/*

* Copyright (c) 2006, 2007 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:  An interface to the hierarchical list tree structure.

*

*/

#ifndef C_AKNTREE_H

#define C_AKNTREE_H

#include <AknIconUtils.h> // TScaleMode

#include <babitflags.h>

#include "akntreenode.h"

#include "akntreeobserver.h"

class CAknTreeList;

class CAknTreeListIcon;

class CAknTreeOrdering;

class CAknMarqueeControl;

class CFont;

class MAknCustomTreeOrdering;

class TAknsItemID;

class TAknTreeIterator;

class TAknTextComponentLayout;

class TRgb;

/**

 *  Hierarchical list tree structure.

 *

 *  The tree structure is formed from hierarchical list items. These items

 *  can be either leaves or nodes. The names do not refer to their dynamic

 *  state; a leaf is a tree item that cannot ever have children in the tree

 *  structure while node can. @c CAknTree is derived from @c CAknTreeNode

 *  class, which is an abstract base class for all tree nodes. An instance of

 *  @c CAknTree is always set as a root of the tree structure, so that it can

 *  be always reached from all the tree items through parent pointers, or

 *  simply by calling the @c CAknTreeItem::Root() method.

 *

 *  @c CAknTree class provides fast access to all the tree items it contains.

 *  The tree structure should always be modified through this class and not

 *  by directly modifying the related tree items, as this class is responsible

 *  for notifying the tree list view of the occurring tree events.

 *

 *  Furthermore, this class can create an iterator (an instance of

 *  @c CAknTreeIterator) for traversing the tree structure, it stores the

 *  ordering of the tree items, and it can also store the icons shared by

 *  several tree items.

 *

 *  @lib aknhlist.lib

 *  @since S60 v3.2

 */

    {

public:

    /** Pre-defined IDs for the icons constructed by the tree. */

    enum TTreeListIcon

        {

        ENone                           = AknTreeListIconID::KNone,

        /** Tree structure line with branch. */

        ELineBranchIndication           = AknTreeListIconID::KLineBranchIndication,

        /** Tree structure end line. */

        ELineEndIndication              = AknTreeListIconID::KLineEndIndication,

        /** Tree structure straight line indication. */

        ELineStraightIndication         = AknTreeListIconID::KLineStraightIndication,

        /** Default file indication. */

        EDefaultFileIndication          = AknTreeListIconID::KDefaultFileIndication,

        /** Closed folder indication. */

        EClosedFolderIndication         = AknTreeListIconID::KClosedFolderIndication,

        /** Open folder indication. */

        EOpenFolderIndication           = AknTreeListIconID::KOpenFolderIndication,

        /** Collapse function indication, superimposed. */

        ECollapseFunctionIndication     = AknTreeListIconID::KCollapseFunctionIndication,

        /** Expand function indication, superimposed. */

        EExpandFunctionIndication       = AknTreeListIconID::KExpandFunctionIndication,

        /** Item marked indication. */

        EMarkedIndication               = AknTreeListIconID::KMarkedIndication,

        /** Highlighted item marked indication. */

        EHighlightedMarkedIndication    = AknTreeListIconID::KHighlightedMarkedIndication,

        /** Denotes the range for pre-defined IDs. */

        EPreDefinedIconIdRange

        };

    /**

     * Two-phased constructor.

     *

     * @param aList Reference to the tree list object which owns the created

     *      tree structure.

     *

     * @param aOrdering Ordering for the tree list items. The ownership of

     *      of the ordering is transferred to the tree.

     *

     * @return Newly created tree instance.

     */

    static CAknTree* NewL( CAknTreeList& aList, CAknTreeOrdering* aOrdering );

    /**

     * Destructor.

     */

    virtual ~CAknTree();

    /**

     * Returns the ID assigned for the specified tree item. The constant

     * @c KAknTreeIIDRoot is returned for the tree root, and constant @c

     * KAknTreeIIDNone for null pointer.

     *

     * @param aItem Pointer to a tree item.

     *

     * @return ID of the given tree item.

     */

    TAknTreeItemID Id( const CAknTreeItem* aItem ) const;

    /**

     * Sets the ordering of the tree list.

     * The ordering defines the order of hierarchical list items. The list

     * items are always kept sorted according the set ordering object, and

     * whenever the ordering object is changed, the tree is sorted according

     * the newly set ordering.

     *

     * @param aOrdering Specialisation specific implementation for the

     *      abstract @c CAknTreeListOrdering class. This object defines the

     *      order of hierarchical list items.

     *

     * @param aDrawNow @c ETrue to redraw the list after it has been sorted.

     *

     * @post The list is sorted according to the set ordering.

     */

    void SetOrdering( CAknTreeOrdering* aOrdering, TBool aDrawNow );

    /**

     * Sets custom ordering for the tree.

     *

     * @param aOrdering Implementation for custom ordering interface defining

     *      the order of hierarchical list items.

     *

     * @param aDrawNow @c ETrue to redraw the list after it has been sorted.

     */

    void SetCustomOrdering( MAknCustomTreeOrdering* aOrdering, TBool aDrawNow );

    /**

     * Sorts the specified tree node.

