borderlayout.as

拓扑图基于SNMP数据采集模块的设计和实现

			remainingHeight -= bottomHeight;
			
			//the height of the center area affects the height of the left and right areas
			var centerHeight:Number = Math.max(remainingHeight, 0);
			
			//position the left children
			var leftWidth:Number = 0;
			var leftChildren:Array = this.getChildrenByConstraint(BorderConstraints.LEFT, true);
			var leftChildCount:int = leftChildren.length;
			for(i = 0; i < leftChildCount; i++)
			{
				var leftChild:DisplayObject = DisplayObject(leftChildren[i]);
				config = this.configurations[this.clients.indexOf(leftChild)];
				
				x = START_X + leftWidth;
				y = START_Y + topHeight;
				
				if(config.maintainAspectRatio)
				{
					DisplayObjectUtil.resizeAndMaintainAspectRatio(leftChild, leftChild.width, centerHeight, config.aspectRatio);
				}
				else
				{
					leftChild.height = centerHeight;
				}
				DisplayObjectUtil.align(leftChild, new Rectangle(x, y, leftChild.width, centerHeight), config.horizontalAlign, config.verticalAlign);
				
				leftWidth += leftChild.width + this.horizontalGap;
			}
			remainingWidth -= leftWidth;
			
			//position the right children
			var rightWidth:Number = 0;
			var rightChildren:Array = this.getChildrenByConstraint(BorderConstraints.RIGHT, true);
			var rightChildCount:int = rightChildren.length;
			for(i = 0; i < rightChildCount; i++)
			{
				var rightChild:DisplayObject = DisplayObject(rightChildren[i]);
				config = this.configurations[this.clients.indexOf(rightChild)];
				
				rightWidth += rightChild.width;
				
				x = START_X + width - rightWidth;
				y = START_Y + topHeight;
				
				if(config.maintainAspectRatio)
				{
					DisplayObjectUtil.resizeAndMaintainAspectRatio(rightChild, rightChild.width, centerHeight, config.aspectRatio);
				}
				else
				{
					rightChild.height = centerHeight;
				}
				DisplayObjectUtil.align(rightChild, new Rectangle(x, y, rightChild.width, centerHeight), config.horizontalAlign, config.verticalAlign);
				
				rightWidth += this.horizontalGap;
			}
			
			//if leftWidth + rightWidth < the total width, fix the overlap
			difference = (START_X + leftWidth) - (START_X + width - rightWidth); 
			if(difference > 0)
			{
				for(i = 0; i < rightChildCount; i++)
				{
					rightChild = DisplayObject(rightChildren[i]);
					rightChild.x += difference;
				}
			}
			remainingWidth -= rightWidth;
			
			//position the center children in the remaining width
			var centerWidth:Number = Math.max(remainingWidth, 0);
			var centerChildren:Array = this.getChildrenByConstraint(BorderConstraints.CENTER, true);
			var centerChildCount:int = centerChildren.length;
			var centerChildHeight:Number = centerHeight / centerChildCount;
			for(i = 0; i < centerChildCount; i++)
			{
				var centerChild:DisplayObject = DisplayObject(centerChildren[i]);
				config = this.configurations[this.clients.indexOf(centerChild)];
				
				x = START_X + leftWidth;
				y = START_Y + topHeight + (i * centerChildHeight);
				
				if(config.maintainAspectRatio)
				{
					DisplayObjectUtil.resizeAndMaintainAspectRatio(centerChild, centerWidth, centerChildHeight, config.aspectRatio);
				}
				else
				{
					centerChild.width = centerWidth;
					centerChild.height = centerChildHeight;
				}
				DisplayObjectUtil.align(centerChild, new Rectangle(x, y, centerWidth, centerChildHeight), config.horizontalAlign, config.verticalAlign);
			}
			
			if(remainingWidth < 0)
			{
				width -= remainingWidth;
			}
			
			if(remainingHeight < 0)
			{
				height -= remainingHeight;
			}
			
			bounds.width = width + this.paddingLeft + this.paddingRight;
			bounds.height = height + this.paddingTop + this.paddingBottom;
			return bounds;
		}
		
