DimensionResizer

DimensionResizer.java

/*
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 * and open the template in the editor.
 */
package dimensionresizer;

import java.awt.Point;

/**
 *
 * @author dev
 */
public class DimensionResizer {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
    }
    
    private int _maxWidth;
    public int getMaxWidth()
    {
        return _maxWidth;
    }
    public void setMaxWidth(int width)
    {
        _maxWidth = width;
    }
    
    public Point Resize(Point p)
    {
        double ratio = p.x / (double)_maxWidth;
        if (ratio <= 1)
            return p;
        int x = (int)Math.floor(p.x / ratio);
        int y = (int)Math.floor(p.y / ratio);
        return new Point(x, y);
    }
}

DimensionResizerTest.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package dimensionresizer;

import java.awt.Point;
import org.hamcrest.core.Is;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;

/**
 *
 * @author dev
 */
public class DimensionResizerTest {
    
    public DimensionResizerTest() {
    }

    @BeforeClass
    public static void setUpClass() throws Exception {
    }

    @AfterClass
    public static void tearDownClass() throws Exception {
    }
    
    @Before
    public void setUp() {
    }
    
    @After
    public void tearDown() {
    }
    
    @Test
    public void CanSetAndGetMaxWidth()
    {
        DimensionResizer resizer = new DimensionResizer();
        int maxWidth = 1000;
        resizer.setMaxWidth(maxWidth);
        
        assertEquals(maxWidth, resizer.getMaxWidth());
    }

    @Test
    public void CanReduceToMaxWidth() {
        // too small
        CheckTheResize(500, 499, 500, 499, 500);
        
        // really tall
        CheckTheResize(500, 500, 2500, 500, 2500);
        
        // just right
        CheckTheResize(500, 500, 500, 500, 500);
        
        // just a tad too large
        CheckTheResize(500, 501, 1002, 500, 1000);
        
        // too large
        CheckTheResize(500, 1000, 1000, 500, 500);
        
        // high precision
        CheckTheResize(500, 666, 333, 500, 250);
        
        // something silly
        CheckTheResize(1, 2, 2, 1, 1);
    }
    
    private void CheckTheResize(int maxWidth, int inputX, int inputY, int expectedX, int expectedY)
    {
        // arrange
        DimensionResizer instance = new DimensionResizer();
        instance.setMaxWidth(maxWidth);
        Point p = new Point(inputX, inputY);
        
        // act
        Point result = instance.Resize(p);
        
        // assert
        assertEquals(new Point(expectedX, expectedY), result);
    }
}