File contents

// Name: Line.java
// Intent: geographic line object class
// Programmer: John P. Kavanagh  #2748 2405
// Date Modified: 9 May 2002
// Audit: Clifford Meyers (cmeyers@buffalo.edu)

public class Line {

	// myFirstSegment will only have a next segment, 
	// no previous segment
	private LineSegment myFirstSegment;

	// The line constructor
	public Line() {
		myFirstSegment = null;
		//System.out.println("Instantiated null line.");		
	}

	public Line(LineSegment firstSegment) {
		myFirstSegment = firstSegment;
		System.out.println("Instantiated line (" + GetBeginPoint().getXvalue() + "," + GetBeginPoint().getYvalue() + "),(" + GetEndPoint().getXvalue() + "," + GetEndPoint().getYvalue() + ")");			
	}	
	
	// Retrieve the beginning point of the entire line
	public Point GetBeginPoint(){

		//System.out.println("Get line begin point: (" + myFirstSegment.GetBeginPoint().getXvalue() + "," + myFirstSegment.GetBeginPoint().getYvalue() + ")");
		return myFirstSegment.GetBeginPoint();	

	}

	// Retrieve the beginning line segment of the entire line
	public LineSegment GetBeginSegment(){

		return myFirstSegment;	

	}	
	
	// Find next point
	// Check each line segment to find the next point
	public Point GetNextPoint(Point thisPoint){

		LineSegment thisSegment = myFirstSegment;
	
		// As long as the given point is not the first point
		// in the given line segment, continue to the next segment
		while ((thisSegment.IsBeginPoint(thisPoint) == false) && !(GetEndPoint().IsEqual(thisPoint))){
			thisSegment = thisSegment.GetNextSegment();
		}

		// Now that you've found the right segment,
		// return this segment's end point
		// this is the "Next" point
		if (GetEndPoint().IsEqual(thisPoint)) {
			//System.out.println("Get line next point: NONE. End of line.");
			return null;
		}
		else {
			//System.out.println("Get line next point: (" + thisSegment.GetEndPoint().getXvalue() + "," + thisSegment.GetEndPoint().getYvalue() + ")");			
			return thisSegment.GetEndPoint();
		}
	}	

	// Retrieve the end point of the entire line	
	public Point GetEndPoint(){

		if (myFirstSegment.GetNextSegment() == null){

			//System.out.println("Get line end point: (" + myFirstSegment.GetEndPoint().getXvalue() + "," + myFirstSegment.GetEndPoint().getYvalue() + ")");			
			return myFirstSegment.GetEndPoint();			
			
		}
		else {

			//System.out.println("Get line end point: (" + FindLastSegment(myFirstSegment).GetEndPoint().getXvalue() + "," + FindLastSegment(myFirstSegment).GetEndPoint().getYvalue() + ")");			
			return FindLastSegment(myFirstSegment).GetEndPoint();
		
		}	
	
	}

	
	// Add segment to line object	
	public void AddLineSegment(LineSegment addMe){
		
			//System.out.println("Adding line segment: (" + addMe.GetBeginPoint().getXvalue() + "," + addMe.GetBeginPoint().getYvalue() + ")");
		
			// Find the last segment in the line object, and then add this new segment
			if (myFirstSegment == null) {
				myFirstSegment = addMe; // if empty line, make it the first segment
			}
			else {
				FindLastSegment(myFirstSegment).AddNextSegment(addMe);
			}
						
	}
	
	// Scale entire line object
	public void Scale(String factor_value){

		RecurseScale(myFirstSegment, factor_value);
		
	}
	
	// Recurse across entire line and scale each segment individually
	public void RecurseScale(LineSegment lineSeg, String factor_value){
		if (lineSeg.GetNextSegment() != null){
		
			RecurseScale(lineSeg.GetNextSegment(), factor_value);
			lineSeg.Scale(factor_value);
					
		}
		else {
		
			lineSeg.Scale(factor_value);
		
		}
	}	
	


	
	
	// Destroy entire line
	public void Destroy(){
    	
		if (myFirstSegment.GetNextSegment() != null){

			RecurseDestroy(myFirstSegment.GetNextSegment());

		}

			myFirstSegment.Destroy();	

	}
	
	// Recurse across line segments and destroy each segment 
	// from end to beginning
	public void RecurseDestroy(LineSegment lineSeg){

		if (lineSeg.GetNextSegment() != null){
		
			RecurseDestroy(lineSeg.GetNextSegment());

		}

		lineSeg.Destroy();

	}

	// If line segment is adjacent to another continue until end of all 
	// segments is reached and return final segment
	
	public LineSegment FindLastSegment(LineSegment lineSeg){
	
		if (lineSeg.GetNextSegment() == null){
		
			return lineSeg;			
			
		}
		else {
		
			return FindLastSegment(lineSeg.GetNextSegment());
		
		}
	}
	
}