这是我在内置 StageOrientationEvents 遇到一些困难后为自己的项目编写的一些代码。请注意，这是一个 WIP，所以如果您有任何建议，请告诉我。我创建了两个类，一个是单例，一个是它调度的事件，为了使用它，我获取单例的实例并为事件添加侦听器：
[AccelerometerManager.as]
package com.shaunhusain.fingerPainting.managers
{
import com.shaunhusain.fingerPainting.events.AccBasedOrientationEvent;
import flash.events.AccelerometerEvent;
import flash.events.EventDispatcher;
import flash.sensors.Accelerometer;
/**
* Centralizes the handling of accelerometer changes, limits events
* dispatched to avoid extraneous jiggle/dithering.
*/
public class AccelerometerManager extends EventDispatcher
{
//--------------------------------------------------------------------------------
// Constants
//--------------------------------------------------------------------------------
public static const LANDSCAPE_LEFT:String = "landscapeLeft";
public static const LANDSCAPE_RIGHT:String = "landscapeRight";
public static const PORTRAIT_DEFAULT:String = "portraitDefault";
public static const PORTRAIT_FLIPPED:String = "portraitFlipped";
public static const TURNED_RIGHT:String = "turnedRight";
public static const TURNED_LEFT:String = "turnedLeft";
public static const FLIPPED:String = "flipped";
//--------------------------------------------------------------------------------
// Variables
//--------------------------------------------------------------------------------
private var acc:Accelerometer;
private var registeredStageListener:Boolean;
private var previousOrientation:String=PORTRAIT_DEFAULT;
private var degreeAllowance:Number = 20;
private var previousAngle:Number=270;
//--------------------------------------------------------------------------------
// Constructor
//--------------------------------------------------------------------------------
/**
* Used to coordinate all the updates to the buttons without having
* multiple instances of accelerometer objects. Creates the handle
* to the Accelerometer.
*
* @param se Blocks creation of new managers instead use static method getInstance
*/
public function AccelerometerManager(se:SingletonEnforcer)
{
acc = new Accelerometer();
}
//--------------------------------------------------------------------------------
// Singleton
//--------------------------------------------------------------------------------
private static var instance:AccelerometerManager;
public static function getIntance():AccelerometerManager
{
if( instance == null ) instance = new AccelerometerManager( new SingletonEnforcer() );
return instance;
}
//--------------------------------------------------------------------------------
// Properties
//--------------------------------------------------------------------------------
private var _currentlyActive:Boolean;
/**
* Allows the manager to be turned on or off from the outside.
*/
public function set currentlyActive(value:Boolean):void{
if(_currentlyActive == value)
return;
_currentlyActive = value;
if(_currentlyActive)
acc.addEventListener(AccelerometerEvent.UPDATE, handleAccelerometerChange);
else
acc.removeEventListener(AccelerometerEvent.UPDATE, handleAccelerometerChange);
}
private var _currentOrientation:String = AccelerometerManager.PORTRAIT_DEFAULT;
public function get currentOrientation():String
{
return _currentOrientation;
}
public function set currentOrientation(value:String):void
{
_currentOrientation = value;
}
//--------------------------------------------------------------------------------
// Handlers
//--------------------------------------------------------------------------------
private function handleAccelerometerChange(event:AccelerometerEvent):void
{
if(Math.abs(event.accelerationZ)<.75)
{
var angle:Number = Math.atan2(event.accelerationY, event.accelerationX);
var degrees:Number = angle*180/Math.PI+180;
if(Math.abs(degrees - previousAngle)<degreeAllowance)
