When created using the default constructor, the renderer attempts
* to use text from the "label" field. To use a different field, use the
* appropriate constructor or use the {@link #setTextField(String)} method.
* To perform custom String selection, subclass this Renderer and override the
* {@link #getText(VisualItem)} method. When the text field is
* null, no text label will be shown.
By default, no image is shown. To show an image, the image field needs * to be set, either using the appropriate constructor or the * {@link #setImageField(String)} method. The value of the image field should * be a text string indicating the location of the image file to use. The * string should be either a URL, a file located on the current classpath, * or a file on the local filesystem. If found, the image will be managed * internally by an {@link ImageFactory} instance, which maintains a * cache of loaded images.
* * @author jeffrey heer */ public class LabelRenderer extends AbstractShapeRenderer { protected ImageFactory m_images = null; protected String m_labelName = "label"; protected String m_imageName = null; protected int m_xAlign = Constants.CENTER; protected int m_yAlign = Constants.CENTER; protected int m_horizBorder = 2; protected int m_vertBorder = 0; protected int m_imageMargin = 0; protected int m_arcWidth = 0; protected int m_arcHeight = 0; protected int m_maxTextWidth = -1; /** Transform used to scale and position images */ AffineTransform m_transform = new AffineTransform(); /** The holder for the currently computed bounding box */ protected RectangularShape m_bbox = new Rectangle2D.Double(); protected Point2D m_pt = new Point2D.Double(); // temp point protected Font m_font; // temp font holder /** * Create a new LabelRenderer. By default the field "label" is used * as the field name for looking up text, and no image is used. */ public LabelRenderer() { } /** * Create a new LabelRenderer. Draws a text label using the given * text data field and does not draw an image. * @param textField the data field for the text label. */ public LabelRenderer(String textField) { this.setTextField(textField); } /** * Create a new LabelRenderer. Draws a text label using the given text * data field, and draws the image at the location reported by the * given image data field. * @param textField the data field for the text label * @param imageField the data field for the image location. This value * in the data field should be a URL, a file within the current classpath, * a file on the filesystem, or null for no image. If the *imageField parameter is null, no images at all will be
* drawn.
*/
public LabelRenderer(String textField, String imageField) {
setTextField(textField);
setImageField(imageField);
}
// ------------------------------------------------------------------------
/**
* Rounds the corners of the bounding rectangle in which the text
* string is rendered. This will only be seen if either the stroke
* or fill color is non-transparent.
* @param arcWidth the width of the curved corner
* @param arcHeight the height of the curved corner
*/
public void setRoundedCorner(int arcWidth, int arcHeight) {
if ( (arcWidth == 0 || arcHeight == 0) &&
!(m_bbox instanceof Rectangle2D) ) {
m_bbox = new Rectangle2D.Double();
} else {
if ( !(m_bbox instanceof RoundRectangle2D) )
m_bbox = new RoundRectangle2D.Double();
((RoundRectangle2D)m_bbox)
.setRoundRect(0,0,10,10,arcWidth,arcHeight);
m_arcWidth = arcWidth;
m_arcHeight = arcHeight;
}
}
/**
* Get the field name to use for text labels.
* @return the data field for text labels, or null for no text
*/
public String getTextField() {
return m_labelName;
}
/**
* Set the field name to use for text labels.
* @param textField the data field for text labels, or null for no text
*/
public void setTextField(String textField) {
m_labelName = textField;
}
/**
* Sets the maximum width that should be allowed of the text label.
* A value of -1 specifies no limit (this is the default).
* @param maxWidth the maximum width of the text or -1 for no limit
*/
public void setMaxTextWidth(int maxWidth) {
m_maxTextWidth = maxWidth;
}
/**
* Returns the text to draw. Subclasses can override this class to
* perform custom text selection.
* @param item the item to represent as a String
* @return a String to draw
*/
protected String getText(VisualItem item) {
String s = null;
if ( item.canGetString(m_labelName) ) {
s = item.getString(m_labelName);
if ( m_maxTextWidth > -1 ) {
Font font = item.getFont();
FontMetrics fm = DEFAULT_GRAPHICS.getFontMetrics(font);
if ( fm.stringWidth(s) > m_maxTextWidth ) {
s = StringLib.abbreviate(s, fm, m_maxTextWidth);
}
}
}
return s;
}
// ------------------------------------------------------------------------
// Image Handling
/**
* Get the data field for image locations. The value stored
* in the data field should be a URL, a file within the current classpath,
* a file on the filesystem, or null for no image.
