Name: jk109818 Date: 09/03/2003


FULL PRODUCT VERSION :
java version "1.4.2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-b28)
Java HotSpot(TM) Client VM (build 1.4.2-b28, mixed mode)


FULL OS VERSION :
Microsoft Windows XP [Version 5.1.2600]
SunOS 5.8 Generic_108528-15 sun4u sparc SUNW,Ultra-60



A DESCRIPTION OF THE PROBLEM :
GlyphVector's getGlyphLogicalBounds returns internal object reference. In the past a copy was returned.

One can create a glyph vector, and then modify a specific glyph by calling setGlyphPosition. The call to setGlyphPosition appears to leave the glyph's internal cache in an invalid state.

A call to getGlyphLogicalBounds returns a GeneralPath which can then be manipulated, for instance by calling GeneralPath's transform method.

Subsequent calls to getGlyphLogicalBounds will return a different value than the first invocation, since the internal reference has been modified.

I think it is okay if getGlyphLogicalBounds returns a reference rather than a copy. However, the method's intended behavior, whether it returns a copy or internal reference, should be clearly described in the method's javadocs.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
  Release last known to work is j2sdk1.4.0

Run program included in this report.



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Output from jdk1.4.0

First object ref java.awt.geom.GeneralPath@9efb05
Before transform java.awt.geom.Rectangle2D$Float[x=0.0,y=-11.05957,w=6.673828,h=
13.013672]
Second object ref java.awt.geom.GeneralPath@8814e9
After transform java.awt.geom.Rectangle2D$Float[x=0.0,y=-11.05957,w=6.673828,h=1
3.013672]
ACTUAL -
Output from jdk1.4.1 and 1.4.2

First object ref java.awt.geom.GeneralPath@1d5550d
Before transform java.awt.geom.Rectangle2D$Float[x=0.0,y=-11.05957,w=6.673828,h=
13.013672]
Second object ref java.awt.geom.GeneralPath@1d5550d
After transform java.awt.geom.Rectangle2D$Float[x=-14.374511,y=213.62721,w=12.28
6541,h=14.607086]


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.Font;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Point2D;


public class GlyphLogicalBoundsTester {


    public static final void main(String [] args)
    {
        Font f = new Font("Arial", Font.PLAIN, 12);
        FontRenderContext frc = new FontRenderContext(null, true, true);
        String text = "a";

        GlyphVector gv = f.createGlyphVector(frc, text);

        // first reset the position of the glyph
        // this is necessary to get the observed behavior
        gv.setGlyphPosition(0, new Point2D.Double(0, 0));

        Shape shape = gv.getGlyphLogicalBounds(0);
        System.out.println("First object ref " + gv.getGlyphLogicalBounds(0));
        System.out.println("Before transform " + gv.getGlyphLogicalBounds(0).getBounds2D());
        AffineTransform at = new AffineTransform();
        at.rotate(Math.PI/6);
        at.translate(100, 200);
        ((GeneralPath)shape).transform(at);
        System.out.println("Second object ref " + gv.getGlyphLogicalBounds(0));
        System.out.println("After transform " + gv.getGlyphLogicalBounds(0).getBounds2D());

    }

}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Do not modify the returned reference. For instance one can call GeneralPath's createTransformedShape rather than transform.

Release Regression From : 1.4.0_00
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.

(Incident Review ID: 191602)
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