1 /*

     2 * Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 

    18 #ifndef PENPOINTEREVENTSUPPRESSOR_H

    19 #define PENPOINTEREVENTSUPPRESSOR_H

    20 

    21 //  INCLUDES

    22 #include <coecntrl.h>

    23 

    24 // CLASS DECLARATION

    25 

    26 /**

    27 *  Utility class for removing unwanted pointer events, for instance

    28 *  when distinguishing tap events from intended drags.

    29 *

    30 *  Usage pattern, where iSuppressor is a CPenPointerEventSuppressor*:

    31 *

    32 *  void CMyControl::HandlePointerEventL(const TPointerEvent& aPointerEvent)

    33 *  	{

    34 *  	if (iSuppressor->SuppressPointerEvent(aPointerEvent))

    35 *  		return;

    36 *  	

    37 *  	switch (aPointerEvent.iType)

    38 *  		{

    39 *  		case TPointerEvent::EButton1Down:

    40 *  			iTap = ETrue;

    41 *  			break;

    42 *  		case TPointerEvent::EButton1Up:

    43 *  			if (iTap)

    44 *  				HandleTapL(aPointerEvent);

    45 *  			break;

    46 *  		case TPointerEvent::EDrag:

    47 *  			iTap = EFalse;

    48 *  			HandleDragL(aPointerEvent);

    49 *  			break;

    50 *  		default:

    51 *  			break;

    52 *  		}

    53 *  	}

    54 *

    55 *  @since S60 5.0

    56 */

    57 class CPenPointerEventSuppressor : public CBase

    58 	{

    59 public:

    60 	/**

    61 	* Factory function

    62 	*

    63 	* This creates a pointer event suppressor that will suppress

    64 	* drag events while the pointer interaction may be a tap.

    65 	*/

    66 	static CPenPointerEventSuppressor* NewL();

    67     /**

    68     * Destructor.

    69     */    

    70 	~CPenPointerEventSuppressor();

    71 	

    72 	/**

    73 	* Tests whether a pointer event should be suppressed.

    74 	*

    75 	* A control that wants pointer event suppression should feed

    76 	* all pointer events to this function. It will return ETrue if

    77 	* the pointer event should be ignored by the control.

    78 	* Only controls that have unrelated behaviour on tap and drag

    79 	* actions need to use pointer event suppression.

    80 	*

    81 	* If this class is used to suppress drag events during a possible

    82 	* tap, and this function does not suppress a drag event, the

    83 	* client can be sure that a drag action is happening.

    84 	*

    85 	* @param aPointerEvent the pointer event which may need to be suppressed.

    86 	* @return ETrue if the pointer event should be suppressed, or EFalse if it should be handled.

    87 	*/

    88 	TBool SuppressPointerEvent(const TPointerEvent& aPointerEvent);

    89 	/**

    90 	* Set the maximum time period that drag events should be

    91 	* ignored during a pointer interaction.

    92 	*

    93 	* @param aDuration the maximum duration of a tap action.

    94 	*/

    95 	void SetMaxTapDuration(TTimeIntervalMicroSeconds aDuration);

    96 	/**

    97 	* Set the maximum pointer movement for which drag events

    98 	* should be ignored during a pointer interaction.

    99 	*

   100 	* @param aMoveLimits the pixel movement limits within which a touch action is considered a tap

   101 	*/

   102 	void SetMaxTapMove(TSize aMoveLimits);

   103 	/**

   104 	* Set the minimum time between drag events.

   105 	* This can be used to reduce the frequency of drag event reception when

   106 	* events are not desired at maximum speed.

   107 	*

   108 	* @param aInterval the minimum interval between which drag events are wanted

   109 	*/

   110 	void SetMinInterDragInterval(TTimeIntervalMicroSeconds aInterval);

   111 

   112 private:

   113 	CPenPointerEventSuppressor();

   114 

   115 private:

   116 	TTimeIntervalMicroSeconds iMaxTapDuration;

   117 	TSize iMaxTapMove;

   118 	TTimeIntervalMicroSeconds iMinInterDragInterval;

   119 	TTime iDownTime;

   120 	TPoint iDownPos;

   121 	TBool iTap;

   122 	TTime iLastEventTime;

   123 	};

   124 

   125 #endif