package org.eclipse.nebula.widgets.nattable.core.layer.axis

import java.io.Serializable
import org.eclipse.nebula.widgets.nattable.core.event.EventListener
import org.eclipse.nebula.widgets.nattable.core.event.EventSource

/**
 * Represents a linear dimension (e.g. horizontal, vertical) that is composed of segments (e.g. columns, rows).
 */
interface Axis extends EventSource, EventListener {
	
	/**
	 * @return The number of segments on this axis.
	 */
	def long getSegmentCount()
	
	/**
	 * Gets the start pixel location of the segment at the given position. This function must be defined for all valid segment position
	 * values and <em>also</em> for segment position = segment count. Technically the segment count is not a valid segment position because
	 * segment positions are 0-indexed and range from 0 to segment count - 1. However, the 'start' pixel location of the segment position after
	 * the last segment is used to calculate the pixel size of the last segment, and also the overall pixel size of the axis.
	 * 
	 * @param segmentPosition
	 * @return The start pixel location of the given segment position.
	 */
	def double getStartPixelOfSegmentPosition(long segmentPosition)
	
	/**
	 * Gets the position of the segment that is nearest to the the given pixel location.
	 * 
	 * @param pixelLocation
	 * @return The position of the segment that contains the given pixel location.
	 * If the given pixel location is less than 0, the segment position returned will be -1.
	 * If the given pixel location is greater than the size of the axis, then the last segment position + 1 will be returned (= segment count).
	 */
	def long getSegmentPositionOfPixelLocation(double pixelLocation)

	/**
	 * @param segmentPosition
	 * @return The identifier associated with the given segment position.
	 */
	def Serializable getIdOfSegmentPosition(long segmentPosition)
	
	/**
	 * @param segmentId
	 * @return The position of the segment associated with the given segment identifier.
	 */
	def long getSegmentPositionOfId(Serializable segmentId)
	
}