rectangleconstraint.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 382 行

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License 
 * along with this library; if not, write to the Free Software Foundation, 
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ------------------------
 * RectangleConstraint.java
 * ------------------------
 * (C) Copyright 2004, 2005, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: RectangleConstraint.java,v 1.5 2005/05/13 15:10:48 mungady Exp $
 *
 * Changes:
 * --------
 * 22-Oct-2004 : Version 1 (DG);
 * 02-Feb-2005 : Added toString() method (DG);
 * 08-Feb-2005 : Separated height and width constraints (DG);
 * 13-May-2005 : Added convenience constructor and new methods for 
 *               transforming constraints (DG);
 * 
 */

package org.jfree.chart.block;

import org.jfree.data.Range;
import org.jfree.ui.Size2D;

/**
 * A description of a constraint for resizing a rectangle.  Constraints are
 * immutable.
 */
public class RectangleConstraint {

    /**
     * An instance representing no constraint. 
     */
    public static final RectangleConstraint NONE = new RectangleConstraint(
        0.0, null, LengthConstraintType.NONE, 
        0.0, null, LengthConstraintType.NONE
    );
    
    /** The width. */
    private double width;
    
    /** The width range. */
    private Range widthRange;
    
    /** The width constraint type. */
    private LengthConstraintType widthConstraintType;
    
    /** The fixed or maximum height. */
    private double height;
    
    private Range heightRange;
    
    /** The constraint type. */
    private LengthConstraintType heightConstraintType;
    
    /**
     * Creates a new "fixed width and height" instance.
     * 
     * @param w  the fixed width.
     * @param h  the fixed height.
     */
    public RectangleConstraint(double w, double h) {
        this(
            w, null, LengthConstraintType.FIXED, 
            h, null, LengthConstraintType.FIXED
        );  
    }
    
    /**
     * Creates a new "range width and height" instance.
     * 
     * @param w  the width range.
     * @param h  the height range.
     */
    public RectangleConstraint(Range w, Range h) {
        this(
            0.0, w, LengthConstraintType.RANGE, 
            0.0, h, LengthConstraintType.RANGE
        );   
    }
    
    /**
     * Creates a new constraint with a range for the width and a
     * fixed height.
     * 
     * @param w  the width range.
     * @param h  the fixed height.
     */
    public RectangleConstraint(Range w, double h) {
        this(
            0.0, w, LengthConstraintType.RANGE, 
            h, null, LengthConstraintType.FIXED
        );   
    }
    
    /**
     * Creates a new constraint with a fixed width and a range for
     * the height.
     * 
     * @param w  the fixed width.
     * @param h  the height range.
     */
    public RectangleConstraint(double w, Range h) {
        this(
            w, null, LengthConstraintType.FIXED, 
            0.0, h, LengthConstraintType.RANGE
        );   
    }

    /**
     * Creates a new constraint.
     * 
     * @param w  the fixed or maximum width.
     * @param widthRange  the width range.
     * @param widthConstraintType  the width type.
     * @param h  the fixed or maximum height.
     * @param heightRange  the height range.
     * @param heightConstraintType  the height type.
     */
    public RectangleConstraint(double w, Range widthRange, 
                               LengthConstraintType widthConstraintType,
                               double h, Range heightRange, 
                               LengthConstraintType heightConstraintType) {
        if (widthConstraintType == null) {
            throw new IllegalArgumentException("Null 'widthType' argument.");
        }
        if (heightConstraintType == null) {
            throw new IllegalArgumentException("Null 'heightType' argument."); 
        }
        this.width = w;
        this.widthRange = widthRange;
        this.widthConstraintType = widthConstraintType;
        this.height = h;
        this.heightRange = heightRange;
        this.heightConstraintType = heightConstraintType;
    }
    
    /**
     * Returns the fixed width.
     * 
     * @return The width.
     */
    public double getWidth() {
        return this.width;
    }
    
    /**
     * Returns the width range.
     * 
     * @return The range (possibly <code>null</code>).
     */
    public Range getWidthRange() {
        return this.widthRange;   
    }
    
    /**
     * Returns the constraint type.
     * 
     * @return The constraint type (never <code>null</code>).
     */
    public LengthConstraintType getWidthConstraintType() {
        return this.widthConstraintType;
    }
    
    /**
     * Returns the fixed height.
     * 
     * @return The height.
     */
    public double getHeight() {
        return this.height;
    }
    
    /**
     * Returns the width range.
     * 
     * @return The range (possibly <code>null</code>).
     */
    public Range getHeightRange() {
        return this.heightRange;   
    }
    
