UnitScalar.java

package com.llamacorp.equate.unit;


public class UnitScalar extends Unit {
//	private static final String JSON_INVERTED = "inverted";

	//flag used to distinguish if the Unit needs to be inverted before converting
	//eg: min/miles should be inverted to miles/min before conversion to mph
	private boolean mInverted = false;

	public UnitScalar(String name, String longName, double value, boolean inverted) {
		super(name, longName, value);
		mInverted = inverted;
	}

	public UnitScalar(String name, String longName, double value) {
		super(name, longName, value);
	}

	public UnitScalar() {
		super();
	}

//	/** Load in the extra inverted flag */
//	public UnitScalar(JSONObject json) throws JSONException {
//		super(json);
//		mInverted = json.getBoolean(JSON_INVERTED);
//	}
//
//	/** Save in the extra inverted flag */
//	@Override
//	public JSONObject toJSON() throws JSONException {
//		JSONObject json = super.toJSON();
//		json.put(JSON_INVERTED, isInverted());
//		return json;
//	}

	public boolean isInverted() {
		return mInverted;
	}

	/**
	 * Perform Unit conversion
	 *
	 * @param toUnit           is desired unit to convert into
	 * @param expressionToConv is the expression to convert
	 * @return returns the expression string to be evaluated, will
	 * contain something like 33*fromValue/toValue.  Will possibly
	 * also include inversion for inverted units. For example, 33 min/mile
	 * to mph would be 1/33*...
	 */
	public String convertTo(Unit toUnit, String expressionToConv) {
		String invertFrom = "";
		String invertTo = "";

		if (isInverted())
			invertFrom = "1/";
		if (((UnitScalar) toUnit).isInverted()){
			invertFrom = "1/";
			invertTo = "1/";
		}
		return invertFrom + expressionToConv + "*" + invertTo + "("
				  + toUnit.getValue() + "/" + getValue() + ")";
	}
}