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/*
 * (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved
 * (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved
 *
 * The original version of this source code and documentation is
 * copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary
 * of IBM. These materials are provided under terms of a License
 * Agreement between Taligent and Sun. This technology is protected
 * by multiple US and International patents.
 *
 * This notice and attribution to Taligent may not be removed.
 * Taligent is a registered trademark of Taligent, Inc.
 *
 */

package java.awt.font;

import java.awt.Graphics2D;
import java.awt.Font;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;


This class is used with the CHAR_REPLACEMENT attribute.


The GraphicAttribute class represents a graphic embedded in text. Clients subclass this class to implement their own char replacement graphics. Clients wishing to embed shapes and images in text need not subclass this class. Instead, clients can use the ShapeGraphicAttribute and ImageGraphicAttribute classes. 

Subclasses must ensure that their objects are immutable once they
are constructed.  Mutating a GraphicAttribute that is used in a TextLayout results in undefined behavior from the TextLayout.

/**
 * This class is used with the CHAR_REPLACEMENT attribute.
 * <p>
 * The <code>GraphicAttribute</code> class represents a graphic embedded
 * in text. Clients subclass this class to implement their own char
 * replacement graphics.  Clients wishing to embed shapes and images in
 * text need not subclass this class.  Instead, clients can use the
 * {@link ShapeGraphicAttribute} and {@link ImageGraphicAttribute}
 * classes.
 * <p>
 * Subclasses must ensure that their objects are immutable once they
 * are constructed.  Mutating a <code>GraphicAttribute</code> that
 * is used in a {@link TextLayout} results in undefined behavior from the
 * <code>TextLayout</code>.
 */
public abstract class GraphicAttribute {

    private int fAlignment;

    
Aligns top of graphic to top of line.

/**
     * Aligns top of graphic to top of line.
     */
    public static final int TOP_ALIGNMENT = -1;

    
Aligns bottom of graphic to bottom of line.

/**
     * Aligns bottom of graphic to bottom of line.
     */
    public static final int BOTTOM_ALIGNMENT = -2;

    
Aligns origin of graphic to roman baseline of line.

/**
     * Aligns origin of graphic to roman baseline of line.
     */
    public static final int ROMAN_BASELINE = Font.ROMAN_BASELINE;

    
Aligns origin of graphic to center baseline of line.

/**
     * Aligns origin of graphic to center baseline of line.
     */
    public static final int CENTER_BASELINE = Font.CENTER_BASELINE;

    
Aligns origin of graphic to hanging baseline of line.

/**
     * Aligns origin of graphic to hanging baseline of line.
     */
    public static final int HANGING_BASELINE = Font.HANGING_BASELINE;

    
Constructs a GraphicAttribute.
Subclasses use this to define the alignment of the graphic.

Params:
  • alignment – an int representing one of the
GraphicAttribute alignment fields
Throws:
/**
     * Constructs a <code>GraphicAttribute</code>.
     * Subclasses use this to define the alignment of the graphic.
     * @param alignment an int representing one of the
     * <code>GraphicAttribute</code> alignment fields
     * @throws IllegalArgumentException if alignment is not one of the
     * five defined values.
     */
    protected GraphicAttribute(int alignment) {
        if (alignment < BOTTOM_ALIGNMENT || alignment > HANGING_BASELINE) {
          throw new IllegalArgumentException("bad alignment");
        }
        fAlignment = alignment;
    }

    
Returns the ascent of this GraphicAttribute.  A
graphic can be rendered above its ascent.

See Also:
Returns:the ascent of this GraphicAttribute.
/**
     * Returns the ascent of this <code>GraphicAttribute</code>.  A
     * graphic can be rendered above its ascent.
     * @return the ascent of this <code>GraphicAttribute</code>.
     * @see #getBounds()
     */
    public abstract float getAscent();


    
Returns the descent of this GraphicAttribute.  A
graphic can be rendered below its descent.

See Also:
Returns:the descent of this GraphicAttribute.
/**
     * Returns the descent of this <code>GraphicAttribute</code>.  A
     * graphic can be rendered below its descent.
     * @return the descent of this <code>GraphicAttribute</code>.
     * @see #getBounds()
     */
    public abstract float getDescent();

    
Returns the advance of this GraphicAttribute.  The
GraphicAttribute object's advance is the distance
from the point at which the graphic is rendered and the point where
the next character or graphic is rendered.  A graphic can be
rendered beyond its advance

See Also:
Returns:the advance of this GraphicAttribute.
/**
     * Returns the advance of this <code>GraphicAttribute</code>.  The
     * <code>GraphicAttribute</code> object's advance is the distance
     * from the point at which the graphic is rendered and the point where
     * the next character or graphic is rendered.  A graphic can be
     * rendered beyond its advance
     * @return the advance of this <code>GraphicAttribute</code>.
     * @see #getBounds()
     */
    public abstract float getAdvance();

    
Returns a Rectangle2D that encloses all of the bits drawn by this GraphicAttribute relative to the
rendering position.
A graphic may be rendered beyond its origin, ascent, descent,
or advance;  but if it is, this method's implementation must
indicate where the graphic is rendered.
Default bounds is the rectangle (0, -ascent, advance, ascent+descent).