		/**
		 * @private
		 * Creates the default configuration for this layout mode.
		 */
		override protected function newConfiguration():Object
		{
			return {
				includeInLayout: true,
				constraint: BorderConstraints.CENTER
			};
		}
		
		/**
		 * @private
		 * If no width is specified for the layout container, we need to
		 * measure the children to determine the best width.
		 */
		protected function measureChildWidths():Number
		{
			var totalWidth:Number = this.paddingLeft + this.paddingRight;
			
			var leftChildren:Array = this.getChildrenByConstraint(BorderConstraints.LEFT, true);
			var childCount:int = leftChildren.length;
			for(var i:int = 0; i < childCount; i++)
			{
				var child:DisplayObject = DisplayObject(leftChildren[i]);
				totalWidth += child.width + this.horizontalGap;
			}
			
			var rightChildren:Array = this.getChildrenByConstraint(BorderConstraints.RIGHT, true);
			childCount = rightChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(rightChildren[i]);
				totalWidth += child.width + this.horizontalGap;
			}
			
			var maxWidth:Number = 0;
			var centerChildren:Array = this.getChildrenByConstraint(BorderConstraints.CENTER, true);
			childCount = centerChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(centerChildren[i]);
				maxWidth = Math.max(maxWidth, child.width);
			}
			totalWidth += maxWidth;
			
			maxWidth = 0;
			var topChildren:Array = this.getChildrenByConstraint(BorderConstraints.TOP, true);
			childCount = topChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(topChildren[i]);
				maxWidth = Math.max(maxWidth, child.width);
			}
			var bottomChildren:Array = this.getChildrenByConstraint(BorderConstraints.BOTTOM, true);
			childCount = bottomChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(bottomChildren[i]);
				maxWidth = Math.max(maxWidth, child.width);
			}
			totalWidth = Math.max(maxWidth, totalWidth);
			return totalWidth;
		}
		
		/**
		 * @private
		 * If no height is specified for the layout container, we need to
		 * measure the children to determine the best height.
		 */
		protected function measureChildHeights():Number
		{
			var totalHeight:Number = this.paddingTop + this.paddingBottom;
			
			var topChildren:Array = this.getChildrenByConstraint(BorderConstraints.TOP, true);
			var childCount:int = topChildren.length;
			for(var i:int = 0; i < childCount; i++)
			{
				var child:DisplayObject = DisplayObject(topChildren[i]);
				totalHeight += child.height;
			}
			
			var bottomChildren:Array = this.getChildrenByConstraint(BorderConstraints.BOTTOM, true);
			childCount = bottomChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(bottomChildren[i]);
				totalHeight += child.height;
			}
			
			var centerTotalHeight:Number = 0;
			var centerChildren:Array = this.getChildrenByConstraint(BorderConstraints.CENTER, true);
			childCount = centerChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(centerChildren[i]);
				centerTotalHeight += child.height;
			}
			
			var maxHeight:Number = centerTotalHeight;
			var rightChildren:Array = this.getChildrenByConstraint(BorderConstraints.RIGHT, true);
			childCount = rightChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(rightChildren[i]);
				maxHeight = Math.max(maxHeight, child.height);
			}
			var leftChildren:Array = this.getChildrenByConstraint(BorderConstraints.LEFT, true);
			childCount = leftChildren.length;
			for(i = 0; i < childCount; i++)
			{
				child = DisplayObject(leftChildren[i]);
				maxHeight = Math.max(maxHeight, child.height);
			}
			totalHeight += maxHeight;
			
			return totalHeight;
		}
		
		/**
		 * @private
		 * A simple filter for getting all the clients with a specific constraint
		 * in their configuration.
		 */
		protected function getChildrenByConstraint(constraint:String, inLayoutOnly:Boolean = false):Array
		{
			return this.clients.filter(function(item:DisplayObject, index:int, source:Array):Boolean
			{
				var configuration:Object = this.configurations[index];
				return configuration.constraint == constraint && (inLayoutOnly ? configuration.includeInLayout : true);
			}, this);
		}
		
	}
}