMIDChoiceGroup::TChoiceType iType;

    // Icon to display the selection state. Depending on the

    // choice type this is either a radiobutton or a checkbox

    CGulIcon* iIconSelected;

    CGulIcon* iIconNotSelected;

    // Dummy icon for elements that have no icon

    CGulIcon* iIconDummy;

    // Element array

    CArrayPtrFlat<CMIDChoiceGroupElement>* iElements;

    // Indicates that the model is being "bulk-updated", ie

    // BeginUpdate() has been called. Icon array and control updates

    // are supressed during an update operation, until EndUpdate().

    TBool iUpdating;

    // Icon array, recreated when elements are added or

    // removed. Owned by the model, not listbox column data.

    CArrayPtrFlat<CGulIcon>* iIconArray;

    // Observer associated with this model. Observer is

    // reported about changes in the model, if set

    MMIDChoiceGroupModelObserver* iObserver;

};

#endif // CMIDCHOICEGROUPMODEL_H