timeaxis.as

拓扑图基于SNMP数据采集模块的设计和实现

package com.yahoo.astra.fl.charts.axes
{
	import com.yahoo.astra.fl.charts.series.ISeries;
	import com.yahoo.astra.utils.DateUtil;
	import com.yahoo.astra.utils.TimeUnit;

	/**
	 * An axis type representing a date and time range from minimum to maximum
	 * with major and minor divisions.
	 * 
	 * @author Josh Tynjala
	 */
	public class TimeAxis extends BaseAxis implements IAxis, IStackingAxis
	{
		
	//--------------------------------------
	//  Static Properties
	//--------------------------------------
	
		/**
		 * A magic number specifying an ideal minimum number of
		 * pixels between each tick/line/label on a major unit.
		 * Used to calculate the major unit if it is not set by
		 * the developer. 
		 */
		private static const IDEAL_PIXELS_BETWEEN_MAJOR_POSITIONS:Number = 75;
		
		/**
		 * A magic number specifying an ideal minimum number of
		 * pixels between each tick/line/label on a minor unit.
		 * Used to calculate the minor unit if it is not set by
		 * the developer. 
		 */
		private static const IDEAL_PIXELS_BETWEEN_MINOR_POSITIONS:Number = 30;
		
		/**
		 * @private
		 */
		private static const TIME_UNITS:Array = [TimeUnit.MILLISECONDS, TimeUnit.SECONDS, TimeUnit.MINUTES, TimeUnit.HOURS, TimeUnit.DAY, TimeUnit.MONTH, TimeUnit.YEAR];
			
	//--------------------------------------
	//  Constructor
	//--------------------------------------
	
		/**
		 * Constructor.
		 */
		public function TimeAxis()
		{
			super();
		}
		
	//--------------------------------------
	//  Properties
	//--------------------------------------
	
		protected var positionMultiplier:Number = 0;
	
		/**
		 * @private
		 * Storage for the minimum value.
		 */
		private var _minimum:Date;
		
		/**
		 * @private
		 * Indicates whether the minimum bound is user-defined or generated by the axis.
		 */
		private var _minimumSetByUser:Boolean = false;
		
		/**
		 * The minimum value displayed on the axis.
		 */
		public function get minimum():Date
		{
			return this._minimum;
		}
		
		/**
		 * @private
		 */
		public function set minimum(value:Date):void
		{
			this._minimum = value;
			this._minimumSetByUser = value != null;
		}
	
		/**
		 * @private
		 * Storage for the maximum value.
		 */
		private var _maximum:Date;
		
		/**
		 * @private
		 * Indicates whether the maximum bound is user-defined or generated by the axis.
		 */
		private var _maximumSetByUser:Boolean = false;
		
		/**
		 * The maximum value displayed on the axis.
		 */
		public function get maximum():Date
		{
			return this._maximum;
		}
		
		/**
		 * @private
		 */
		public function set maximum(value:Date):void
		{
			this._maximum = value;
			this._maximumSetByUser = value != null;
		}
	
	//-- Units
	
		/**
		 * @private
		 * Storage for the major unit.
		 */
		private var _majorUnit:int = 1;
		
		/**
		 * @private
		 * Indicates whether the major unit is user-defined or generated by the axis.
		 */
		private var _majorUnitSetByUser:Boolean = false;
		
		/**
		 * The major unit at which new lines are drawn.
		 */
		public function get majorUnit():Number
		{
			return this._majorUnit;
		}
		
		/**
		 * @private
		 */
		public function set majorUnit(value:Number):void
		{
			this._majorUnit = value;
			this._majorUnitSetByUser = !isNaN(value);
		}
	
		/**
		 * @private
		 * Storage for the majorTimeUnit property.
		 */
		private var _majorTimeUnit:String = TimeUnit.MONTH;
		
		/**
		 * @private
		 * Indicates whether the major time unit is user-defined or generated by the axis.
		 */
		private var _majorTimeUnitSetByUser:Boolean = false;
		
		/**
		 * Combined with majorUnit, determines the amount of time between major ticks and labels.
		 * 
		 * @see com.yahoo.astra.fl.charts.TimeUnit;
		 */
		public function get majorTimeUnit():String
		{
			return this._majorTimeUnit;
		}
		
		/**
		 * @private
		 */
		public function set majorTimeUnit(value:String):void
		{
			this._majorTimeUnit = value;
			this._majorTimeUnitSetByUser = value != null;
		}
	
		/**
		 * @private
		 * Storage for the minor unit.
		 */
		private var _minorUnit:int = 1;
		
		/**
		 * @private
		 * Indicates whether the minor unit is user-defined or generated by the axis.
		 */
		private var _minorUnitSetByUser:Boolean = false;
		
		/**
		 * The minor unit at which new lines are drawn.
		 */
		public function get minorUnit():Number
		{
			return this._minorUnit;
		}
		
		/**
		 * @private
		 */
		public function set minorUnit(value:Number):void
		{
			this._minorUnit = value;
			this._minorUnitSetByUser = !isNaN(value);
		}
	
		/**
		 * @private
		 * Storage for the minorTimeUnit property.
		 */
		private var _minorTimeUnit:String = TimeUnit.MONTH;
		
