I'm trying to draw something on a Canvas, add it to a JFrame and then set this JFrame to Fullscreen. My problem is: in fullscreenmode I only see a black screen. Before the screen turns black I shortly can see the pink background of the canvas.
Drawing directly on a JFrame and then setting it to fullscreen works perfectly fine and I can see the testtext. I assume there is a problem with displaying the Canvas properly.
Here is my code:
public class FullscreenTest extends Canvas {
private JFrame mainFrame;
public FullscreenTest(){
this.mainFrame = new JFrame();
JPanel contentPane = (JPanel) mainFrame.getContentPane();
contentPane.add(this);
}
public void run(DisplayMode dm){
setBackground(Color.PINK);
setForeground(Color.WHITE);
setFont(new Font("Arial", Font.PLAIN, 24));
Screen s = new Screen();
s.setFullScreen(dm, this.mainFrame);
try {
Thread.sleep(5000);
} catch (InterruptedException exc) { exc.printStackTrace(); }
s.closeFullScreenWindow();
}
public void paint(Graphics g){
g.drawString("This is some testtext", 200, 200);
}
public static void main(String[] args){
DisplayMode dm = new DisplayMode(800, 600, 32, DisplayMode.REFRESH_RATE_UNKNOWN);
FullscreenTest test = new FullscreenTest();
test.run(dm);
}
}
Here is what the Screen.setFullScreen(DisplayMode dm, JFrame window) method does:
//graphicsDevice = GraphicsEnvironment.getLocalGraphicsEnvironment()
// .getDefaultScreenDevice();
public void setFullScreen(DisplayMode dm, JFrame window){
window.setUndecorated(true);
window.setResizable(false);
graphicsDevice.setFullScreenWindow(window);
if(dm != null && graphicsDevice.isDisplayChangeSupported()){
graphicsDevice.setDisplayMode(dm);
}
}
Does anyone have a clue why I don't see the JFrame's content in fullscreen?
1) you have three general issues
never block EDT by using Thread.sleep(5000);
use Swing Timer instead, demonstrations here
(if aren't there really important reasons) don't mixing AWT with Swing the rest is here , and use JPanel
instead of Canvas
(for Canvas
is there paint
method, for JPanel
is there paintComponent
)
your public void paint(Graphics g){
is to the JFrame
instead of Canvas
and locked by Thread.sleep(5000);
2) Swing GUI rellated should be wrapped into invokeLater()
meaning
public static void main(String[] args){
more in the Initial Thread
3) in linked code example you can find out demostrations how to use background thread in the Swing
hey i had he same problem and the screen turns black every time i run the program. in the part of the paint method , you wrote, which i think that it is from Bucky tutorial which is amazing by the way :
public void paint(Graphics g){
g.drawString("This is some testtext", 200, 200);
}
all you have to do is to use "super"
public void paint(Graphics g){
super.paint(g);
g.drawString("This is some testtext", 200, 200);
}
I tried it myself and it is working just fine.
I agree with mKorbel (actually, I have your code working with corrections he suggest). Just one hint to achieve more predictable results further: take control on colors in paint()
method. Default color for background may vary on different systems. On my system it draws white text on light-red background. But if it will draw black text on black background, test will look like "not working".
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