     *

     * @param aNode Item ID of the node that has to be sorted.

     *

     * @param aSortDescendants @c ETrue to sort the content of the specified

     *      node including the content of its descendant nodes, @c EFalse to

     *      to sort only the child items within the specified node.

     *

     * @param aDrawNow @c ETrue to redraw the list after sorting.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    void Sort( TAknTreeItemID aNode, TBool aSortDescendants, TBool aDrawNow );

    /**

     * Compares two tree items.

     *

     * @param aFirst First item.

     *

     * @param aSecond Second item.

     *

     * @return Positive, if the first item is greater than the second item;

     *      negative, if the first item is less than the second item;

     *      and zero, if the items are equal.

     */

    TInt Compare( const CAknTreeItem& aFirst, const CAknTreeItem& aSecond ) const;

    /**

     * Returns the number of items in the tree.

     *

     * @return Number of items.

     */

    TInt ItemCount() const;

    /**

     * Returns the number of visible items in the tree. This excludes all the

     * items in collapsed folders.

     *

     * @return Number of visible items.

     */

    TInt VisibleItemCount() const;

    /**

     * Returns the index of specified item. The index is equal to the number

     * of tree items in the tree structure before the specified item.

     *

     * @param aItem Pointer to tree item.

     *

     * @return The index of specified item. Value @c KErrNotFound is returned

     *      if the specified item is not found.

     */

    TInt ItemIndex( const CAknTreeItem* aItem ) const;

    /**

     * Returns the index from subset of visible items. The index is equal to

     * the number of tree items in the expanded tree structure before the 

     * specified item.

     *

     * @param aItem Pointer to tree item.

     *

     * @return The index of specified item. Value @c KErrNotFound is returned

     *      if the specified item is not found, or not in the expanded tree

     *      structure.

     */

    TInt VisibleItemIndex( const CAknTreeItem* aItem ) const;

    /**

     * Returns visible item based on the given index.

     *

     * @param aIndex Index defining the items position in expanded tree.

     *

     * @return Pointer to tree item. @c NULL, if item with given index is found.

     */ 

    CAknTreeItem* VisibleItem( TInt aIndex ) const;

    /**

     * Returns the depth of the tree, which equals to number of levels in the

     * expanded part of the tree.

     *

     * @return The depth of expanded tree structure.

     */

    TInt Depth() const;

    /**

     * Retrieves the specified item from the tree.

     *

     * @param aItemId ID of the item to be retrieved.

     *

     * @param aItem Reference to a pointer, which is replaced with a pointer

     *      to the specified item, if it is found from the tree.

     *

     * @return @c KErrNone, if the item is found from the tree. The return

     *      value @c KErrNotFound indicates that the item was not found.

     */

    TInt GetItem( TAknTreeItemID aItemId, CAknTreeItem*& aItem ) const;

    /**

     * Retrieves the specified item from the tree structure.

     *

     * @param aItemId ID of the item to be retrieved.

     *

     * @return The retrieved tree item.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    CAknTreeItem* Item( TAknTreeItemID aItemId ) const;

    /**

     * Retrieves the specified node from the tree structure.

     *

     * @param aNodeId ID of the node to be retrieved.

     *

     * @return The retrieved tree node.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    CAknTreeNode* Node( TAknTreeItemID aNodeId ) const;

    /** 

     * Add a new item to the tree. The constant @c KAknTreeIIDRoot is to be

     * used as the ID of parent node, when item is added to the the top-most

     * level of the tree.

     *

     * @param aItem The item to be added to the tree structure.

     *

     * @param aParent ID of the parent node to which the item is to be added.

     *

     * @param aDrawNow @c ETrue, if the view is to be updated after the

     *      item has been added to the tree.

     *

     * @return Item ID assigned for the added item.

     */

    TAknTreeItemID AddItemL( CAknTreeItem* aItem, TAknTreeItemID aParent,

        TBool aDrawNow );

    /**

     * Moves the specified item to the specified target node. The constant

     * @c KAknTreeIIDRoot can be used as the ID of target node, when moving

     * the item to the top-most level of the tree.

     *

     * @param aItem ID of the item to be moved.

     *

     * @param aTargetNode ID of the node, where the item is to be moved.

     *

     * @param aDrawNow @c ETrue, if the view is to be updated after the

     *      item has been moved.

     *

     * @leave KErrArgument The specified item is the same as the target node

     *      or one of the ancestors of target node. 

     *

     * @leave KErrNoMemory Not enough memory is available for adding the

     *      specified item to the target node.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified target node is not a node.

     */

    void MoveItemL( TAknTreeItemID aItem, TAknTreeItemID aTargetNode,

        TBool aDrawNow );

    /**

     * Remove an existing item from the tree. If the specified item is a node,

     * all of its descendants will be removed from the tree as well.

     *

     * @param aItem The item to be removed from the tree structure.

     *

     * @param aDrawNow @c ETrue, if the view is to be updated after the

     *      item has been removed from the tree.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    void RemoveItem( TAknTreeItemID aItem, TBool aDrawNow );

    /**

     * Changes the state of the specified node to expanded. Using constant

     * @c KAknTreeIIDRoot as the node ID expands every node in the tree.

