/*

* Copyright (c) 2009 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:  AknTreeListView physics handler

*

*/

#ifndef C_AKNTREELISTPHYSICSHANDLER_H

#define C_AKNTREELISTPHYSICSHANDLER_H

#include <e32base.h>

#include <aknphysicsobserveriface.h>

class CAknPhysics;

class CAknTreeItem;

class CAknTree;

class CAknTreeListView;

class CWindowGc;

class MTouchFeedback;

/**

 *  Tree list physics handler.

 *

 *  @lib aknhlist

 *  @since S60 v5.0

 */

NONSHARABLE_CLASS( CAknTreeListPhysicsHandler ) : public CBase,

                                                  public MAknPhysicsObserver

    {

public:

    /**

     * Two-phased constructor.

     */

    static CAknTreeListPhysicsHandler* NewL( CAknTreeListView* aTreeListView,

                                             CAknTree* aTree,

                                             RArray<TAknTreeListViewItem>* aItems );

    /**

     * Two-phased constructor.

     */

    static CAknTreeListPhysicsHandler* NewLC( CAknTreeListView* aTreeListView,

                                              CAknTree* aTree,

                                              RArray<TAknTreeListViewItem>* aItems );

    /**

     * Destructor.

     */

    virtual ~CAknTreeListPhysicsHandler();

public:

    /**

     * Handles the pointer event received by tree list view.

     *

     * @param aPointerEvent Pointer event to handle.

     * @param aViewLevel Tree list view level.

     * @param aMarking Item marking mode.

     * @param aShiftPressed Hw shift key.

     * @param aCtrlPressed Hw control key.

     */

    void HandlePointerEventL( const TPointerEvent& aPointerEvent,

                              const TInt& aViewLevel,

                              TBool aMarking,

                              TBool aShiftPressed,

                              TBool aCtrlPressed );

    /**

     * Handles the scroll event received by tree list view.

     *

     * @param aEventType Scroll event to handle.

     * @param aThumbPosition Scroll bar thumb position.

     */

    void HandleScrollEventL( TEikScrollEvent aEventType,

                             const TInt& aThumbPosition );

    /**

     * Handles key events for scroll physics

     *

     * @param aKeyCode Hw key code.

     */                         

    void HandleKeyEvent( TInt aKeyCode );                        

    /**

     * Sets view rect.

     *

     * @param aRect New view rect.

     */

    void SetViewRect( const TRect& aRect );

    /**

     * Returns view rect.

     */

    TRect ViewRect( ) const;

    /**

     * Sets item height.

     *

     * @param aHeight New item height.

     */

    void SetItemHeight( const TInt& aHeight );

    /**

     * Returns offset. Used to draw partial items.

     */

    TInt Offset() const;

    /**

     * Initializes physics.

     */

    void InitPhysicsL();

    /**

     * Resets the pointer event disabling/enabling status.

     */

    void ResetEventBlockingStatus();

    /**

     * Provides vertical scroll bar parameters.

     *

     * @param aThumbSpan

     * @param aThumbPos

     * @param aScrollSpan

     */

    void GetVScrollbarParams( TInt& aThumbSpan, 

                              TInt& aThumbPos, 

                              TInt& aScrollSpan );

    /**

     * Returns ETrue if focused item is visible.

     *

     * @param aFocusedIndex Focused item index.

     * @return ETrue if focused item is visible.

     */

    TBool FocusedItemVisible( const TInt& aFocusedIndex ) const;

    /**

     * Returns the first visible item index.

     *

     * @return First visible item index.

     */

    TInt FirstVisibleItemIndex() const;

    /**

     * Returns the last visible item index.

     *

     * @return Last visible item index.

     */

    TInt LastVisibleItemIndex() const;

    /**

     * Updates the scroll index.

     *

     * @param aScrollTop ETrue if scroll index should be adjusted according to

     * first visible item, EFalse if last item.

     */

    void UpdateScrollIndex( const TBool& aScrollTop );

public: // From base class MAknPhysicsObserver.

    /**

     * Called when view position changes.

     *

     * @param  aNewPosition  The new position of the view.

     * @param  aDrawNow      @c ETrue if the screen is to be redrawn,

     *                       otherwise @c EFalse.

     * @param  aFlags        Additional flags, not used currently.

     */

    virtual void ViewPositionChanged( const TPoint& aNewPosition,

                                      TBool aDrawNow = ETrue,

                                      TUint aFlags = 0 );

    /**

     * Called when emulation has ended.