return;
previousAngle = degrees;
var accEventExtra:AccBasedOrientationEvent = new AccBasedOrientationEvent(event.type,event.bubbles,event.cancelable);
if(degrees>225&°rees<315)
currentOrientation = PORTRAIT_DEFAULT;
else if(degrees>45&°rees<135)
currentOrientation = PORTRAIT_FLIPPED;
else if(degrees>=135&°rees<=225)
currentOrientation = LANDSCAPE_LEFT;
else if(degrees>=315||degrees<=45)
currentOrientation = LANDSCAPE_RIGHT;
if(currentOrientation == previousOrientation)
return;
accEventExtra.oldOrientation = previousOrientation;
accEventExtra.newOrientation = currentOrientation;
accEventExtra.directionOfChange = determineDirectionOfChange(previousOrientation,currentOrientation);
previousOrientation = currentOrientation;
dispatchEvent(accEventExtra);
}
}
private function determineDirectionOfChange(oldOrientation:String, newOrientation:String):String
{
var turned:String;
switch(oldOrientation)
{
case PORTRAIT_DEFAULT:
switch(newOrientation)
{
case LANDSCAPE_LEFT:
turned = TURNED_LEFT;
break;
case LANDSCAPE_RIGHT:
turned = TURNED_RIGHT;
break;
case PORTRAIT_FLIPPED:
turned = FLIPPED;
break;
}
break;
case LANDSCAPE_LEFT:
switch(newOrientation)
{
case PORTRAIT_DEFAULT:
turned = TURNED_RIGHT;
break;
case LANDSCAPE_RIGHT:
turned = FLIPPED;
break;
case PORTRAIT_FLIPPED:
turned = TURNED_LEFT;
break;
}
break;
case LANDSCAPE_RIGHT:
switch(newOrientation)
{
case LANDSCAPE_LEFT:
turned = FLIPPED;
break;
case PORTRAIT_DEFAULT:
turned = TURNED_LEFT;
break;
case PORTRAIT_FLIPPED:
turned = TURNED_RIGHT;
break;
}
break;
case PORTRAIT_FLIPPED:
switch(newOrientation)
{
case LANDSCAPE_LEFT:
turned = TURNED_RIGHT;
break;
case LANDSCAPE_RIGHT:
turned = TURNED_LEFT;
break;
case PORTRAIT_DEFAULT:
turned = FLIPPED;
break;
}
break;
}
return turned;
}
}
}
internal class SingletonEnforcer {public function SingletonEnforcer(){}}
[AccBasedOrientationEvent.as]
package com.shaunhusain.fingerPainting.events
{
import flash.events.Event;
/**
* Added a property to store the current linearRotation pre-computed so
* each handler doesn't have to compute it.
*/
public class AccBasedOrientationEvent extends Event
{
public var oldOrientation:String;
public var newOrientation:String;
public var directionOfChange:String;
public function AccBasedOrientationEvent(type:String, bubbles:Boolean=false, cancelable:Boolean=false, oldOrientation:String=null, newOrientation:String=null, directionOfChange:String=null)
{
super(type, bubbles, cancelable);
this.oldOrientation = oldOrientation;
this.newOrientation = newOrientation;
this.directionOfChange = directionOfChange;
}
}
}
用法最终应该看起来像这样：
{
...
var accManager:AccelerometerManager = AccelerometerManager.getIntance();
accManager.addEventListener(AccelerometerEvent.UPDATE, handleAccelerometerChange);
var locRot:Number;
switch(accManager.currentOrientation)
{
case AccelerometerManager.PORTRAIT_DEFAULT:
locRot = 0;
break;
case AccelerometerManager.PORTRAIT_FLIPPED:
locRot = Math.PI;
break;
case AccelerometerManager.LANDSCAPE_LEFT:
locRot = Math.PI/2;
break;
case AccelerometerManager.LANDSCAPE_RIGHT:
locRot = -Math.PI/2;
break;
}
var ge:GenericActuator = Actuate.tween(this, 1, {rotateAroundCenter:locRot});
...
}
private function handleAccelerometerChange(event:AccBasedOrientationEvent):void
{
var locRot:Number;
switch(event.newOrientation)
{
case AccelerometerManager.PORTRAIT_DEFAULT:
locRot = 0;
break;
case AccelerometerManager.PORTRAIT_FLIPPED:
locRot = Math.PI;
break;
case AccelerometerManager.LANDSCAPE_LEFT:
locRot = Math.PI/2;
break;
case AccelerometerManager.LANDSCAPE_RIGHT:
locRot = -Math.PI/2;
break;
}
var ge:GenericActuator = Actuate.tween(this, 1, {rotateAroundCenter:locRot});
//rotateAroundCenter = event.linearRotation;
}
注意：我在示例中使用 Actuate 库为旋转设置动画，这根本不是必需的，这里的所有其他内容都应该内置或在上面提供。