epoc32/include/mw/aknpointereventsuppressor.h
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:33:34 +0100
branchSymbian3
changeset 4 837f303aceeb
parent 2 2fe1408b6811
permissions -rw-r--r--
Current Symbian^3 public API header files (from PDK 3.0.h)
This is the epoc32/include tree with the "platform" subtrees removed, and
all but a selected few mbg and rsg files removed.
     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 AKNPOINTEREVENTSUPPRESSOR_H
    19 #define AKNPOINTEREVENTSUPPRESSOR_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 CAknPointerEventSuppressor*:
    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 NONSHARABLE_CLASS(CAknPointerEventSuppressor) : 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 	IMPORT_C static CAknPointerEventSuppressor* NewL();
    67     /**
    68     * Destructor.
    69     */    
    70 	IMPORT_C ~CAknPointerEventSuppressor();
    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 	IMPORT_C 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 	IMPORT_C 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 	IMPORT_C 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 	IMPORT_C void SetMinInterDragInterval(TTimeIntervalMicroSeconds aInterval);
   111 
   112 private:
   113 	CAknPointerEventSuppressor();
   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 
   126 #endif