Displaying a scroll bar only when necessary

Question

I'd like to do something like the following:

    public class MyCustomDialog extends JDialog 
    {

       public MyCustomDialog()
       {
          if (getClientVertScreenSize() < 800)
          {
            // Set the vertical size as 600, and give them a scroll pane to navigate to the bottom of the gui.
          }
          else
          {
             setSize(600, 800); // No need to add a scroll pane.
          }
       }

    }

The trouble is I don't know how to check the clients' screen size, so I don't know how to write the method my constructor relies on.

Answer 1

请参见Toolkit.getDefaultToolkit（）。getScreenSize（）

Answer 2

What you could do is just put your component in a JScrollPane and set the horizontal and vertical scroll bar policies to [VERTICAL|HORIZONTAL]_SCROLLBAR_AS_NEEDED . This way, the scroll bar will only appear when the JScrollPane 's size is smaller than your component's preferred size.

Answer 3

The class java.awt.Toolkit has an instance method named getScreenSize() , which returns an object of type java.awt.Dimension . A Dimension is an immutable object (it cannot be changed) with two public, final fields: width and height . You can obtain an instance of java.awt.Toolkit and perform your

You should use the following code:

import java.awt.Dimension;
import java.awt.Toolkit;

public class MyCustomDialog extends javax.swing.JDialog {
    public MyCustomDialog() {

        super(); // Invoke any JDialog initialization code.

        Toolkit t = Toolkit.getDefaultToolkit();
        if (t.getScreenSize().height < 600) {
            setSize(getWidth(), 600);
            // Add your scrollpane, etc.
        } else {
            setSize(600, 800); // No need to add a scroll pane.
        }
    }
}