     */

    virtual void PhysicEmulationEnded();

    /**

     * Returns the observer's view position.

     *

     * @return Physics observer's view position.

     */

    virtual TPoint ViewPosition() const;

public: // New methods.

    /**

     * Sets graphics context used by listbox effects.

     */

    void SetGc( CWindowGc* aGc );

private:

    /**

     * C++ constructor.

     */

    CAknTreeListPhysicsHandler( CAknTreeListView* aTreeListView,

                                CAknTree* aTree,

                                RArray<TAknTreeListViewItem>* aItems );

    /**

     * Symbian second-phase constructor.

     */

    void ConstructL();

    /**

     * Returns drag threshold.

     *

     * @return drag threshold.

     */

    TInt DragThreshold();

    /**

     * Launches the highlight timer.

     * 

     * @param aWasScrolling ETrue if content was scrolling. In that case

     *                      highlight is drawn with timeout.

     */

    void LaunchHighlightTimer( TBool aWasScrolling );

    /**

     * Callback method for highlight timer.

     *

     * @param aThis Pointer to an instance of @c CAknTreeListView class.

     *

     * @return @c NULL, as function is intended to be called only once.

     */

    static TInt HighlightTimerCallback( TAny* aPtr );

    /**

     * Sets highlight to focused item.

     */

    void SetHighlight();

    /**

     * Moves view to correct position.

     *

     * @param ETrue to redraw the view after movement 

     */

    void ScrollView( TBool aDrawNow );

    /**

     * Stops physics.

     */

    void StopPhysics();

    /**

     * Returns world height.

     *

     * @return World height.

     */

    TInt WorldHeight();

    /**

     *

     * @return ETrue if aPosition is in empty list area.

     */    

private: // data

    /**

     * Scroll index.

     */

    TInt iScrollIndex;

    /**

     * Previous scroll index.

     */

    TInt iPreviousIndex;

    /**

     * Height of one item.

     */

    TInt iItemHeight;

    /**

     * Current pointer position.

     */   

    TPoint iPosition;

    /**

     * Start (pointer down) position.

     */

    TPoint iStartPosition;

    /**

     * View rect.

     */

    TRect iViewRect;

    /**

     * ETrue if pointer events are blocked.

     */

    TBool iEventsBlocked;

    /**

     * ETrue if pointer events are enabled.

     */

    TBool iEnableEvents;

    /**

     * ETrue if panning functionality is activated.

     */

    TBool iPanningActivated;

    /**

     * Pointer down start time.

     */

    TTime iStartTime;

    /**

     * Physics. 

     * Own.

     */

    CAknPhysics *iPhysics;

    /**

     * Highlight timer.

     * Own.

     */

    CPeriodic* iHighlightTimer;

    /**

     * Pointer to the list item to be focused by highlight timer.

     * Not own.

     */

    CAknTreeItem* iItemToBeFocused;

    /**

     * Pointer to the list item to be selected.

     * Not own.

     */

    CAknTreeItem* iItemToBeSelected;

    /**

     * Index of the list item to be focused by highlight timer.

     */

    TInt iIndexToBeFocused;

    /**

     * Physics handler flags.

     */

    TBitFlags iFlags;

    /**

     * Pointer to tree.

     * Not own.

     */

    CAknTree* iTree;

    /**

     * Pointer to tree list view.

     * Not own.

     */

    CAknTreeListView* iTreeListView;

    /**

     * Pointer to array for visible view items.

     * Not own.

     */

    RArray<TAknTreeListViewItem>* iItems;

    /**

     * Offset between list first item position and view rect position.

     */

    TInt iListTopOffset;

    /**

     * Graphics context used by the parent listbox. Needed for transition

     * effects.

     */

    CWindowGc* iTfxGc;

    /**

     * Determines whether or not next up event should cause basic list 

     * feedback. The value is determined always on down event. If the value

     * on up event is EFalse, feedback is not played. If the value is ETrue,

     * basic list feedback is produced.

     */

    TBool iPlayFeedbackOnUp;

    /**

     * Pointer to the feedback object. Not owned.

     */    

    MTouchFeedback* iFeedback;

    // when touch down, it is true for recording physics Y of current view

    TBool iPenDown;

    // top item in current view, -1 if item's Y is negative

    TInt iOldTopItem;

    // bottom item in current view, fields count when Y is larger than

    // the last item's Y

    TInt iOldBottomItem; 

    /**

     */    

    };

#endif // C_AKNPHYSICSPARAMETERPROVIDER_H