     *

     * @param aNode Item ID of the node to be expanded.

     *

     * @param aDrawNow @c ETrue, if the view is to be updated after the node

     *      has been expanded.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    void ExpandNode( TAknTreeItemID aNode, TBool aDrawNow );

    /**

     * Changes the state of the specified node to collapsed. All the children

     * that are not set persistent will be deleted. Using constant @c

     * KAknTreeIIDRoot as the node ID collapses every node in the tree.

     *

     * @param aNode Item ID of the node to be collapsed.

     *

     * @param aDrawNow @c ETrue, if the view is to be updated after the node

     *      has been collapsed.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    void CollapseNode( TAknTreeItemID aNode, TBool aDrawNow );

    /**

     * Checks if the specified node is expanded. 

     *

     * @param aNode Item ID of the node.

     *

     * @return @c ETrue, if the node is expanded.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    TBool IsExpanded( TAknTreeItemID aNode ) const;

    /**

     * Returns the number of children of a tree node. This method, along with

     * @c Child() method, can be used for enquiring information of the tree

     * structure. Constant @c KAknTreeIIDRoot can be used to get the

     * item count on the top-most level of the list.

     *

     * @param aNode Item ID of a node.

     *

     * @return Number of children of specified node.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    TInt ChildCount( TAknTreeItemID aNode ) const;

    /**

     * Returns the item ID of a child of a tree node. The specific child is

     * specified with an index. The child count for any hierarchical

     * list node can be get with @c ChildCount() method.

     *

     * @param aNode Item ID of the node, whose child is enquiried.

     *

     * @param aIndex Index of the enquiried child.

     *

     * @return Item ID of the specified child. Value @c KAknTreeIIDNone is

     *      returned, if the child with specified index does not exist.

     * 

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    TAknTreeItemID Child( TAknTreeItemID aNode, TInt aIndex ) const;

    /**

     * Returns the item ID of a parent node of specified tree item.

     * 

     * @param aItem Item ID of the item, whose parent is queried.

     *

     * @return Item ID of the parent node.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    TAknTreeItemID Parent( TAknTreeItemID aItem ) const;

    /**

     * Adds new observer for the tree. The ownership of the observer interface

     * is not transferred to the tree.

     *

     * @param aObserver Observer.

     */

    void AddObserverL( MAknTreeObserver* aObserver );

    /**

     * Removes an observer from the tree.

     *

     * @param aObserver Observer to be removed.

     *

     * @return @c KErrNotFound, if the specified observer is not found.

     *      Otherwise, the value @c KErrNone is used.

     */

    TInt RemoveObserver( MAknTreeObserver* aObserver );

    /**

     * Checks whether the specified item is marked.

     *

     * @param aItem Item ID.

     *

     * @return @c ETrue, if the item is marked.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    TBool IsMarked( TAknTreeItemID aItem ) const;

    /**

     * Sets the specified item marked or unmarked.

     *

     * @param aItem Item ID of modified item.

     *

     * @param aMarked @c ETrue to set item marked, @c EFalse to unmarked.

     *

     * @param aDrawNow @c ETrue to redraw the view.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    void SetMarked( TAknTreeItemID aItem, TBool aMarked, TBool aDrawNow );

    /**

     * Enables or disables marking of specified list item.

     *

     * @param aItem Item ID of the list item.

     *

     * @param aEnable @c ETrue to enable marking, @c EFalse to disable it.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     */

    void EnableMarking( TAknTreeItemID aItem, TBool aEnable );

    /**

     * Gets all the marked items from the specified node. The marked items

     * are appended to the end of the array passed as parameter.

     *

     * @param aNode Item ID of a node from where the marked items are

     *      retrieved.

     *

     * @param aMarkedItems On return, contains item IDs of marked items in

     *      the specified node.

     *

     * @leave KErrNoMemory Appending item to the array fails.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified item is not a node.

     */

    void GetMarkedItemsL( TAknTreeItemID aNode,

        RArray<TAknTreeItemID>& aMarkedItems ) const;

    /**

     * Checks whether the specified node is empty.

     *

     * @param aNode Item ID for a node.

     *

     * @return @c ETrue, if the item is empty.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified target item is not a node.

     */

    TBool IsEmpty( TAknTreeItemID aNode ) const;

    /**

     * Sets whether the specified node appears as non-empty when empty.

     *

     * @param aNode Item ID for a node.

     *

     * @param aNonEmpty @c ETrue to set node appear non-empty, @c EFalse to

     *      to remove previously set flag.

     *

     * @param aDrawNow @c ETrue to redraw the list.

     *

     * @panic EAknHListPanicInvalidItemID Item with specified ID is not found.

     *

     * @panic EAknHListPanicInvalidItemType Specified target item is not a node.

     */

    void SetNonEmpty( TAknTreeItemID aNode, TBool aNonEmpty, TBool aDrawNow );

    /**

     * Checks whether the specified item is persistent.

     *

     * @param aItem Item ID.

     *