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Improve internal algorithm for ZoomGesture

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This commit is contained in:
Pavel fljot 2012-07-10 17:11:46 +03:00
parent fd55468579
commit f8149935db
1 changed files with 49 additions and 38 deletions

87
src/org/gestouch/gestures/ZoomGesture.as
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@ -13,19 +13,18 @@ package org.gestouch.gestures
*/
[Event(name="gestureZoom", type="org.gestouch.events.ZoomGestureEvent")]
/**
* TODO:
* -check native behavior on iDevice
*
* @author Pavel fljot
*/
public class ZoomGesture extends Gesture
{
public var slop:Number = Gesture.DEFAULT_SLOP >> 1;
public var slop:Number = Gesture.DEFAULT_SLOP;
public var lockAspectRatio:Boolean = true;
protected var _touch1:Touch;
protected var _touch2:Touch;
protected var _transformVector:Point;
protected var _initialDistance:Number;
public function ZoomGesture(target:Object = null)
@ -73,6 +72,7 @@ package org.gestouch.gestures
_touch2 = touch;
_transformVector = _touch2.location.subtract(_touch1.location);
_initialDistance = _transformVector.length;
}
}
@ -82,48 +82,59 @@ package org.gestouch.gestures
if (touchesCount < 2)
return;
var recognized:Boolean = true;
var currTransformVector:Point = _touch2.location.subtract(_touch1.location);
var scaleX:Number;
var scaleY:Number;
if (state == GestureState.POSSIBLE && slop > 0 && touch.locationOffset.length < slop)
if (state == GestureState.POSSIBLE)
{
recognized = false;
const d:Number = currTransformVector.length - _initialDistance;
const absD:Number = d >= 0 ? d : -d;
if (absD < slop)
{
// Not recognized yet
return;
}
if (slop > 0)
{
// adjust _transformVector to avoid initial "jump"
const slopVector:Point = currTransformVector.clone();
slopVector.normalize(_initialDistance + (d >= 0 ? slop : -slop));
_transformVector = slopVector;
}
}
if (recognized)
if (lockAspectRatio)
{
var currTransformVector:Point = _touch2.location.subtract(_touch1.location);
var scaleX:Number;
var scaleY:Number;
if (lockAspectRatio)
scaleX = scaleY = currTransformVector.length / _transformVector.length;
}
else
{
scaleX = currTransformVector.x / _transformVector.x;
scaleY = currTransformVector.y / _transformVector.y;
}
_transformVector.x = currTransformVector.x;
_transformVector.y = currTransformVector.y;
updateLocation();
if (state == GestureState.POSSIBLE)
{
if (setState(GestureState.BEGAN) && hasEventListener(ZoomGestureEvent.GESTURE_ZOOM))
{
scaleX = scaleY = currTransformVector.length / _transformVector.length;
dispatchEvent(new ZoomGestureEvent(ZoomGestureEvent.GESTURE_ZOOM, false, false, GestureState.BEGAN,
_location.x, _location.y, _localLocation.x, _localLocation.y, scaleX, scaleY));
}
else
}
else
{
if (setState(GestureState.CHANGED) && hasEventListener(ZoomGestureEvent.GESTURE_ZOOM))
{
scaleX = currTransformVector.x / _transformVector.x;
scaleY = currTransformVector.y / _transformVector.y;
}
_transformVector.x = currTransformVector.x;
_transformVector.y = currTransformVector.y;
updateLocation();
if (state == GestureState.POSSIBLE)
{
if (setState(GestureState.BEGAN) && hasEventListener(ZoomGestureEvent.GESTURE_ZOOM))
{
dispatchEvent(new ZoomGestureEvent(ZoomGestureEvent.GESTURE_ZOOM, false, false, GestureState.BEGAN,
_location.x, _location.y, _localLocation.x, _localLocation.y, scaleX, scaleY));
}
}
else
{
if (setState(GestureState.CHANGED) && hasEventListener(ZoomGestureEvent.GESTURE_ZOOM))
{
dispatchEvent(new ZoomGestureEvent(ZoomGestureEvent.GESTURE_ZOOM, false, false, GestureState.CHANGED,
_location.x, _location.y, _localLocation.x, _localLocation.y, scaleX, scaleY));
}
dispatchEvent(new ZoomGestureEvent(ZoomGestureEvent.GESTURE_ZOOM, false, false, GestureState.CHANGED,
_location.x, _location.y, _localLocation.x, _localLocation.y, scaleX, scaleY));
}
}
}
@ -144,7 +155,7 @@ package org.gestouch.gestures
else if (state == GestureState.POSSIBLE)
{
setState(GestureState.FAILED);
}
}
}
else//== 1
{