* @return the data field for image locations, or null for no images
*/
public String getImageField() {
return m_imageName;
}
/**
* Set the data field for image locations. The value stored
* in the data field should be a URL, a file within the current classpath,
* a file on the filesystem, or null for no image. If the
* imageField parameter is null, no images at all will be
* drawn.
* @param imageField the data field for image locations, or null for
* no images
*/
public void setImageField(String imageField) {
if ( imageField != null ) m_images = new ImageFactory();
m_imageName = imageField;
}
/**
* Sets the maximum image dimensions, used to control scaling of loaded
* images. This scaling is enforced immediately upon loading of the image.
* @param width the maximum width of images (-1 for no limit)
* @param height the maximum height of images (-1 for no limit)
*/
public void setMaxImageDimensions(int width, int height) {
if ( m_images == null ) m_images = new ImageFactory();
m_images.setMaxImageDimensions(width, height);
}
/**
* Returns a location string for the image to draw. Subclasses can override
* this class to perform custom image selection beyond looking up the value
* from a data field.
* @param item the item for which to select an image to draw
* @return the location string for the image to use, or null for no image
*/
protected String getImageLocation(VisualItem item) {
return item.canGetString(m_imageName)
? item.getString(m_imageName)
: null;
}
/**
* Get the image to include in the label for the given VisualItem.
* @param item the item to get an image for
* @return the image for the item, or null for no image
*/
protected Image getImage(VisualItem item) {
String imageLoc = getImageLocation(item);
return ( imageLoc == null ? null : m_images.getImage(imageLoc) );
}
// ------------------------------------------------------------------------
// Rendering
/**
* @see prefuse.render.AbstractShapeRenderer#getRawShape(prefuse.visual.VisualItem)
*/
protected Shape getRawShape(VisualItem item) {
String text = getText(item);
Image img = getImage(item);
double size = item.getSize();
boolean sizeAdjust = (size != 1);
// get image dimensions
double iw=0, ih=0;
if ( img != null ) {
ih = img.getHeight(null);
iw = img.getWidth(null);
}
// get text dimensions
int tw=0, th=0;
if ( text != null ) {
// put item font in temp member variable
m_font = item.getFont();
// scale the font as needed
if ( sizeAdjust ) {
m_font = FontLib.getFont(m_font.getName(), m_font.getStyle(),
size*m_font.getSize());
}
FontMetrics fm = DEFAULT_GRAPHICS.getFontMetrics(m_font);
th = fm.getHeight();
tw = fm.stringWidth(text);
}
// get bounding box dimensions
double w = tw + size*(iw + 2*m_horizBorder
+ (tw>0 && iw>0 ? m_imageMargin : 0));
double h = Math.max(th, size*ih) + size*2*m_vertBorder;
// get the top-left point, using the current alignment settings
getAlignedPoint(m_pt, item, w, h, m_xAlign, m_yAlign);
if ( m_bbox instanceof RoundRectangle2D ) {
RoundRectangle2D rr = (RoundRectangle2D)m_bbox;
rr.setRoundRect(m_pt.getX(), m_pt.getY(), w, h,
size*m_arcWidth, size*m_arcHeight);
} else {
m_bbox.setFrame(m_pt.getX(), m_pt.getY(), w, h);
}
return m_bbox;
}
/**
* Helper method, which calculates the top-left co-ordinate of an item
* given the item's alignment.
