CD Actual 25/CDROM25.iso/Share/prog/VJ11/VJTRIAL.EXE/IE30Java.exe/classd.exe/sun/awt/VariableGridLayout.java

Java Source | 1997-01-27 | 5.7 KB | 227 lines

/*
 * @(#)VariableGridLayout.java    1.3 95/10/04 Herb Jellinek
 *
 * Copyright (c) 1995 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */

package sun.awt;

import java.awt.*;
import java.util.BitSet;


/**
 * A layout manager for a container that lays out grids.  Allows setting
 * the relative sizes of rows and columns.
 *
 * @version 1.3, 10/04/95
 * @author Herb Jellinek
 */


public class VariableGridLayout extends GridLayout {

    BitSet rowsSet = new BitSet();
    double rowFractions[] = null;

    BitSet colsSet = new BitSet();
    double colFractions[] = null;

    int rows;
    int cols;
    int hgap;
    int vgap;

    /**
     * Creates a grid layout with the specified rows and specified columns.
     * @param rows the rows
     * @param cols the columns
     */
    public VariableGridLayout(int rows, int cols) {
    this(rows, cols, 0, 0);

    if (rows != 0) {
        rowsSet = new BitSet(rows);
        stdRowFractions(rows);
    }

    if (cols != 0) {
        colsSet = new BitSet(cols);
        stdColFractions(cols);
    }
    }

    /**
     * Creates a grid layout with the specified rows, columns,
     * horizontal gap, and vertical gap.
     * @param rows the rows
     * @param cols the columns
     * @param hgap the horizontal gap variable
     * @param vgap the vertical gap variable
     * @exception IllegalArgumentException If the rows and columns are invalid.
     */
    public VariableGridLayout(int rows, int cols, int hgap, int vgap) {
    super(rows, cols, hgap, vgap);

    this.rows = rows;
    this.cols = cols;
    this.hgap = hgap;
    this.vgap = vgap;

    if (rows != 0) {
        rowsSet = new BitSet(rows);
        stdRowFractions(rows);
    }

    if (cols != 0) {
        colsSet = new BitSet(cols);
        stdColFractions(cols);
    }
    }

    void stdRowFractions(int nrows) {
    rowFractions = new double[nrows];
    for (int i = 0; i < nrows; i++) {
        rowFractions[i] = 1.0 / nrows;
    }
    }

    void stdColFractions(int ncols) {
    colFractions = new double[ncols];
    for (int i = 0; i < ncols; i++) {
        colFractions[i] = 1.0 / ncols;
    }
    }

    public void setRowFraction(int rowNum, double fraction) {
    rowsSet.set(rowNum);
    rowFractions[rowNum] = fraction;
    }

    public void setColFraction(int colNum, double fraction) {
    colsSet.set(colNum);
    colFractions[colNum] = fraction;
    }

    public double getRowFraction(int rowNum) {
    return rowFractions[rowNum];
    }

    public double getColFraction(int colNum) {
    return colFractions[colNum];
    }

    void allocateExtraSpace(double vec[], BitSet userSet) {
    // collect the space that's been explicitly allocated...
    double total = 0.0;
    int unallocated = 0;
    int i;
    for (i = 0; i < vec.length; i++) {
        if (userSet.get(i)) {
        total += vec[i];
        } else {
        unallocated++;
        }
    }

    // ... then spread the extra space
    if (unallocated != 0) {
        double space = (1.0 - total) / unallocated;
        for (i = 0; i < vec.length; i++) {
        if (!userSet.get(i)) {
            vec[i] = space;
            userSet.set(i);
        }
        }
    }
    }


    void allocateExtraSpace() {
    allocateExtraSpace(rowFractions, rowsSet);
    allocateExtraSpace(colFractions, colsSet);
    }

    /**
     * Lays out the container in the specified panel.
     * @param parent the specified component being laid out
     * @see Container
     */
    public void layoutContainer(Container parent) {
    Insets insets = parent.insets();
    int ncomponents = parent.countComponents();
    int nrows = rows;
    int ncols = cols;

    if (nrows > 0) {
        ncols = (ncomponents + nrows - 1) / nrows;
    } else {
        nrows = (ncomponents + ncols - 1) / ncols;
    }

    if (rows == 0) {
        stdRowFractions(nrows);
    }
    if (cols == 0) {
        stdColFractions(ncols);
    }

    Dimension size = parent.size();
    int w = size.width - (insets.left + insets.right);
    int h = size.height - (insets.top + insets.bottom);

    w = (w - (ncols - 1) * hgap);
    h = (h - (nrows - 1) * vgap);

    allocateExtraSpace();

    for (int c = 0, x = insets.left ; c < ncols ; c++) {
        int colWidth = (int)(getColFraction(c) * w);
        for (int r = 0, y = insets.top ; r < nrows ; r++) {
        int i = r * ncols + c;
        int rowHeight = (int)(getRowFraction(r) * h);

        if (i < ncomponents) {
            parent.getComponent(i).reshape(x, y, colWidth, rowHeight);
        }
        y += rowHeight + vgap;
        }
        x += colWidth + hgap;
    }
    }

    static String fracsToString(double array[]) {
    String result = "["+array.length+"]";

    for (int i = 0; i < array.length; i++) {
        result += "<"+array[i]+">";
    }
    return result;
    }

    /**
     * Returns the String representation of this VariableGridLayout's values.
     */
    public String toString() {
    return getClass().getName() + "[hgap=" + hgap + ",vgap=" + vgap +
                           ",rows=" + rows + ",cols=" + cols +
                       ",rowFracs=" +
                       fracsToString(rowFractions) +
                       ",colFracs=" +
                       fracsToString(colFractions) + "]";
    }
}