Normally, I would just create the JLabel using a string as the first parameter and JLabel.CENTER as the second parameter; adding the label to the panel using BorderLayout.CENTER would then cause the text in the label to be aligned in the center of the panel.
However, I’m using the ‘RichJLabel’ class in order to get a drop shadow on my text. To do this, it overrides Component.paintComponent in such a way that the alignment information is lost, and the label’s text is drawn in the top left of the panel no matter what I do.
From what I understand, the workaround for this is to encase the label inside of another panel; that way, I can align the panel itself inside the parent panel, but I’m uncertain of how exactly to do this.
My complete goal is to:
- Figure out what font size a given string needs in order to fill up its parent JPanel
- Add a drop shadow to that text
- Center the text within its JPanel
Here’s what I’ve got so far:
import java.awt.*;
import javax.swing.*;
import javax.swing.border.BevelBorder;
public class RichJLabel extends JLabel {
private int tracking;
public RichJLabel(String text, int tracking) {
super(text, JLabel.CENTER);
this.tracking = tracking;
}
private int left_x, left_y, right_x, right_y;
private Color left_color, right_color;
public void setLeftShadow(int x, int y, Color color) {
left_x = x;
left_y = y;
left_color = color;
}
public void setRightShadow(int x, int y, Color color) {
right_x = x;
right_y = y;
right_color = color;
}
public Dimension getPreferredSize() {
String text = getText();
FontMetrics fm = this.getFontMetrics(getFont());
int w = fm.stringWidth(text);
w += (text.length()-1)*tracking;
w += left_x + right_x;
int h = fm.getHeight();
h += left_y + right_y;
return new Dimension(w,h);
}
public void paintComponent(Graphics g) {
((Graphics2D)g).setRenderingHint(
RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
char[] chars = getText().toCharArray();
FontMetrics fm = this.getFontMetrics(getFont());
int h = fm.getAscent();
int x = 0;
for(int i=0; i<chars.length; i++) {
char ch = chars[i];
int w = fm.charWidth(ch) + tracking;
g.setColor(left_color);
g.drawString(""+chars[i],x-left_x,h-left_y);
g.setColor(right_color);
g.drawString(""+chars[i],x+right_x,h+right_y);
g.setColor(getForeground());
g.drawString(""+chars[i],x,h);
x+=w;
}
((Graphics2D)g).setRenderingHint(
RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_DEFAULT);
} // end paintComponent()
public static void main(String[] args) {
JPanel panel1 = new JPanel( new BorderLayout() );
panel1.setBackground( Color.BLUE );
panel1.setBorder( BorderFactory.createBevelBorder( BevelBorder.LOWERED ));
JPanel interiorPanel = new JPanel( new BorderLayout() );
panel1.add(interiorPanel, BorderLayout.CENTER);
RichJLabel label = new RichJLabel("100", 0);
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalAlignment(JLabel.CENTER);
label.setVisible( true );
label.setForeground( Color.YELLOW );
interiorPanel.add(label, BorderLayout.CENTER);
label.setFont(new Font("Arial", Font.BOLD, 140));
label.setFont(label.getFont().deriveFont(140f));
//resize code
Font labelFont = label.getFont();
String labelText = label.getText();
int stringWidth = label.getFontMetrics(labelFont).stringWidth(labelText);
int componentWidth = interiorPanel.getWidth();
// Find out how much the font can grow in width.
double widthRatio = (double)componentWidth / (double)stringWidth;
int newFontSize = (int)(labelFont.getSize() * widthRatio);
int componentHeight = interiorPanel.getHeight();
// Pick a new font size so it will not be larger than the height of label.
int fontSizeToUse = Math.min(newFontSize, componentHeight);
// Set the label's font size to the newly determined size.
label.setFont(new Font(labelFont.getName(), Font.BOLD, fontSizeToUse));
label.setLeftShadow(-3,-3,Color.BLACK);
// drop shadow w/ highlight
label.setRightShadow(2,3,Color.black);
label.setForeground(Color.gray);
JFrame frame = new JFrame("Label SSCCEE");
frame.getContentPane().add(panel1);
frame.pack();
frame.setVisible(true);
}
}
What it does right now is this:
The code was checking for the size of the container too soon. Before it is displayed, it has a width/height of 0.
Altered code