It’s not two competing mechanisms – a JPanel is a Container (just look at the class hierarchy at the top of the JPanel javadocs). JFrame.getContentPane() just returns a Container to place the Components that you want to display in the JFrame. Internally, it’s using a JPanel (by default – you can change this by calling … Read more
You don’t need to extend JFrame and in fact many of us who do a lot of Swing programming make it a point not to extend this class. Myself, I try to extend classes where I plan on altering the innate behavior of the class — i.e., override one of the non-static methods of the … Read more
When you do heavy task you should run them in another threads rather in the same as gui. If you run in Event Dispatch Thread then the gui is gonna freeze until finish. You can use SwingWorker here is an example i really like Swing Worker Example Example: class Worker extends SwingWorker<String, Object> { @Override … Read more
frame.getContentPane().getSize();
@David is correct that the host platform owns the JFrame decorations, but you may be able to leverage the JInternalFrame icons, which typically recapitulate those of the platform. For example, private static final Icon ICON = (Icon) UIManager.get(“InternalFrame.closeIcon”); Other decorative defaults are enumerated here. SSCCE: import java.awt.EventQueue; import java.awt.GridLayout; import javax.swing.BorderFactory; import javax.swing.Icon; import javax.swing.JFrame; … Read more
Use a modal dialog. See How to Make Dialogs for more details.
The last time I checked, this didn’t work on Mac’s, but that might have changed with Java 7… Now, remember, when it comes to drag’n’drop, there is no easy answer that will do everything. import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.Transferable; import java.awt.datatransfer.UnsupportedFlavorException; import java.awt.dnd.DnDConstants; import java.awt.dnd.DropTarget; import … Read more
A working example, using your code and displaying the progress in a progress bar could look like this: import java.io.BufferedOutputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URL; import javax.swing.JFrame; import javax.swing.JProgressBar; import javax.swing.SwingUtilities; import javax.swing.WindowConstants; public class Progressbar { public static void main(String[] args) { final JProgressBar jProgressBar = new JProgressBar(); jProgressBar.setMaximum(100000); JFrame frame … Read more
You want the drawImage() that scales to the target container. See the article cited here for alternatives. For example, g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
Call the requestFocus() method. This is not guaranteed to work, because there are many reasons why an operating system would not allow a frame to have focus. There could be another frame with higher priority in a different application. There are also some linux desktops which (if I recall correctly) do not allow frames to … Read more