学步园

Overview

S60第五版平台支持触摸屏，因此提供了更强大的应用程序界面特性。 如果一个界面过分复杂繁琐，有很多弹出菜单和工具栏按钮，那么对用户来说就十分讨厌和不便。甚至只是简单选择一个菜单或按一个工具栏按钮，都得十分小心的看着程序。

触摸界面可以帮助减少程序操作所需动作，例如将程序主要功能映射到触摸动作上。

基本的触摸动作包括如下:

上下/下上，左右/右左，右上到左下/左下到右上，以及右下到左上/左上到右下。当程序的主要功能都映射到触摸动作之后，用户就不需要盯着程序界面了。例如，当在媒体播放器中左右滑动就会切换到下一首，右左移动就会切换到上一首。

为了简化手势动作的类型，我们将基本的手势假设为他们的开始和结束位置。这样知道了他们的相对位置就可以推算手势类型了。此外，使用触摸手指也可以丰富用户体验（这样将菜单和按钮解放出来做其他事情）

八个基本的触摸手势

四个用来识别触摸类型的基本区域

前提

下列代码示例可以在触摸手机上运行，如果要检查是否支持笔触，可以调用knLayoutUtils::PenEnabled()方法。为了简化问题，这个程序假设手机可以支持触摸界面。

MMP文件

LIBRARY avkon.lib euser.lib
CAPABILITY could be self-signed

头文件

// Eight basic touch gestures
enum TGestureType
{
	ENoneGesture = -1,
	EUpDown,
	EDownUp,
	ERightLeft,
	ELeftRight,
	ELeftUpRightDown,
	ELeftDownRightUp,
	ERightUpLeftDown,
	ERightDownLeftUp	
};
 
// Four basic types of positions.
// The control rectangle can be devided into four main areas, for example A, B, C, and D .
enum TPositionType
{
	ENonePosition = -1,
	EAreaA,
	EAreaB,
	EAreaC,
	EAreaD
};
 
/**
 * Container class
 */
 
class CBasicGesturesExContainer : public CCoeControl
    {	
    ...
private:
        /* 
	* From CCoeControl, HandleResourceChange
	* This function gets called whenever a pointer event occurs.
	* @param aEvent The pointer event.
	*/
    void HandlePointerEventL( const TPointerEvent& aEvent );
 
private:
	/*
	* Identifies the gesture type.
	* @param aStartPoint The start point coordinates.
	* @param aEndPoint The end point coordinates.
	*/
	TGestureType GetGestureType(const TPoint& aStartPoint, const TPoint& aEndPoint);
 
	/*
	* Handles the specified gesture.
	* @param aGesture The gesture type.
	*/
	void HandleGesture(const TGestureType& aGesture);
 
private: // data
	/*
	* Stores the gesture start point coordinate
	*/
	TPoint iStartPoint;
 
	/*
	* Indicates whether there is any gesture.
        * EFalse by default.
	*/
	TBool iGesture;
   ...
 
    };

源文件

...
void CBasicGesturesExContainer::ConstructL(const TRect& aRect)
    {
	...
 
	// Enables handling of drag events
	EnableDragEvents();
        ...
    }
void CBasicGesturesExContainer::HandlePointerEventL( const TPointerEvent& aEvent )
    {
	    switch (aEvent.iType)
	    {
			case TPointerEvent::EButton1Down:
			// Save tap position (because it could be the beginning of the gesture)
			iStartPoint = aEvent.iPosition;
			break;
 
			case TPointerEvent::EButton1Up:
			if (iGesture)
			{
				// Idenditify type of gesture
				TGestureType gesture = GetGestureType(iStartPoint, aEvent.iPosition);
 
				// Perform necessary action depends on gesture type
				HandleGesture(gesture);		
			}
 
			// Reset gesture indicator
			iGesture = EFalse;
			break;
 
			case TPointerEvent::EDrag:
			iGesture = ETrue;
			break;
 
	      default:
	      break;
	    }
    }
 
TGestureType CBasicGesturesExContainer::GetGestureType(const TPoint& aStartPoint, const TPoint& aEndPoint)
{
	// Default return value
	TGestureType returnValue = EUpDown;
 
	// Control's extent
	TRect rect(Rect());
	TInt rectHalfWidth = rect.Width()/2;
	TInt rectHalfHeight = rect.Height()/2;	
 
	// Start point position type
	TInt startPointLocation = EAreaA;
	// End point position type
	TInt endPointLocation = EAreaA;
 
