fsgradient.java

利用opensource的开源jar实现生成flash文件

/*
 * FSGradient.java
 * Transform
 * 
 * Copyright (c) 2001-2006 Flagstone Software Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 *  * Neither the name of Flagstone Software Ltd. nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.flagstone.transform;

/**
FSGradient defines a control point that is used to specify how a gradient colour is displayed. 

<p>Two or more control points are used to define how the colour changes across the gradient square. Each control point specifies:</p>

<table class="datasheet">

<tr><th align="left" colspan="2">Attributes</th></tr>

<tr><td><a name="FSGradient_0">ratio</a></td>
<td>The location of the control point across the gradient square.</td>
</tr>

<tr><td><a name="FSGradient_1">color</a></td>
<td>The colour displayed at the control point.</td>
</tr>
</table>

<p>The location of the control point is defined by a ratio - a number between 0 and 255 - that specifies the relative location in the square. For Linear Gradient Fills a ratio of zero is mapped to the left side of the gradient square and 255 is mapped to the right side of the square. For Radial Gradient Fills a ratio of zero is mapped to the centre of the gradient square and 255 is mapped to the edge of the largest circle that fits inside the gradient square. A ratio is used rather than specifying coordinates within the gradient square as the coordinate space is transformed to fit the shape that the gradient is being displayed in.</p>

<p>Note that the object used to create the shape definition determines whether the alpha channel is encoded in the gradient colours. Simply specifying the level of transparency in the FSColor object is not sufficient.</p>

<h1 class="datasheet">History</h1>

<p>The FSGradient class represents the GradientRecord structure from the Macromedia Flash (SWF) File Format Specification. It was introduced in Flash 1.</p>
 */
public class FSGradient extends FSTransformObject
{
    private int ratio = 0;
    private FSColor color = null;
    
    /**
     * Construct an FSGradient object, initalizing it with values decoded from
     * an encoded object.
     * 
     * @param coder an FSCoder containing the binary data.
     */
    public FSGradient(FSCoder coder)
    {
        decode(coder);
    }
    /** Constructs an FSGradient object with the specified ratio and color.

        @param aRatio the ratio along the gradient square.
        @param aColor the color at the control point.
        */
    public FSGradient(int aRatio, FSColor aColor)
    {
        setRatio(aRatio);
        setColor(aColor);
    }
    /**
     * Constructs an FSGradient object by copying values from an existing 
     * object.
     *
     * @param obj an FSGradient object.
     */
    public FSGradient(FSGradient obj)
    {
        ratio = obj.ratio;
        color = new FSColor(obj.color);
    }    

    /** Gets the ratio that defines the relative point across the gradient square.

        @return the ratio where the control point is located.
        */
    public int getRatio() 
    {
        return ratio;
    }

    /** Gets the colour that is displayed at the control point across the gradient square defined by the ratio.

        @return the color at the control point.
        */
    public FSColor getColor() 
    {
        return color;
    }

    /** Sets the ratio that defines the control point across the gradient square.

        @param aNumber the ratio along the gradient square.
        */
    public void setRatio(int aNumber)
    {
        ratio = aNumber;
    }

    /** Sets the colour that is displayed at the control point across the gradient square.

        @param aColor the color at the control point.
        */
    public void setColor(FSColor aColor)
    {
        color = aColor;
    }

    public Object clone()
    {
        FSGradient anObject = (FSGradient)super.clone();
        
        anObject.color = (color != null) ? (FSColor)color.clone() : null;

        return anObject;
    }

    /** 
     * Returns true if anObject is equal to this one. Objects are considered 
     * equal if they would generate identical binary data when they are encoded 
     * to a Flash file.
     *
     * @return true if this object would be identical to anObject when encoded.
     */
    public boolean equals(Object anObject)
    {
        boolean result = false;
        
        if (super.equals(anObject))
        {
            FSGradient typedObject = (FSGradient)anObject;
            
            result = ratio == typedObject.ratio;

            if (color != null)
                result = result && color.equals(typedObject.color);
            else
                result = result && color == typedObject.color;
        }
        return result;
    }

    public void appendDescription(StringBuffer buffer, int depth)
    {
        buffer.append(name());
        
        if (depth > 0)
        {
            buffer.append(": { ");
            Transform.append(buffer, "ratio", ratio);
            Transform.append(buffer, "color", color, depth);
            buffer.append("}");
        }
    }

    public int length(FSCoder coder)
    {
        int length = 1;
    
        length += color.length(coder);
    
        return length;
    }
    
    public void encode(FSCoder coder)
    {
        coder.writeWord(ratio, 1);
        color.encode(coder);
    }
    
    public void decode(FSCoder coder)
    {
        ratio = coder.readWord(1, false);
        color = new FSColor(coder);
    }
}