The following screenshot shows a test of TextBubbleBorder
1. I would like to make the corners of the component that are outside the rectangle to be entirely transparent & show whatever component is beneath it. I found a way to restrict the BG color of a label to 'inside the border' by setting a Clip
(representing the area outside the rounded corners) on the Graphics2D
instance and calling clearRect()
. That can be seen in Label 1
.
However you can see the downside of this approach when there is a red BG (or any non-standard color) on the parent panel. The corners default to the default panel color (easiest to see in Panel 2
).
Ultimately I would like this to work for a non-standard color in the parent container, but it was partly inspired by What do I need to do to replicate this component with gradient paint?
Does anybody know a way to get those corners transparent?
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.border.*;
public class BorderTest {
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
JPanel gui = new JPanel(new GridLayout(1,0,5,5));
gui.setBorder(new EmptyBorder(10,10,10,10));
gui.setBackground(Color.RED);
AbstractBorder brdr = new TextBubbleBorder(Color.BLACK,2,16,0);
JLabel l1 = new JLabel("Label 1");
l1.setBorder(brdr);
gui.add(l1);
JLabel l2 = new JLabel("Label 2");
l2.setBorder(brdr);
l2.setBackground(Color.YELLOW);
l2.setOpaque(true);
gui.add(l2);
JPanel p1 = new JPanel();
p1.add(new JLabel("Panel 1"));
p1.setBorder(brdr);
p1.setOpaque(false);
gui.add(p1);
JPanel p2 = new JPanel();
p2.add(new JLabel("Panel 2"));
p2.setBorder(brdr);
gui.add(p2);
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class TextBubbleBorder extends AbstractBorder {
private Color color;
private int thickness = 4;
private int radii = 8;
private int pointerSize = 7;
private Insets insets = null;
private BasicStroke stroke = null;
private int strokePad;
private int pointerPad = 4;
RenderingHints hints;
TextBubbleBorder(
Color color) {
new TextBubbleBorder(color, 4, 8, 7);
}
TextBubbleBorder(
Color color, int thickness, int radii, int pointerSize) {
this.thickness = thickness;
this.radii = radii;
this.pointerSize = pointerSize;
this.color = color;
stroke = new BasicStroke(thickness);
strokePad = thickness / 2;
hints = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int pad = radii + strokePad;
int bottomPad = pad + pointerSize + strokePad;
insets = new Insets(pad, pad, bottomPad, pad);
}
@Override
public Insets getBorderInsets(Component c) {
return insets;
}
@Override
public Insets getBorderInsets(Component c, Insets insets) {
return getBorderInsets(c);
}
@Override
public void paintBorder(
Component c,
Graphics g,
int x, int y,
int width, int height) {
Graphics2D g2 = (Graphics2D) g;
int bottomLineY = height - thickness - pointerSize;
RoundRectangle2D.Double bubble = new RoundRectangle2D.Double(
0 + strokePad,
0 + strokePad,
width - thickness,
bottomLineY,
radii,
radii);
Polygon pointer = new Polygon();
// left point
pointer.addPoint(
strokePad + radii + pointerPad,
bottomLineY);
// right point
pointer.addPoint(
strokePad + radii + pointerPad + pointerSize,
bottomLineY);
// bottom point
pointer.addPoint(
strokePad + radii + pointerPad + (pointerSize / 2),
height - strokePad);
Area area = new Area(bubble);
area.add(new Area(pointer));
g2.setRenderingHints(hints);
Area spareSpace = new Area(new Rectangle(0, 0, width, height));
spareSpace.subtract(area);
g2.setClip(spareSpace);
g2.clearRect(0, 0, width, height);
g2.setClip(null);
g2.setColor(color);
g2.setStroke(stroke);
g2.draw(area);
}
}
TextBubbleBorder
was devised for Internal padding for JTextArea with background Image (& ended up using a JLabel
since the text area was a mess for the reasons mentioned above), by specifying a pointerSize
of 0 we end up with a 'rounded rectangle' instead.
N.B. There is a clipping bug in this code, which is fixed in the accepted answer to paintComponent() is drawing on other components. This should only be considered as a solution if the 'clipping bug fix' is incorporated.