		/**
		 * @private
		 * Indicates whether the minor time unit is user-defined or generated by the axis.
		 */
		private var _minorTimeUnitSetByUser:Boolean = false;
		
		/**
		 * Combined with minorUnit, determines the amount of time between minor ticks.
		 * 
		 * @see com.yahoo.astra.fl.charts.TimeUnit;
		 */
		public function get minorTimeUnit():String
		{
			return this._minorTimeUnit;
		}
		
		/**
		 * @private
		 */
		public function set minorTimeUnit(value:String):void
		{
			this._minorTimeUnit = value;
			this._minorTimeUnitSetByUser = value != null;
		}
		
		/**
		 * @private
		 * Storage for the stackingEnabled property.
		 */
		private var _stackingEnabled:Boolean = false;
		
		/**
		 * @inheritDoc
		 */
		public function get stackingEnabled():Boolean
		{
			return this._stackingEnabled;
		}
		
		/**
		 * @private
		 */
		public function set stackingEnabled(value:Boolean):void
		{
			this._stackingEnabled = value;
		}
	
		/**
		 * @private
		 * Storage for the snapToUnits property.
		 */
		private var _snapToUnits:Boolean = true;
		
		/**
		 * If true, the labels, ticks, gridlines, and other objects will snap to
		 * the nearest major or minor unit. If false, their position will be based
		 * on the minimum value.
		 */
		public function get snapToUnits():Boolean
		{
			return this._snapToUnits;
		}
		
		/**
		 * @private
		 */
		public function set snapToUnits(value:Boolean):void
		{
			this._snapToUnits = value;
		}
		
		/**
		 * @private
		 */
		private var _dataMinimum:Date;
		
		/**
		 * @private
		 */
		private var _dataMaximum:Date;
		
	//--------------------------------------
	//  Public Methods
	//--------------------------------------
	
		/**
		 * @inheritDoc
		 */
		public function stack(top:Object, ...rest:Array):Object
		{
			var value:Number = this.valueToNumber(top);
			var restCount:int = rest.length;
			for(var i:int = 0; i < restCount; i++)
			{
				value += this.valueToNumber(rest[i]);
			}
			return value;
		}
	
		/**
		 * @inheritDoc
		 */
		public function updateScale(data:Array):void
		{
			var seriesCount:int = data.length;
			var min:Number = NaN;
			var max:Number = NaN;
			for(var i:int = 0; i < seriesCount; i++)
			{
				var series:ISeries = ISeries(data[i]);
				var seriesLength:int = series.length;
				for(var j:int = 0; j < seriesLength; j++)
				{
					var item:Object = series.dataProvider[j];
					var value:Object = this.chart.itemToAxisValue(series, j, this);
					var numericValue:Number = this.valueToNumber(value);
					
					if(isNaN(min))
					{
						min = numericValue;
					}
					else
					{
						min = Math.min(min, numericValue);
					}
					if(isNaN(max))
					{
						max = numericValue;
					}
					else
					{
						max = Math.max(max, numericValue);
					}
				}
			}
			
			//bad data. show yesterday through today.
			if(isNaN(min) || isNaN(max))
			{
				var today:Date = new Date();
				max = today.valueOf();
				today.setDate(today.getDate() - 1);
				min = today.valueOf();
			}
			
			this._dataMinimum = new Date(min);
			this._dataMaximum = new Date(max);
			
			this.resetScale();
			this.calculatePositionMultiplier();
			
			this.renderer.ticks = this.createAxisData(this.majorUnit, this.majorTimeUnit);
			this.renderer.minorTicks = this.createAxisData(this.minorUnit, this.minorTimeUnit);
		}
		
		/**
		 * @inheritDoc
		 */
		public function valueToLocal(value:Object):Number
		{
			var numericValue:Number = this.valueToNumber(value);
			
			var position:Number = (numericValue - this.minimum.valueOf()) * this.positionMultiplier;
			if(this.reverse)
			{
				position = this.renderer.length - position;
			}
				
			return position;
		}
	
		/**
		 * @inheritDoc
		 */
		override public function valueToLabel(value:Object):String
		{
			var text:String = value.toString();
			if(this.labelFunction != null)
			{
				var numericValue:Number = this.valueToNumber(value);
				text = this.labelFunction(new Date(numericValue), this.majorTimeUnit);
			}			
			if(text == null)
			{
				text = "";
			}
			return text;
		}
		
	//--------------------------------------
	//  Protected Methods
	//--------------------------------------
		
		/**
		 * @private
		 * Converts one of the accepted values to a Number that can be
		 * used for position calculation.
		 */
		protected function valueToNumber(value:Object):Number
		{
			var convertedValue:Number = 0;
			if(value is Date)
			{
				convertedValue = (value as Date).valueOf();
			}
			else if(!(value is Number))
			{
				convertedValue = new Date(value.toString()).valueOf();
			}
			else
			{
				convertedValue = value as Number;
			}
			return convertedValue;
		}
		
		/**
		 * @private
		 * Calculates the best scale.
		 */
		protected function resetScale():void
		{
			if(!this._minimumSetByUser)
			{
				this._minimum = new Date(this._dataMinimum.valueOf());
			}
				
			if(!this._maximumSetByUser)
			{
				this._maximum = new Date(this._dataMaximum.valueOf());
			}