/**
 * ThisTime 2.0 (2008-03-30)
 * Copyright 2007 Zach Scrivena
 * zachscrivena@gmail.com
 * http://thistime.sourceforge.net/
 *
 * Simple clock and timer program.
 *
 * TERMS AND CONDITIONS:
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package thistime;

import java.awt.Dimension;


/**
 * Perform miscellaneous graphics-related operations.
 */
class GraphicsManipulator
{
    /**
    * Scale an image to fit a canvas, while keeping the aspect ratio of the image.
    * This method takes the widths and heights of the image and canvas, and returns
    * the width and height of the scaled image in a Dimension object.
    *
    * @param imageWidth
    *      image width
    * @param imageHeight
    *      image height
    * @param canvasWidth
    *      canvas width
    * @param canvasHeight
    *      canvas height
    * @return
    *      Dimension object representing the width and height of the scaled image
    */
    static Dimension scaleToFitKeepRatio(
            final int imageWidth,
            final int imageHeight,
            final int canvasWidth,
            final int canvasHeight)
    {
        final int width;
        final int height;

        final int unconstrainedWidth = imageWidth * canvasHeight / imageHeight;
        final int unconstrainedHeight = imageHeight * canvasWidth / imageWidth;

        if (unconstrainedWidth >= canvasWidth)
        {
            /* canvas width is the limiting constraint */
            width = canvasWidth;
            height = unconstrainedHeight;
        }
        else
        {
            /* canvas height is the limiting constraint */
            width = unconstrainedWidth;
            height = canvasHeight;
        }

        return new Dimension(width, height);
    }
}