Returns:a Rectangle2D that encloses all of the bits
rendered by this GraphicAttribute.
/**
     * Returns a {@link Rectangle2D} that encloses all of the
     * bits drawn by this <code>GraphicAttribute</code> relative to the
     * rendering position.
     * A graphic may be rendered beyond its origin, ascent, descent,
     * or advance;  but if it is, this method's implementation must
     * indicate where the graphic is rendered.
     * Default bounds is the rectangle (0, -ascent, advance, ascent+descent).
     * @return a <code>Rectangle2D</code> that encloses all of the bits
     * rendered by this <code>GraphicAttribute</code>.
     */
    public Rectangle2D getBounds() {
        float ascent = getAscent();
        return new Rectangle2D.Float(0, -ascent,
                                        getAdvance(), ascent+getDescent());
    }

    
Return a Shape that represents the region that this GraphicAttribute renders. This is used when a TextLayout is requested to return the outline of the text. The (untransformed) shape must not extend outside the rectangular bounds returned by getBounds. The default implementation returns the rectangle returned by getBounds, transformed by the provided AffineTransform if present. 
Params:
  • tx – an optional AffineTransform to apply to the outline of this GraphicAttribute. This can be null.
Returns:a Shape representing this graphic attribute,
  suitable for stroking or filling.
Since:1.6
/**
     * Return a {@link java.awt.Shape} that represents the region that
     * this <code>GraphicAttribute</code> renders.  This is used when a
     * {@link TextLayout} is requested to return the outline of the text.
     * The (untransformed) shape must not extend outside the rectangular
     * bounds returned by <code>getBounds</code>.
     * The default implementation returns the rectangle returned by
     * {@link #getBounds}, transformed by the provided {@link AffineTransform}
     * if present.
     * @param tx an optional {@link AffineTransform} to apply to the
     *   outline of this <code>GraphicAttribute</code>. This can be null.
     * @return a <code>Shape</code> representing this graphic attribute,
     *   suitable for stroking or filling.
     * @since 1.6
     */
    public Shape getOutline(AffineTransform tx) {
        Shape b = getBounds();
        if (tx != null) {
            b = tx.createTransformedShape(b);
        }
        return b;
    }

    
Renders this GraphicAttribute at the specified
location.

Params:
  • graphics – the Graphics2D into which to render the graphic
  • x – the user-space X coordinate where the graphic is rendered
  • y – the user-space Y coordinate where the graphic is rendered
/**
     * Renders this <code>GraphicAttribute</code> at the specified
     * location.
     * @param graphics the {@link Graphics2D} into which to render the
     * graphic
     * @param x the user-space X coordinate where the graphic is rendered
     * @param y the user-space Y coordinate where the graphic is rendered
     */
    public abstract void draw(Graphics2D graphics, float x, float y);

    
Returns the alignment of this GraphicAttribute.
Alignment can be to a particular baseline, or to the absolute top
or bottom of a line.

Returns:the alignment of this GraphicAttribute.
/**
     * Returns the alignment of this <code>GraphicAttribute</code>.
     * Alignment can be to a particular baseline, or to the absolute top
     * or bottom of a line.
     * @return the alignment of this <code>GraphicAttribute</code>.
     */
    public final int getAlignment() {

        return fAlignment;
    }

    
Returns the justification information for this
GraphicAttribute.  Subclasses
can override this method to provide different justification
information.

Returns:a GlyphJustificationInfo object that contains the justification information for this GraphicAttribute.
/**
     * Returns the justification information for this
     * <code>GraphicAttribute</code>.  Subclasses
     * can override this method to provide different justification
     * information.
     * @return a {@link GlyphJustificationInfo} object that contains the
     * justification information for this <code>GraphicAttribute</code>.
     */
    public GlyphJustificationInfo getJustificationInfo() {

        // should we cache this?
        float advance = getAdvance();

        return new GlyphJustificationInfo(
                                     advance,   // weight
                                     false,     // growAbsorb
                                     2,         // growPriority
                                     advance/3, // growLeftLimit
                                     advance/3, // growRightLimit
                                     false,     // shrinkAbsorb
                                     1,         // shrinkPriority
                                     0,         // shrinkLeftLimit
                                     0);        // shrinkRightLimit
    }
}