	// Determine in which logical part of the control is the start point
	if (aStartPoint.iX <= rectHalfWidth)
	{
		if (aStartPoint.iY <= rectHalfHeight)
		{
			startPointLocation = EAreaA;
		}
		else if (aStartPoint.iY > rectHalfHeight)
		{
			startPointLocation = EAreaD;
		}
	}
	else if (aStartPoint.iX > rectHalfWidth)
	{
		if (aStartPoint.iY <= rectHalfHeight)
		{
			startPointLocation = EAreaB;
		}
		else if (aStartPoint.iY > rectHalfHeight)
		{
			startPointLocation = EAreaC;
		}
	}
 
	// Determine in which logical part of the control is the end point
	if (aEndPoint.iX <= rectHalfWidth)
	{
		if (aEndPoint.iY <= rectHalfHeight)
		{
			endPointLocation = EAreaA;
		}
		else if (aEndPoint.iY > rectHalfHeight)
		{
			endPointLocation = EAreaD;
		}
	}
	else if (aEndPoint.iX > rectHalfWidth)
	{
		if (aEndPoint.iY <= rectHalfHeight)
		{
			endPointLocation = EAreaB;
		}
		else if (aEndPoint.iY > rectHalfHeight)
		{
			endPointLocation = EAreaC;
		}
	}
 
	// Get the actual type of the gesture
	switch (startPointLocation)
	{
		case EAreaA:
			switch (endPointLocation)
			{
				case EAreaA:
					returnValue = ENoneGesture;
				break;
 
				case EAreaB:			
					returnValue = ELeftRight;
				break;
 
				case EAreaC:
					returnValue = ELeftUpRightDown;
				break;
 
				case EAreaD:		
					returnValue = EUpDown;
				break;
 
				default:
					returnValue = ENoneGesture;
				break;
			}
		break;
 
		case EAreaB:
			switch (endPointLocation)
			{
				case EAreaA:
					returnValue = ERightLeft;
				break;
 
				case EAreaB:
					returnValue = ENoneGesture;
				break;
 
				case EAreaC:
					returnValue = EUpDown;
				break;
 
				case EAreaD:
					returnValue = ERightUpLeftDown;
				break;
 
				default:
					returnValue = ENoneGesture;
				break;
			}
		break;
 
		case EAreaC:
			switch (endPointLocation)
			{
				case EAreaA:
					returnValue = ERightDownLeftUp;
				break;
 
				case EAreaB:
					returnValue = EDownUp;
				break;
 
				case EAreaC:
					returnValue = ENoneGesture;
				break;
 
				case EAreaD:
					returnValue = ERightLeft;
				break;
 
				default:
					returnValue = ENoneGesture;
				break;
			}
		break;
 
		case EAreaD:
			switch (endPointLocation)
			{
				case EAreaA:
					returnValue = EDownUp;
				break;
 
				case EAreaB:
					returnValue = ELeftDownRightUp;
				break;
 
				case EAreaC:
					returnValue = ELeftRight;
				break;
 
				case EAreaD:
					returnValue = ENoneGesture;
				break;
 
				default:
					returnValue = ENoneGesture;
				break;
			}
		break;
 
		default:
			returnValue = ENoneGesture;
		break;
	}
 
	return returnValue;
}
 
void CBasicGesturesExContainer::HandleGesture(const TGestureType& aGesture)
{
	TBuf<64> messageText(KNullDesC);
 
	// Handle gesture
	switch(aGesture)
	{
		case EUpDown:
			messageText = _L("Gesture: from Up to Down");
		break;
 
		case EDownUp:
			messageText = _L("Gesture: from Down to Up");
		break;
 
		case ERightLeft:
			messageText = _L("Gesture: from Right to Left");
		break;
 
		case ELeftRight:
			messageText = _L("Gesture: from Left to Right");
		break;
 
		case ELeftUpRightDown:
			messageText = _L("Gesture: from Left-Up to Right-Down");
		break;
 
		case ELeftDownRightUp:
			messageText = _L("Gesture: from Left-Down to Right-Up");
		break;
 
		case ERightUpLeftDown:
			messageText = _L("Gesture: from Right-Up to Left-Down");
		break;
 
		case ERightDownLeftUp:
			messageText = _L("Gesture: from Right-Down to Left-Up");
		break;
 
		default:
			// Gesture type's not identified, 
			// do nothing
                        return;
		break;
	}
 
	CAknInformationNote* note = new ( ELeave ) CAknInformationNote;
 
    // Show the information note with a previously defined text
    note->ExecuteLD(messageText);
}
...

限制

触摸手势很容易识别，只有8个基本类型可以判断

后记

基本的手势动作都能映射到所需的程序功能上

相关资料