Why is JFrame still not transparent?
I am using Java 6.
Hope the following code can display a transparent window. But it still shows a normal window with a white background. What for? I think it makes sense that if I hide all the panels this should give me a transparent window.
package MaskingEffect;
import java.awt.EventQueue;
import javax.swing.JFrame;
public class GlassMaskTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
GlassMaskFrame frame=new GlassMaskFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setVisible(false);
frame.getLayeredPane().setVisible(false);
frame.getRootPane().setVisible(false);
frame.getGlassPane().setVisible(false);
frame.setVisible(true);
//AWTUtilities.setWindowOpacity(frame, 0.1f);
}
});
}
}
And so GlassMaskFrame
:
package MaskingEffect;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics2D;
import javax.swing.JComponent;
import javax.swing.JFrame;
import com.sun.awt.AWTUtilities;
import com.sun.xml.internal.ws.api.server.Container;
public class GlassMaskFrame extends JFrame {
/**
*
*/
private static final long serialVersionUID = 1L;
public GlassMaskFrame() {
this.setSize(new Dimension(500, 600));
}
}
I have also tried setBackground(new Color(0,0,0,0))
for each of the 4 panels. But still don't get a transparent window.
I don't want to use the method AWTUtilities.setWindowOpacity()
.
This is what I get:
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3 answers
public TransparentJFrame()
{
setTitle("Transparent JFrame Demo");
setSize(400,400);
setLayout(new GridBagLayout());
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
//For Java 1.7 or above
setOpacity(0.4f);
//For lower java versions
//com.sun.awt.AWTUtilities.setWindowOpacity(this,0.4f);
}
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Easier with Java 7+ with Java 6 you need to use private API com.sun.awt.AWTUtilities
For this, I wrote a utility class that makes it easy to use. It uses reflection to determine if it is possible for the actual call, in case you are using a Java version below 6u10
public static boolean supportsPerAlphaPixel() {
boolean support = false;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
support = true;
} catch (Exception exp) {
}
return support;
}
public static void setOpaque(Window window, boolean opaque) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpaque", Window.class, boolean.class);
method.invoke(null, window, opaque);
}
} catch (Exception exp) {
}
}
public static void setOpacity(Window window, float opacity) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpacity", Window.class, float.class);
method.invoke(null, window, opacity);
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
public static float getOpacity(Window window) {
float opacity = 1f;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("getWindowOpacity", Window.class);
Object value = method.invoke(null, window);
if (value != null && value instanceof Float) {
opacity = ((Float) value).floatValue();
}
}
} catch (Exception exp) {
exp.printStackTrace();
}
return opacity;
}
Opaque
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Window;
import java.lang.reflect.Method;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setUndecorated(true);
setOpaque(frame, false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setOpaque(false);
setBorder(new LineBorder(Color.RED));
setLayout(new GridBagLayout());
add(new JLabel("Look no hands"));
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public static boolean supportsPerAlphaPixel() {
boolean support = false;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
support = true;
} catch (Exception exp) {
}
return support;
}
public static void setOpaque(Window window, boolean opaque) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpaque", Window.class, boolean.class);
method.invoke(null, window, opaque);
}
} catch (Exception exp) {
}
}
public static void setOpacity(Window window, float opacity) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpacity", Window.class, float.class);
method.invoke(null, window, opacity);
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
public static float getOpacity(Window window) {
float opacity = 1f;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("getWindowOpacity", Window.class);
Object value = method.invoke(null, window);
if (value != null && value instanceof Float) {
opacity = ((Float) value).floatValue();
}
}
} catch (Exception exp) {
exp.printStackTrace();
}
return opacity;
}
}
Transparent
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.Window;
import java.lang.reflect.Method;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setUndecorated(true);
setOpacity(frame, 0.5f);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
add(new JLabel("Look no hands"));
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public static boolean supportsPerAlphaPixel() {
boolean support = false;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
support = true;
} catch (Exception exp) {
}
return support;
}
public static void setOpaque(Window window, boolean opaque) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpaque", Window.class, boolean.class);
method.invoke(null, window, opaque);
}
} catch (Exception exp) {
}
}
public static void setOpacity(Window window, float opacity) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpacity", Window.class, float.class);
method.invoke(null, window, opacity);
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
public static float getOpacity(Window window) {
float opacity = 1f;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("getWindowOpacity", Window.class);
Object value = method.invoke(null, window);
if (value != null && value instanceof Float) {
opacity = ((Float) value).floatValue();
}
}
} catch (Exception exp) {
exp.printStackTrace();
}
return opacity;
}
}
Now, before you go to the frame, this is "borderless", it is far from everything to make it work, but it may not work on all platforms (like macOS), it requires you to use the look and feel that provides border frames (e.g. metal), which is not particularly nice ...
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