paintComponent on JPanel, image flashes and then disappears
- by mark
I have a JApplet (MainClass extends JApplet), a JPanel (ChartWindow extends JPanel) and a Grafico class.
The problem is that the Grafico class instance has 2 JPanel that should show 2 images (1 for each panel) but the images are shown and after a little while they disappears: instead of them i get a gray background (like an empty JPanel). This happens for every repaint() call (that are made in the ChartWindow class)
the MainClass init() contains
chartwindow=new ChartWindow();
add(chartwindow)
chartwindow has a Grafico instance.
it's the ChartWindow's paintComponent (override)
paintComponent(Graphics g)
{
super.paintComponent(g);
Image immagineGrafico=createImage(grafico.pannelloGrafico.getWidth()
,grafico.pannelloGrafico.getHeight());
Image immagineVolumi=createImage(grafico.pannelloVolumi.getWidth()
,grafico.pannelloVolumi.getHeight());
Graphics2D imgGrafico=(Graphics2D)immagineGrafico.getGraphics();
Graphics2D imgVolumi=(Graphics2D)immagineVolumi.getGraphics();
grafico.draw(imgGrafico,imgVolumi,mouseX,mouseY);
((Graphics2D)grafico.pannelloGrafico.getGraphics()).drawImage(immagineGrafico,0,0,this);
((Graphics2D)grafico.pannelloVolumi.getGraphics()).drawImage(immagineVolumi,0,0,this);
}
grafico's JPanels are added this way in the ChartWindow's constructor
grafico=new Grafico()
................
add(grafico.pannelloGrafico);
add(grafico.pannelloVolumi);
Tell me if you need more information, thank you very much :-)