// Paint the BG color of the parent, everywhere outside the clip
// of the text bubble.
See this point in the code for the source that shows correctly as:
import java.awt.*;
import java.awt.image.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.border.*;
public class BorderTest {
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
JPanel gui = new JPanel(new GridLayout(2,0,5,5));
gui.setBorder(new EmptyBorder(10,10,10,10));
gui.setBackground(Color.RED);
AbstractBorder brdrLeft = new TextBubbleBorder(Color.BLACK,2,16,16);
AbstractBorder brdrRight = new TextBubbleBorder(Color.BLACK,2,16,16,false);
JLabel l1 = new JLabel("Label 1");
l1.setBorder(brdrRight);
gui.add(l1);
JLabel l2 = new JLabel("Label 2");
l2.setBorder(brdrLeft);
l2.setBackground(Color.YELLOW);
l2.setOpaque(true);
gui.add(l2);
JPanel p1 = new JPanel();
p1.add(new JLabel("Panel 1"));
p1.setBorder(brdrRight);
p1.setOpaque(false);
gui.add(p1);
JPanel p2 = new JPanel();
p2.add(new JLabel("Panel 2"));
p2.setBorder(brdrLeft);
gui.add(p2);
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class TextBubbleBorder extends AbstractBorder {
private Color color;
private int thickness = 4;
private int radii = 8;
private int pointerSize = 7;
private Insets insets = null;
private BasicStroke stroke = null;
private int strokePad;
private int pointerPad = 4;
private boolean left = true;
RenderingHints hints;
TextBubbleBorder(
Color color) {
this(color, 4, 8, 7);
}
TextBubbleBorder(
Color color, int thickness, int radii, int pointerSize) {
this.thickness = thickness;
this.radii = radii;
this.pointerSize = pointerSize;
this.color = color;
stroke = new BasicStroke(thickness);
strokePad = thickness / 2;
hints = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int pad = radii + strokePad;
int bottomPad = pad + pointerSize + strokePad;
insets = new Insets(pad, pad, bottomPad, pad);
}
TextBubbleBorder(
Color color, int thickness, int radii, int pointerSize, boolean left) {
this(color, thickness, radii, pointerSize);
this.left = left;
}
@Override
public Insets getBorderInsets(Component c) {
return insets;
}
@Override
public Insets getBorderInsets(Component c, Insets insets) {
return getBorderInsets(c);
}
@Override
public void paintBorder(
Component c,
Graphics g,
int x, int y,
int width, int height) {
Graphics2D g2 = (Graphics2D) g;
int bottomLineY = height - thickness - pointerSize;
RoundRectangle2D.Double bubble = new RoundRectangle2D.Double(
0 + strokePad,
0 + strokePad,
width - thickness,
bottomLineY,
radii,
radii);
Polygon pointer = new Polygon();
if (left) {
// left point
pointer.addPoint(
strokePad + radii + pointerPad,
bottomLineY);
// right point
pointer.addPoint(
strokePad + radii + pointerPad + pointerSize,
bottomLineY);
// bottom point
pointer.addPoint(
strokePad + radii + pointerPad + (pointerSize / 2),
height - strokePad);
} else {
// left point
pointer.addPoint(
width - (strokePad + radii + pointerPad),
bottomLineY);
// right point
pointer.addPoint(
width - (strokePad + radii + pointerPad + pointerSize),
bottomLineY);
// bottom point
pointer.addPoint(
width - (strokePad + radii + pointerPad + (pointerSize / 2)),
height - strokePad);
}
Area area = new Area(bubble);
area.add(new Area(pointer));
g2.setRenderingHints(hints);
// Paint the BG color of the parent, everywhere outside the clip
// of the text bubble.
Component parent = c.getParent();
if (parent!=null) {
Color bg = parent.getBackground();
Rectangle rect = new Rectangle(0,0,width, height);
Area borderRegion = new Area(rect);
borderRegion.subtract(area);
g2.setClip(borderRegion);
g2.setColor(bg);
g2.fillRect(0, 0, width, height);
g2.setClip(null);
}
g2.setColor(color);
g2.setStroke(stroke);
g2.draw(area);
}
}