*/
protected static void getAlignedPoint(Point2D p, VisualItem item,
double w, double h, int xAlign, int yAlign)
{
double x = item.getX(), y = item.getY();
if ( Double.isNaN(x) || Double.isInfinite(x) )
x = 0; // safety check
if ( Double.isNaN(y) || Double.isInfinite(y) )
y = 0; // safety check
if ( xAlign == Constants.CENTER ) {
x = x-(w/2);
} else if ( xAlign == Constants.RIGHT ) {
x = x-w;
}
if ( yAlign == Constants.CENTER ) {
y = y-(h/2);
} else if ( yAlign == Constants.BOTTOM ) {
y = y-h;
}
p.setLocation(x,y);
}
/**
* @see prefuse.render.Renderer#render(java.awt.Graphics2D, prefuse.visual.VisualItem)
*/
public void render(Graphics2D g, VisualItem item) {
RectangularShape shape = (RectangularShape)getShape(item);
if ( shape == null ) return;
// fill the shape, if requested
int type = getRenderType(item);
if ( type==RENDER_TYPE_FILL || type==RENDER_TYPE_DRAW_AND_FILL )
GraphicsLib.paint(g, item, shape, getStroke(item), RENDER_TYPE_FILL);
// now render the image and text
String text = getText(item);
Image img = getImage(item);
if ( text == null && img == null )
return;
double size = item.getSize();
boolean useInt = 1.5 > Math.max(g.getTransform().getScaleX(),
g.getTransform().getScaleY());
double x = shape.getMinX() + size*m_horizBorder;
// render image
if ( img != null ) {
double w = size * img.getWidth(null);
double h = size * img.getHeight(null);
double y = shape.getMinY() + (shape.getHeight()-h)/2;
if ( useInt && size == 1.0 ) {
// if possible, use integer precision
// results in faster, flicker-free image rendering
g.drawImage(img, (int)x, (int)y, null);
} else {
m_transform.setTransform(size,0,0,size,x,y);
g.drawImage(img, m_transform, null);
}
x += w + (text!=null && w>0 ? size*m_imageMargin : 0);
}
// render text
if ( text != null ) {
int textColor = item.getTextColor();
if ( ColorLib.alpha(textColor) > 0 ) {
g.setPaint(ColorLib.getColor(textColor));
g.setFont(m_font);
FontMetrics fm = DEFAULT_GRAPHICS.getFontMetrics(m_font);
double y = shape.getCenterY() -
((fm.getHeight()>>1)-fm.getAscent());
if ( useInt ) {
// use integer precision unless zoomed-in
// results in more stable drawing
g.drawString(text, (int)x, (int)y);
} else {
g.drawString(text, (float)x, (float)y);
}
}
}
// draw border
if (type==RENDER_TYPE_DRAW || type==RENDER_TYPE_DRAW_AND_FILL) {
GraphicsLib.paint(g,item,shape,getStroke(item),RENDER_TYPE_DRAW);
}
}
/**
* Returns the image factory used by this renderer.
* @return the image factory
*/
public ImageFactory getImageFactory() {
if ( m_images == null ) m_images = new ImageFactory();
return m_images;
}
/**
* Sets the image factory used by this renderer.
* @param ifact the image factory
*/
public void setImageFactory(ImageFactory ifact) {
m_images = ifact;
}
/**
* Get the horizontal alignment of this node with respect to it's
* location co-ordinate.
* @return the horizontal alignment, one of
* {@link prefuse.Constants#LEFT}, {@link prefuse.Constants#RIGHT}, or
* {@link prefuse.Constants#CENTER}.
*/
public int getHorizontalAlignment() {
return m_xAlign;
}
/**
* Get the vertical alignment of this node with respect to it's
* location co-ordinate.
* @return the vertical alignment, one of
* {@link prefuse.Constants#TOP}, {@link prefuse.Constants#BOTTOM}, or
* {@link prefuse.Constants#CENTER}.
*/
public int getVerticalAlignment() {
return m_yAlign;
}
/**
* Set the horizontal alignment of this node with respect to it's
* location co-ordinate.
* @param align the horizontal alignment, one of
* {@link prefuse.Constants#LEFT}, {@link prefuse.Constants#RIGHT}, or
* {@link prefuse.Constants#CENTER}.
*/
public void setHorizontalAlignment(int align) {
m_xAlign = align;
}
/**
* Set the vertical alignment of this node with respect to it's
* location co-ordinate.
* @param align the vertical alignment, one of
* {@link prefuse.Constants#TOP}, {@link prefuse.Constants#BOTTOM}, or
* {@link prefuse.Constants#CENTER}.
*/
public void setVerticalAlignment(int align) {
m_yAlign = align;
}
/**
* Returns the amount of padding in pixels between text
* and the border of this item along the horizontal dimension.
* @return the horizontal padding
*/
public int getHorizontalPadding() {
return m_horizBorder;
}
/**
* Sets the amount of padding in pixels between text
* and the border of this item along the horizontal dimension.
* @param xpad the horizontal padding to set
*/
public void setHorizontalPadding(int xpad) {
m_horizBorder = xpad;
}
/**
* Returns the amount of padding in pixels between text
* and the border of this item along the vertical dimension.
* @return the vertical padding
*/
public int getVerticalPadding() {
return m_vertBorder;
}
/**
* Sets the amount of padding in pixels between text
* and the border of this item along the vertical dimension.
* @param ypad the vertical padding
*/
public void setVerticalPadding(int ypad) {
m_vertBorder = ypad;
}
} // end of class LabelRenderer