/*

 * Copyright (c) 2002 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: 

 *

 */

 // AknQueryValue.h

 //

 // Copyright (c) 2001 Symbian Ltd.  All rights reserved.

 //

 #if !defined(__AKNQUERYVALUE_H__)

 #define __AKNQUERYVALUE_H__

 #include <eikenv.h>

 #include <babitflags.h>

 class MDesCArray;

 /**

  * Mixin class representing a value that is accessed as text.

  * <p> The Value can be changed by creating an editor dialog, 

  * which may be either a query or a setting page

  * or optionally by choosing an entry from an array of values. 

  * The array can be accessed as a descriptor array, and the value 

  * can be accessed as a descriptor.

  */

 class MAknQueryValue

 	{

 public:

 	/**

 	 * Possible modes are query & setting page 

 	 * 

 	 */

 	enum TMode

 		{

 		EQueryMode,

 		ESettingPageMode

 		};

 protected:

 	/**

 	 * If EAutoAppendBitIndex is set, 

 	 * the query value auto appends new values

 	 */

 	enum TFlagBits

 		{

 		ESettingPageModeBitIndex = 0,

 		EAutoAppendBitIndex

 		};

 public:

 	virtual ~MAknQueryValue() {}

 	/**

 	 * Returns the array as a descriptor array, 

 	 * ownership will be not passed 

 	 */	

 	virtual const MDesCArray* MdcArray() const = 0;

     /**

      * This should be implemented so that it returns the current value as text

      * 

      * @return	descriptor representing current value, new 

      * descriptor is created and left on cleanup stack, ownership passed back to client

     */	

 	virtual HBufC* CurrentValueTextLC() = 0;

 	/**

      * Returns the index in the array of the current value. 

      * If no matches, returns zero

      *

     */

 	virtual TInt CurrentValueIndex() const = 0;

 	/**

      * Changes the current value to correspond to a value in the array.

      *

      * @param aIndex	index in array of value to set as current

     */

 	virtual void SetCurrentValueIndex(const TInt aIndex) = 0;

     /**

      * Creates an editor within context. If the value is edited and OK'd,

      * the new value will be set as the current value. Otherwise the current value 

      * remains unchanged.

      *

      * @return	ETrue if current value was altered; EFalse otherwise

      */	

 	virtual TBool CreateEditorL() = 0;

 	/**

 	 * Set QueryMode to be whether query or settingpage -mode

 	 *

      * @param aMode	value from <p>TMode	 

 	 */

 	virtual void SetQueryMode( MAknQueryValue::TMode aMode ) = 0;

 	/**

 	 * Override the default resource IDs used if a Setting Page mode query is put up.

 	 * All Queryvalue implementations should have default resource set up. Hence this

 	 * need not be called unless non-default resource is required.

 	 *

 	 * THE IMPLEMENTATION OF THESE RESOURCE OVERRIDES IS RESERVED FOR FUTURE VERSIONS

 	 * OF SERIES 60. NOT CURRENTLY FUNCTIONAL. DO NOT USE.

 	 *

 	 * The rules for usage of these ids is the same as that for the CAknSettingPage constructors

 	 * that take both these resources

 	 *		Editor Resource		Setting Page Resource

 	 *			present				present				Both are used (but text & number overridden)

 	 *			 = 0					present				Editor resource is used via SP resource 

 	 *			present					= 0					default SP resource for the query type is used + this editor resource

 	 *

 	 * The type of the editor resource is fixed. If editor resource override is being

 	 * used, then the resource must be for that control type of editor used in the

 	 * CAknQueryValueXXXX class.

 	 * 

 	 * @param aSettingPageResourceId		AVKON_SETTING_PAGE resource ID to use

 	 * @param aSettingPageEditorResourceId	Editor resource ID to use (takes precedence)

 	 *

 	 */

 	virtual void SetSettingPageResourceIds( 

 		TInt aSettingPageResourceId, 

 		TInt aSettingPageEditorResourceId ) = 0;

 	/**

 	 * Set the QueryValue to append a new user value, if distinct from former value 

 	 *

      * @param aAppend	set/unset flag EAutoAppendBitIndex	 

 	 */

 	virtual void SetAutoAppend( TBool aAppend ) = 0;

 protected:

 	/**

 	 * Method to add the current value to the QueryValueArray if it is new.

 	 * The new value is not owned by QueryValue object, but is "given away"

 	 *

 	 */

 	virtual void AppendValueIfNewL() = 0;

 private:

 	IMPORT_C virtual void Reserved_MAknQueryValue();

    };

 /** 

  * Pure virtual class that adds some standard functionality for queries

  *

  */

 class CAknQueryValue : public CBase, public MAknQueryValue

 	{

 public:

 	/**

 	 * Set QueryMode to be whether query or settingpage -mode

 	 *

      * @param aMode	value from <p>TMode	 

 	 */

 	IMPORT_C virtual void SetQueryMode( MAknQueryValue::TMode aMode );

 	/**

 	 * Override the default resource IDs used if a Setting Page mode query is put up.

 	 * 

 	 * @param aSettingPageResourceId		AVKON_SETTING_PAGE resource ID to use

 	 * @param aSettingPageEditorResourceId	Editor resource ID to use (takes precedence)

 	 *

 	 */	

 	IMPORT_C virtual void SetSettingPageResourceIds( TInt aSettingPageResourceId, TInt aSettingPageEditorResourceId );

 	/**

 	 * Set the QueryValue to append a new user value, if distinct from former value 

 	 *

      * @param aAppend	set/unset flag EAutoAppendBitIndex	 

 	 */	

 	IMPORT_C virtual void SetAutoAppend( TBool aAppend );

 	/**

 	 * Method to add the current value to the QueryValueArray if it is new.

 	 * The new value is not owned by QueryValue object, but is "given away"

 	 *

 	 */	

 	IMPORT_C virtual void AppendValueIfNewL();

 protected:

 	/**

 	 * Check if given index is valid within descriptor array

 	 *

      * @param aIndex   index to be checked	 	 

 	 */

 	TBool IsValidIndex(TInt aIndex) 

 	{

 	if (MdcArray()->MdcaCount() < 1) return ETrue;

 	if (aIndex < 0 || aIndex >= MdcArray()->MdcaCount())

 	    return EFalse;

 	return ETrue;

 	}

 protected:

     /** 

      * Flags that determine behavior

      *

      */

 	TBitFlags16	iFlags;

     /** 

      * Resource id for setting page

      *

      */

 	TInt iSettingPageResourceId;

     /** 

      * Resource id for editor in setting page

      *

      */	

 	TInt iSettingPageEditorResourceId;

 private:

 	TInt iSpare;

 // from MAknQueryValue

 	IMPORT_C void Reserved_MAknQueryValue();

 	};

 #endif // __AKNQUERYVALUE_H__