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GlyphPainter1.javaAPI DocJava SE 5 API6687Fri Aug 26 14:58:16 BST 2005javax.swing.text

GlyphPainter1

public class GlyphPainter1 extends GlyphView$GlyphPainter
A class to perform rendering of the glyphs. This can be implemented to be stateless, or to hold some information as a cache to facilitate faster rendering and model/view translation. At a minimum, the GlyphPainter allows a View implementation to perform its duties independent of a particular version of JVM and selection of capabilities (i.e. shaping for i18n, etc).

This implementation is intended for operation under the JDK1.1 API of the Java Platform. Since the JDK is backward compatible with JDK1.1 API, this class will also function on Java 2. The JDK introduces improved API for rendering text however, so the GlyphPainter2 is recommended for the DK.

author
Timothy Prinzing
version
1.18 06/28/04
see
GlyphView

Fields Summary
FontMetrics
metrics
Constructors Summary
Methods Summary
public floatgetAscent(javax.swing.text.GlyphView v)
Fetches the ascent above the baseline for the glyphs corresponding to the given range in the model.

	sync(v);
	return metrics.getAscent();
    
public intgetBoundedPosition(javax.swing.text.GlyphView v, int p0, float x, float len)
Determines the best location (in the model) to break the given view. This method attempts to break on a whitespace location. If a whitespace location can't be found, the nearest character location is returned.

param
v the view
param
p0 the location in the model where the fragment should start its representation >= 0
param
pos the graphic location along the axis that the broken view would occupy >= 0; this may be useful for things like tab calculations
param
len specifies the distance into the view where a potential break is desired >= 0
return
the model location desired for a break
see
View#breakView

	sync(v);
	TabExpander expander = v.getTabExpander();
	Segment s = v.getText(p0, v.getEndOffset());
	int index = Utilities.getTabbedTextOffset(s, metrics, (int)x, (int)(x+len),
						  expander, p0, false);
        SegmentCache.releaseSharedSegment(s);
	int p1 = p0 + index;
	return p1;
    
public floatgetDescent(javax.swing.text.GlyphView v)
Fetches the descent below the baseline for the glyphs corresponding to the given range in the model.

	sync(v);
	return metrics.getDescent();
    
public floatgetHeight(javax.swing.text.GlyphView v)

	sync(v);
	return metrics.getHeight();
    
public floatgetSpan(javax.swing.text.GlyphView v, int p0, int p1, javax.swing.text.TabExpander e, float x)
Determine the span the glyphs given a start location (for tab expansion).

	sync(v);
	Segment text = v.getText(p0, p1);
	int width = Utilities.getTabbedTextWidth(text, metrics, (int) x, e, p0);
        SegmentCache.releaseSharedSegment(text);
	return width;
    
public java.awt.ShapemodelToView(javax.swing.text.GlyphView v, int pos, javax.swing.text.Position$Bias bias, java.awt.Shape a)


        sync(v);
	Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
	int p0 = v.getStartOffset();
	int p1 = v.getEndOffset();
	TabExpander expander = v.getTabExpander();
	Segment text;

	if(pos == p1) {
	    // The caller of this is left to right and borders a right to
	    // left view, return our end location.
	    return new Rectangle(alloc.x + alloc.width, alloc.y, 0,
				 metrics.getHeight());
	}
	if ((pos >= p0) && (pos <= p1)) {
	    // determine range to the left of the position
	    text = v.getText(p0, pos);
	    int width = Utilities.getTabbedTextWidth(text, metrics, alloc.x, expander, p0);
            SegmentCache.releaseSharedSegment(text);
	    return new Rectangle(alloc.x + width, alloc.y, 0, metrics.getHeight());
	}
	throw new BadLocationException("modelToView - can't convert", p1);
    
public voidpaint(javax.swing.text.GlyphView v, java.awt.Graphics g, java.awt.Shape a, int p0, int p1)
Paints the glyphs representing the given range.

	sync(v);
	Segment text;
	TabExpander expander = v.getTabExpander();
	Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();

	// determine the x coordinate to render the glyphs
	int x = alloc.x;
	int p = v.getStartOffset();
	if (p != p0) {
	    text = v.getText(p, p0);
	    int width = Utilities.getTabbedTextWidth(text, metrics, x, expander, p);
	    x += width;
            SegmentCache.releaseSharedSegment(text);
	}

	// determine the y coordinate to render the glyphs
	int y = alloc.y + metrics.getHeight() - metrics.getDescent();

	// render the glyphs
	text = v.getText(p0, p1);
	g.setFont(metrics.getFont());
	Utilities.drawTabbedText(v, text, x, y, g, expander,p0);
        SegmentCache.releaseSharedSegment(text);
    
voidsync(javax.swing.text.GlyphView v)

	Font f = v.getFont();
	if ((metrics == null) || (! f.equals(metrics.getFont()))) {
	    // fetch a new FontMetrics
            Container c = v.getContainer();
            metrics = (c != null) ? c.getFontMetrics(f) :
                Toolkit.getDefaultToolkit().getFontMetrics(f);
	}
    
public intviewToModel(javax.swing.text.GlyphView v, float x, float y, java.awt.Shape a, javax.swing.text.Position$Bias[] biasReturn)
Provides a mapping from the view coordinate space to the logical coordinate space of the model.

param
v the view containing the view coordinates
param
x the X coordinate
param
y the Y coordinate
param
a the allocated region to render into
param
biasReturn always returns Position.Bias.Forward as the zero-th element of this array
return
the location within the model that best represents the given point in the view
see
View#viewToModel


        sync(v);
	Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
	int p0 = v.getStartOffset();
	int p1 = v.getEndOffset();
	TabExpander expander = v.getTabExpander();
	Segment text = v.getText(p0, p1);

	int offs = Utilities.getTabbedTextOffset(text, metrics, 
						 alloc.x, (int) x, expander, p0);
        SegmentCache.releaseSharedSegment(text);
	int retValue = p0 + offs;
	if(retValue == p1) {
            // No need to return backward bias as GlyphPainter1 is used for
            // ltr text only.
            retValue--;
        }
        biasReturn[0] = Position.Bias.Forward;
	return retValue;