Re: [Layout] get position of component with getBounds()

dmoyne wrote:


....


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I didn't expressly find this in the Javadocs, but I'm 99% sure that a
component that isn't visible isn't going to get laid out. Why would the
system bother?

I dumped the bounds for your components AFTER it was made visible and
got real numbers. I think the is the right way to do it. I also called
"pack()" on your JFrame, just to make sure.

Example output:

GetBoundsTest: java.awt.Rectangle[x=0,y=0,width=300,height 0]
   JRootPane: java.awt.Rectangle[x=9,y=32,width=282,height=159]
     JPanel: java.awt.Rectangle[x=0,y=0,width=282,height=159]
     JLayeredPane: java.awt.Rectangle[x=0,y=0,width=282,height=159]
       JPanel: java.awt.Rectangle[x=0,y=0,width=282,height=159]
         JScrollPane: java.awt.Rectangle[x=0,y=0,width=282,height=159]
           JViewport: java.awt.Rectangle[x=1,y=1,width=264,height=156]
             JPanel: java.awt.Rectangle[x=0,y=0,width=264,height=1090]
               JScrollPane: java.awt.Rectangle[x=0,y=0,width=264,height=100]
                 JViewport: java.awt.Rectangle[x=1,y=1,width=261,height=97]
                   JTree: java.awt.Rectangle[x=0,y=0,width=261,height=97]
                     CellRendererPane:
java.awt.Rectangle[x=0,y=0,width=0,height=0]

Etc.

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JPanel;
import javax.swing.JTree;
import java.awt.Dimension;
import javax.swing.SwingUtilities;

public class GetBoundsTest extends JFrame {

   JScrollPane mainJScrollPane;

   public GetBoundsTest() {
     super("JScrollPane Demonstration");
     setDefaultCloseOperation(EXIT_ON_CLOSE);
     init();
     pack();
     setSize(300, 200);
     setVisible(true);
   }

   public void init() {
     // we set main container with GridLayout
     JPanel mainJPanel = new JPanel();
     GridLayout layout = new GridLayout(0, 1, 20, 10);
     mainJPanel.setLayout(layout);
     mainJPanel.setSize(600, 400);
     // we add 10 jScrollPane containing tree
     for (int i = 0; i < 10; i++) {
       // we create a jScrollPane containing tree
       JScrollPane jScrollPaneForJTree = new JScrollPane();
       jScrollPaneForJTree.setName("jScrollPaneForJTree");
       JTree jTree = new JTree();
       jTree.setName("jTree");
       jScrollPaneForJTree.setViewportView(jTree);
       // we set height to avoid shrinking when reducing height of window
       jScrollPaneForJTree.setPreferredSize(new Dimension(-1,100));
       mainJPanel.add(jScrollPaneForJTree);
       mainJPanel.validate();
       // we display inofrmation of getBounds() for each jScrollPane
       System.out.println("INFO :" + jScrollPaneForJTree.getBounds());
     }
     mainJScrollPane = new JScrollPane(mainJPanel);
     getContentPane().add(mainJScrollPane, BorderLayout.CENTER);
     // we try to scroll panel to 9th component
     mainJPanel.scrollRectToVisible(mainJPanel.getComponent(8).getBounds());
   }

   public static void main(String args[]) {
      SwingUtilities.invokeLater( new Runnable() {

          public void run()
          {
           dumpBounds( new GetBoundsTest(), 0 );

          }

          private void dumpBounds( Component comp, int level )
          {
             indent( level );
             System.out.println( comp.getClass().getSimpleName()+": "
                     +comp.getBounds() );
             if( comp instanceof Container ) {
                Container cont = (Container) comp;
                for( Component newC : cont.getComponents() ){
                   dumpBounds( newC, level+1 );
                }
             }
          }

          private void indent( int level ) {
             for( int i = 0; i < level; i++ ) {
                System.out.print( " " );
             }
          }
       } );
   }
}