// This file copied directly from the "How to Use SpringLayout" page on the "The Java Tutorial"
// (http://java.sun.com/docs/books/tutorial/uiswing/layout/spring.html).
//
// The only change made to this file was the inclusion of this comment and the package name
// that immediately follows.
//
// This class is used by multiplot.java.
//
package nxm.ucl.lib;


import java.awt.Component;
import java.awt.Container;

import javax.swing.Spring;
import javax.swing.SpringLayout;

/**
 * A 1.4 file that provides utility methods for
 * creating form- or grid-style layouts with SpringLayout.
 * These utilities are used by several programs, such as
 * SpringBox and SpringCompactGrid.
 */
public class SpringUtilities {

  /** This constructor was automatically provided by Java,
   *  but it is unneeded as all the methods are static methods.
   *  @deprecated now that Javadocs are required, it is temporarily
   *              being explicitely provided but deprecated
   */
  @Deprecated
  public SpringUtilities () {}

  /** A debugging utility that prints to stdout the component's
   *  minimum, preferred, and maximum sizes.
   *  @param c the Component
   */
  public static void printSizes(Component c) {
    System.out.println("minimumSize = " + c.getMinimumSize());
    System.out.println("preferredSize = " + c.getPreferredSize());
    System.out.println("maximumSize = " + c.getMaximumSize());
  }

  /**
   * Aligns the first <code>rows</code> * <code>cols</code>
   * components of <code>parent</code> in
   * a grid. Each component is as big as the maximum
   * preferred width and height of the components.
   * The parent is made just big enough to fit them all.
   * @param parent the parent Container
   * @param rows number of rows
   * @param cols number of columns
   * @param initialX x location to start the grid at
   * @param initialY y location to start the grid at
   * @param xPad x padding between cells
   * @param yPad y padding between cells
   */
  public static void makeGrid(Container parent,
                              int rows, int cols,
                              int initialX, int initialY,
                              int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout)parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeGrid must use SpringLayout.");
      return;
    }

    Spring xPadSpring = Spring.constant(xPad);
    Spring yPadSpring = Spring.constant(yPad);
    Spring initialXSpring = Spring.constant(initialX);
    Spring initialYSpring = Spring.constant(initialY);
    int max = rows * cols;

    //Calculate Springs that are the max of the width/height so that all
    //cells have the same size.
    Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).
                                getWidth();
    Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).
                                getWidth();
    for (int i = 1; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(
                                      parent.getComponent(i));

      maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
    }

    //Apply the new width/height Spring. This forces all the
    //components to have the same size.
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(
                                      parent.getComponent(i));

      cons.setWidth(maxWidthSpring);
      cons.setHeight(maxHeightSpring);
    }

    //Then adjust the x/y constraints of all the cells so that they
    //are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(
                                           parent.getComponent(i));
      if (i % cols == 0) { //start of new row
        lastRowCons = lastCons;
        cons.setX(initialXSpring);
      } else { //x position depends on previous component
        cons.setX(Spring.sum(lastCons.getConstraint(SpringLayout.EAST),
                             xPadSpring));
      }

      if (i / cols == 0) { //first row
        cons.setY(initialYSpring);
      } else { //y position depends on previous row
        cons.setY(Spring.sum(lastRowCons.getConstraint(SpringLayout.SOUTH),
                             yPadSpring));
      }
      lastCons = cons;
    }

    //Set the parent's size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH,
                        Spring.sum(
                            Spring.constant(yPad),
                            lastCons.getConstraint(SpringLayout.SOUTH)));
    pCons.setConstraint(SpringLayout.EAST,
                        Spring.sum(
                            Spring.constant(xPad),
                            lastCons.getConstraint(SpringLayout.EAST)));
  }

  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell(
                                              int row, int col,
                                              Container parent,
                                              int cols) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component c = parent.getComponent(row * cols + col);
    return layout.getConstraints(c);
  }

  /**
   * Aligns the first <code>rows</code> * <code>cols</code>
   * components of <code>parent</code> in
   * a grid. Each component in a column is as wide as the maximum
   * preferred width of the components in that column;
   * height is similarly determined for each row.
   * The parent is made just big enough to fit them all.
   * @param parent the parent Container
   * @param rows number of rows
   * @param cols number of columns
   * @param initialX x location to start the grid at
   * @param initialY y location to start the grid at
   * @param xPad x padding between cells
   * @param yPad y padding between cells
   */
  public static void makeCompactGrid(Container parent,
                                     int rows, int cols,
                                     int initialX, int initialY,
                                     int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout)parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }

    //Align all cells in each column and make them the same width.
    Spring x = Spring.constant(initialX);
    for (int c = 0; c < cols; c++) {
      Spring width = Spring.constant(0);
      for (int r = 0; r < rows; r++) {
        width = Spring.max(width,
                           getConstraintsForCell(r, c, parent, cols).
                               getWidth());
      }
      for (int r = 0; r < rows; r++) {
        SpringLayout.Constraints constraints =
                getConstraintsForCell(r, c, parent, cols);
        constraints.setX(x);
        constraints.setWidth(width);
      }
      x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
    }

    //Align all cells in each row and make them the same height.
    Spring y = Spring.constant(initialY);
    for (int r = 0; r < rows; r++) {
      Spring height = Spring.constant(0);
      for (int c = 0; c < cols; c++) {
        height = Spring.max(height,
                            getConstraintsForCell(r, c, parent, cols).
                                getHeight());
      }
      for (int c = 0; c < cols; c++) {
        SpringLayout.Constraints constraints =
                getConstraintsForCell(r, c, parent, cols);
        constraints.setY(y);
        constraints.setHeight(height);
      }
      y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
    }

    //Set the parent's size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, y);
    pCons.setConstraint(SpringLayout.EAST, x);
  }
}
