package no.uio.ifi.refaktor.textselection;

import no.uio.ifi.refaktor.debugging.RefaktorDebug;

import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.JavaModelException;


public class MethodRelativeCompilationUnitTextSelection extends CompilationUnitTextSelection {

	private final IMethod method;
	private final int relativeOffset;

	public MethodRelativeCompilationUnitTextSelection(IMethod method, CompilationUnitTextSelection textSelection) {
		super(textSelection);
		this.method = method;

		// Using the name of the method as reference point
		// in case the method's access modifier changes
		int methodNameOffset = 0;
		try {
			methodNameOffset = freshMethodNameOffset();
		} catch (JavaModelException e) {
			RefaktorDebug.log(e);
		}
		relativeOffset = textSelection.getOffset() - methodNameOffset;
	}

	private int freshMethodNameOffset() throws JavaModelException {
		return method.getNameRange().getOffset();
	}
	
	@Override
	public int getOffset() {
		try {
			return freshMethodNameOffset() + relativeOffset;
		} catch (JavaModelException e) {
			RefaktorDebug.log(e);
			return super.getOffset();
		}
	}
	
}