    /**
     * Returns the constraint type.
     * 
     * @return The constraint type (never <code>null</code>).
     */
    public LengthConstraintType getHeightConstraintType() {
        return this.heightConstraintType;
    }
    
    /**
     * Returns a constraint that matches this one on the height attributes,
     * but has no width constraint.
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toUnconstrainedWidth() {
        if (this.widthConstraintType == LengthConstraintType.NONE) {
            return this;   
        }
        else {
            return new RectangleConstraint(
                this.width, this.widthRange, LengthConstraintType.NONE,
                this.height, this.heightRange, this.heightConstraintType
            );
        }
    }
    
    /**
     * Returns a constraint that matches this one on the width attributes,
     * but has no height constraint.
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toUnconstrainedHeight() {
        if (this.heightConstraintType == LengthConstraintType.NONE) {
            return this;   
        }
        else {
            return new RectangleConstraint(
                this.width, this.widthRange, this.widthConstraintType,
                0.0, this.heightRange, LengthConstraintType.NONE
            );
        }
    }
    
    /**
     * Returns a constraint that matches this one on the height attributes,
     * but has a fixed width constraint.
     * 
     * @param width  the fixed width.
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toFixedWidth(double width) {
        return new RectangleConstraint(
            width, this.widthRange, LengthConstraintType.FIXED,
            this.height, this.heightRange, this.heightConstraintType
        );
    }
    
    /**
     * Returns a constraint that matches this one on the width attributes,
     * but has a fixed height constraint.
     * 
     * @param height  the fixed height.
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toFixedHeight(double height) {
        return new RectangleConstraint(
            this.width, this.widthRange, this.widthConstraintType,
            height, this.heightRange, LengthConstraintType.FIXED
        );
    }
    
    /**
     * Returns a constraint that matches this one on the height attributes,
     * but has a range width constraint.
     * 
     * @param range  the width range (<code>null</code> not permitted).
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toRangeWidth(Range range) {
        if (range == null) {
            throw new IllegalArgumentException("Null 'range' argument.");   
        }
        return new RectangleConstraint(
            range.getUpperBound(), range, LengthConstraintType.RANGE,
            this.height, this.heightRange, this.heightConstraintType
        );
    }
    
    /**
     * Returns a constraint that matches this one on the width attributes,
     * but has a range height constraint.
     * 
     * @param range  the height range (<code>null</code> not permitted).
     * 
     * @return A new constraint.
     */
    public RectangleConstraint toRangeHeight(Range range) {
        if (range == null) {
            throw new IllegalArgumentException("Null 'range' argument.");   
        }
        return new RectangleConstraint(
            this.width, this.widthRange, this.widthConstraintType,
            range.getUpperBound(), range, LengthConstraintType.RANGE
        );
    }
    
    /**
     * Returns a string representation of this instance, mostly used for
     * debugging purposes.
     * 
     * @return A string.
     */
    public String toString() {
        return "RectangleConstraint[" 
            + this.widthConstraintType.toString() + ": width=" 
            + this.width + ", height=" + this.height + "]";   
    }
    
    /**
     * Returns the new size that reflects the constraints defined by this 
     * instance.
     * 
     * @param base  the base size.
     * 
     * @return The constrained size.
     */
    public Size2D calculateConstrainedSize(Size2D base) {
        Size2D result = new Size2D();
        if (this.widthConstraintType == LengthConstraintType.NONE) {
            result.width = base.width;
            if (this.heightConstraintType == LengthConstraintType.NONE) {
               result.height = base.height;
            }
            else if (this.heightConstraintType == LengthConstraintType.RANGE) {
               result.height = this.heightRange.constrain(base.height);
            }
            else if (this.heightConstraintType == LengthConstraintType.FIXED) {
               result.height = this.height;
            }
        }
        else if (this.widthConstraintType == LengthConstraintType.RANGE) {
            result.width = this.widthRange.constrain(base.width);
            if (this.heightConstraintType == LengthConstraintType.NONE) {
                result.height = base.height;
            }
            else if (this.heightConstraintType == LengthConstraintType.RANGE) {
                result.height = this.heightRange.constrain(base.height);
            }
            else if (this.heightConstraintType == LengthConstraintType.FIXED) {
                result.height = this.height;
            }
        }
        else if (this.widthConstraintType == LengthConstraintType.FIXED) {
            result.width = this.width;
            if (this.heightConstraintType == LengthConstraintType.NONE) {
                result.height = base.height;
            }
            else if (this.heightConstraintType == LengthConstraintType.RANGE) {
                result.height = this.heightRange.constrain(base.height);
            }
            else if (this.heightConstraintType == LengthConstraintType.FIXED) {
                result.height = this.height;
            }
        }
        return result;
    }
    
}